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Sample records for alk kinase domain

  1. Anaplastic lymphoma kinase (ALK) inhibitors in the treatment of ALK-driven lung cancers.

    PubMed

    Roskoski, Robert

    2017-03-01

    Anaplastic lymphoma kinase is expressed in two-thirds of the anaplastic large-cell lymphomas as an NPM-ALK fusion protein. Physiological ALK is a receptor protein-tyrosine kinase within the insulin receptor superfamily of proteins that participates in nervous system development. The EML4-ALK fusion protein and four other ALK-fusion proteins play a fundamental role in the development in about 5% of non-small cell lung cancers. The amino-terminal portions of the ALK fusion proteins result in dimerization and subsequent activation of the ALK protein kinase domain that plays a key role in the pathogenesis of various tumors. Downstream signaling from the ALK fusion protein leads to the activation of the Ras/Raf/MEK/ERK1/2 cell proliferation module and the JAK/STAT cell survival pathways. Moreover, nearly two dozen ALK activating mutations are involved in the pathogenesis of childhood neuroblastomas. The occurrence of oncogenic ALK-fusion proteins, particularly in non-small cell lung cancer, has fostered considerable interest in the development of ALK inhibitors. Crizotinib was the first such inhibitor approved by the US Food and Drug Administration for the treatment of ALK-positive non-small cell lung cancer in 2011. The median time for the emergence of crizotinib drug resistance is 10.5 months after the initiation of therapy. Such resistance prompted the development of second-generation drugs including ceritinib and alectinib, which are approved for the treatment of non-small cell lung cancer. Unlike the single gatekeeper mutation that occurs in drug-resistant epidermal growth factor receptor in lung cancer, nearly a dozen different mutations in the catalytic domain of ALK fusion proteins have been discovered that result in crizotinib resistance. Crizotinib, ceritinib, and alectinib form a complex within the front cleft between the small and large lobes of an inactive ALK protein-kinase domain with a compact activation segment. These drugs are classified as type I½ B

  2. An interaction map of small-molecule kinase inhibitors with anaplastic lymphoma kinase (ALK) mutants in ALK-positive non-small cell lung cancer.

    PubMed

    Ai, Xinghao; Shen, Shengping; Shen, Lan; Lu, Shun

    2015-05-01

    Human anaplastic lymphoma kinase (ALK) has become a well-established target for the treatment of ALK-positive non-small cell lung cancer (NSCLC). Here, we have profiled seven small-molecule inhibitors, including 2 that are approved drugs, against a panel of clinically relevant mutations in ALK tyrosine kinase (TK) domain, aiming at a comprehensive understanding of molecular mechanism and biological implication underlying inhibitor response to ALK TK mutation. We find that (i) the gatekeeper mutation L1196M causes crizotinib resistance by simultaneously increasing and decreasing the binding affinities of, respectively, ATP and inhibitor to ALK, whereas the secondary mutation C1156Y, which is located far away from the ATP-binding site of ALK TK domain, causes the resistance by inducing marked allosteric effect on the site, (ii) the 2nd and 3rd generation kinase inhibitors exhibit relatively high sensitivity towards ALK mutants as compared to 1st generation inhibitors, (iii) the pan-kinase inhibitor staurosporine is insensitive for most mutations due to its high structural compatibility, and (iv) ATP affinity to ALK is generally reduced upon most clinically relevant mutations. Furthermore, we also identify six novel mutation-inhibitor pairs that are potentially associated with drug resistance. In addition, the G1202R and C1156Y mutations are expected to generally cause resistance for many existing inhibitors, since they can address significant effect on the geometric shape and physicochemical property of ALK active pocket.

  3. ALK: a tyrosine kinase target for cancer therapy

    PubMed Central

    Holla, Vijaykumar R.; Elamin, Yasir Y.; Bailey, Ann Marie; Johnson, Amber M.; Litzenburger, Beate C.; Khotskaya, Yekaterina B.; Sanchez, Nora S.; Zeng, Jia; Shufean, Md Abu; Shaw, Kenna R.; Mendelsohn, John; Mills, Gordon B.; Meric-Bernstam, Funda; Simon, George R.

    2017-01-01

    The anaplastic lymphoma kinase (ALK) gene plays an important physiologic role in the development of the brain and can be oncogenically altered in several malignancies, including non-small-cell lung cancer (NSCLC) and anaplastic large cell lymphomas (ALCL). Most prevalent ALK alterations are chromosomal rearrangements resulting in fusion genes, as seen in ALCL and NSCLC. In other tumors, ALK copy-number gains and activating ALK mutations have been described. Dramatic and often prolonged responses are seen in patients with ALK alterations when treated with ALK inhibitors. Three of these—crizotinib, ceritinib, and alectinib—are now FDA approved for the treatment of metastatic NSCLC positive for ALK fusions. However, the emergence of resistance is universal. Newer ALK inhibitors and other targeting strategies are being developed to counteract the newly emergent mechanism(s) of ALK inhibitor resistance. This review outlines the recent developments in our understanding and treatment of tumors with ALK alterations. PMID:28050598

  4. EML4-ALK fusion gene and efficacy of an ALK kinase inhibitor in lung cancer

    PubMed Central

    Koivunen, Jussi P.; Mermel, Craig; Zejnullahu, Kreshnik; Murphy, Carly; Lifshits, Eugene; Holmes, Alison J.; Choi, Hwan Geun; Kim, Jhingook; Chiang, Derek; Thomas, Roman; Lee, Jinseon; Richards, William G.; Sugarbaker, David J.; Ducko, Christopher; Lindeman, Neal; Marcoux, J. Paul; Engelman, Jeffrey A.; Gray, Nathanael S.; Lee, Charles; Meyerson, Matthew; Jänne, Pasi A.

    2011-01-01

    Purpose The EML4-ALK fusion gene has been detected in ~7% of Japanese non-small cell lung cancers (NSCLC). We determined the frequency of EML4-ALK in Caucasian NSCLCs and in NSCLC cell lines. We also determined whether TAE684, a specific ALK kinase inhibitor, would inhibit the growth of EML4-ALK containing cell lines in vitro and in vivo. Experimental Design We screened 305 primary NSCLCs (both US (n=138) and Korean (n=167) patients) and 83 NSCLC cell lines using RT-PCR and by exon array analyses. We evaluated the efficacy of TAE684 against NSCLC cell lines in vitro and in vivo. Results We detected 4 different variants, including two novel variants, of EML4-ALK using RT-PCR in 8/305 tumors (3%) and in 3/83 (3.6%) NSCLC cell lines. All EML4-ALK containing tumors and cell lines were adenocarcinomas. EML4-ALK was detected more frequently in NSCLC patients who were never or light (< 10 pack years) cigarette smokers compared to current/former smokers (6% vs. 1%; p=0.049). TAE684 inhibited the growth of 1 of 3 (H3122) EML4-ALK containing cell lines in vitro and in vivo, inhibited Akt phosphorylation and caused apoptosis. In another EML4-ALK cell line, DFCI032, TAE684 was ineffective due to co-activation of EGFR and ERBB2. The combination of TAE684 and CL-387,785 (EGFR/ERBB2 kinase inhibitor), inhibited growth and Akt phosphorylation and led to apoptosis in the DFCI032 cell line. Conclusions EML4-ALK is found in the minority of NSCLCs. ALK kinase inhibitors alone or in combination may nevertheless be clinically effective treatments for NSCLC patients whose tumors contain EML4-ALK. PMID:18594010

  5. Activation of the orphan receptor tyrosine kinase ALK by zinc.

    PubMed

    Bennasroune, Aline; Mazot, Pierre; Boutterin, Marie-Claude; Vigny, Marc

    2010-08-06

    Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase essentially and transiently expressed during development of the central and peripheral nervous system. The nature of the cognate ligand of this receptor in Vertebrates is still a matter of debate. During synaptic transmission the release of ionic zinc found in vesicles of certain glutamatergic and gabaergic terminals may act as a neuromodulator by binding to pre- or post-synaptic receptors. Recently, zinc has been shown to activate the receptor tyrosine kinase, TrkB, independently of neurotrophins. This activation occurs via increasing the Src family kinase activity. In the present study, we investigated whether the ALK activity could be modulated by extracellular zinc. We first showed that zinc alone rapidly activates ALK. This activation is dependent of ALK tyrosine kinase activity and dimerization of the receptor but is independent of Src family kinase activity. In contrast, addition of sodium pyrithione, a zinc ionophore, led to a further activation of ALK. This stronger activation is dependent of Src family kinase but independent of ALK activity and dimerization. In conclusion, zinc could constitute an endogenous ligand of ALK in vertebrates.

  6. Atypical Carcinoid Tumor with Anaplastic Lymphoma Kinase (ALK) Rearrangement Successfully Treated by an ALK Inhibitor.

    PubMed

    Nakajima, Masayuki; Uchiyama, Naoki; Shigemasa, Rie; Matsumura, Takeshi; Matsuoka, Ryota; Nomura, Akihiro

    This is the first report in which crizotinib, an anaplastic lymphoma kinase (ALK) inhibitor, reduced an atypical carcinoid tumor with ALK rearrangement. A 70-year-old man developed a tumor in the left lung and multiple metastases to the lung and brain. The pathology of transbronchial biopsied specimens demonstrated an atypical carcinoid pattern. Combined with immunohistochemical findings, we diagnosed the tumor as atypical carcinoid. ALK gene rearrangement was observed by both immunohistochemical (IHC) and fluorescence in situ hybridization. He was treated with chemotherapy as first-line therapy, however, the tumor did not respond to chemotherapy. Thereafter, he was treated with crizotinib, which successfully reduced the tumors.

  7. Detection of anaplastic lymphoma kinase (ALK) gene rearrangement in non-small cell lung cancer and related issues in ALK inhibitor therapy: a literature review.

    PubMed

    Yi, Eunhee S; Chung, Jin-Haeng; Kulig, Kimary; Kerr, Keith M

    2012-06-01

    Anaplastic lymphoma kinase (ALK) encodes a receptor tyrosine kinase, and ALK gene rearrangement (ALK+) is implicated in the oncogenesis of non-small cell lung carcinomas (NSCLCs), especially adenocarcinomas. The ALK inhibitor crizotinib was approved in August 2011 by the US Food and Drug Administration (FDA) for treating late-stage NSCLCs that are ALK+, with a companion fluorescent in situ hybridization (FISH) test using the Vysis ALK Break Apart FISH Probe Kit. This review covers pertinent issues in ALK testing, including approaches to select target patients for the test, pros and cons of different detection methods, and mechanisms as well as monitoring of acquired crizotinib resistance in ALK+ NSCLCs.

  8. Therapeutic strategies and mechanisms of drug resistance in Anaplastic Lymphoma Kinase (ALK)-rearranged lung cancer.

    PubMed

    Katayama, Ryohei

    2017-02-06

    Anaplastic lymphoma kinase (ALK) gene encoding the receptor tyrosine kinase ALK is expressed as a fusion gene in a variety of carcinomas. The expression of ALK is nearly undetectable in adults, and its activation is normally regulated by its ligands, FAM150A/B. However, ALK gene rearrangements result in different ALK fusion proteins that are constitutively expressed via the active promoter of fusion partner genes. ALK fusion proteins dimerize in a ligand-independent manner and lead to the dysregulation of cell proliferation via abnormal constitutive activation of ALK tyrosine kinase. Many ALK tyrosine kinase inhibitors (TKIs) have been developed to date, are three of which are currently in clinical use for the treatment of ALK-rearranged non-small cell lung cancer (NSCLC). ALK TKIs often achieve marked tumor regression in NSCLC patients with ALK rearrangements; however, ALK TKI-resistant tumors inevitably emerge within a few years in most cases. In this review, we summarize diverse ALK TKI resistance mechanisms identified in NSCLC with ALK rearrangements, and review potential therapeutic strategies to overcome ALK TKI resistance in these patients.

  9. Specificity and Structure of a High Affinity Activin Receptor-like Kinase 1 (ALK1) Signaling Complex

    PubMed Central

    Townson, Sharon A.; Martinez-Hackert, Erik; Greppi, Chloe; Lowden, Patricia; Sako, Dianne; Liu, June; Ucran, Jeffrey A.; Liharska, Katia; Underwood, Kathryn W.; Seehra, Jasbir; Kumar, Ravindra; Grinberg, Asya V.

    2012-01-01

    Activin receptor-like kinase 1 (ALK1), an endothelial cell-specific type I receptor of the TGF-β superfamily, is an important regulator of normal blood vessel development as well as pathological tumor angiogenesis. As such, ALK1 is an important therapeutic target. Thus, several ALK1-directed agents are currently in clinical trials as anti-angiogenic cancer therapeutics. Given the biological and clinical importance of the ALK1 signaling pathway, we sought to elucidate the biophysical and structural basis underlying ALK1 signaling. The TGF-β family ligands BMP9 and BMP10 as well as the three type II TGF-β family receptors ActRIIA, ActRIIB, and BMPRII have been implicated in ALK1 signaling. Here, we provide a kinetic and thermodynamic analysis of BMP9 and BMP10 interactions with ALK1 and type II receptors. Our data show that BMP9 displays a significant discrimination in type II receptor binding, whereas BMP10 does not. We also report the crystal structure of a fully assembled ternary complex of BMP9 with the extracellular domains of ALK1 and ActRIIB. The structure reveals that the high specificity of ALK1 for BMP9/10 is determined by a novel orientation of ALK1 with respect to BMP9, which leads to a unique set of receptor-ligand interactions. In addition, the structure explains how BMP9 discriminates between low and high affinity type II receptors. Taken together, our findings provide structural and mechanistic insights into ALK1 signaling that could serve as a basis for novel anti-angiogenic therapies. PMID:22718755

  10. Highly prolific Booroola sheep have a mutation in the intracellular kinase domain of bone morphogenetic protein IB receptor (ALK-6) that is expressed in both oocytes and granulosa cells.

    PubMed

    Wilson, T; Wu, X Y; Juengel, J L; Ross, I K; Lumsden, J M; Lord, E A; Dodds, K G; Walling, G A; McEwan, J C; O'Connell, A R; McNatty, K P; Montgomery, G W

    2001-04-01

    The Booroola fecundity gene (FecB) increases ovulation rate and litter size in sheep and is inherited as a single autosomal locus. The effect of FecB is additive for ovulation rate (increasing by about 1.6 corpora lutea per cycle for each copy) and has been mapped to sheep chromosome 6q23-31, which is syntenic to human chromosome 4q21-25. Bone morphogenetic protein IB (BMP-IB) receptor (also known as ALK-6), which binds members of the transforming growth factor-beta (TGF-beta) superfamily, is located in the region containing the FecB locus. Booroola sheep have a mutation (Q249R) in the highly conserved intracellular kinase signaling domain of the BMP-IB receptor. The mutation segregated with the FecB phenotype in the Booroola backcross and half-sib flocks of sheep with no recombinants. The mutation was not found in individuals from a number of sheep breeds not derived from the Booroola strain. BMPR-IB was expressed in the ovary and in situ hybridization revealed its specific location to the oocyte and the granulosa cell. Expression of mRNA encoding the BMP type II receptor was widespread throughout the ovary. The mutation in BMPR-IB found in Booroola sheep is the second reported defect in a gene from the TGF-beta pathway affecting fertility in sheep following the recent discovery of mutations in the growth factor, GDF9b/BMP15.

  11. Analysis of nucleophosmin-anaplastic lymphoma kinase (NPM-ALK)-reactive CD8(+) T cell responses in children with NPM-ALK(+) anaplastic large cell lymphoma.

    PubMed

    K Singh, V; Werner, S; Hackstein, H; Lennerz, V; Reiter, A; Wölfel, T; Damm-Welk, C; Woessmann, W

    2016-10-01

    Cellular immune responses against the oncoantigen anaplastic lymphoma kinase (ALK) in patients with ALK-positive anaplastic large cell lymphoma (ALCL) have been detected using peptide-based approaches in individuals preselected for human leucocyte antigen (HLA)-A*02:01. In this study, we aimed to evaluate nucleophosmin (NPM)-ALK-specific CD8(+) T cell responses in ALCL patients ensuring endogenous peptide processing of ALK antigens and avoiding HLA preselection. We also examined the HLA class I restriction of ALK-specific CD8(+) T cells. Autologous dendritic cells (DCs) transfected with in-vitro-transcribed RNA (IVT-RNA) encoding NPM-ALK were used as antigen-presenting cells for T cell stimulation. Responder T lymphocytes were tested in interferon-gamma enzyme-linked immunospot (ELISPOT) assays with NPM-ALK-transfected autologous DCs as well as CV-1 in Origin with SV40 genes (COS-7) cells co-transfected with genes encoding the patients' HLA class I alleles and with NPM-ALK encoding cDNA to verify responses and define the HLA restrictions of specific T cell responses. NPM-ALK-specific CD8(+) T cell responses were detected in three of five ALK-positive ALCL patients tested between 1 and 13 years after diagnosis. The three patients had also maintained anti-ALK antibody responses. No reactivity was detected in samples from five healthy donors. The NPM-ALK-specific CD8(+) T cell responses were restricted by HLA-C-alleles (C*06:02 and C*12:02) in all three cases. This approach allowed for the detection of NPM-ALK-reactive T cells, irrespective of the individual HLA status, up to 9 years after ALCL diagnosis.

  12. Alectinib: a novel second generation anaplastic lymphoma kinase (ALK) inhibitor for overcoming clinically-acquired resistance

    PubMed Central

    Song, Zilan; Wang, Meining; Zhang, Ao

    2015-01-01

    The development of inhibitors for the tyrosine anaplastic lymphoma kinase (ALK) has advanced rapidly, driven by biology and medicinal chemistry. The first generation ALK inhibitor crizotinib was granted US FDA approval with only four years of preclinical and clinical testing. Although this drug offers significant clinical benefit to the ALK-positive patients, resistance has been developed through a variety of mechanisms. In addition to ceritinib, alectinib is another second-generation ALK inhibitor launched in 2014 in Japan. This drug has a unique chemical structure bearing a 5H-benzo[b]carbazol-11(6H)-one structural scaffold with an IC50 value of 1.9 nmol/L, and is highly potent against ALK bearing the gatekeeper mutation L1196M with an IC50 of 1.56 nmol/L. In the clinic, alectinib is highly efficacious in treatment of ALK-positive non-small cell lung cancer (NSCLC), and retains potency to combat crizotinib-resistant ALK mutations L1196M, F1174L, R1275Q and C1156Y. PMID:26579422

  13. New therapeutic strategies in neuroblastoma: combined targeting of a novel tyrosine kinase inhibitor and liposomal siRNAs against ALK

    PubMed Central

    Di Paolo, Daniela; Yang, D.; Pastorino, Fabio; Emionite, Laura; Cilli, Michele; Daga, Antonio; Destefanis, Elisa; Di Fiore, Annarita; Piaggio, Francesca; Brignole, Chiara; Xu, Xiaobao; Liang, Chris; Gibbons, James

    2015-01-01

    Many different aberrations in the Anaplastic Lymphoma Kinase (ALK) were found to be oncogenic drivers in several cancers including neuroblastoma (NB), therefore ALK is now considered a critical player in NB oncogenesis and a promising therapeutic target. The ALK-inhibitor crizotinib has a limited activity against the various ALK mutations identified in NB patients. We tested: the activity of the novel ALK-inhibitor X-396 administered alone or in combination with Targeted Liposomes carrying ALK-siRNAs (TL[ALK-siRNA]) that are active irrespective of ALK gene mutational status; the pharmacokinetic profiles and the biodistribution of X-396; the efficacy of X-396 versus crizotinib treatment in NB xenografts; whether the combination of X-396 with the TL[ALK-siRNA] could promote long-term survival in NB mouse models. X-396 revealed good bioavailability, moderate half-life, high mean plasma and tumor concentrations. X-396 was more effective than crizotinib in inhibiting in vitro cell proliferation of NB cells and in reducing tumor volume in subcutaneous NB models in a dose-dependent manner. In orthotopic NB xenografts, X-396 significantly increased life span independently of the ALK mutation status. In combination studies, all effects were significantly improved in the mice treated with TL[ALK-siRNA] and X-396 compared to mice receiving the single agents. Our findings provide a rational basis to design innovative molecular-based treatment combinations for clinical application in ALK-driven NB tumors. PMID:26299615

  14. New therapeutic strategies in neuroblastoma: combined targeting of a novel tyrosine kinase inhibitor and liposomal siRNAs against ALK.

    PubMed

    Di Paolo, Daniela; Yang, D; Pastorino, Fabio; Emionite, Laura; Cilli, Michele; Daga, Antonio; Destafanis, Elisa; Di Fiore, Annarita; Piaggio, Francesca; Brignole, Chiara; Xu, Xiaobao; Liang, Chris; Gibbons, James; Ponzoni, Mirco; Perri, Patrizia

    2015-10-06

    Many different aberrations in the Anaplastic Lymphoma Kinase (ALK) were found to be oncogenic drivers in several cancers including neuroblastoma (NB), therefore ALK is now considered a critical player in NB oncogenesis and a promising therapeutic target. The ALK-inhibitor crizotinib has a limited activity against the various ALK mutations identified in NB patients. We tested: the activity of the novel ALK-inhibitor X-396 administered alone or in combination with Targeted Liposomes carrying ALK-siRNAs (TL[ALK-siRNA]) that are active irrespective of ALK gene mutational status; the pharmacokinetic profiles and the biodistribution of X-396; the efficacy of X-396 versus crizotinib treatment in NB xenografts; whether the combination of X-396 with the TL[ALK-siRNA] could promote long-term survival in NB mouse models. X-396 revealed good bioavailability, moderate half-life, high mean plasma and tumor concentrations. X-396 was more effective than crizotinib in inhibiting in vitro cell proliferation of NB cells and in reducing tumor volume in subcutaneous NB models in a dose-dependent manner. In orthotopic NB xenografts, X-396 significantly increased life span independently of the ALK mutation status. In combination studies, all effects were significantly improved in the mice treated with TL[ALK-siRNA] and X-396 compared to mice receiving the single agents. Our findings provide a rational basis to design innovative molecular-based treatment combinations for clinical application in ALK-driven NB tumors.

  15. Nucleophosmin/anaplastic lymphoma kinase (NPM/ALK) oncoprotein induces the T regulatory cell phenotype by activating STAT3

    PubMed Central

    Kasprzycka, Monika; Marzec, Michal; Liu, Xiaobin; Zhang, Qian; Wasik, Mariusz A.

    2006-01-01

    The mechanisms of malignant cell transformation mediated by the oncogenic, chimeric nucleophosmin/anaplastic lymphoma kinase (NPM/ALK) tyrosine kinase remain only partially understood. Here we report that the NPM/ALK-carrying T cell lymphoma (ALK+TCL) cells secrete IL-10 and TGF-β and express FoxP3, indicating their T regulatory (Treg) cell phenotype. The secreted IL-10 suppresses proliferation of normal immune, CD3/CD28-stimulated peripheral blood mononuclear cells and enhances viability of the ALK+TCL cells. The Treg phenotype of the affected cells is strictly dependent on NPM/ALK expression and function as demonstrated by transfection of the kinase into BaF3 cells and inhibition of its enzymatic activity and expression in ALK+TCL cells. NPM/ALK, in turn, induces the phenotype through activation of its key signal transmitter, signal transducer and activator of transcription 3 (STAT3). These findings identify a mechanism of NPM/ALK-mediated oncogenesis based on induction of the Treg phenotype of the transformed CD4+ T cells. These results also provide an additional rationale to therapeutically target the chimeric kinase and/or STAT3 in ALK+TCL. PMID:16766651

  16. Design, synthesis and pharmacological evaluation of 2-(thiazol-2-amino)-4-arylaminopyrimidines as potent anaplastic lymphoma kinase (ALK) inhibitors.

    PubMed

    Liu, Zhiqing; Yue, Xihua; Song, Zilan; Peng, Xia; Guo, Junfeng; Ji, Yinchun; Cheng, Zhen; Ding, Jian; Ai, Jing; Geng, Meiyu; Zhang, Ao

    2014-10-30

    A series of new 2,4-diarylaminopyrimidine analogues (DAAPalogues) was developed by incorporation of a substituted 2-aminothiazole component as the C-2 substituent of the center pyrimidine core. Compound 5i showed highest potency of 12.4 nM against ALK and 24.1 nM against ALK gatekeeper mutation L1196M. Although only having moderate cellular potency in the SUP-M2 cells harboring NPM-ALK, compound 5i showed good kinase selectivity and dose-dependently inhibited phosphorylation of ALK and its down-stream signaling pathways.

  17. Activin Receptor-Like Kinase Receptors ALK5 and ALK1 Are Both Required for TGFβ-Induced Chondrogenic Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells

    PubMed Central

    de Kroon, Laurie M. G.; Narcisi, Roberto; Blaney Davidson, Esmeralda N.; Cleary, Mairéad A.; van Beuningen, Henk M.; Koevoet, Wendy J. L. M.; van Osch, Gerjo J. V. M.; van der Kraan, Peter M.

    2015-01-01

    Introduction Bone marrow-derived mesenchymal stem cells (BMSCs) are promising for cartilage regeneration because BMSCs can differentiate into cartilage tissue-producing chondrocytes. Transforming Growth Factor β (TGFβ) is crucial for inducing chondrogenic differentiation of BMSCs and is known to signal via Activin receptor-Like Kinase (ALK) receptors ALK5 and ALK1. Since the specific role of these two TGFβ receptors in chondrogenesis is unknown, we investigated whether ALK5 and ALK1 are expressed in BMSCs and whether both receptors are required for chondrogenic differentiation of BMSCs. Materials & Methods ALK5 and ALK1 gene expression in human BMSCs was determined with RT-qPCR. To induce chondrogenesis, human BMSCs were pellet-cultured in serum-free chondrogenic medium containing TGFβ1. Chondrogenesis was evaluated by aggrecan and collagen type IIα1 RT-qPCR analysis, and histological stainings of proteoglycans and collagen type II. To overexpress constitutively active (ca) receptors, BMSCs were transduced either with caALK5 or caALK1. Expression of ALK5 and ALK1 was downregulated by transducing BMSCs with shRNA against ALK5 or ALK1. Results ALK5 and ALK1 were expressed in in vitro-expanded as well as in pellet-cultured BMSCs from five donors, but mRNA levels of both TGFβ receptors did not clearly associate with chondrogenic induction. TGFβ increased ALK5 and decreased ALK1 gene expression in chondrogenically differentiating BMSC pellets. Neither caALK5 nor caALK1 overexpression induced cartilage matrix formation as efficient as that induced by TGFβ. Moreover, short hairpin-mediated downregulation of either ALK5 or ALK1 resulted in a strong inhibition of TGFβ-induced chondrogenesis. Conclusion ALK5 as well as ALK1 are required for TGFβ-induced chondrogenic differentiation of BMSCs, and TGFβ not only directly induces chondrogenesis, but also modulates ALK5 and ALK1 receptor signaling in BMSCs. These results imply that optimizing cartilage formation by

  18. Effect of single-chain antibody targeting of the ligand-binding domain in the anaplastic lymphoma kinase receptor

    PubMed Central

    Stylianou, DC; Auf der Maur, A; Kodack, DP; Henke, RT; Hohn, S; Toretsky, JA; Riegel, AT; Wellstein, A

    2013-01-01

    The tyrosine kinase receptor anaplastic lymphoma kinase (ALK) and its ligand, the growth factor pleiotrophin (PTN), are highly expressed during the development of the nervous system and have been implicated in the malignant progression of different tumor types. Here, we describe human single-chain variable fragment (scFv) antibodies that target the ligand-binding domain (LBD) in ALK and show the effect in vitro and in vivo. The ALK LBD was used as a bait in a yeast two-hybdrid system to select human scFv from a library with randomized complementarity-determining region 3 domains. Surface plasmon resonance showed high-affinity binding of the selected scFv. The anti-ALK scFv competed for binding of PTN to ALK in intact cells and inhibited PTN-dependent signal transduction through endogenous ALK. Invasion of an intact endothelial cell monolayer by U87MG human glioblastoma cells was inhibited by the anti-ALK scFv. In addition, the growth of established tumor xenografts in mice was reversed after the induction of the conditional expression of the anti-ALK scFv. In archival malignant brain tumors expression levels of ALK and PTN were found elevated and appear correlated with poor patient survival. This suggests a rate-limiting function of the PTN/ALK interaction that may be exploited therapeutically. PMID:19633684

  19. Structure Based Drug Design of Crizotinib (PF-02341066), a Potent and Selective Dual Inhibitor of Mesenchymal-Epithelial Transition Factor (c-MET) Kinase and Anaplastic Lymphoma Kinase (ALK)

    SciTech Connect

    Cui, J Jean; Tran-Dube,; #769; Michelle,; Shen, Hong; Nambu, Mitchell; Kung, Pei-Pei; Pairish, Mason; Jia, Lei; Meng, Jerry; Funk, Lee; Botrous, Iriny; McTigue, Michele; Grodsky, Neil; Ryan, Kevin; Padrique, Ellen; Alton, Gordon; Timofeevski, Sergei; Yamazaki, Shinji; Li, Qiuhua; Zou, Helen; Christensen, James; Mroczkowski, Barbara; Bender, Steve; Kania, Robert S; Edwards, Martin P

    2011-08-03

    Because of the critical roles of aberrant signaling in cancer, both c-MET and ALK receptor tyrosine kinases are attractive oncology targets for therapeutic intervention. The cocrystal structure of 3 (PHA-665752), bound to c-MET kinase domain, revealed a novel ATP site environment, which served as the target to guide parallel, multiattribute drug design. A novel 2-amino-5-aryl-3-benzyloxypyridine series was created to more effectively make the key interactions achieved with 3. In the novel series, the 2-aminopyridine core allowed a 3-benzyloxy group to reach into the same pocket as the 2,6-dichlorophenyl group of 3 via a more direct vector and thus with a better ligand efficiency (LE). Further optimization of the lead series generated the clinical candidate crizotinib (PF-02341066), which demonstrated potent in vitro and in vivo c-MET kinase and ALK inhibition, effective tumor growth inhibition, and good pharmaceutical properties.

  20. Augmentor α and β (FAM150) are ligands of the receptor tyrosine kinases ALK and LTK: Hierarchy and specificity of ligand–receptor interactions

    PubMed Central

    Reshetnyak, Andrey V.; Murray, Phillip B.; Shi, Xiarong; Mo, Elizabeth S.; Mohanty, Jyotidarsini; Tome, Francisco; Bai, Hanwen; Gunel, Murat; Lax, Irit; Schlessinger, Joseph

    2015-01-01

    Receptor tyrosine kinases (RTKs) are a class of cell surface receptors that, upon ligand binding, stimulate a variety of critical cellular functions. The orphan receptor anaplastic lymphoma kinase (ALK) is one of very few RTKs that remain without a firmly established protein ligand. Here we present a novel cytokine, FAM150B, which we propose naming augmentor-α (AUG-α), as a ligand for ALK. AUG-α binds ALK with high affinity and activates ALK in cells with subnanomolar potency. Detailed binding experiments using cells expressing ALK or the related receptor leukocyte tyrosine kinase (LTK) demonstrate that AUG-α binds and robustly activates both ALK and LTK. We show that the previously established LTK ligand FAM150A (AUG-β) is specific for LTK and only weakly binds to ALK. Furthermore, expression of AUG-α stimulates transformation of NIH/3T3 cells expressing ALK, induces IL-3 independent growth of Ba/F3 cells expressing ALK, and is expressed in neuroblastoma, a cancer partly driven by ALK. These experiments reveal the hierarchy and specificity of two cytokines as ligands for ALK and LTK and set the stage for elucidating their roles in development and disease states. PMID:26630010

  1. Molecular Testing Guideline for Selection of Lung Cancer Patients for EGFR and ALK Tyrosine Kinase Inhibitors

    PubMed Central

    Lindeman, Neal I.; Cagle, Philip T.; Beasley, Mary Beth; Chitale, Dhananjay Arun; Dacic, Sanja; Giaccone, Giuseppe; Jenkins, Robert Brian; Kwiatkowski, David J.; Saldivar, Juan-Sebastian; Squire, Jeremy; Thunnissen, Erik; Ladanyi, Marc

    2014-01-01

    Objective To establish evidence-based recommendations for the molecular analysis of lung cancers that are that are required to guide EGFR- and ALK-directed therapies, addressing which patients and samples should be tested, and when and how testing should be performed. Participants Three cochairs without conflicts of interest were selected, one from each of the 3 sponsoring professional societies: College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology. Writing and advisory panels were constituted from additional experts from these societies. Evidence Three unbiased literature searches of electronic databases were performed to capture articles published published from January 2004 through February 2012, yielding 1533 articles whose abstracts were screened to identify 521 pertinent articles that were then reviewed in detail for their relevance to the recommendations. Evidence was formally graded for each recommendation. Consensus Process Initial recommendations were formulated by the cochairs and panel members at a public meeting. Each guideline section was assigned to at least 2 panelists. Drafts were circulated to the writing panel (version 1), advisory panel (version 2), and the public (version 3) before submission (version 4). Conclusions The 37 guideline items address 14 subjects, including 15 recommendations (evidence grade A/B). The major recommendations are to use testing for EGFR mutations and ALK fusions to guide patient selection for therapy with an epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) inhibitor, respectively, in all patients with advanced-stage adenocarcinoma, regardless of sex, race, smoking history, or other clinical risk factors, and to prioritize EGFR and ALK testing over other molecular predictive tests. As scientific discoveries and clinical practice outpace the completion of randomized clinical trials, evidence-based guidelines developed

  2. Oncogenic kinase NPM/ALK induces through STAT3 expression of immunosuppressive protein CD274 (PD-L1, B7-H1)

    PubMed Central

    Marzec, Michal; Zhang, Qian; Goradia, Ami; Raghunath, Puthiyaveettil N.; Liu, Xiaobin; Paessler, Michele; Wang, Hong Yi; Wysocka, Maria; Cheng, Mangeng; Ruggeri, Bruce A.; Wasik, Mariusz A.

    2008-01-01

    The mechanisms of malignant cell transformation caused by the oncogenic, chimeric nucleophosmin (NPM)/anaplastic lymphoma kinase (ALK) remain only partially understood, with most of the previous studies focusing mainly on the impact of NPM/ALK on cell survival and proliferation. Here we report that the NPM/ALK-carrying T cell lymphoma (ALK+TCL) cells strongly express the immunosuppressive cell-surface protein CD274 (PD-L1, B7-H1), as determined on the mRNA and protein level. The CD274 expression is strictly dependent on the expression and enzymatic activity of NPM/ALK, as demonstrated by inhibition of the NPM/ALK function in ALK+TCL cells by the small molecule ALK inhibitor CEP-14083 and by documenting CD274 expression in IL-3-depleted BaF3 cells transfected with the wild-type NPM/ALK, but not the kinase-inactive NPM/ALK K210R mutant or empty vector alone. NPM/ALK induces CD274 expression by activating its key signal transmitter, transcription factor STAT3. STAT3 binds to the CD274 gene promoter in vitro and in vivo, as shown in the gel electromobility shift and chromatin immunoprecipitation assays, and is required for the PD-L1 gene expression, as demonstrated by siRNA-mediated STAT3 depletion. These findings identify an additional cell-transforming property of NPM/ALK and describe a direct link between an oncoprotein and an immunosuppressive cell-surface protein. These results also provide an additional rationale to therapeutically target NPM/ALK and STAT3 in ALK+TCL. Finally, they suggest that future immunotherapeutic protocols for this type of lymphoma may need to include the inhibition of NPM/ALK and STAT3 to achieve optimal clinical efficacy. PMID:19088198

  3. Variant translocation partners of the anaplastic lymphoma kinase (ALK) gene in two cases of anaplastic large cell lymphoma, identified by inverse cDNA polymerase chain reaction.

    PubMed

    Takeoka, Kayo; Okumura, Atsuko; Honjo, Gen; Ohno, Hitoshi

    2014-01-01

    In anaplastic large cell lymphoma (ALCL), the anaplastic lymphoma kinase (ALK) gene is rearranged with diverse partners due to variant translocations/inversions. Case 1 was a 39-year-old man who developed multiple tumors in the mediastinum, psoas muscle, lung, and lymph nodes. A biopsy specimen of the inguinal node was effaced by large tumor cells expressing CD30, epithelial membrane antigen, and cytoplasmic ALK, which led to a diagnosis of ALK(+) ALCL. Case 2 was a 51-year-old man who was initially diagnosed with undifferentiated carcinoma. He developed multiple skin tumors eight years after his initial presentation, and was finally diagnosed with ALK(+) ALCL. He died of therapy-related acute myeloid leukemia. G-banding and fluorescence in situ hybridization using an ALK break-apart probe revealed the rearrangement of ALK and suggested variant translocation in both cases. We applied an inverse cDNA polymerase chain reaction (PCR) strategy to identify the partner of ALK. Nucleotide sequencing of the PCR products and a database search revealed that the sequences of ATIC in case 1 and TRAF1 in case 2 appeared to follow those of ALK. We subsequently confirmed ATIC-ALK and TRAF1-ALK fusions by reverse transcriptase PCR and nucleotide sequencing. We successfully determined the partner gene of ALK in two cases of ALK(+) ALCL. ATIC is the second most common partner of variant ALK rearrangements, while the TRAF1-ALK fusion gene was first reported in 2013, and this is the second reported case of ALK(+) ALCL carrying TRAF1-ALK.

  4. Rearranged Anaplastic Lymphoma Kinase (ALK) Gene in Adult-Onset Papillary Thyroid Cancer Amongst Atomic Bomb Survivors

    PubMed Central

    Mukai, Mayumi; Takahashi, Keiko; Hayashi, Yuzo; Nakachi, Kei; Kusunoki, Yoichiro

    2012-01-01

    Background We previously noted that among atomic bomb survivors (ABS), the relative frequency of cases of adult papillary thyroid cancer (PTC) with chromosomal rearrangements (mainly RET/PTC) was significantly greater in those with relatively higher radiation exposure than those with lower radiation exposure. In contrast, the frequency of PTC cases with point mutations (mainly BRAFV600E) was significantly lower in patients with relatively higher radiation exposure than those with lower radiation exposure. We also found that among ABS, the frequency of PTC cases with no detectable gene alterations in RET, neurotrophic tyrosine kinase receptor 1 (NTRK1), BRAF, or RAS was significantly higher in patients with relatively higher radiation exposure than those with lower radiation exposure. However, in ABS with PTC, the relationship between the presence of the anaplastic lymphoma kinase (ALK) gene fused with other gene partners and radiation exposure has received little study. In this study, we tested the hypothesis that the relative frequency of rearranged ALK in ABS with PTC, and with no detectable gene alterations in RET, NTRK1, BRAF, or RAS, would be greater in those having relatively higher radiation exposures. Methods The 105 subjects in the study were drawn from the Life Span Study cohort of ABS of Hiroshima and Nagasaki who were diagnosed with PTC between 1956 and 1993. Seventy-nine were exposed (>0 mGy), and 26 were not exposed to A-bomb radiation. In the 25 ABS with PTC, and with no detectable gene alterations in RET, NTRK1, BRAF, or RAS, we examined archival, formalin-fixed, paraffin-embedded PTC specimens for rearrangement of ALK using reverse transcription–polymerase chain reaction and 5′ rapid amplification of cDNA ends (5′ RACE). Results We found rearranged ALK in 10 of 19 radiation-exposed PTC cases, but none among 6 patients with PTC with no radiation exposure. In addition, solid/trabecular-like architecture in PTC was closely associated with ALK

  5. The ALK inhibitor PF-06463922 is effective as a single agent in neuroblastoma driven by expression of ALK and MYCN

    PubMed Central

    Guan, J.; Tucker, E. R.; Wan, H.; Chand, D.; Danielson, L. S.; Ruuth, K.; El Wakil, A.; Witek, B.; Jamin, Y.; Umapathy, G.; Robinson, S. P.; Johnson, T. W.; Smeal, T.; Martinsson, T.; Chesler, L.; Palmer, R. H.

    2016-01-01

    ABSTRACT The first-in-class inhibitor of ALK, c-MET and ROS1, crizotinib (Xalkori), has shown remarkable clinical efficacy in treatment of ALK-positive non-small cell lung cancer. However, in neuroblastoma, activating mutations in the ALK kinase domain are typically refractory to crizotinib treatment, highlighting the need for more potent inhibitors. The next-generation ALK inhibitor PF-06463922 is predicted to exhibit increased affinity for ALK mutants prevalent in neuroblastoma. We examined PF-06463922 activity in ALK-driven neuroblastoma models in vitro and in vivo. In vitro kinase assays and cell-based experiments examining ALK mutations of increasing potency show that PF-06463922 is an effective inhibitor of ALK with greater activity towards ALK neuroblastoma mutants. In contrast to crizotinib, single agent administration of PF-06463922 caused dramatic tumor inhibition in both subcutaneous and orthotopic xenografts as well as a mouse model of high-risk neuroblastoma driven by Th-ALKF1174L/MYCN. Taken together, our results suggest PF-06463922 is a potent inhibitor of crizotinib-resistant ALK mutations, and highlights an important new treatment option for neuroblastoma patients. PMID:27483357

  6. PF-06463922, an ALK/ROS1 inhibitor, overcomes resistance to 1st and 2nd generation ALK inhibitors in pre-clinical models

    PubMed Central

    Zou, Helen Y.; Friboulet, Luc; Kodack, David P.; Engstrom, Lars D.; Li, Qiuhua; West, Melissa; Tang, Ruth W.; Wang, Hui; Tsaparikos, Konstantinos; Wang, Jinwei; Timofeevski, Sergei; Katayama, Ryohei; Dinh, Dac M.; Lam, Hieu; Lam, Justine L.; Yamazaki, Shinji; Hu, Wenyue; Patel, Bhushankumar; Bezwada, Divya; Frias, Rosa L.; Lifshits, Eugene; Mahmood, Sidra; Gainor, Justin F.; Affolter, Timothy; Lappin, Patrick B.; Gukasyan, Hovhannes; Lee, Nathan; Deng, Shibing; Jain, Rakesh K; Johnson, Ted W.; Shaw, Alice T.; Fantin, Valeria R.; Smeal, Tod

    2015-01-01

    SUMMARY We report the preclinical evaluation of PF-06463922, a potent and brain penetrant ALK/ROS1 inhibitor. Compared to other clinically available ALK inhibitors, PF-06463922 displayed superior potency against all known clinically acquired ALK mutations, including the highly resistant G1202R mutant. Furthermore, PF-06463922 treatment led to regression of EML4-ALK driven brain metastases, leading to prolonged mouse survival, in a superior manner. Finally, PF-06463922 demonstrated high selectivity and safety margins in a variety of preclinical studies. These results suggest that PF-06463922 will be highly effective for the treatment of patients with ALK-driven lung cancers, including those who relapsed on clinically available ALK inhibitors due to secondary ALK kinase domain mutations and/or due to the failed control of brain metastases. PMID:26144315

  7. ALK and ROS1 as a joint target for the treatment of lung cancer: a review.

    PubMed

    Puig de la Bellacasa, Raimon; Karachaliou, Niki; Estrada-Tejedor, Roger; Teixidó, Jordi; Costa, Carlota; Borrell, José I

    2013-04-01

    Rearrangements of the anaplastic lymphoma kinase (ALK) have been described in multiple malignancies, including non-small cell lung cancer (NSCLC). ALK fusions have gain of function properties while activating mutations in wild-type ALK can also occur within the tyrosine kinase domain. ALK rearrangements define a new molecular subtype of NSCLC that is exquisitely sensitive to ALK inhibition. Crizotinib, an orally available small molecule ATP-mimetic compound which was originally designed as a MET inhibitor, was recognized to have "off-target" anti-ALK activity and has been approved in the USA for the treatment of patients with ALK-positive NSCLC. Chromosomal rearrangements involving the ROS1 receptor tyrosine kinase have also been recently described in NSCLC, while crizotinib is currently under clinical trial in this molecular subset of NSCLC patients. The basic approaches of any computer aided drug design work in terms of structure and ligand based drug design. Details of each of these approaches should be covered with an emphasis on utilizing both in order to develop multi-targeted small-molecule kinase inhibitors. Such multi-targeted tyrosine kinase inhibitors can have antiproliferative activity against both ROS1and ALK rearranged NSCLC. Herein, we highlight the importance of targeting these proteins and the advances in optimizing more potent and selective ALK and ROS1 kinase inhibitors.

  8. ALK and ROS1 as a joint target for the treatment of lung cancer: a review

    PubMed Central

    Puig de la Bellacasa, Raimon; Karachaliou, Niki; Estrada-Tejedor, Roger; Teixidó, Jordi; Costa, Carlota

    2013-01-01

    Rearrangements of the anaplastic lymphoma kinase (ALK) have been described in multiple malignancies, including non-small cell lung cancer (NSCLC). ALK fusions have gain of function properties while activating mutations in wild-type ALK can also occur within the tyrosine kinase domain. ALK rearrangements define a new molecular subtype of NSCLC that is exquisitely sensitive to ALK inhibition. Crizotinib, an orally available small molecule ATP-mimetic compound which was originally designed as a MET inhibitor, was recognized to have “off-target” anti-ALK activity and has been approved in the USA for the treatment of patients with ALK-positive NSCLC. Chromosomal rearrangements involving the ROS1 receptor tyrosine kinase have also been recently described in NSCLC, while crizotinib is currently under clinical trial in this molecular subset of NSCLC patients. The basic approaches of any computer aided drug design work in terms of structure and ligand based drug design. Details of each of these approaches should be covered with an emphasis on utilizing both in order to develop multi-targeted small-molecule kinase inhibitors. Such multi-targeted tyrosine kinase inhibitors can have antiproliferative activity against both ROS1and ALK rearranged NSCLC. Herein, we highlight the importance of targeting these proteins and the advances in optimizing more potent and selective ALK and ROS1 kinase inhibitors. PMID:25806218

  9. Kinase impact assessment in the landscape of fusion genes that retain kinase domains: a pan-cancer study.

    PubMed

    Kim, Pora; Jia, Peilin; Zhao, Zhongming

    2016-12-24

    Assessing the impact of kinase in gene fusion is essential for both identifying driver fusion genes (FGs) and developing molecular targeted therapies. Kinase domain retention is a crucial factor in kinase fusion genes (KFGs), but such a systematic investigation has not been done yet. To this end, we analyzed kinase domain retention (KDR) status in chimeric protein sequences of 914 KFGs covering 312 kinases across 13 major cancer types. Based on 171 kinase domain-retained KFGs including 101 kinases, we studied their recurrence, kinase groups, fusion partners, exon-based expression depth, short DNA motifs around the break points and networks. Our results, such as more KDR than 5'-kinase fusion genes, combinatorial effects between 3'-KDR kinases and their 5'-partners and a signal transduction-specific DNA sequence motif in the break point intronic sequences, supported positive selection on 3'-kinase fusion genes in cancer. We introduced a degree-of-frequency (DoF) score to measure the possible number of KFGs of a kinase. Interestingly, kinases with high DoF scores tended to undergo strong gene expression alteration at the break points. Furthermore, our KDR gene fusion network analysis revealed six of the seven kinases with the highest DoF scores (ALK, BRAF, MET, NTRK1, NTRK3 and RET) were all observed in thyroid carcinoma. Finally, we summarized common features of 'effective' (highly recurrent) kinases in gene fusions such as expression alteration at break point, redundant usage in multiple cancer types and 3'-location tendency. Collectively, our findings are useful for prioritizing driver kinases and FGs and provided insights into KFGs' clinical implications.

  10. In contrast to agonist monoclonal antibodies, both C-terminal truncated form and full length form of Pleiotrophin failed to activate vertebrate ALK (anaplastic lymphoma kinase)?

    PubMed

    Mathivet, Thomas; Mazot, Pierre; Vigny, Marc

    2007-12-01

    Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase essentially and transiently expressed during development in specific regions of the central and peripheral nervous system. ALK expression persists at a lower level in the adult brain. Thus, it might play an important role in both the normal development and function of the nervous system. The nature of the cognate ligand of this receptor in vertebrates is still a matter of debate. Pleiotrophin and midkine have been proposed as ligands of ALK but several independent studies do not confirm this hypothesis. Interestingly, a recent study proposed that a C-terminal truncated form of Pleiotrophin (Pleiotrophin.15) and not the full length form (Pleiotrophin.18) promotes glioblastoma proliferation in an ALK-dependent fashion. These data were obviously a strong basis to conciliate the conflicting results so far reported in the literature. In the present study, we first purified to homogeneity the two forms of Pleiotrophin secreted by HEK 293 cells. In contrast to agonist monoclonal antibodies, both Pleiotrophin.15 and Pleiotrophin.18 failed to activate ALK in neuroblastoma and glioblastoma cells expressing this receptor. Thus, for our point of view, ALK is still an orphan receptor in vertebrates.

  11. Identification of the transforming STRN-ALK fusion as a potential therapeutic target in the aggressive forms of thyroid cancer

    PubMed Central

    Kelly, Lindsey M.; Barila, Guillermo; Liu, Pengyuan; Evdokimova, Viktoria N.; Trivedi, Sumita; Panebianco, Federica; Gandhi, Manoj; Carty, Sally E.; Hodak, Steven P.; Luo, Jianhua; Dacic, Sanja; Yu, Yan P.; Nikiforova, Marina N.; Ferris, Robert L.; Altschuler, Daniel L.; Nikiforov, Yuri E.

    2014-01-01

    Thyroid cancer is a common endocrine malignancy that encompasses well-differentiated as well as dedifferentiated cancer types. The latter tumors have high mortality and lack effective therapies. Using a paired-end RNA-sequencing approach, we report the discovery of rearrangements involving the anaplastic lymphoma kinase (ALK) gene in thyroid cancer. The most common of these involves a fusion between ALK and the striatin (STRN) gene, which is the result of a complex rearrangement involving the short arm of chromosome 2. STRN-ALK leads to constitutive activation of ALK kinase via dimerization mediated by the coiled-coil domain of STRN and to a kinase-dependent, thyroid-stimulating hormone–independent proliferation of thyroid cells. Moreover, expression of STRN-ALK transforms cells in vitro and induces tumor formation in nude mice. The kinase activity of STRN-ALK and the ALK-induced cell growth can be blocked by the ALK inhibitors crizotinib and TAE684. In addition to well-differentiated papillary cancer, STRN-ALK was found with a higher prevalence in poorly differentiated and anaplastic thyroid cancers, and it did not overlap with other known driver mutations in these tumors. Our data demonstrate that STRN-ALK fusion occurs in a subset of patients with highly aggressive types of thyroid cancer and provide initial evidence suggesting that it may represent a therapeutic target for these patients. PMID:24613930

  12. Clinicopathological features and relation between anaplastic lymphoma kinase (ALK) mutation and histological subtype of lung adenocarcinoma in Eastern European Caucasian population

    PubMed Central

    Zaric, Bojan; Stojsic, Vladimir; Panjkovic, Milana; Tegeltija, Dragana; Stepanov, Vanesa; Kovacevic, Tomi; Sarcev, Tatjana; Radosavljevic, Davorin; Milovancev, Aleksandar; Adamidis, Vasilis; Zarogoulidis, Paul; Hohenforst-Schmidt, Wolfgang; Trakada, Georgia; Rapti, Aggeliki; Perin, Branislav

    2016-01-01

    Introduction: The incidence of echinoderm microtubule-associated protein-like4-anaplastic lymphoma kinase (EML4-ALK) mutation among surgically treated patients with adenocarcinoma of the lung of the Eastern European ethnicity is underreported. The aim of this trial was the determination of EML4-ALK mutation frequency in investigated population, and the evaluation of correlations between lung adenocarcinoma subtype and clinical characteristics with mutation status. Patients and methods: This was a prospective trial which included 195 patients with adenocarcinoma of the lung who underwent surgical treatment. ALK mutation screening was performed by immunohistochemistry (IHC). IHC scores of 2+ and 3+ were regarded as positive. Confirmatory FISH was performed in all IHC positive and in 2:1 ratio in negative patients. Results: Overall ALK mutation rate established by IHC was 6.2%, while FISH confirmed rate of 5.1%. The FISH confirmed ALK positivity in 7.6% Hungarians, 5.5% Serbians, and 6.6% Slovakians. Acinar subtype of adenocarcinoma of the lung was significantly (p=0.02) related to EML4-ALK positive mutation status. Most of the patients were males (56.9%), smokers (50.8%), or former smokers (28.7%) with acinar (55.4%) or solid (35.9%) adenocarcinoma of the lung. Sensitivity and specificity of IHC were 100% and 98.9% respectively. Conclusions: ALK mutation rate in surgically treated patients with adenocarcinoma of the lung was found to be 6.2% by IHC and 5.1% by FISH. Acinar subtype of the adenocarcinoma of the lung was significantly related to ALK positive mutation. PMID:27994656

  13. Crizotinib-Resistant Mutants of EML4-ALK Identified Through an Accelerated Mutagenesis Screen

    PubMed Central

    Zhang, Sen; Wang, Frank; Keats, Jeffrey; Zhu, Xiaotian; Ning, Yaoyu; Wardwell, Scott D; Moran, Lauren; Mohemmad, Qurish K; Anjum, Rana; Wang, Yihan; Narasimhan, Narayana I; Dalgarno, David; Shakespeare, William C; Miret, Juan J; Clackson, Tim; Rivera, Victor M

    2011-01-01

    Activating gene rearrangements of anaplastic lymphoma kinase (ALK) have been identified as driver mutations in non-small-cell lung cancer, inflammatory myofibroblastic tumors, and other cancers. Crizotinib, a dual MET/ALK inhibitor, has demonstrated promising clinical activity in patients with non-small-cell lung cancer and inflammatory myofibroblastic tumors harboring ALK translocations. Inhibitors of driver kinases often elicit kinase domain mutations that confer resistance, and such mutations have been successfully predicted using in vitro mutagenesis screens. Here, this approach was used to discover an extensive set of ALK mutations that can confer resistance to crizotinib. Mutations at 16 residues were identified, structurally clustered into five regions around the kinase active site, which conferred varying degrees of resistance. The screen successfully predicted the L1196M, C1156Y, and F1174L mutations, recently identified in crizotinib-resistant patients. In separate studies, we demonstrated that crizotinib has relatively modest potency in ALK-positive non-small-cell lung cancer cell lines. A more potent ALK inhibitor, TAE684, maintained substantial activity against mutations that conferred resistance to crizotinib. Our study identifies multiple novel mutations in ALK that may confer clinical resistance to crizotinib, suggests that crizotinib's narrow selectivity window may underlie its susceptibility to such resistance and demonstrates that a more potent ALK inhibitor may be effective at overcoming resistance. PMID:22034911

  14. Identification of ALK germline mutation (3605delG) in pediatric anaplastic medulloblastoma.

    PubMed

    Coco, Simona; De Mariano, Marilena; Valdora, Francesca; Servidei, Tiziana; Ridola, Vita; Andolfo, Immacolata; Oberthuer, André; Tonini, Gian Paolo; Longo, Luca

    2012-10-01

    The anaplastic lymphoma kinase (ALK) gene has been found either rearranged or mutated in several neoplasms such as anaplastic large-cell lymphoma, non-small-cell lung cancer, neuroblastoma and anaplastic thyroid cancer. Medulloblastoma (MB) is an embryonic pediatric cancer arising from nervous system, a tissue in which ALK is expressed during embryonic development. We performed an ALK mutation screening in 52 MBs and we found a novel heterozygous germline deletion of a single base in exon 23 (3605delG) in a case with marked anaplasia. This G deletion results in a frameshift mutation producing a premature stop codon in exon 25 of ALK tyrosine kinase domain. We also screened three human MB cell lines without finding any mutation of ALK gene. Quantitative expression analysis of 16 out of 52 samples showed overexpression of ALK mRNA in three MBs. In the present study, we report the first mutation of ALK found in MB. Moreover, a deletion of ALK gene producing a stop codon has not been detected in human tumors up to now. Further investigations are now required to elucidate whether the truncated form of ALK may have a role in signal transduction.

  15. Targeting stemness is an effective strategy to control EML4-ALK+ non-small cell lung cancer cells.

    PubMed

    Oh, Se Jin; Noh, Kyung Hee; Lee, Young-Ho; Hong, Soon-Oh; Song, Kwon-Ho; Lee, Hyo-Jung; Kim, Soyeon; Kim, Tae Min; Jeon, Ju-Hong; Seo, Jae Hong; Kim, Dong-Wan; Kim, Tae Woo

    2015-11-24

    The fusion between anaplastic lymphoma kinase (ALK) and echinoderm microtubule-associated protein-like 4 (EML4) is a causative factor in a unique subset of patients with non-small cell lung carcinoma (NSCLC). Although the inhibitor crizotinib, as it blocks the kinase activity of the resulting EML4-ALK fusion protein, displays remarkable initial responses, a fraction of NSCLC cases eventually become resistant to crizotinib by acquiring mutations in the ALK domain or activating bypass pathways via EGFR, KIT, or KRAS. Cancer stem cell (CSC) theory provides a plausible explanation for acquisition of tumorigenesis and resistance. However, the question as to whether EML4-ALK-driven tumorigenesis is linked with the stem-like property and whether the stemness is an effective target in controlling EML4-ALK+ NSCLC including crizotinib-resistant NSCLC cells has not been addressed. Here, we report that stem-like properties stem from ALK activity in EML4-ALK+ NSCLC cells. Notably, treatment with rapamycin, a CSC targeting agent, attenuates stem-like phenotypes of the EML4-ALK+ cells, which increased capability of tumor formation and higher expression of stemness-associated molecules such as ALDH, NANOG, and OCT4. Importantly, combinational treatment with rapamycin and crizotinib leads to synergistic anti-tumor effects on EML4-ALK+ NSCLC cells as well as on those resistant to crizotinib. Thus, we provide a proof of principle that targeting stemness would be a novel strategy to control intractable EML4-ALK+ NSCLC.

  16. Design, synthesis, and biological activity of urea derivatives as anaplastic lymphoma kinase inhibitors.

    PubMed

    af Gennäs, Gustav Boije; Mologni, Luca; Ahmed, Shaheen; Rajaratnam, Mohanathas; Marin, Oriano; Lindholm, Niko; Viltadi, Michela; Gambacorti-Passerini, Carlo; Scapozza, Leonardo; Yli-Kauhaluoma, Jari

    2011-09-05

    In anaplastic large-cell lymphomas, chromosomal translocations involving the kinase domain of anaplastic lymphoma kinase (ALK), generally fused to the 5' part of the nucleophosmin gene, produce highly oncogenic ALK fusion proteins that deregulate cell cycle, apoptosis, and differentiation in these cells. Other fusion oncoproteins involving ALK, such as echinoderm microtubule-associated protein-like 4-ALK, were recently found in patients with non-small-cell lung, breast, and colorectal cancers. Recent research has focused on the development of inhibitors for targeted therapy of these ALK-positive tumors. Because kinase inhibitors that target the inactive conformation are thought to be more specific than ATP-targeted inhibitors, we investigated the possibility of using two known inhibitors, doramapimod and sorafenib, which target inactive kinases, to design new urea derivatives as ALK inhibitors. We generated a homology model of ALK in its inactive conformation complexed with doramapimod or sorafenib in its active site. The results elucidated why doramapimod is a weak inhibitor and why sorafenib does not inhibit ALK. Virtual screening of commercially available compounds using the homology model of ALK yielded candidate inhibitors, which were tested using biochemical assays. Herein we present the design, synthesis, biological activity, and structure-activity relationships of a novel series of urea compounds as potent ALK inhibitors. Some compounds showed inhibition of purified ALK in the high nanomolar range and selective antiproliferative activity on ALK-positive cells.

  17. Anaplastic lymphoma kinase (ALK 1) staining and molecular analysis in inflammatory myofibroblastic tumours of the bladder: a preliminary clinicopathological study of nine cases and review of the literature.

    PubMed

    Freeman, Alex; Geddes, Nicola; Munson, Philippa; Joseph, Jean; Ramani, Pramila; Sandison, Ann; Fisher, Cyril; Parkinson, M Connie

    2004-07-01

    Inflammatory myofibroblastic tumours (IMFT) may arise at any anatomical site, including lung, soft tissues, retroperitoneum and bladder. Although morphologically similar, these lesions encompass a spectrum of entities with differing aetiology, ranging from reactive/regenerative proliferations to low-grade neoplasms with a risk of local recurrence, but no significant metastatic potential. Vesical IMFT usually presents as a polypoid mass with a pale firm cut surface and can be of considerable size, mimicking a malignant tumour clinically and radiologically. Its good outcome, however, warrants conservative surgical excision, emphasising the importance of identification and distinction from malignant tumours of the bladder that may require more radical surgery and/or adjuvant therapy. We conducted a preliminary retrospective, comparative immunocytochemical study of 20 bladder tumours, including nine IMFTs, five spindle cell (sarcomatoid) carcinomas, two rhabdomyosarcomas, two leiomyosarcomas and two neurofibromas. The results confirmed IMFT positivity for smooth muscle actin, desmin and cytokeratin in 78-89% cases, resulting in potential confusion with sarcomatoid carcinoma or leiomyosarcoma. In contrast, cytoplasmic anaplastic lymphoma kinase (ALK 1) staining was present in eight IMFT (89%), but was not seen in any other lesion examined. The ALK 1 staining was confirmed by fluorescence in situ hybridisation, with translocation of the ALK gene present in 15-60% tumour cells in four of six IMFT examined, but not in four cases of sarcomatoid carcinoma or three of leiomyosarcoma. In conclusion, ALK 1 staining may be of value in the distinction of vesical IMFT from morphologically similar entities, and often reflects ALK gene translocations in these lesions.

  18. Resensitization to Crizotinib by the Lorlatinib ALK Resistance Mutation L1198F.

    PubMed

    Shaw, Alice T; Friboulet, Luc; Leshchiner, Ignaty; Gainor, Justin F; Bergqvist, Simon; Brooun, Alexei; Burke, Benjamin J; Deng, Ya-Li; Liu, Wei; Dardaei, Leila; Frias, Rosa L; Schultz, Kate R; Logan, Jennifer; James, Leonard P; Smeal, Tod; Timofeevski, Sergei; Katayama, Ryohei; Iafrate, A John; Le, Long; McTigue, Michele; Getz, Gad; Johnson, Ted W; Engelman, Jeffrey A

    2016-01-07

    In a patient who had metastatic anaplastic lymphoma kinase (ALK)-rearranged lung cancer, resistance to crizotinib developed because of a mutation in the ALK kinase domain. This mutation is predicted to result in a substitution of cysteine by tyrosine at amino acid residue 1156 (C1156Y). Her tumor did not respond to a second-generation ALK inhibitor, but it did respond to lorlatinib (PF-06463922), a third-generation inhibitor. When her tumor relapsed, sequencing of the resistant tumor revealed an ALK L1198F mutation in addition to the C1156Y mutation. The L1198F substitution confers resistance to lorlatinib through steric interference with drug binding. However, L1198F paradoxically enhances binding to crizotinib, negating the effect of C1156Y and resensitizing resistant cancers to crizotinib. The patient received crizotinib again, and her cancer-related symptoms and liver failure resolved. (Funded by Pfizer and others; ClinicalTrials.gov number, NCT01970865.).

  19. Therapeutic strategies to overcome crizotinib resistance in non-small cell lung cancers harboring the fusion oncogene EML4-ALK

    PubMed Central

    Katayama, Ryohei; Khan, Tahsin M.; Benes, Cyril; Lifshits, Eugene; Ebi, Hiromichi; Rivera, Victor M.; Shakespeare, William C.; Iafrate, A. John; Engelman, Jeffrey A.; Shaw, Alice T.

    2011-01-01

    The echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusion oncogene represents a molecular target in a small subset of non-small cell lung cancers (NSCLCs). This fusion leads to constitutive ALK activation with potent transforming activity. In a pivotal phase 1 clinical trial, the ALK tyrosine kinase inhibitor (TKI) crizotinib (PF-02341066) demonstrated impressive antitumor activity in the majority of patients with NSCLC harboring ALK fusions. However, despite these remarkable initial responses, cancers eventually develop resistance to crizotinib, usually within 1 y, thereby limiting the potential clinical benefit. To determine how cancers acquire resistance to ALK inhibitors, we established a model of acquired resistance to crizotinib by exposing a highly sensitive EML4-ALK–positive NSCLC cell line to increasing doses of crizotinib until resistance emerged. We found that cells resistant to intermediate doses of crizotinib developed amplification of the EML4-ALK gene. Cells resistant to higher doses (1 μM) also developed a gatekeeper mutation, L1196M, within the kinase domain, rendering EML4-ALK insensitive to crizotinib. This gatekeeper mutation was readily detected using a unique and highly sensitive allele-specific PCR assay. Although crizotinib was ineffectual against EML4-ALK harboring the gatekeeper mutation, we observed that two structurally different ALK inhibitors, NVP-TAE684 and AP26113, were highly active against the resistant cancer cells in vitro and in vivo. Furthermore, these resistant cells remained highly sensitive to the Hsp90 inhibitor 17-AAG. Thus, we have developed a model of acquired resistance to ALK inhibitors and have shown that second-generation ALK TKIs or Hsp90 inhibitors are effective in treating crizotinib-resistant tumors harboring secondary gatekeeper mutations. PMID:21502504

  20. CRKL mediates EML4-ALK signaling and is a potential therapeutic target for ALK-rearranged lung adenocarcinoma

    PubMed Central

    Voeller, Donna; Gower, Arjan; Kim, In-Kyu; Zhang, Yu-Wen; Giaccone, Giuseppe

    2016-01-01

    Anaplastic lymphoma kinase (ALK) gene rearrangements are oncogenic drivers in a small subset of patients with non-small-cell lung cancer (NSCLC). The ALK inhibitors are highly effective in NSCLC patients harboring ALK rearrangements; however, most patients acquire resistance to the therapy following an initial response. Mechanisms of acquired resistance are complex. We used LC-MS/MS-based phosphotyrosine-peptide profiling in the EML4-ALK rearranged H3122 and H2228 cells treated with ALK inhibitors, to identify downstream effectors of ALK. We then used Western blot, siRNA experiments, cell proliferation, viability and migration assays to validate our findings. We identified CRKL as a novel downstream effector of ALK signaling. We demonstrated that CRKL tyrosine phosphorylation was repressed by pharmacological inhibition or small interfering RNA (siRNA) knockdown of ALK in the ALK-rearranged cells. More importantly, CRKL knockdown attenuated their cell proliferation, viability, and migration, but it had no effect on ALK phosphorylation and expression in these cells. Furthermore, CRKL tyrosine phosphorylation was inhibited by dasatinib (an inhibitor of ABL and SRC kinases), which in combination with the ALK inhibitor crizotinib displayed a synergistic inhibitory effect in vitro. In conclusion, our study suggests that CRKL is a key downstream effector of ALK, and combined inhibition of ALK and CRKL may represent an effective strategy for treating ALK-rearranged NSCLC patients. PMID:27078848

  1. Structure of the pseudokinase-kinase domains from protein kinase TYK2 reveals a mechanism for Janus kinase (JAK) autoinhibition.

    PubMed

    Lupardus, Patrick J; Ultsch, Mark; Wallweber, Heidi; Bir Kohli, Pawan; Johnson, Adam R; Eigenbrot, Charles

    2014-06-03

    Janus kinases (JAKs) are receptor-associated multidomain tyrosine kinases that act downstream of many cytokines and interferons. JAK kinase activity is regulated by the adjacent pseudokinase domain via an unknown mechanism. Here, we report the 2.8-Å structure of the two-domain pseudokinase-kinase module from the JAK family member TYK2 in its autoinhibited form. We find that the pseudokinase and kinase interact near the kinase active site and that most reported mutations in cancer-associated JAK alleles cluster in or near this interface. Mutation of residues near the TYK2 interface that are analogous to those in cancer-associated JAK alleles, including the V617F and "exon 12" JAK2 mutations, results in increased kinase activity in vitro. These data indicate that JAK pseudokinases are autoinhibitory domains that hold the kinase domain inactive until receptor dimerization stimulates transition to an active state.

  2. Dickkopf-3 Upregulates VEGF in Cultured Human Endothelial Cells by Activating Activin Receptor-Like Kinase 1 (ALK1) Pathway

    PubMed Central

    Busceti, Carla L.; Marchitti, Simona; Bianchi, Franca; Di Pietro, Paola; Riozzi, Barbara; Stanzione, Rosita; Cannella, Milena; Battaglia, Giuseppe; Bruno, Valeria; Volpe, Massimo; Fornai, Francesco; Nicoletti, Ferdinando; Rubattu, Speranza

    2017-01-01

    Dkk-3 is a member of the dickkopf protein family of secreted inhibitors of the Wnt pathway, which has been shown to enhance angiogenesis. The mechanism underlying this effect is currently unknown. Here, we used cultured HUVECs to study the involvement of the TGF-β and VEGF on the angiogenic effect of Dkk-3. Addition of hrDkk-3 peptide (1 or 10 ng/ml) to HUVECs for 6 or 12 h enhanced the intracellular and extracellular VEGF protein levels, as assessed by RTPCR, immunoblotting, immunocytochemistry and ELISA. The increase in the extracellular VEGF levels was associated to the VEGFR2 activation. Pharmacological blockade of VEGFR2 abrogated Dkk-3-induced endothelial cell tubes formation, indicating that VEGF is a molecular player of the angiogenic effects of Dkk-3. Moreover, Dkk-3 enhanced Smad1/5/8 phosphorylation and recruited Smad4 to the VEGF gene promoter, suggesting that Dkk-3 activated ALK1 receptor leading to a transcriptional activation of VEGF. This mechanism was instrumental to the increased VEGF expression and endothelial cell tubes formation mediated by Dkk-3, because both effects were abolished by siRNA-mediated ALK1 knockdown. In summary, we have found that Dkk-3 activates ALK1 to stimulate VEGF production and induce angiogenesis in HUVECs. PMID:28352232

  3. Structural insight into selectivity and resistance profiles of ROS1 tyrosine kinase inhibitors

    PubMed Central

    Davare, Monika A.; Vellore, Nadeem A.; Wagner, Jacob P.; Eide, Christopher A.; Goodman, James R.; Drilon, Alexander; Deininger, Michael W.; O’Hare, Thomas; Druker, Brian J.

    2015-01-01

    Oncogenic ROS1 fusion proteins are molecular drivers in multiple malignancies, including a subset of non-small cell lung cancer (NSCLC). The phylogenetic proximity of the ROS1 and anaplastic lymphoma kinase (ALK) catalytic domains led to the clinical repurposing of the Food and Drug Administration (FDA)-approved ALK inhibitor crizotinib as a ROS1 inhibitor. Despite the antitumor activity of crizotinib observed in both ROS1- and ALK-rearranged NSCLC patients, resistance due to acquisition of ROS1 or ALK kinase domain mutations has been observed clinically, spurring the development of second-generation inhibitors. Here, we profile the sensitivity and selectivity of seven ROS1 and/or ALK inhibitors at various levels of clinical development. In contrast to crizotinib’s dual ROS1/ALK activity, cabozantinib (XL-184) and its structural analog foretinib (XL-880) demonstrate a striking selectivity for ROS1 over ALK. Molecular dynamics simulation studies reveal structural features that distinguish the ROS1 and ALK kinase domains and contribute to differences in binding site and kinase selectivity of the inhibitors tested. Cell-based resistance profiling studies demonstrate that the ROS1-selective inhibitors retain efficacy against the recently reported CD74-ROS1G2032R mutant whereas the dual ROS1/ALK inhibitors are ineffective. Taken together, inhibitor profiling and stringent characterization of the structure–function differences between the ROS1 and ALK kinase domains will facilitate future rational drug design for ROS1- and ALK-driven NSCLC and other malignancies. PMID:26372962

  4. Alk1 and Alk2 are two new cell cycle-regulated haspin-like proteins in budding yeast.

    PubMed

    Nespoli, Alessandro; Vercillo, Raffaella; di Nola, Lisa; Diani, Laura; Giannattasio, Michele; Plevani, Paolo; Muzi-Falconi, Marco

    2006-07-01

    Haspin is a protein kinase identified in mouse and human cells, and genes coding for haspin-like proteins are present in virtually all eukaryotic genomes sequenced so far. Two haspin homologues, called Alk1 and Alk2, are present in the yeast Saccharomyces cerevisiae. Both Alk1 and Alk2 exhibit a weak auto-kinase activity in vitro, are phosphoproteins in vivo and are hyperphosphorylated in response to DNA damage. The amount and modification of the two proteins is greatly regulated during the cell cycle. In fact, Alk1 and Alk2 levels peak in mitosis and late-S/G2, respectively, and phosphorylation of both proteins is maximal in mitosis. Control of protein stability plays a major role in Alk2 regulation. The half-life of Alk2 is particularly short in G1; mutagenesis and genetic analysis indicate that its degradation is controlled by the APC pathway. Overexpression of ALK2, but not of ALK1, causes a mitotic arrest, which is correlated to the kinase activity of the protein. This finding, together with its cell cycle regulation, suggests a role for Alk2 in the control of mitosis.

  5. Crystal structure of domain-swapped STE20 OSR1 kinase domain

    SciTech Connect

    Lee, Seung-Jae; Cobb, Melanie H.; Goldsmith, Elizabeth J.

    2009-09-15

    OSR1 (oxidative stress-responsive-1) and SPAK (Ste20/Sps1-related proline/alanine-rich kinase) belong to the GCK-VI subfamily of Ste20 group kinases. OSR1 and SPAK are key regulators of NKCCs (Na{sup +}/K{sup +}/2Cl{sup -} cotransporters) and activated by WNK family members (with-no-lysine kinase), mutations of which are known to cause Gordon syndrome, an autosomal dominant form of inherited hypertension. The crystal structure of OSR1 kinase domain has been solved at 2.25 {angstrom}. OSR1 forms a domain-swapped dimer in an inactive conformation, in which P+1 loop and {alpha}EF helix are swapped between dimer-related monomers. Structural alignment with nonswapped Ste20 TAO2 kinase indicates that the integrity of chemical interactions in the kinase domain is well preserved in the domain-swapped interfaces. The OSR1 kinase domain has now been added to a growing list of domain-swapped protein kinases recently reported, suggesting that the domain-swapping event provides an additional layer of complexity in regulating protein kinase activity.

  6. Conformational features and binding affinities to Cripto, ALK7 and ALK4 of Nodal synthetic fragments.

    PubMed

    Calvanese, Luisa; Sandomenico, Annamaria; Caporale, Andrea; Focà, Annalia; Focà, Giuseppina; D'Auria, Gabriella; Falcigno, Lucia; Ruvo, Menotti

    2015-04-01

    Nodal, a member of the TGF-β superfamily, is a potent embryonic morphogen also implicated in tumor progression. As for other TGF-βs, it triggers the signaling functions through the interaction with the extracellular domains of type I and type II serine/threonine kinase receptors and with the co-receptor Cripto. Recently, we reported the molecular models of Nodal in complex with its type I receptors (ALK4 and ALK7) as well as with Cripto, as obtained by homology modeling and docking simulations. From such models, potential binding epitopes have been identified. To validate such hypotheses, a series of mutated Nodal fragments have been synthesized. These peptide analogs encompass residues 44-67 of the Nodal protein, corresponding to the pre-helix loop and the H3 helix, and reproduce the wild-type sequence or bear some modifications to evaluate the hot-spot role of modified residues in the receptor binding. Here, we show the structural characterization in solution by CD and NMR of the Nodal peptides and the measurement of binding affinity toward Cripto by surface plasmon resonance. Data collected by both conformational analyses and binding measurements suggest a role for Y58 of Nodal in the recognition with Cripto and confirm that previously reported for E49 and E50. Surface plasmon resonance binding assays with recombinant proteins show that Nodal interacts in vitro also with ALK7 and ALK4 and preliminary data, generated using the Nodal synthetic fragments, suggest that Y58 of Nodal may also be involved in the recognition with these protein partners.

  7. Polyomavirus middle-T antigen associates with the kinase domain of Src-related tyrosine kinases.

    PubMed Central

    Dunant, N M; Senften, M; Ballmer-Hofer, K

    1996-01-01

    Middle-T antigen of mouse polyomavirus, an oncogenic DNA virus, associates with and activates the cellular tyrosine kinases c-Src, c-Yes, and Fyn. This interaction is essential for polyomavirus-mediated transformation of cells in culture and tumor formation in animals. To determine the domain of c-Src directing association with middle-T, mutant c-Src proteins lacking the amino-terminal unique domain and the myristylation signal, the SH2 domain, the SH3 domain, or all three of these domains were coexpressed with middle-T in NIH 3T3 cells. All mutants were found to associate with middle-T, demonstrating that the kinase domain of c-Src, including the carboxy-terminal regulatory tail, is sufficient for association with middle-T. Moreover, we found that Hck, another member of the Src kinase family, does not bind middle-T, while chimeric kinases consisting of the amino-terminal domains of c-Src fused to the kinase domain of Hck or the amino-terminal domains of Hck fused to the kinase domain of c-Src associated with middle-T. Hck mutated at its carboxy-terminal regulatory residue, tyrosine 501, was also found to associate with middle-T. These results suggest that in Hck, the postulated intramolecular interaction between the carboxy-terminal regulatory tyrosine and the SH2 domain prevents association with middle-T. This intramolecular interaction apparently also limits the ability of c-Src to associate with middle-T, since removal of the SH2 or SH3 domain increases the efficiency with which middle-T binds c-Src. PMID:8627648

  8. The ErbB Kinase Domain: Structural Perspectives into Kinase Activation and Inhibition

    PubMed Central

    Bose, Ron; Zhang, Xuewu

    2009-01-01

    Epidermal growth factor receptor (EGFR) and its family members, ErbB2, ErB3 and ErB4, are receptor tyrosine kinases which send signals into the cell to regulate many critical processes including development, tissue homeostasis, and tumorigenesis. Central to the signaling of these receptors is their intracellular kinase domain, which is activated by ligand-induced dimerization of the receptor and phosphorylates several tyrosine residues in the C-terminal tail. The phosphorylated tail then recruits other signaling molecules and relays the signal to downstream pathways. A model of the autoinhibition, activation and feedback inhibition mechanisms for the ErbB kinase domain has emerged from a number of recent structural studies. Meanwhile, recent clinical studies have revealed the relationship between specific ErbB kinase mutations and the responsiveness to kinase inhibitor drugs. We will review these regulation mechanisms of the ErbB kinase domain, and discuss the binding specificity of kinase inhibitors and the effects of kinase domain mutations found in cancer patients from a structural perspective. PMID:18761339

  9. Myosin 3A Kinase Activity Is Regulated by Phosphorylation of the Kinase Domain Activation Loop*

    PubMed Central

    Quintero, Omar A.; Unrath, William C.; Stevens, Stanley M.; Manor, Uri; Kachar, Bechara; Yengo, Christopher M.

    2013-01-01

    Class III myosins are unique members of the myosin superfamily in that they contain both a motor and kinase domain. We have found that motor activity is decreased by autophosphorylation, although little is known about the regulation of the kinase domain. We demonstrate by mass spectrometry that Thr-178 and Thr-184 in the kinase domain activation loop and two threonines in the loop 2 region of the motor domain are autophosphorylated (Thr-908 and Thr-919). The kinase activity of MYO3A 2IQ with the phosphomimic (T184E) or phosphoblock (T184A) mutations demonstrates that kinase activity is reduced 30-fold as a result of the T184A mutation, although the Thr-178 site only had a minor impact on kinase activity. Interestingly, the actin-activated ATPase activity of MYO3A 2IQ is slightly reduced as a result of the T178A and T184A mutations suggesting coupling between motor and kinase domains. Full-length GFP-tagged T184A and T184E MYO3A constructs transfected into COS7 cells do not disrupt the ability of MYO3A to localize to filopodia structures. In addition, we demonstrate that T184E MYO3A reduces filopodia elongation in the presence of espin-1, whereas T184A enhances filopodia elongation in a similar fashion to kinase-dead MYO3A. Our results suggest that as MYO3A accumulates at the tips of actin protrusions, autophosphorylation of Thr-184 enhances kinase activity resulting in phosphorylation of the MYO3A motor and reducing motor activity. The differential regulation of the kinase and motor activities allows for MYO3A to precisely self-regulate its concentration in the actin bundle-based structures of cells. PMID:24214986

  10. ALK F1174V mutation confers sensitivity while ALK I1171 mutation confers resistance to alectinib. The importance of serial biopsy post progression.

    PubMed

    Ou, Sai-Hong; Milliken, Jeffrey C; Azada, Michele C; Miller, Vincent A; Ali, Siraj M; Klempner, Samuel J

    2016-01-01

    Many acquired resistant mutations to the anaplastic lymphoma kinase (ALK) gene have been identified during treatment of ALK-rearranged non-small cell lung cancer (NSCLC) patients with crizotinib, ceritinib, and alectinib. These various acquired resistant ALK mutations confer differential sensitivities to various ALK inhibitors and may provide guidance on how to sequence the use of many of the second generation ALK inhibitors. We described a patient who developed an acquired ALK F1174V resistant mutation on progression from crizotinib that responded to alectinib for 18 months but then developed an acquired ALK I1171S mutation to alectinib. Both tumor samples had essentially the same genomic profile by comprehensive genomic profiling otherwise. This is the first patient report that demonstrates ALK F1174V mutation is sensitive to alectinib and further confirms missense acquired ALK I1171 mutation is resistant to alectinib. Sequential tumor re-biopsy for comprehensive genomic profiling (CGP) is important to appreciate the selective pressure during treatment with various ALK inhibitors underpinning the evolution of the disease course of ALK+NSCLC patients while on treatment with the various ALK inhibitors. This approach will likely help inform the optimal sequencing strategy as more ALK inhibitors become available. This case report also validates the importance of developing structurally distinct ALK inhibitors for clinical use to overcome non-cross resistant ALK mutations.

  11. Activity of second-generation ALK inhibitors against crizotinib-resistant mutants in an NPM-ALK model compared to EML4-ALK

    PubMed Central

    Fontana, Diletta; Ceccon, Monica; Gambacorti-Passerini, Carlo; Mologni, Luca

    2015-01-01

    Anaplastic lymphoma kinase (ALK) is a tyrosine kinase receptor involved in both solid and hematological tumors. About 80% of ALK-positive anaplastic large-cell lymphoma (ALCL) cases are characterized by the t(2;5)(p23;q35) translocation, encoding for the aberrant fusion protein nucleophosmin (NPM)-ALK, whereas 5% of non-small-cell lung cancer (NSCLC) patients carry the inv(2)(p21;p23) rearrangement, encoding for the echinoderm microtubule-associated protein-like 4 (EML4)-ALK fusion. The ALK/c-MET/ROS inhibitor crizotinib successfully improved the treatment of ALK-driven diseases. However, several cases of resistance appeared in NSCLC patients, and ALK amino acid substitutions were identified as a leading cause of resistance to crizotinib. Second-generation ALK inhibitors have been developed in order to overcome crizotinib resistance. In this work, we profiled in vitro the activity of crizotinib, AP26113, ASP3026, alectinib, and ceritinib against six mutated forms of ALK associated with clinical resistance to crizotinib (C1156Y, L1196M, L1152R, G1202R, G1269A, and S1206Y) and provide a classification of mutants according to their level of sensitivity/resistance to the drugs. Since the biological activity of ALK mutations extends beyond the specific type of fusion, both NPM-ALK- and EML4-ALK-positive cellular models were used. Our data revealed that most mutants may be targeted by using different inhibitors. One relevant exception is represented by the G1202R substitution, which was highly resistant to all drugs (>10-fold increased IC50 compared to wild type) and may represent the most challenging mutation to overcome. These results provide a prediction of cross-resistance of known crizotinib-resistant mutations against all second-generation tyrosine kinase inhibitors (TKIs) clinically available, and therefore could be a useful tool to help clinicians in the management of crizotinib-resistance cases. PMID:25727400

  12. The SH2 domain of Abl kinases regulates kinase autophosphorylation by controlling activation loop accessibility

    NASA Astrophysics Data System (ADS)

    Lamontanara, Allan Joaquim; Georgeon, Sandrine; Tria, Giancarlo; Svergun, Dmitri I.; Hantschel, Oliver

    2014-11-01

    The activity of protein kinases is regulated by multiple molecular mechanisms, and their disruption is a common driver of oncogenesis. A central and almost universal control element of protein kinase activity is the activation loop that utilizes both conformation and phosphorylation status to determine substrate access. In this study, we use recombinant Abl tyrosine kinases and conformation-specific kinase inhibitors to quantitatively analyse structural changes that occur after Abl activation. Allosteric SH2-kinase domain interactions were previously shown to be essential for the leukemogenesis caused by the Bcr-Abl oncoprotein. We find that these allosteric interactions switch the Abl activation loop from a closed to a fully open conformation. This enables the trans-autophosphorylation of the activation loop and requires prior phosphorylation of the SH2-kinase linker. Disruption of the SH2-kinase interaction abolishes activation loop phosphorylation. Our analysis provides a molecular mechanism for the SH2 domain-dependent activation of Abl that may also regulate other tyrosine kinases.

  13. Activated type I TGFbeta receptor (Alk5) kinase confers enhancedsurvival to mammary epithelial cells and accelerates mammary tumorprogression

    SciTech Connect

    Muraoka-Cook, Rebecca S.; Shin, Incheol; Yi, Jae Youn; Easterly,Evangeline; Barcellos-Hoff, Mary Helen; Yingling, Jonathan M.; Zent, Roy; Arteaga, Carlos L.

    2005-01-02

    The transforming growth factor-betas (TGF{beta}s) are members of a large superfamily of pleiotropic cytokines that also includes the activins and the bone morphogenetic proteins (BMPs). Members of the TGF{beta} family regulate complex physiological processes such cell proliferation, differentiation, adhesion, cell-cell and cell-matrix interactions, motility, and cell death, among others (Massague, 1998). Dysregulation of TGF{beta} signaling contributes to several pathological processes including cancer, fibrosis, and auto-immune disorders (Massague et al., 2000). The TGF{beta}s elicit their biological effects by binding to type II and type I transmembrane receptor serine-threonine kinases (T{beta}RII and T{beta}RI) which, in turn, phosphorylated Smad 2 and Smad 3. Phosphorylated Smad 2/3 associate with Smad 4 and, as a heteromeric complex, translocate to the nucleus where they regulate gene transcription. The inhibitory Smad7 down regulates TGF{beta} signaling by binding to activated T{beta}RI and interfering with its ability to phosphorylate Smad 2/3 (Derynck and Zhang, 2003; Shi and Massague, 2003). Signaling is also regulated by Smad proteolysis. TGF{beta} receptor-mediated activation results in multi-ubiquitination of Smad 2 in the nucleus and subsequent degradation of Smad 2 by the proteasome (Lo and Massague, 1999). Activation of TGF{beta} receptors also induces mobilization of a Smad 7-Smurf complex from the nucleus to the cytoplasm; this complex recognizes the activated receptors and mediates their ubiquitination and internalization via caveolin-rich vesicles, leading to termination of TGF{beta} signaling (Di Guglielmo et al., 2003). Other signal transducers/pathways have been implicated in TGF{beta} actions. These include the extracellular signal-regulated kinase (Erk), c-Jun N-terminal kinase (Jnk), p38 mitogen-activated protein kinase (MAPK), protein phosphatase PP2A, phosphatidylinositol-3 kinase (PI3K), and the family of Rho GTPases [reviewed in

  14. Crystal Structure of the Protein Kinase Domain of Yeast AMP-Activated Protein Kinase Snf1

    SciTech Connect

    Rudolph,M.; Amodeo, G.; Bai, Y.; Tong, L.

    2005-01-01

    AMP-activated protein kinase (AMPK) is a master metabolic regulator, and is an important target for drug development against diabetes, obesity, and other diseases. AMPK is a hetero-trimeric enzyme, with a catalytic ({alpha}) subunit, and two regulatory ({beta} and {gamma}) subunits. Here we report the crystal structure at 2.2 Angstrom resolution of the protein kinase domain (KD) of the catalytic subunit of yeast AMPK (commonly known as SNF1). The Snf1-KD structure shares strong similarity to other protein kinases, with a small N-terminal lobe and a large C-terminal lobe. Two negative surface patches in the structure may be important for the recognition of the substrates of this kinase.

  15. A causal link from ALK to hexokinase II overexpression and hyperactive glycolysis in EML4-ALK-positive lung cancer

    PubMed Central

    Ma, Yibao; Yu, Chunrong; Mohamed, Esraa M.; Shao, Huanjie; Wang, Li; Sundaresan, Gobalakrishnan; Zweit, Jamal; Idowu, Michael; Fang, Xianjun

    2016-01-01

    A high rate of aerobic glycolysis is a hallmark of malignant transformation. Accumulating evidence suggests that diverse regulatory mechanisms mediate this cancer-associated metabolic change seen in a wide spectrum of cancer. The echinoderm microtubule associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion protein is found in approximately 3-7% of non-small cell lung carcinomas (NSCLC). Molecular evidence and therapeutic effectiveness of FDA-approved ALK inhibitors indicated that EML4-ALK is a driving factor of lung tumorigenesis. A recent clinical study showed that NSCLC harboring EML4-ALK rearrangements displayed higher glucose metabolism compared to EML4-ALK-negative NSCLC. In the current work, we presented evidence that EML4-ALK is coupled to overexpression of hexokinase II (HK2), one of the rate-limiting enzymes of the glycolytic pathway. The link from EML4-ALK to HK2 upregulation is essential for a high rate of glycolysis and proliferation of EML4-ALK-rearranged NSCLC cells. We identified hypoxia-inducible factor 1α (HIF1α) as a key transcription factor to drive HK2 gene expression in normoxia in these cells. EML4-ALK induced hypoxia-independent but glucose-dependent accumulation of HIF1α protein via both transcriptional activation of HIF1α mRNA and the PI3K-AKT pathway to enhance HIF1α protein synthesis. The EML4-ALK-mediated upregulation of HIF1α, HK2 and glycolytic metabolism was also highly active in vivo as demonstrated by FDG-PET imaging of xenografts grown from EML4-ALK-positive NSCLC cells. Our data reveal a novel EML4-ALK-HIF1α-HK2 cascade to enhance glucose metabolism in EML4-ALK-positive NSCLC. PMID:27132509

  16. A lipid binding domain in sphingosine kinase 2

    SciTech Connect

    Don, Anthony S.; Rosen, Hugh

    2009-02-27

    The lipid second messenger sphingosine 1-phosphate (S1P) is a critical mediator of cellular proliferation and survival signals, and is essential for vasculogenesis and neurogenesis. S1P formation is catalysed by sphingosine kinases 1 and 2 (Sphk1 and Sphk2). We have found that the endogenous glycolipid sulfatide (3-O-sulfogalactosylceramide) binds to and inhibits the activity of Sphk2 and the closely related ceramide kinase (Cerk), but not Sphk1. Using sulfatide as a probe, we mapped the lipid binding domain to the N-terminus of Sphk2 (residues 1-175), a region of sequence that is absent in Sphk1, but aligns with a pleckstrin homology domain in Cerk. Accordingly, Sphk2 bound to phosphatidylinositol monophosphates but not to abundant cellular phospholipids. Deleting the N-terminal domain reduced Sphk2 membrane localisation in cells. We have therefore identified a lipid binding domain in Sphk2 that is important for the enzyme's sub-cellular localisation.

  17. ALK Gene Copy Number Gain and Immunohistochemical Expression Status Using Three Antibodies in Neuroblastoma.

    PubMed

    Kim, Eun Kyung; Kim, Sewha

    2017-01-01

    Anaplastic lymphoma kinase ( ALK) gene aberrations-such as mutations, amplifications, and copy number gains-represent a major genetic predisposition to neuroblastoma (NB). This study aimed to evaluate the correlation between ALK gene copy number status, ALK protein expression, and clinicopathological parameters. We retrospectively retrieved 30 cases of poorly differentiated NB and constructed tissue microarrays (TMAs). ALK copy number changes were assessed by fluorescence in situ hybridization (FISH) assays, and ALK immunohistochemistry (IHC) testing was performed using three different antibodies (ALK1, D5F3, and 5A4 clones). ALK amplification and copy number gain were observed in 10% (3/30) and 53.3% (16/30) of the cohort, respectively. There were positive correlations between ALK copy number and IHC-positive rate in ALK1 and 5A4 antibodies ( P < 0.001 and P = 0.019, respectively). ALK1, D5F3, and 5A4 antibodies equally showed 100% sensitivity in detecting ALK amplification. However, the sensitivity for detecting copy number gain differed among the three antibodies, with 75% sensitivity in D5F3 and 0% sensitivity in ALK1. ALK-amplified NBs were correlated with synchronous MYCN amplification and chromosome 1p deletion. ALK IHC positivity was frequently observed in INSS stage IV and high-risk group patients. In conclusion, this study identified that an increase in the ALK copy number is a frequent genetic alteration in poorly differentiated NB. ALK-amplified NBs showed consistent ALK IHC positivity with all kinds of antibodies. In contrast, the detection performance of ALK copy number gain was antibody dependent, with the D5F3 antibody showing the best sensitivity.

  18. Rate limiting domain and loop motions in arginine kinase

    PubMed Central

    Davulcu, Omar; Skalicky, Jack J.; Chapman, Michael S.

    2011-01-01

    Arginine kinase catalyzes the reversible transfer of a phosphoryl group between ATP and arginine. It is the arthropod homolog of creatine kinase, buffering cellular ATP levels. Crystal structures of arginine kinase, in substrate-free and substrate-bound forms, have revealed large conformational changes associated with the catalytic cycle. Recent NMR identified movements of the N-terminal domain and a loop comprising residues I182-G209 with conformational exchange rates in the substrate-free enzyme similar to the turnover rate. Here, to understand whether these motions might be rate-limiting, activation barriers for both the intrinsic dynamics and enzyme turnover are determined using measurements over a temperature range of 15 to 30°C. 15N transverse relaxation dispersion yields activation barriers of 46 ± 8 and 34 ± 12 kJ/mol for of the N-terminal domain and I182-G209 loop, respectively. An activation barrier of 34 ± 13 kJ/mol was obtained for enzyme turnover from steady-state kinetics. The similarity between the activation barriers is indeed consistent with turnover being limited by backbone conformational dynamics, and pinpoints the locations of potentially rate limiting motions. PMID:21425868

  19. Excess of NPM-ALK oncogenic signaling promotes cellular apoptosis and drug dependency

    PubMed Central

    Mologni, Luca; Poggio, Teresa; Varesio, Lydia M.; Menotti, Matteo; Bombelli, Silvia; Rigolio, Roberta; Manazza, Andrea D.; Di Giacomo, Filomena; Ambrogio, Chiara; Giudici, Giovanni; Casati, Cesare; Mastini, Cristina; Compagno, Mara; Turner, Suzanne D.; Gambacorti-Passerini, Carlo; Chiarle, Roberto; Voena, Claudia

    2016-01-01

    Most of Anaplastic Large Cell Lymphoma (ALCL) cases carry the t(2;5; p23;q35) that produces the fusion protein NPM-ALK. NPM-ALK deregulated kinase activity drives several pathways that support malignant transformation of lymphoma cells. We found that in ALK-rearranged ALCL cell lines NPM-ALK was distributed in equal amounts between the cytoplasm and the nucleus. Only the cytoplasmic portion was catalytically active in both cell lines and primary ALCL, whereas the nuclear portion was inactive due to heterodimerization with NPM1. Thus, about 50% of the NPM-ALK is not active and sequestered as NPM-ALK/NPM1 heterodimers in the nucleus. Overexpression or re-localization of NPM-ALK to the cytoplasm by NPM genetic knock-out or knock-down caused ERK1/2 increased phosphorylation and cell death through the engagement of an ATM/Chk2 and γH2AX mediated DNA damage response. Remarkably, human NPM-ALK amplified cell lines resistant to ALK tyrosine kinase inhibitors (TKIs) underwent apoptosis upon drug withdrawal as a consequence of ERK1/2 hyperactivation. Altogether, these findings indicate that an excess of NPM-ALK activation and signaling induces apoptosis via oncogenic stress responses. A “drug holiday” where the ALK TKI treatment is suspended could represent a therapeutic option in cells that become resistant by NPM-ALK amplification. PMID:26657151

  20. Activated Alk triggers prolonged neurogenesis and Ret upregulation providing a therapeutic target in ALK-mutated neuroblastoma

    PubMed Central

    Cazes, Alex; Lopez-Delisle, Lucille; Tsarovina, Konstantina; Pierre-Eugène, Cécile; De Preter, Katleen; Peuchmaur, Michel; Nicolas, André; Provost, Claire; Louis-Brennetot, Caroline; Daveau, Romain; Kumps, Candy; Cascone, Ilaria; Schleiermacher, Gudrun; Prignon, Aurélie; Speleman, Frank; Rohrer, Hermann; Delattre, Olivier; Janoueix-Lerosey, Isabelle

    2014-01-01

    Activating mutations of the ALK (Anaplastic lymphoma Kinase) gene have been identified in sporadic and familial cases of neuroblastoma, a cancer of early childhood arising from the sympathetic nervous system (SNS). To decipher ALK function in neuroblastoma predisposition and oncogenesis, we have characterized knock-in (KI) mice bearing the two most frequent mutations observed in neuroblastoma patients. A dramatic enlargement of sympathetic ganglia is observed in AlkF1178L mice from embryonic to adult stages associated with an increased proliferation of sympathetic neuroblasts from E14.5 to birth. In a MYCN transgenic context, the F1178L mutation displays a higher oncogenic potential than the R1279Q mutation as evident from a shorter latency of tumor onset. We show that tumors expressing the R1279Q mutation are sensitive to ALK inhibition upon crizotinib treatment. Furthermore, our data provide evidence that activated ALK triggers RET upregulation in mouse sympathetic ganglia at birth as well as in murine and human neuroblastoma. Using vandetanib, we show that RET inhibition strongly impairs tumor growth in vivo in both MYCN/KI AlkR1279Q and MYCN/KI AlkF1178L mice. Altogether, our findings demonstrate the critical role of activated ALK in SNS development and pathogenesis and identify RET as a therapeutic target in ALK mutated neuroblastoma. PMID:24811913

  1. Inhibition of Axl improves the targeted therapy against ALK-mutated neuroblastoma

    SciTech Connect

    Xu, Fei; Li, Hongling; Sun, Yong

    2014-11-28

    Highlights: • First reported Axl is co-expressed with ALK in neuroblastoma tissues and cell lines. • Axl activation promotes cell growth and impairs the efficiency of ALK inhibitor. • Further found silence of Axl leads to increased sensitivity to ALK inhibitors. • Axl inhibitor promotes the efficiency of targeted therapy in vitro and in vivo. • Axl activation should be considered in the clinical application of ALK inhibitors. - Abstract: Neuroblastoma (NB) patients harboring mutated ALK can be expected to potentially benefit from targeted therapy based on ALK tyrosine kinase inhibitor (TKI), such as crizotinib and ceritinib. However, the effect of the treatment varies with different individuals, although with the same genic changes. Axl receptor tyrosine kinase is expressed in a variety of human cancers, but little data are reported in NB, particularly in which carrying mutated ALK. In this study, we focus on the roles of Axl in ALK-mutated NB for investigating rational therapeutic strategy. We found that Axl is expressed in ALK-positive NB tissues and cell lines, and could be effectively activated by its ligand GAS6. Ligand-dependent Axl activation obviously rescued crizotinib-mediated suppression of cell proliferation in ALK-mutated NB cells. Genetic inhibition of Axl with specific small interfering RNA markedly increased the sensitivity of cells to ALK-TKIs. Furthermore, a small-molecule inhibitor of Axl significantly enhanced ALK-targeted therapy, as an increased frequency of apoptosis was observed in NB cells co-expressing ALK and Axl. Taken together, our results demonstrated that activation of Axl could lead to insensitivity to ALK inhibitors, and dual inhibition of ALK and Axl might be a potential therapeutic strategy against ALK-mutated NB.

  2. Reversal of microRNA-150 silencing disadvantages crizotinib-resistant NPM-ALK(+) cell growth

    PubMed Central

    Hoareau-Aveilla, Coralie; Valentin, Thibaud; Daugrois, Camille; Quelen, Cathy; Mitou, Géraldine; Quentin, Samuel; Jia, Jinsong; Spicuglia, Salvatore; Ferrier, Pierre; Ceccon, Monica; Giuriato, Sylvie; Gambacorti-Passerini, Carlo; Brousset, Pierre; Lamant, Laurence; Meggetto, Fabienne

    2015-01-01

    The regulatory microRNA miR-150 is involved in the development of hemopathies and is downregulated in T-lymphomas, such as anaplastic large-cell lymphoma (ALCL) tumors. ALCL is defined by the presence or absence of translocations that activate the anaplastic lymphoma kinase (ALK), with nucleophosmin-ALK (NPM-ALK) fusions being the most common. Here, we compared samples of primary NPM-ALK(+) and NPM-ALK(–) ALCL to investigate the role of miR-150 downstream of NPM-ALK. Methylation of the MIR150 gene was substantially elevated in NPM-ALK(+) biopsies and correlated with reduced miR-150 expression. In NPM-ALK(+) cell lines, DNA hypermethylation–mediated miR-150 repression required ALK-dependent pathways, as ALK inhibition restored miR-150 expression. Moreover, epigenetic silencing of miR-150 was due to the activation of STAT3, a major downstream substrate of NPM-ALK, in cooperation with DNA methyltransferase 1 (DNMT1). Accordingly, miR-150 repression was turned off following treatment with the DNMT inhibitor, decitabine. In murine NPM-ALK(+) xenograft models, miR-150 upregulation induced antineoplastic activity. Treatment of crizotinib-resistant NPM-ALK(+) KARPAS-299-CR06 cells with decitabine or ectopic miR-150 expression reduced viability and growth. Altogether, our results suggest that hypomethylating drugs, alone or in combination with other agents, may benefit ALK(+) patients harboring tumors resistant to crizotinib and other anti-ALK tyrosine kinase inhibitors (TKIs). Moreover, these results support further work on miR-150 in these and other ALK(+) malignancies. PMID:26258416

  3. Kinase Associated-1 Domains Drive MARK/PAR1 Kinases to Membrane Targets by Binding Acidic Phospholipids

    SciTech Connect

    Moravcevic, Katarina; Mendrola, Jeannine M.; Schmitz, Karl R.; Wang, Yu-Hsiu; Slochower, David; Janmey, Paul A.; Lemmon, Mark A.

    2011-09-28

    Phospholipid-binding modules such as PH, C1, and C2 domains play crucial roles in location-dependent regulation of many protein kinases. Here, we identify the KA1 domain (kinase associated-1 domain), found at the C terminus of yeast septin-associated kinases (Kcc4p, Gin4p, and Hsl1p) and human MARK/PAR1 kinases, as a membrane association domain that binds acidic phospholipids. Membrane localization of isolated KA1 domains depends on phosphatidylserine. Using X-ray crystallography, we identified a structurally conserved binding site for anionic phospholipids in KA1 domains from Kcc4p and MARK1. Mutating this site impairs membrane association of both KA1 domains and intact proteins and reveals the importance of phosphatidylserine for bud neck localization of yeast Kcc4p. Our data suggest that KA1 domains contribute to coincidence detection, allowing kinases to bind other regulators (such as septins) only at the membrane surface. These findings have important implications for understanding MARK/PAR1 kinases, which are implicated in Alzheimer's disease, cancer, and autism.

  4. Conformational instability of the MARK3 UBA domain compromises ubiquitin recognition and promotes interaction with the adjacent kinase domain

    SciTech Connect

    Murphy, James M.; Korzhnev, Dmitry M.; Ceccarelli, Derek F.; Briant, Douglas J.; Zarrine-Afsar, Arash; Sicheri, Frank; Kay, Lewis E.; Pawson, Tony

    2012-10-23

    The Par-1/MARK protein kinases play a pivotal role in establishing cellular polarity. This family of kinases contains a unique domain architecture, in which a ubiquitin-associated (UBA) domain is located C-terminal to the kinase domain. We have used a combination of x-ray crystallography and NMR dynamics experiments to understand the interaction of the human (h) MARK3 UBA domain with the adjacent kinase domain as compared with ubiquitin. The x-ray crystal structure of the linked hMARK3 kinase and UBA domains establishes that the UBA domain forms a stable intramolecular interaction with the N-terminal lobe of the kinase domain. However, solution-state NMR studies of the isolated UBA domain indicate that it is highly dynamic, undergoing conformational transitions that can be explained by a folding-unfolding equilibrium. NMR titration experiments indicated that the hMARK3 UBA domain has a detectable but extremely weak affinity for mono ubiquitin, which suggests that conformational instability of the isolated hMARK3 UBA domain attenuates binding to ubiquitin despite the presence of residues typically involved in ubiquitin recognition. Our data identify a molecular mechanism through which the hMARK3 UBA domain has evolved to bind the kinase domain, in a fashion that stabilizes an open conformation of the N- and C-terminal lobes, at the expense of its capacity to engage ubiquitin. These results may be relevant more generally to the 30% of UBA domains that lack significant ubiquitin-binding activity, and they suggest a unique mechanism by which interaction domains may evolve new binding properties.

  5. Phosphoproteomics reveals ALK promote cell progress via RAS/JNK pathway in neuroblastoma

    PubMed Central

    Xu, Guofeng; Zhang, Min; Wu, Yeming; Wu, Zhixiang

    2016-01-01

    Emerging evidence suggests receptor tyrosine kinase ALK as a promising therapeutic target in neuroblastoma. However, clinical trials reveal that a limited proportion of ALK-positive neuroblastoma patients experience clinical benefits from Crizotinib, a clinically approved specific inhibitor of ALK. The precise molecular mechanisms of aberrant ALK activity in neuroblastoma remain elusive, limiting the clinical application of ALK as a therapeutic target in neuroblastoma. Here, we describe a deep quantitative phosphoproteomic approach in which Crizotinib-treated neuroblastoma cell lines bearing aberrant ALK are used to investigate downstream regulated phosphoproteins. We identified more than 19,500—and quantitatively analyzed approximately 10,000—phosphorylation sites from each cell line, ultimately detecting 450–790 significantly-regulated phosphorylation sites. Multiple layers of bioinformatic analysis of the significantly-regulated phosphoproteins identified RAS/JNK as a downstream signaling pathway of ALK, independent of the ALK variant present. Further experiments demonstrated that ALK/JNK signaling could be inactivated by either ALK- or JNK-specific inhibitors, resulting in cell growth inhibition by induction of cell cycle arrest and cell apoptosis. Our study broadly defines the phosphoproteome in response to ALK inhibition and provides a resource for further clinical investigation of ALK as therapeutic target for the treatment of neuroblastoma. PMID:27732954

  6. Achievements and future developments of ALK-TKIs in the management of CNS metastases from ALK-positive NSCLC

    PubMed Central

    Cappuzzo, Federico

    2016-01-01

    Non-small cell lung cancer (NSCLC) represents the paradigm of personalized treatment of human cancer. Several oncogenic druggable alterations have been so far identified, with anaplastic lymphoma kinase (ALK) gene rearrangements being one of the newest and most appealing. Presence of ALK fusions is associated with some particular clinical and pathological features, including a preferential seeding into the central nervous system (CNS). In addition, ALK rearrangements are recognized as the strongest predictor for benefit of anti-ALK therapy. Crizotinib, the first ALK inhibitor (ALK-I) licensed in clinical practice, is the standard of care for newly diagnosed patients. Unfortunately, within the first year of treatment the majority of patients become insensitive to crizotinib, with approximately one third of them developing brain metastases (BMs). Optimal management of BMs is one of the major challenges in treating ALK positive NSCLC. Several novel and highly CNS penetrant ALK-Is are currently under investigation and available data clearly indicated their ability in controlling intracranial disease. PMID:28149753

  7. Src-homology 3 domain of protein kinase p59fyn mediates binding to phosphatidylinositol 3-kinase in T cells.

    PubMed Central

    Prasad, K V; Janssen, O; Kapeller, R; Raab, M; Cantley, L C; Rudd, C E

    1993-01-01

    The Src-related tyrosine kinase p59fyn(T) plays an important role in the generation of intracellular signals from the T-cell antigen receptor TCR zeta/CD3 complex. A key question concerns the nature and the binding sites of downstream components that interact with this Src-related kinase. p59fyn(T) contains Src-homology 2 and 3 domains (SH2 and SH3) with a capacity to bind to intracellular proteins. One potential downstream target is phosphatidylinositol 3-kinase (PI 3-kinase). In this study, we demonstrate that anti-CD3 and anti-Fyn immunoprecipitates possess PI 3-kinase activity as assessed by TLC and HPLC. Both free and receptor-bound p59fyn(T) were found to bind to the lipid kinase. Further, our results indicate that Src-related kinases have developed a novel mechanism to interact with PI 3-kinase. Precipitation using GST fusion proteins containing Fyn SH2, SH3, and SH2/SH3 domains revealed that PI 3-kinase bound principally to the SH3 domain of Fyn. Fyn SH3 bound directly to the p85 subunit of PI 3-kinase as expressed in a baculoviral system. Anti-CD3 crosslinking induced an increase in the detection of Fyn SH3-associated PI 3-kinase activity. Thus PI 3-kinase is a target of SH3 domains and is likely to play a major role in the signals derived from the TCR zeta/CD3-p59fyn complex. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8394019

  8. Structure of a double-domain phosphagen kinase reveals an asymmetric arrangement of the tandem domains.

    PubMed

    Wang, Zhiming; Qiao, Zhu; Ye, Sheng; Zhang, Rongguang

    2015-04-01

    Tandem duplications and fusions of single genes have led to magnificent expansions in the divergence of protein structures and functions over evolutionary timescales. One of the possible results is polydomain enzymes with interdomain cooperativities, few examples of which have been structurally characterized at the full-length level to explore their innate synergistic mechanisms. This work reports the crystal structures of a double-domain phosphagen kinase in both apo and ligand-bound states, revealing a novel asymmetric L-shaped arrangement of the two domains. Unexpectedly, the interdomain connections are not based on a flexible hinge linker but on a rigid secondary-structure element: a long α-helix that tethers the tandem domains in relatively fixed positions. Besides the connective helix, the two domains also contact each other directly and form an interdomain interface in which hydrogen bonds and hydrophobic interactions further stabilize the L-shaped domain arrangement. Molecular-dynamics simulations show that the interface is generally stable, suggesting that the asymmetric domain arrangement crystallographically observed in the present study is not a conformational state simply restrained by crystal-packing forces. It is possible that the asymmetrically arranged tandem domains could provide a structural basis for further studies of the interdomain synergy.

  9. Anaplastic lymphoma kinase status in rhabdomyosarcomas.

    PubMed

    Yoshida, Akihiko; Shibata, Tatsuhiro; Wakai, Susumu; Ushiku, Tetsuo; Tsuta, Koji; Fukayama, Masashi; Makimoto, Atsushi; Furuta, Koh; Tsuda, Hitoshi

    2013-06-01

    Rhabdomyosarcoma is a rare soft tissue sarcoma that typically affects children, adolescents, and young adults. Despite treatment via a multidisciplinary approach, the prognosis of advance-stage rhabdomyosarcomas remains poor, and a new treatment strategy is needed. Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase that is a potential target for specific inhibitors. In this study, we investigated 116 rhabdomyosarcomas using a polymer-based ALK immunostaining method and correlated the results with clinicopathological parameters. In addition, we examined ALK status using dual-color fluorescence in situ hybridization, PCR, and sequencing. In immunohistochemical analysis, ALK was detected in 2 (6%) of 33 embryonal rhabdomyosarcomas, 42 (69%) of 61 alveolar rhabdomyosarcomas, and 0 (0%) of 22 other subtypes, including pleomorphic, adult-spindle-cell/sclerosing, and epithelioid variants. Compared with ALK-negative alveolar rhabdomyosarcomas, ALK-positive ones are presented with metastatic spread more frequently and showed a greater extent of myogenin reactivity. Overall survival was not associated with ALK expression. FOXO1 rearrangement was significantly associated with ALK immunoreactivity. The median ALK copy number was greater in ALK-positive tumors than in ALK-negative tumors. Most (93%) cases tested showed no selective increase in the ALK gene dosage. ALK selective amplification and low-level selective gain were noted in one and three cases, respectively. Further, a high-polysomy pattern (≥4 ALK copies in ≥40% of cells) was observed in seven cases. A significant increase in the ALK copy number was exclusive to the ALK-immunopositive cohort, but it was uncommon, accounting for only 30% of the 37 ALK-positive rhabdomyosarcomas. ALK gene rearrangement was not observed in either cohort, while an ALK somatic mutation (I1277T) was found in one ALK-negative embryonal case. Although it remains controversial whether ALK expression without gene rearrangement

  10. TRPM7 is regulated by halides through its kinase domain

    PubMed Central

    Yu, Haijie; Zhang, Zheng; Lis, Annette; Penner, Reinhold; Fleig, Andrea

    2013-01-01

    Transient receptor potential melastatin 7 (TRPM7) is a divalent-selective cation channel fused to an atypical α-kinase. TRPM7 is a key regulator of cell growth and proliferation, processes accompanied by mandatory cell volume changes. Osmolarity-induced cell volume alterations regulate TRPM7 through molecular crowding of solutes that affect channel activity, including magnesium (Mg2+), Mg-nucleotides and a further unidentified factor. Here, we assess whether chloride and related halides can act as negative feedback regulators of TRPM7. We find that chloride and bromide inhibit heterologously expressed TRPM7 in synergy with intracellular Mg2+ ([Mg2+]i) and this is facilitated through the ATP-binding site of the channel’s kinase domain. The synergistic block of TRPM7 by chloride and Mg2+ is not reversed during divalent-free or acidic conditions, indicating a change in protein conformation that leads to channel inactivation. Iodide has the strongest inhibitory effect on TRPM7 at physiological [Mg2+]i. Iodide also inhibits endogenous TRPM7-like currents as assessed in MCF-7 breast cancer cells, where upregulation of SLC5A5 sodium-iodide symporter enhances iodide uptake and inhibits cell proliferation. These results indicate that chloride could be an important factor in modulating TRPM7 during osmotic stress and implicate TRPM7 as a possible molecular mechanism contributing to the anti-proliferative characteristics of intracellular iodide accumulation in cancer cells. PMID:23471296

  11. The enzymatic activity of 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase is enhanced by NPM-ALK: new insights in ALK-mediated pathogenesis and the treatment of ALCL.

    PubMed

    Boccalatte, Francesco E; Voena, Claudia; Riganti, Chiara; Bosia, Amalia; D'Amico, Lucia; Riera, Ludovica; Cheng, Mangeng; Ruggeri, Bruce; Jensen, Ole N; Goss, Valerie L; Lee, Kimberly; Nardone, Julie; Rush, John; Polakiewicz, Roberto D; Comb, Michael J; Chiarle, Roberto; Inghirami, Giorgio

    2009-03-19

    Anaplastic large cell lymphoma represents a subset of neoplasms caused by translocations that juxtapose the anaplastic lymphoma kinase (ALK) to dimerization partners. The constitutive activation of ALK fusion proteins leads to cellular transformation through a complex signaling network. To elucidate the ALK pathways sustaining lymphomagenesis and tumor maintenance, we analyzed the tyrosine-kinase protein profiles of ALK-positive cell lines using 2 complementary proteomic-based approaches, taking advantage of a specific ALK RNA interference (RNAi) or cell-permeable inhibitors. A well-defined set of ALK-associated tyrosine phosphopeptides, including metabolic enzymes, kinases, ribosomal and cytoskeletal proteins, was identified. Validation studies confirmed that vasodilator-stimulated phosphoprotein and 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/inosine monophosphate cyclohydrolase (ATIC) associated with nucleophosmin (NPM)-ALK, and their phosphorylation required ALK activity. ATIC phosphorylation was documented in cell lines and primary tumors carrying ALK proteins and other tyrosine kinases, including TPR-Met and wild type c-Met. Functional analyses revealed that ALK-mediated ATIC phosphorylation enhanced its enzymatic activity, dampening the methotrexate-mediated transformylase activity inhibition. These findings demonstrate that proteomic approaches in well-controlled experimental settings allow the definition of informative proteomic profiles and the discovery of novel ALK downstream players that contribute to the maintenance of the neoplastic phenotype. Prediction of tumor responses to methotrexate may justify specific molecular-based chemotherapy.

  12. A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN

    DTIC Science & Technology

    2015-09-01

    AWARD NUMBER: W81XWH-13-1-0220 TITLE: A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN PRINCIPAL...4. TITLE AND SUBTITLE A Genetically Engineered Mouse Model of Neuroblastoma Driven by Mutated ALK and MYCN 5a. CONTRACT NUMBER 5b. GRANT NUMBER... genetic and epigenetic changes that occur during tumorigenesis. 15. SUBJECT TERMS Anaplastic lymphoma kinase, neuroblastoma, ALK, ALKF1174L, MYCN, CDK7

  13. Canadian consensus: inhibition of ALK-positive tumours in advanced non-small-cell lung cancer

    PubMed Central

    Melosky, B.; Agulnik, J.; Albadine, R.; Banerji, S.; Bebb, D.G.; Bethune, D.; Blais, N.; Butts, C.; Cheema, P.; Cheung, P.; Cohen, V.; Deschenes, J.; Ionescu, D.N.; Juergens, R.; Kamel-Reid, S.; Laurie, S.A.; Liu, G.; Morzycki, W.; Tsao, M.S.; Xu, Z.; Hirsh, V.

    2016-01-01

    Anaplastic lymphoma kinase (alk) is an oncogenic driver in non-small-cell lung cancer (nsclc). Chromosomal rearrangements involving the ALK gene occur in up to 4% of nonsquamous nsclc patients and lead to constitutive activation of the alk signalling pathway. ALK-positive nsclc is found in relatively young patients, with a median age of 50 years. Patients frequently have brain metastasis. Targeted inhibition of the alk pathway prolongs progression-free survival in patients with ALK-positive advanced nsclc. The results of several recent clinical trials confirm the efficacy and safety benefit of crizotinib and ceritinib in this population. Canadian oncologists support the following consensus statement: All patients with advanced nonsquamous nsclc (excluding pure neuroendocrine carcinoma) should be tested for the presence of an ALK rearrangement. If an ALK rearrangement is present, treatment with a targeted alk inhibitor in the first-line setting is recommended. As patients become resistant to first-generation alk inhibitors, other treatments, including second-generation alk inhibitors can be considered. PMID:27330348

  14. Distribution of PASTA domains in penicillin-binding proteins and serine/threonine kinases of Actinobacteria.

    PubMed

    Ogawara, Hiroshi

    2016-09-01

    PASTA domains (penicillin-binding protein and serine/threonine kinase-associated domains) have been identified in penicillin-binding proteins and serine/threonine kinases of Gram-positive Firmicutes and Actinobacteria. They are believed to bind β-lactam antibiotics, and be involved in peptidoglycan metabolism, although their biological function is not definitively clarified. Actinobacteria, especially Streptomyces species, are distinct in that they undergo complex cellular differentiation and produce various antibiotics including β-lactams. This review focuses on the distribution of PASTA domains in penicillin-binding proteins and serine/threonine kinases in Actinobacteria. In Actinobacteria, PASTA domains are detectable exclusively in class A but not in class B penicillin-binding proteins, in sharp contrast to the cases in other bacteria. In penicillin-binding proteins, PASTA domains distribute independently from taxonomy with some distribution bias. Particularly interesting thing is that no Streptomyces species have penicillin-binding protein with PASTA domains. Protein kinases in Actinobacteria possess 0 to 5 PASTA domains in their molecules. Protein kinases in Streptomyces can be classified into three groups: no PASTA domain, 1 PASTA domain and 4 PASTA domain-containing groups. The 4 PASTA domain-containing groups can be further divided into two subgroups. The serine/threonine kinases in different groups may perform different functions. The pocket region in one of these subgroup is more dense and extended, thus it may be involved in binding of ligands like β-lactams more efficiently.

  15. Efficiency of Crizotinib on an ALK-Positive Inflammatory Myofibroblastic Tumor of the Central Nervous System: A Case Report

    PubMed Central

    Chennouf, Anas; Arslanian, Elizabeth; Roberge, David; Berthelet, France; Bojanowski, Michel; Bahary, Jean-Paul; Masucci, Laura; Belanger, Karl; Florescu, Marie

    2017-01-01

    Inflammatory myofibroblastic tumors (IMT) of the central nervous system (CNS) are rare entities that have a predilection for local recurrences. Approximately half of the inflammatory myofibroblastic tumors contain translocations that result in the over-expression of the anaplastic lymphoma kinase (ALK) gene. We hereby present the case of a patient diagnosed with a left parieto-occipital IMT that recurred after multiple surgeries and radiotherapy. Immuno-histochemical examination of the tumor demonstrated ALK overexpression and the presence of an ALK rearrangement observed in lung cancers. The patient was subsequently started on an ALK inhibitor. A response evaluation criteria in solid tumors (RECIST) partial response was observed by the seventh month of ALK inhibition and the tumor remained in control for 14 months. The current case reiterates the activity of ALK inhibitors within the CNS and suggests that radiotherapy may potentiate the permeability of ALK inhibitors in CNS tumors addicted to ALK signalling.

  16. PTB domain-directed substrate targeting in a tyrosine kinase from the unicellular choanoflagellate Monosiga brevicollis.

    PubMed

    Prieto-Echagüe, Victoria; Chan, Perry M; Craddock, Barbara P; Manser, Edward; Miller, W Todd

    2011-04-26

    Choanoflagellates are considered to be the closest living unicellular relatives of metazoans. The genome of the choanoflagellate Monosiga brevicollis contains a surprisingly high number and diversity of tyrosine kinases, tyrosine phosphatases, and phosphotyrosine-binding domains. Many of the tyrosine kinases possess combinations of domains that have not been observed in any multicellular organism. The role of these protein interaction domains in M. brevicollis kinase signaling is not clear. Here, we have carried out a biochemical characterization of Monosiga HMTK1, a protein containing a putative PTB domain linked to a tyrosine kinase catalytic domain. We cloned, expressed, and purified HMTK1, and we demonstrated that it possesses tyrosine kinase activity. We used immobilized peptide arrays to define a preferred ligand for the third PTB domain of HMTK1. Peptide sequences containing this ligand sequence are phosphorylated efficiently by recombinant HMTK1, suggesting that the PTB domain of HMTK1 has a role in substrate recognition analogous to the SH2 and SH3 domains of mammalian Src family kinases. We suggest that the substrate recruitment function of the noncatalytic domains of tyrosine kinases arose before their roles in autoinhibition.

  17. ALK gene expression status in pleural effusion predicts tumor responsiveness to crizotinib in Chinese patients with lung adenocarcinoma

    PubMed Central

    Wang, Zheng; Wu, Xiaonan; Han, Xiaohong; Cheng, Gang; Mu, Xinlin; Zhang, Yuhui; Cui, Di; Liu, Chang; Liu, Dongge; Shi, Yuankai

    2016-01-01

    Objective The relationship between anaplastic lymphoma kinase (ALK) expression in malignant pleural effusion (MPE) samples detected only by Ventana immunohistochemistry (IHC) ALK (D5F3) and the efficacy of ALK-tyrosine kinase inhibitor therapy is uncertain. Methods Ventana anti-ALK (D5F3) rabbit monoclonal primary antibody testing was performed on 313 cell blocks of MPE samples from Chinese patients with advanced lung adenocarcinoma, and fluorescence in situ hybridization (FISH) was used to verify the ALK gene status in Ventana IHC ALK (D5F3)-positive samples. The follow-up clinical data on patients who received crizotinib treatment were recorded. Results Of the 313 MPE samples, 27 (8.6%) were confirmed as ALK expression-positive, and the Ventana IHC ALK (D5F3)-positive rate was 17.3% (27/156) in wild-type epidermal growth factor receptor (EGFR) MPE samples. Twenty-three of the 27 IHC ALK (D5F3)-positive samples were positive by FISH. Of the 11 Ventana IHC ALK (D5F3)-positive patients who received crizotinib therapy, 2 patients had complete response (CR), 5 had partial response (PR) and 3 had stable disease (SD). Conclusions The ALK gene expression status detected by the Ventana IHC ALK (D5F3) platform in MPE samples may predict tumor responsiveness to crizotinib in Chinese patients with advanced lung adenocarcinoma. PMID:28174489

  18. Personalized treatment in advanced ALK-positive non-small cell lung cancer: from bench to clinical practice

    PubMed Central

    Passaro, Antonio; Lazzari, Chiara; Karachaliou, Niki; Spitaleri, Gianluca; Pochesci, Alessia; Catania, Chiara; Rosell, Rafael; de Marinis, Filippo

    2016-01-01

    The discovery of anaplastic lymphoma kinase (ALK) gene rearrangements and the development of tyrosine kinase inhibitors (TKI) that target them have achieved unprecedented success in the management of patients with ALK-positive non-small cell lung cancer (NSCLC). Despite the high efficacy of crizotinib, the first oral ALK TKI approved for the treatment of ALK-positive NSCLC, almost all patients inevitably develop acquired resistance, showing disease progression in the brain or in other parenchymal sites. Second- or third-generation ALK TKIs have shown to be active in crizotinib-pretreated or crizotinib-naïve ALK-positive patients, even in those with brain metastases. In this review, the current knowledge regarding ALK-positive NSCLC, focusing on the biology of the disease and the available therapeutic options are discussed. PMID:27799783

  19. Discovery of Brigatinib (AP26113), a Phosphine Oxide-Containing, Potent, Orally Active Inhibitor of Anaplastic Lymphoma Kinase.

    PubMed

    Huang, Wei-Sheng; Liu, Shuangying; Zou, Dong; Thomas, Mathew; Wang, Yihan; Zhou, Tianjun; Romero, Jan; Kohlmann, Anna; Li, Feng; Qi, Jiwei; Cai, Lisi; Dwight, Timothy A; Xu, Yongjin; Xu, Rongsong; Dodd, Rory; Toms, Angela; Parillon, Lois; Lu, Xiaohui; Anjum, Rana; Zhang, Sen; Wang, Frank; Keats, Jeffrey; Wardwell, Scott D; Ning, Yaoyu; Xu, Qihong; Moran, Lauren E; Mohemmad, Qurish K; Jang, Hyun Gyung; Clackson, Tim; Narasimhan, Narayana I; Rivera, Victor M; Zhu, Xiaotian; Dalgarno, David; Shakespeare, William C

    2016-05-26

    In the treatment of echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase positive (ALK+) non-small-cell lung cancer (NSCLC), secondary mutations within the ALK kinase domain have emerged as a major resistance mechanism to both first- and second-generation ALK inhibitors. This report describes the design and synthesis of a series of 2,4-diarylaminopyrimidine-based potent and selective ALK inhibitors culminating in identification of the investigational clinical candidate brigatinib. A unique structural feature of brigatinib is a phosphine oxide, an overlooked but novel hydrogen-bond acceptor that drives potency and selectivity in addition to favorable ADME properties. Brigatinib displayed low nanomolar IC50s against native ALK and all tested clinically relevant ALK mutants in both enzyme-based biochemical and cell-based viability assays and demonstrated efficacy in multiple ALK+ xenografts in mice, including Karpas-299 (anaplastic large-cell lymphomas [ALCL]) and H3122 (NSCLC). Brigatinib represents the most clinically advanced phosphine oxide-containing drug candidate to date and is currently being evaluated in a global phase 2 registration trial.

  20. Screening for ALK abnormalities in central nervous system metastases of non-small-cell lung cancer: ALK abnormalities in CNS metastases of NSCLC.

    PubMed

    Nicoś, Marcin; Jarosz, Bożena; Krawczyk, Paweł; Wojas-Krawczyk, Kamila; Kucharczyk, Tomasz; Sawicki, Marek; Pankowski, Juliusz; Trojanowski, Tomasz; Milanowski, Janusz

    2016-11-23

    Anaplastic lymphoma kinase (ALK) gene rearrangement was reported in 3-7% of primary non-small-cell lung cancer (NSCLC) and its presence is commonly associated with adenocarcinoma (AD) type and non-smoking history. ALK tyrosine kinase inhibitors (TKIs) such as crizotinib, alectinib and ceritinib showed efficiency in patients with primary NSCLC harboring ALK gene rearrangement. Moreover, response to ALK TKIs was observed in central nervous system (CNS) metastatic lesions of NSCLC. However, there are no reports concerning the frequency of ALK rearrangement in CNS metastases. We assessed the frequency of ALK abnormalities in 145 formalin fixed paraffin embedded (FFPE) tissue samples from CNS metastases of NSCLC using immunohistochemical (IHC) automated staining (BenchMark GX, Ventana, USA) and fluorescence in situ hybridization (FISH) technique (Abbot Molecular, USA). The studied group was heterogeneous in terms of histopathology and smoking status. ALK abnormalities were detected in 4.8% (7/145) of CNS metastases. ALK abnormalities were observed in six AD (7.5%; 6/80) and in single patients with adenosuqamous lung carcinoma. Analysis of clinical and demographic factors indicated that expression of abnormal ALK was significantly more frequently observed (p=0.0002; χ(2) =16.783) in former-smokers. Comparison of IHC and FISH results showed some discrepancies, which were caused by unspecific staining of macrophages and glial/nerve cells, which constitute the background of CNS tissues. Our results indicate high frequency of ALK gene rearrangement in CNS metastatic sites of NSCLC that are in line with prior studies concerning evaluation of the presence of ALK abnormalities in such patients. However, we showed that assessment of ALK by IHC and FISH methods in CNS tissues require additional standardizations. This article is protected by copyright. All rights reserved.

  1. Efficacy of ALK5 inhibition in myelofibrosis

    PubMed Central

    Zhao, Wanke; Ho, Wanting Tina; Han, Ying; Murdun, Cem; Mailloux, Adam W.; Zhang, Ling; Wang, Xuefeng; Budhathoki, Anjali; Pradhan, Kith; Rapaport, Franck; Wang, Huaquan; Shao, Zonghong; Ren, Xiubao; Steidl, Ulrich; Levine, Ross L.; Zhao, Zhizhuang Joe; Verma, Amit; Epling-Burnette, Pearlie K.

    2017-01-01

    Myelofibrosis (MF) is a bone marrow disorder characterized by clonal myeloproliferation, aberrant cytokine production, extramedullary hematopoiesis, and bone marrow fibrosis. Although somatic mutations in JAK2, MPL, and CALR have been identified in the pathogenesis of these diseases, inhibitors of the Jak2 pathway have not demonstrated efficacy in ameliorating MF in patients. TGF-β family members are profibrotic cytokines and we observed significant TGF-β1 isoform overexpression in a large cohort of primary MF patient samples. Significant overexpression of TGF-β1 was also observed in murine clonal MPLW515L megakaryocytic cells. TGF-β1 stimulated the deposition of excessive collagen by mesenchymal stromal cells (MSCs) by activating the TGF-β receptor I kinase (ALK5)/Smad3 pathway. MSCs derived from MPLW515L mice demonstrated sustained overproduction of both collagen I and collagen III, effects that were abrogated by ALK5 inhibition in vitro and in vivo. Importantly, use of galunisertib, a clinically active ALK5 inhibitor, significantly improved MF in both MPLW515L and JAK2V617F mouse models. These data demonstrate the role of malignant hematopoietic stem cell (HSC)/TGF-β/MSC axis in the pathogenesis of MF, and provide a preclinical rationale for ALK5 blockade as a therapeutic strategy in MF.

  2. Autophosphorylation in the Leucine-Rich Repeat Kinase 2 (LRRK2) GTPase Domain Modifies Kinase and GTP-Binding Activities

    PubMed Central

    Webber, Philip J.; Smith, Archer D.; Sen, Saurabh; Renfrow, Matthew B.; Mobley, James A.; West, Andrew B.

    2011-01-01

    The LRRK2 protein has both GTPase and kinase activities and mutation in either enzymatic domain can cause late-onset Parkinson’s disease (PD). Nucleotide binding in the GTPase domain may be required for kinase activity and residues in the GTPase domain are potential sites for autophosphorylation, suggesting a complex mechanism of intrinsic regulation. To further define the effects of LRRK2 autophosphorylation, we applied a technique optimal for detection of protein phosphorylation, electron transfer dissociation (ETD), and identified autophosphorylation events exclusively nearby the nucleotide binding pocket in the GTPase domain. PD-linked mutations alter kinase activity but did not alter autophosphorylation site specificity or sites of phosphorylation in a robust in vitro substrate myelin basic protein. Amino-acid substitutions in the GTPase domain have large effects on kinase activity, as insertion of the GTPase-associated R1441C pathogenic mutation together with the G2019S kinase-domain mutation resulted in a multiplicative increase (~7-fold) in activity. Removal of a conserved autophosphorylation site (T1503) by mutation to an alanine residue resulted in greatly decreased GTP-binding and kinase activity. While autophosphorylation likely serves to potentiate kinase activity, we find that oligomerization and loss of the active dimer species occurs in an ATP and autophosphorylation independent manner. LRRK2 autophosphorylation sites are overall robustly protected from dephosphorylation in vitro, suggesting tight control over activity in vivo. We developed highly specific antibodies targeting pT1503 but failed to detect endogenous autophosphorylation in protein derived from transgenic mice and cell lines. LRRK2 activity in vivo is unlikely to be constitutive but rather refined to specific responses. PMID:21806997

  3. The insulin and IGF1 receptor kinase domains are functional dimers in the activated state

    NASA Astrophysics Data System (ADS)

    Cabail, M. Zulema; Li, Shiqing; Lemmon, Eric; Bowen, Mark E.; Hubbard, Stevan R.; Miller, W. Todd

    2015-03-01

    The insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1R) are highly related receptor tyrosine kinases with a disulfide-linked homodimeric architecture. Ligand binding to the receptor ectodomain triggers tyrosine autophosphorylation of the cytoplasmic domains, which stimulates catalytic activity and creates recruitment sites for downstream signalling proteins. Whether the two phosphorylated tyrosine kinase domains within the receptor dimer function independently or cooperatively to phosphorylate protein substrates is not known. Here we provide crystallographic, biophysical and biochemical evidence demonstrating that the phosphorylated kinase domains of IR and IGF1R form a specific dimeric arrangement involving an exchange of the juxtamembrane region proximal to the kinase domain. In this dimer, the active position of α-helix C in the kinase N lobe is stabilized, which promotes downstream substrate phosphorylation. These studies afford a novel strategy for the design of small-molecule IR agonists as potential therapeutic agents for type 2 diabetes.

  4. DISCOIDIN DOMAIN RECEPTOR TYROSINE KINASES: NEW PLAYERS IN CANCER PROGRESSION

    PubMed Central

    Valiathan, Rajeshwari R.; Marco, Marta; Leitinger, Birgit; Kleer, Celina G.; Fridman, Rafael

    2012-01-01

    Almost all human cancers display dysregulated expression and/or function of one or more receptor tyrosine kinases (RTKs). The strong causative association between altered RTK function and cancer progression has translated into novel therapeutic strategies that target these cell surface receptors in the treatment of cancer. Yet, the full spectrum of RTKs that may alter the oncogenic process is not completely understood. Accumulating evidence suggests that a unique set of RTKs known as the Discoidin Domain Receptors (DDRs) play a role in cancer progression by regulating the interactions of tumor cells with their surrounding collagen matrix. The DDRs are the only RTKs that specifically bind to, and are activated by collagen. Hence, the DDRs are part of the signaling networks that translate information from the extracellular matrix thereby acting as key regulators of cell-matrix interactions. Under physiological conditions, DDRs control cell and tissue homeostasis by acting as collagen sensors, transducing signals that regulate cell polarity, tissue morphogenesis, and cell differentiation. In cancer, DDRs are hijacked by tumor cells to disrupt normal cell-matrix communication and initiate pro-migratory and pro-invasive programs. Importantly, several cancer types exhibit DDR mutations, which are thought to alter receptor function and contribute to cancer progression. Other evidence suggests that the actions of DDRs in cancer are complex, either promoting or suppressing tumor cell behavior in a DDR type/isoform specific and context dependent manner. Thus, there is still a considerable gap in our knowledge of DDR actions in cancer tissues. This review summarizes the current knowledge on DDR expression and function in cancer and discusses the potential implications of DDRs in cancer biology. It is hoped that this effort will encourage more research into these poorly understood but unique RTKs, which have the potential of becoming novel therapeutics targets in cancer. PMID

  5. Alk7 Depleted Mice Exhibit Prolonged Cardiac Repolarization and Are Predisposed to Ventricular Arrhythmia

    PubMed Central

    Ying, Shaozhen; Cao, Hong; Hu, He; Wang, Xin; Tang, Yanhong; Huang, Congxin

    2016-01-01

    We aimed to investigate the role of activin receptor-like kinase (ALK7) in regulating cardiac electrophysiology. Here, we showed that Alk7-/- mice exhibited prolonged QT intervals in telemetry ECG recordings. Furthermore, Langendorff-perfused Alk7-/- hearts had significantly longer action potential duration (APD) and greater incidence of ventricular arrhythmia (AV) induced by burst pacing. Using whole-cell patch clamp, we found that the densities of repolarizing K+ currents Ito and IK1 were profoundly reduced in Alk7-/- ventricular cardiomyocytes. Mechanistically, the expression of Kv4.2 (a major subunit of Ito carrying channel) and KCHIP2 (a key accessory subunit of Ito carrying channel), was markedly decreased in Alk7-/- hearts. These findings suggest that endogenous expression of ALK7 is necessary to maintain repolarizing K+ currents in ventricular cardiomyocytes, and finally prevent action potential prolongation and ventricular arrhythmia. PMID:26882027

  6. Activation of the EGF receptor tyrosine kinase by divalent metal ions: comparison of holoreceptor and isolated kinase domain properties.

    PubMed

    Koland, J G; Cerione, R A

    1990-05-22

    The activation of the epidermal growth factor (EGF) receptor tyrosine kinase activity is thought to represent a key initial step in EGF-mediated mitogenesis. The mechanisms underlying the regulation of the EGF receptor tyrosine kinase activity were examined through comparisons of the holoreceptor, purified from human placenta, and a soluble 42 kDa tyrosine kinase domain (TKD), generated by the limited trypsin proteolysis of the holoreceptor. The results of these studies highlight the importance of divalent metal ions (Me2+), i.e., Mn2+ and Mg2+, as activators of the tyrosine kinase activity. Manganese is an extremely effective activator of the holoreceptor tyrosine kinase, and under some conditions (low ionic strength) it completely alleviates the need for EGF to stimulate activity. In contrast, Mg2+ only weakly stimulates the holoreceptor tyrosine kinase activity in the absence of EGF, but promotes essentially full activity in the presence of the growth factor. Like the holoreceptor, the soluble TKD is highly active in the presence of Mn2+. However, the isolated TKD is completely inactive in the presence of Mg2+, and, in fact, Mg2+ inhibits the Mn2(+)-stimulated tyrosine kinase activity. The differences in the effects of Mn2+ and Mg2+ on the isolated TKD were further demonstrated by monitoring the effects of Me2+ on the modification of a reactive cysteine residue(s) on the TKD. While Mn2+ potentiates the inhibition by cysteine-directed reagents of the tyrosine kinase activity, Mg2+ has no effect on either the rate or the extent of the inhibition. Both the regulation by Mn2+ of the kinase activity of the TKD and the potentiation by Mn2+ of the cysteine reactivity of the TKD occur over a millimolar concentration range, which implicates a direct binding interaction by the metal ion. Overall, these results demonstrate that there are two key activator sites on the EGF receptor, i.e., the EGF binding site on the extracellular domain and a Me2+ binding site on the

  7. Constitutive ALK5-Independent c-Jun N-Terminal Kinase Activation Contributes to Endothelin-1 Overexpression in Pulmonary Fibrosis: Evidence of an Autocrine Endothelin Loop Operating through the Endothelin A and B Receptors

    PubMed Central

    Shi-Wen, Xu; Rodríguez-Pascual, Fernando; Lamas, Santiago; Holmes, Alan; Howat, Sarah; Pearson, Jeremy D.; Dashwood, Michael R.; du Bois, Roland M.; Denton, Christopher P.; Black, Carol M.; Abraham, David J.; Leask, Andrew

    2006-01-01

    The signal transduction mechanisms generating pathological fibrosis are almost wholly unknown. Endothelin-1 (ET-1), which is up-regulated during tissue repair and fibrosis, induces lung fibroblasts to produce and contract extracellular matrix. Lung fibroblasts isolated from scleroderma patients with chronic pulmonary fibrosis produce elevated levels of ET-1, which contribute to the persistent fibrotic phenotype of these cells. Transforming growth factor β (TGF-β) induces fibroblasts to produce and contract matrix. In this report, we show that TGF-β induces ET-1 in normal and fibrotic lung fibroblasts in a Smad-independent ALK5/c-Jun N-terminal kinase (JNK)/Ap-1-dependent fashion. ET-1 induces JNK through TAK1. Fibrotic lung fibroblasts display constitutive JNK activation, which was reduced by the dual ETA/ETB receptor inhibitor, bosentan, providing evidence of an autocrine endothelin loop. Thus, ET-1 and TGF-β are likely to cooperate in the pathogenesis of pulmonary fibrosis. As elevated JNK activation in fibrotic lung fibroblasts contributes to the persistence of the myofibroblast phenotype in pulmonary fibrosis by promoting an autocrine ET-1 loop, targeting the ETA and ETB receptors or constitutive JNK activation by fibrotic lung fibroblasts is likely to be of benefit in combating chronic pulmonary fibrosis. PMID:16809784

  8. The histidine kinase CusS senses silver ions through direct binding by its sensor domain

    PubMed Central

    Gudipaty, Swapna A.; McEvoy, Megan M.

    2014-01-01

    The Cus system of Escherichia coli aids in protection of cells from high concentrations of Ag(I) and Cu(I). The histidine kinase CusS of the CusRS two-component system functions as a Ag(I)/Cu(I)-responsive sensor kinase and is essential for induction of the genes encoding the CusCFBA efflux pump. In this study, we have examined the molecular features of the sensor domain of CusS in order to understand how a metal-responsive histidine kinase senses specific metal ions. We find that the predicted periplasmic sensor domain of CusS directly interacts with Ag(I) ions and undergoes a conformational change upon metal binding. Metal binding also enhances the tendency of the domain to dimerize. These findings suggest a model for activation of the histidine kinase through metal binding events in the periplasmic sensor domain. PMID:24948475

  9. ALK and ROS1 as targeted therapy paradigms and clinical implications to overcome crizotinib resistance.

    PubMed

    Ye, Mingxiang; Zhang, Xinxin; Li, Nan; Zhang, Yong; Jing, Pengyu; Chang, Ning; Wu, Jianxiong; Ren, Xinling; Zhang, Jian

    2016-03-15

    During the past decade, more than 10 targetable oncogenic driver genes have been validated in non-small cell lung cancer (NSCLC). Anaplastic lymphoma kinase (ALK) and ROS1 kinase are two new driver genes implicated in ALK- and ROS1-rearranged NSCLC. Inhibition of ALK and ROS1 by crizotinib has been reported to be highly effective and well tolerated in these patients. However, resistance to crizotinib emerges years after treatment, and increasing efforts have been made to overcome this issue. Here, we review the biology of ALK and ROS1 and their roles in cancer progression. We also summarize the ongoing and completed clinical trials validating ALK and ROS1 as targets for cancer treatment. In the last section of the review, we will discuss the molecular mechanisms of crizotinib resistance and focus approaches to overcome it. This review describes an exciting new area of research and may provide new insights for targeted cancer therapies.

  10. Alk1 controls arterial endothelial cell migration in lumenized vessels.

    PubMed

    Rochon, Elizabeth R; Menon, Prahlad G; Roman, Beth L

    2016-07-15

    Heterozygous loss of the arterial-specific TGFβ type I receptor, activin receptor-like kinase 1 (ALK1; ACVRL1), causes hereditary hemorrhagic telangiectasia (HHT). HHT is characterized by development of fragile, direct connections between arteries and veins, or arteriovenous malformations (AVMs). However, how decreased ALK1 signaling leads to AVMs is unknown. To understand the cellular mis-steps that cause AVMs, we assessed endothelial cell behavior in alk1-deficient zebrafish embryos, which develop cranial AVMs. Our data demonstrate that alk1 loss has no effect on arterial endothelial cell proliferation but alters arterial endothelial cell migration within lumenized vessels. In wild-type embryos, alk1-positive cranial arterial endothelial cells generally migrate towards the heart, against the direction of blood flow, with some cells incorporating into endocardium. In alk1-deficient embryos, migration against flow is dampened and migration in the direction of flow is enhanced. Altered migration results in decreased endothelial cell number in arterial segments proximal to the heart and increased endothelial cell number in arterial segments distal to the heart. We speculate that the consequent increase in distal arterial caliber and hemodynamic load precipitates the flow-dependent development of downstream AVMs.

  11. Functional domains of plant chimeric calcium/calmodulin-dependent protein kinase: regulation by autoinhibitory and visinin-like domains

    NASA Technical Reports Server (NTRS)

    Ramachandiran, S.; Takezawa, D.; Wang, W.; Poovaiah, B. W.

    1997-01-01

    A novel calcium-binding calcium/calmodulin-dependent protein kinase (CCaMK) with a catalytic domain, calmodulin-binding domain, and a neural visinin-like domain was cloned and characterized from plants [Patil et al., (1995) Proc. Natl. Acad. Sci. USA 92, 4797-4801; Takezawa et al. (1996) J. Biol. Chem. 271, 8126-8132]. The mechanisms of CCaMK activation by calcium and calcium/calmodulin were investigated using various deletion mutants. The use of deletion mutants of CCaMK lacking either one, two, or all three calcium-binding EF hands indicated that all three calcium-binding sites in the visinin-like domain were crucial for the full calcium/calmodulin-dependent kinase activity. As each calcium-binding EF hand was deleted, there was a gradual reduction in calcium/calmodulin-dependent kinase activity from 100 to 4%. Another mutant (amino acids 1-322) which lacks both the visinin-like domain containing three EF hands and the calmodulin-binding domain was constitutively active, indicating the presence of an autoinhibitory domain around the calmodulin-binding domain. By using various synthetic peptides and the constitutively active mutant, we have shown that CCaMK contains an autoinhibitory domain within the residues 322-340 which overlaps its calmodulin-binding domain. Kinetic studies with both ATP and the GS peptide substrate suggest that the autoinhibitory domain of CCaMK interacts only with the peptide substrate binding motif of the catalytic domain, but not with the ATP-binding motif.

  12. A patient previously treated with ALK inhibitors for central nervous system lesions from ALK rearranged lung cancer: a case report

    PubMed Central

    Kashima, Jumpei; Okuma, Yusuke; Hishima, Tsunekazu

    2016-01-01

    Background Patients with anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC) are now preferentially treated with tyrosine kinase inhibitors (TKIs). However, patients treated with ALK inhibitors end up with acquired resistance. Case presentation We present a patient with recurrent ALK-rearranged NSCLC that developed multiple brain metastases and meningitis carcinomatosa after sequential treatment with several lines of cytotoxic chemotherapy, crizotinib, and alectinib. After the patient underwent retreatment with crizotinib as salvage therapy because of poor performance status, the intracranial metastatic foci and meningeal thickening were shrank within 1 week. Conclusion Our experience with this case suggests that alectinib may restore sensitivity to crizotinib or amplified pathway such as MET which bestowed alectinib resistance was inhibited with crizotinib. PMID:27785052

  13. The mobility of two kinase domains in the Escherichia coli chemoreceptor array varies with signaling state

    PubMed Central

    Briegel, Ariane; Ames, Peter; Gumbart, James C.; Oikonomou, Catherine M.; Parkinson, John S.; Jensen, Grant J.

    2013-01-01

    Summary Motile bacteria sense their physical and chemical environment through highly cooperative, ordered arrays of chemoreceptors. These signaling complexes phosphorylate a response regulator which in turn governs flagellar motor reversals, driving cells towards favorable environments. The structural changes that translate chemoeffector binding into the appropriate kinase output are not known. Here, we apply high-resolution electron cryotomography to visualize mutant chemoreceptor signaling arrays in well-defined kinase activity states. The arrays were well ordered in all signaling states, with no discernible differences in receptor conformation at 2-3 nm resolution. Differences were observed, however, in a keel-like density that we identify here as CheA kinase domains P1 and P2, which are the phosphorylation site domain and the binding domain for response regulator target proteins, respectively. Mutant receptor arrays with high kinase activities all exhibited small keels and high proteolysis susceptibility, indicative of mobile P1 and P2 domains. In contrast, arrays in kinase-off signaling states exhibited a range of keel sizes. These findings confirm that chemoreceptor arrays do not undergo large structural changes during signaling, and suggest instead that kinase activity is modulated at least in part by changes in the mobility of key domains. PMID:23802570

  14. Allosteric inhibition of Aurora-A kinase by a synthetic vNAR domain

    PubMed Central

    Burgess, Selena G.; Oleksy, Arkadiusz; Cavazza, Tommaso; Richards, Mark W.; Vernos, Isabelle; Matthews, David

    2016-01-01

    The vast majority of clinically approved protein kinase inhibitors target the ATP-binding pocket directly. Consequently, many inhibitors have broad selectivity profiles and most have significant off-target effects. Allosteric inhibitors are generally more selective, but are difficult to identify because allosteric binding sites are often unknown or poorly characterized. Aurora-A is activated through binding of TPX2 to an allosteric site on the kinase catalytic domain, and this knowledge could be exploited to generate an inhibitor. Here, we generated an allosteric inhibitor of Aurora-A kinase based on a synthetic, vNAR single domain scaffold, vNAR-D01. Biochemical studies and a crystal structure of the Aurora-A/vNAR-D01 complex show that the vNAR domain overlaps with the TPX2 binding site. In contrast with the binding of TPX2, which stabilizes an active conformation of the kinase, binding of the vNAR domain stabilizes an inactive conformation, in which the αC-helix is distorted, the canonical Lys-Glu salt bridge is broken and the regulatory (R-) spine is disrupted by an additional hydrophobic side chain from the activation loop. These studies illustrate how single domain antibodies can be used to characterize the regulatory mechanisms of kinases and provide a rational basis for structure-guided design of allosteric Aurora-A kinase inhibitors. PMID:27411893

  15. Allosteric inhibition of Aurora-A kinase by a synthetic vNAR domain.

    PubMed

    Burgess, Selena G; Oleksy, Arkadiusz; Cavazza, Tommaso; Richards, Mark W; Vernos, Isabelle; Matthews, David; Bayliss, Richard

    2016-07-01

    The vast majority of clinically approved protein kinase inhibitors target the ATP-binding pocket directly. Consequently, many inhibitors have broad selectivity profiles and most have significant off-target effects. Allosteric inhibitors are generally more selective, but are difficult to identify because allosteric binding sites are often unknown or poorly characterized. Aurora-A is activated through binding of TPX2 to an allosteric site on the kinase catalytic domain, and this knowledge could be exploited to generate an inhibitor. Here, we generated an allosteric inhibitor of Aurora-A kinase based on a synthetic, vNAR single domain scaffold, vNAR-D01. Biochemical studies and a crystal structure of the Aurora-A/vNAR-D01 complex show that the vNAR domain overlaps with the TPX2 binding site. In contrast with the binding of TPX2, which stabilizes an active conformation of the kinase, binding of the vNAR domain stabilizes an inactive conformation, in which the αC-helix is distorted, the canonical Lys-Glu salt bridge is broken and the regulatory (R-) spine is disrupted by an additional hydrophobic side chain from the activation loop. These studies illustrate how single domain antibodies can be used to characterize the regulatory mechanisms of kinases and provide a rational basis for structure-guided design of allosteric Aurora-A kinase inhibitors.

  16. Oncogenic TPM3-ALK activation requires dimerization through the coiled-coil structure of TPM3

    SciTech Connect

    Amano, Yosuke; Ishikawa, Rie; Sakatani, Toshio; Ichinose, Junji; Sunohara, Mitsuhiro; Watanabe, Kousuke; Kage, Hidenori; Nakajima, Jun; Nagase, Takahide; Ohishi, Nobuya; Takai, Daiya

    2015-02-13

    Inflammatory myofibroblastic tumor (IMT) is a mesenchymal tumor that can arise from anywhere in the body. Anaplastic lymphoma kinase (ALK) gene rearrangements, most often resulting in the tropomyosin 3 (TPM3)-ALK fusion gene, are the main causes of IMT. However, the mechanism of malignant transformation in IMT has yet to be elucidated. The purpose of this study was to clarify the role of the TPM3 region in the transformation of IMT via TPM3-ALK. Lentivirus vectors containing a TPM3-ALK fusion gene lacking various lengths of TPM3 were constructed and expressed in HEK293T and NIH3T3 cell lines. Focus formation assay revealed loss of contact inhibition in NIH3T3 cells transfected with full-length TPM3-ALK, but not with ALK alone. Blue-native polyacrylamide gel electrophoresis (BN-PAGE) revealed that TPM3-ALK dimerization increased in proportion to the length of TPM3. Western blot showed phosphorylation of ALK, ERK1/2, and STAT3 in HEK293T cells transfected with TPM3-ALK. Thus, the coiled-coil structure of TPM3 contributes to the transforming ability of the TPM3-ALK fusion protein, and longer TPM3 region leads to higher dimer formation. - Highlights: • TPM3-ALK fusion protein dimerizes through the coiled-coil structure of TPM3. • Longer coiled-coil structure of TPM3 leads to higher TPM3-ALK dimer formation. • Presence of TPM3-ALK dimer leads to ALK, STAT3, and ERK1/2 phosphorylation. • Presence of TPM3-ALK leads to loss of contact inhibition. • BN-PAGE is a simple technique for visualizing oncogenic dimerization.

  17. Molecular determinants of KA1 domain-mediated autoinhibition and phospholipid activation of MARK1 kinase

    PubMed Central

    Emptage, Ryan P.; Lemmon, Mark A.; Ferguson, Kathryn M.

    2017-01-01

    Protein kinases are frequently regulated by intramolecular autoinhibitory interactions between protein modules that are reversed when these modules bind other ‘activating’ protein or membrane-bound targets. One group of kinases, the MAP/microtubule affinity-regulating kinases (MARKs) contain a poorly understood regulatory module, the KA1 (kinase associated-1) domain, at their C-terminus. KA1 domains from MARK1 and several related kinases from yeast to humans have been shown to bind membranes containing anionic phospholipids, and peptide ligands have also been reported. Deleting or mutating the C-terminal KA1 domain has been reported to activate the kinase in which it is found — also suggesting an intramolecular autoinhibitory role. Here, we show that the KA1 domain of human MARK1 interacts with, and inhibits, the MARK1 kinase domain. Using site-directed mutagenesis, we identify residues in the KA1 domain required for this auto-inhibitory activity, and find that residues involved in autoinhibition and in anionic phospholipid binding are the same. We also demonstrate that a ‘mini’ MARK1 becomes activated upon association with vesicles containing anionic phospholipids, but only if the protein is targeted to these vesicles by a second signal. These studies provide a mechanistic basis for understanding how MARK1 and its relatives may require more than one signal at the membrane surface to control their activation at the correct location and time. MARK family kinases have been implicated in a plethora of disease states including Alzheimer’s, cancer, and autism, so advancing our understanding of their regulatory mechanisms may ultimately have therapeutic value. PMID:27879374

  18. Prospective and clinical validation of ALK immunohistochemistry: results from the phase I/II study of alectinib for ALK-positive lung cancer (AF-001JP study)

    PubMed Central

    Takeuchi, K.; Togashi, Y.; Kamihara, Y.; Fukuyama, T.; Yoshioka, H.; Inoue, A.; Katsuki, H.; Kiura, K.; Nakagawa, K.; Seto, T.; Maemondo, M.; Hida, T.; Harada, M.; Ohe, Y.; Nogami, N.; Yamamoto, N.; Nishio, M.; Tamura, T.

    2016-01-01

    Background Anaplastic lymphoma kinase (ALK) fusions need to be accurately and efficiently detected for ALK inhibitor therapy. Fluorescence in situ hybridization (FISH) remains the reference test. Although increasing data are supporting that ALK immunohistochemistry (IHC) is highly concordant with FISH, IHC screening needed to be clinically and prospectively validated. Patients and methods In the AF-001JP trial for alectinib, 436 patients were screened for ALK fusions through IHC (n = 384) confirmed with FISH (n = 181), multiplex RT-PCR (n = 68), or both (n = 16). IHC results were scored with iScore. Result ALK fusion was positive in 137 patients and negative in 250 patients. Since the presence of cancer cells in the samples for RT-PCR was not confirmed, ALK fusion negativity could not be ascertained in 49 patients. IHC interpreted with iScore showed a 99.4% (173/174) concordance with FISH. All 41 patients who had iScore 3 and were enrolled in phase II showed at least 30% tumor reduction with 92.7% overall response rate. Two IHC-positive patients with an atypical FISH pattern responded to ALK inhibitor therapy. The reduction rate was not correlated with IHC staining intensity. Conclusions Our study showed (i) that when sufficiently sensitive and appropriately interpreted, IHC can be a stand-alone diagnostic for ALK inhibitor therapies; (ii) that when atypical FISH patterns are accompanied by IHC positivity, the patients should be considered as candidates for ALK inhibitor therapies, and (iii) that the expression level of ALK fusion is not related to the level of response to ALK inhibitors and is thus not required for patient selection. Registration number JapicCTI-101264 (This study is registered with the Japan Pharmaceutical Information Center). PMID:26487585

  19. RecA stimulates AlkB-mediated direct repair of DNA adducts

    PubMed Central

    Shivange, Gururaj; Monisha, Mohan; Nigam, Richa; Kodipelli, Naveena; Anindya, Roy

    2016-01-01

    The Escherichia coli AlkB protein is a 2-oxoglutarate/Fe(II)-dependent demethylase that repairs alkylated single stranded and double stranded DNA. Immunoaffinity chromatography coupled with mass spectrometry identified RecA, a key factor in homologous recombination, as an AlkB-associated protein. The interaction between AlkB and RecA was validated by yeast two-hybrid assay; size-exclusion chromatography and standard pull down experiment and was shown to be direct and mediated by the N-terminal domain of RecA. RecA binding results AlkB–RecA heterodimer formation and RecA–AlkB repairs alkylated DNA with higher efficiency than AlkB alone. PMID:27378775

  20. Detection of ALK rearrangements in lung cancer patients using a homebrew PCR assay.

    PubMed

    Yu, Hui; Chang, JianHua; Liu, Fang; Wang, Qifeng; Lu, YongMing; Zhang, ZhuanXu; Shen, Jiabing; Zhai, Qing; Meng, Xia; Wang, Jialei; Ye, Xun

    2017-01-31

    Lung cancer patients with anaplastic lymphoma kinase (ALK) rearrangements are candidates for targeted therapeutics. However, patients must be tested with a companion diagnostic assay to realize their ALK rearrangement status. We analyzed the publicly available E-GEOD-31210 microarray dataset and identified a non-coding RNA, sweyjawbu, which is strongly associated with ALK rearrangements. We validated these results using quantitative real-time PCR in an independent cohort consisting of 4 cell lines and 83 clinical samples. We could differentiate between ALK rearrangement-positive and -negative lung cancer samples by comparing sweyjawbu expression. Additionally, ALK rearrangement status was determined by comparing the expression of the 5' and 3' regions of the ALK transcript or by detecting known ALK hybrid subtypes. Thus, using our homebrew PCR assay, we were able to accurately detect ALK rearrangements, which could be used for diagnostic screening of lung cancer patients. The prototype could potentially be transferred to an automatic multiplex PCR platform (FilmArray) to differentiate between ALK rearrangement-positive and -negative patients in point-of-care settings.

  1. Novel CAD-ALK gene rearrangement is drugable by entrectinib in colorectal cancer

    PubMed Central

    Amatu, Alessio; Somaschini, Alessio; Cerea, Giulio; Bosotti, Roberta; Valtorta, Emanuele; Buonandi, Pasquale; Marrapese, Giovanna; Veronese, Silvio; Luo, David; Hornby, Zachary; Multani, Pratik; Murphy, Danielle; Shoemaker, Robert; Lauricella, Calogero; Giannetta, Laura; Maiolani, Martina; Vanzulli, Angelo; Ardini, Elena; Galvani, Arturo; Isacchi, Antonella; Sartore-Bianchi, Andrea; Siena, Salvatore

    2015-01-01

    Background: Activated anaplastic lymphoma kinase (ALK) gene fusions are recurrent events in a small fraction of colorectal cancers (CRCs), although these events have not yet been exploited as in other malignancies. Methods: We detected ALK protein expression by immunohistochemistry and gene rearrangements by fluorescence in situ hybridisation in the ALKA-372-001 phase I study of the pan-Trk, ROS1, and ALK inhibitor entrectinib. One out of 487 CRCs showed ALK positivity with a peculiar pattern that prompted further characterisation by targeted sequencing using anchored multiplex PCR. Results: A novel ALK fusion with the carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase (CAD) gene (CAD-ALK fusion gene) was identified. It resulted from inversion within chromosome 2 and the fusion of exons 1–35 of CAD with exons 20–29 of ALK. After failure of previous standard therapies, treatment of this patient with the ALK inhibitor entrectinib resulted in a durable objective tumour response. Conclusions: We describe the novel CAD-ALK rearrangement as an oncogene and provide the first evidence of its drugability as a new molecular target in CRC. PMID:26633560

  2. GTP binding to the ROC domain of DAP-kinase regulates its function through intramolecular signalling.

    PubMed

    Carlessi, Rodrigo; Levin-Salomon, Vered; Ciprut, Sara; Bialik, Shani; Berissi, Hanna; Albeck, Shira; Peleg, Yoav; Kimchi, Adi

    2011-09-01

    Death-associated protein kinase (DAPk) was recently suggested by sequence homology to be a member of the ROCO family of proteins. Here, we show that DAPk has a functional ROC (Ras of complex proteins) domain that mediates homo-oligomerization and GTP binding through a defined P-loop motif. Upon binding to GTP, the ROC domain negatively regulates the catalytic activity of DAPk and its cellular effects. Mechanistically, GTP binding enhances an inhibitory autophosphorylation at a distal site that suppresses kinase activity. This study presents a new mechanism of intramolecular signal transduction, by which GTP binding operates in cis to affect the catalytic activity of a distal domain in the protein.

  3. Crystallization of the Focal Adhesion Kinase Targeting (FAT) Domain in a Primitive Orthorhombic Space Group

    SciTech Connect

    Magis,A.; Bailey, K.; Kurenova, E.; Hernandez Prada, J.; Cance, W.; Ostrov, D.

    2008-01-01

    X-ray diffraction data from the targeting (FAT) domain of focal adhesion kinase (FAK) were collected from a single crystal that diffracted to 1.99 Angstroms resolution and reduced to the primitive orthorhombic lattice. A single molecule was predicted to be present in the asymmetric unit based on the Matthews coefficient. The data were phased using molecular-replacement methods using an existing model of the FAK FAT domain. All structures of human focal adhesion kinase FAT domains solved to date have been solved in a C-centered orthorhombic space group.

  4. Insights into brain metastasis in patients with ALK+ lung cancer: is the brain truly a sanctuary?

    PubMed

    Toyokawa, Gouji; Seto, Takashi; Takenoyama, Mitsuhiro; Ichinose, Yukito

    2015-12-01

    Anaplastic lymphoma kinase (ALK) has been identified to exert a potent transforming activity through its rearrangement in non-small cell lung cancer (NSCLC), and patients (pts) with ALK rearrangement can be treated more successfully with ALK inhibitors, such as crizotinib, alectinib, and ceritinib, than with chemotherapy. Despite the excellent efficacy of ALK inhibitors, resistance to these drugs is inevitably encountered in most ALK-rearranged pts. Cases of resistance are subtyped into three groups, i.e., systemic, oligo, and central nervous system (CNS) types, with the CNS being used to be considered a sanctuary. With regard to the management of CNS lesions in pts with ALK+ NSCLC, a growing body of evidence has gradually demonstrated the intracranial (IC) efficacy of ALK inhibitor (ALKi) in ALK+ NSCLC pts with brain metastases (BMs). Although the efficacy of crizotinib for the CNS lesions remains controversial, a recent retrospective investigation of ALK+ pts with BM enrolled in PROFILE 1005 and PROFILE 1007 demonstrated that crizotinib is associated with a high disease control rate for BM. However, BM comprises the most common site of progressive disease in pts with or without baseline BMs, which is a serious problem for crizotinib. Furthermore, alectinib can be used to achieve strong and long-lasting inhibitory effects on BM. In addition to alectinib, the IC efficacy of other next-generation ALK inhibitors, such as ceritinib, AP26113 and PF-06463922, has been demonstrated. In this article, we review the latest evidence regarding the BM and IC efficacy of ALK inhibitors in pts with ALK+ NSCLC.

  5. Diversity in domain architectures of Ser/Thr kinases and their homologues in prokaryotes

    PubMed Central

    Krupa, A; Srinivasan, N

    2005-01-01

    Background Ser/Thr/Tyr kinases (STYKs) commonly found in eukaryotes have been recently reported in many bacterial species. Recent studies elucidating their cellular functions have established their roles in bacterial growth and development. However functions of a large number of bacterial STYKs still remain elusive. The organisation of domains in a large dataset of bacterial STYKs has been investigated here in order to recognise variety in domain combinations which determine functions of bacterial STYKs. Results Using sensitive sequence and profile search methods, domain organisation of over 600 STYKs from 125 prokaryotic genomes have been examined. Kinase catalytic domains of STYKs tethered to a wide range of enzymatic domains such as phosphatases, HSP70, peptidyl prolyl isomerases, pectin esterases and glycoproteases have been identified. Such distinct preferences for domain combinations are not known to be present in either the Histidine kinase or the eukaryotic STYK families. Domain organisation of STYKs specific to certain groups of bacteria has also been noted in the current anlaysis. For example, Hydrophobin like domains in Mycobacterial STYK and penicillin binding domains in few STYKs of Gram-positive organisms and FHA domains in cyanobacterial STYKs. Homologues of characterised substrates of prokaryotic STYKs have also been identified. Conclusion The domains and domain architectures of most of the bacterial STYKs identified are very different from the known domain organisation in STYKs of eukaryotes. This observation highlights distinct biological roles of bacterial STYKs compared to eukaryotic STYKs. Bacterial STYKs reveal high diversity in domain organisation. Some of the modular organisations conserved across diverse bacterial species suggests their central role in bacterial physiology. Unique domain architectures of few other groups of STYKs reveal recruitment of functions specific to the species. PMID:16171520

  6. Novel receptor-like kinases in cacao contain PR-1 extracellular domains.

    PubMed

    Teixeira, Paulo José Pereira Lima; Costa, Gustavo Gilson Lacerda; Fiorin, Gabriel Lorencini; Pereira, Gonçalo Amarante Guimarães; Mondego, Jorge Maurício Costa

    2013-08-01

    Members of the pathogenesis-related protein 1 (PR-1) family are well-known markers of plant defence responses, forming part of the arsenal of the secreted proteins produced on pathogen recognition. Here, we report the identification of two cacao (Theobroma cacao L.) PR-1s that are fused to transmembrane regions and serine/threonine kinase domains, in a manner characteristic of receptor-like kinases (RLKs). These proteins (TcPR-1f and TcPR-1g) were named PR-1 receptor kinases (PR-1RKs). Phylogenetic analysis of RLKs and PR-1 proteins from cacao indicated that PR-1RKs originated from a fusion between sequences encoding PR-1 and the kinase domain of a LecRLK (Lectin Receptor-Like Kinase). Retrotransposition marks surround TcPR-1f, suggesting that retrotransposition was involved in the origin of PR-1RKs. Genes with a similar domain architecture to cacao PR-1RKs were found in rice (Oryza sativa), barrel medic (Medicago truncatula) and a nonphototrophic bacterium (Herpetosiphon aurantiacus). However, their kinase domains differed from those found in LecRLKs, indicating the occurrence of convergent evolution. TcPR-1g expression was up-regulated in the biotrophic stage of witches' broom disease, suggesting a role for PR-1RKs during cacao defence responses. We hypothesize that PR-1RKs transduce a defence signal by interacting with a PR-1 ligand.

  7. The structure of the PERK kinase domain suggests the mechanism for its activation

    PubMed Central

    Cui, Wenjun; Li, Jingzhi; Ron, David; Sha, Bingdong

    2011-01-01

    The endoplasmic reticulum (ER) unfolded protein response (UPR) is comprised of several intracellular signaling pathways that alleviate ER stress. The ER-localized transmembrane kinase PERK is one of three major ER stress transducers. Oligomerization of PERK’s N-terminal ER luminal domain by ER stress promotes PERK trans-autophosphorylation of the C-terminal cytoplasmic kinase domain at multiple residues including Thr980 on the kinase activation loop. Activated PERK phosphorylates Ser51 of the α-subunit of translation initiation factor 2 (eIF2α), which inhibits initiation of protein synthesis and reduces the load of unfolded proteins entering the ER. The crystal structure of PERK’s kinase domain has been determined to 2.8 Å resolution. The structure resembles the back-to-back dimer observed in the related eIF2α kinase PKR. Phosphorylation of Thr980 stabilizes both the activation loop and helix αG in the C-terminal lobe, preparing the latter for eIF2α binding. The structure suggests conservation in the mode of activation of eIF2α kinases and is consistent with a ‘line-up’ model for PERK activation triggered by oligomerization of its luminal domain. PMID:21543844

  8. Deficient BIM Expression as a Mechanism of Intrinsic and Acquired Resistance to Targeted Therapies in EGFR-Mutant and ALK-Positive Lung Cancers

    DTIC Science & Technology

    2015-08-01

    EGFR- Mutant and ALK-Positive Lung Cancers PRINCIPAL INVESTIGATOR: Lecia Sequist MD. CONTRACTING ORGANIZATION: Massachusetts General Hospital Boston...and Acquired Resistance to Targeted Therapies in EGFR- Mutant and ALK-Positive Lung Cancers 5b. GRANT NUMBER W81XWH-13-1-0227 5c. PROGRAM ELEMENT...to a specific kinase, inhibition of that kinase often leads to cell growth arrest and apoptosis. For example, EGFR mutant and EML4-ALK lung cancers

  9. Deficient BIM Expression as a Mechanism of Intrinsic and Acquired Resistance to Targeted Therapies in EGFR-Mutant and ALK-Positive Lung Cancers

    DTIC Science & Technology

    2015-08-01

    EGFR- Mutant and ALK-Positive Lung Cancers PRINCIPAL INVESTIGATOR: Jeffrey Engelman MD PhD. CONTRACTING ORGANIZATION: Massachusetts General Hospital...Intrinsic and Acquired Resistance to Targeted Therapies in EGFR- Mutant and ALK-Positive Lung Cancers 5b. GRANT NUMBER W81XWH-13-1-0226 5c. PROGRAM...to a specific kinase, inhibition of that kinase often leads to cell growth arrest and apoptosis. For example, EGFR mutant and EML4-ALK lung cancers

  10. Structural Insights into the HWE Histidine Kinase Family: The Brucella Blue Light-Activated Histidine Kinase Domain.

    PubMed

    Rinaldi, Jimena; Arrar, Mehrnoosh; Sycz, Gabriela; Cerutti, María Laura; Berguer, Paula M; Paris, Gastón; Estrín, Darío Ariel; Martí, Marcelo Adrián; Klinke, Sebastián; Goldbaum, Fernando Alberto

    2016-03-27

    In response to light, as part of a two-component system, the Brucella blue light-activated histidine kinase (LOV-HK) increases its autophosphorylation, modulating the virulence of this microorganism. The Brucella histidine kinase (HK) domain belongs to the HWE family, for which there is no structural information. The HWE family is exclusively present in proteobacteria and usually coupled to a wide diversity of light sensor domains. This work reports the crystal structure of the Brucella HK domain, which presents two different dimeric assemblies in the asymmetric unit: one similar to the already described canonical parallel homodimers (C) and the other, an antiparallel non-canonical (NC) dimer, each with distinct relative subdomain orientations and dimerization interfaces. Contrary to these crystallographic structures and unlike other HKs, in solution, the Brucella HK domain is monomeric and still active, showing an astonishing instability of the dimeric interface. Despite this instability, using cross-linking experiments, we show that the C dimer is the functionally relevant species. Mutational analysis demonstrates that the autophosphorylation activity occurs in cis. The different relative subdomain orientations observed for the NC and C states highlight the large conformational flexibility of the HK domain. Through the analysis of these alternative conformations by means of molecular dynamics simulations, we also propose a catalytic mechanism for Brucella LOV-HK.

  11. Purification of catalytic domain of rat spleen p72syk kinase and its phosphorylation and activation by protein kinase C.

    PubMed Central

    Borowski, P; Heiland, M; Kornetzky, L; Medem, S; Laufs, R

    1998-01-01

    The catalytic domain of p72(syk) kinase (CDp72(syk)) was purified from a 30000 g particulate fraction of rat spleen. The purification procedure employed sequential chromatography on columns of DEAE-Sephacel and Superdex-200, and elution from HA-Ultrogel by chloride. The analysis of the final CDp72(syk) preparation by SDS/PAGE revealed a major silver-stained 40 kDa protein. The kinase was identified by covalent modification of its ATP-binding site with [14C]5'-fluorosulphonylbenzoyladenosine and by immunoblotting with a polyclonal antibody against the 'linker' region of p72(syk). By using poly(Glu4, Tyr1) as a substrate, the specific activity of the enzyme was determined as 18.5 nmol Pi/min per mg. Casein, histones H1 and H2B and myelin basic protein were efficiently phosphorylated by CDp72(syk). The kinase exhibited a limited ability to phosphorylate random polymers containing tyrosine residues. CDp72(syk) autophosphorylation activity was associated with an activation of the kinase towards exogenous substrates. The extent of activation was dependent on the substrates added. CDp72(syk) was phosphorylated by protein kinase C (PKC) on serine and threonine residues. With a newly developed assay method, we demonstrated that the PKC-mediated phosphorylation had a strong activating effect on the tyrosine kinase activity of CDp72(syk). Studies extended to conventional PKC isoforms revealed an isoform-dependent manner (alpha > betaI = betaII > gamma) of CDp72(syk) phosphorylation. The different phosphorylation efficiencies of the PKC isoforms closely correlated with the ability to enhance the tyrosine kinase activity. PMID:9531509

  12. Domain compatibility in Ire1 kinase is critical for the Unfolded Protein Response

    PubMed Central

    Poothong, Juthakorn; Sopha, Pattarawut; Kaufman, Randal J.; Tirasophon, Witoon

    2013-01-01

    The unfolded phrotein response is a mechanism to cope with endoplasmic reticulum stress. In Saccharomyces cerevisiae, Ire1 senses the stress and mediates a signaling cascade to upregulate responsive genes through an unusual HAC1 mRNA splicing. The splicing requires interconnected activity (kinase and endoribonuclease) of Ire1 to cleave HAC1 mRNA at the non-canonical splice sites before translation into Hac1 transcription factor. Analysis of the truncated kinase domain from Ire1 homologs revealed that this domain is highly conserved. Characterization by domain swapping indicated that a functional ATP/ADP binding domain is minimally required. However the overall domain compatibility is critical for eliciting its full endoribonuclease function. PMID:20541549

  13. Domain compatibility in Ire1 kinase is critical for the unfolded protein response.

    PubMed

    Poothong, Juthakorn; Sopha, Pattarawut; Kaufman, Randal J; Tirasophon, Witoon

    2010-07-16

    The unfolded protein response is a mechanism to cope with endoplasmic reticulum stress. In Saccharomyces cerevisiae, Ire1 senses the stress and mediates a signaling cascade to upregulate responsive genes through an unusual HAC1 mRNA splicing. The splicing requires interconnected activity (kinase and endoribonuclease (RNase)) of Ire1 to cleave HAC1 mRNA at the non-canonical splice sites before translation into Hac1 transcription factor. Analysis of the truncated kinase domain from Ire1 homologs revealed that this domain is highly conserved. Characterization by domain swapping indicated that a functional ATP/ADP binding domain is minimally required. However the overall domain compatibility is critical for eliciting its full RNase function.

  14. CNK and HYP form a discrete dimer by their SAM domains to mediate RAF kinase signaling.

    PubMed

    Rajakulendran, Thanashan; Sahmi, Malha; Kurinov, Igor; Tyers, Mike; Therrien, Marc; Sicheri, Frank

    2008-02-26

    RAF kinase functions in the mitogen-activated protein kinase (MAPK) pathway to transmit growth signals to the downstream kinases MEK and ERK. Activation of RAF catalytic activity is facilitated by a regulatory complex comprising the proteins CNK (Connector enhancer of KSR), HYP (Hyphen), and KSR (Kinase Suppressor of Ras). The sterile alpha-motif (SAM) domain found in both CNK and HYP plays an essential role in complex formation. Here, we have determined the x-ray crystal structure of the SAM domain of CNK in complex with the SAM domain of HYP. The structure reveals a single-junction SAM domain dimer of 1:1 stoichiometry in which the binding mode is a variation of polymeric SAM domain interactions. Through in vitro and in vivo mutational analyses, we show that the specific mode of dimerization revealed by the crystal structure is essential for RAF signaling and facilitates the recruitment of KSR to form the CNK/HYP/KSR regulatory complex. We present two docking-site models to account for how SAM domain dimerization might influence the formation of a higher-order CNK/HYP/KSR complex.

  15. The Unique Domain Forms a Fuzzy Intramolecular Complex in Src Family Kinases.

    PubMed

    Arbesú, Miguel; Maffei, Mariano; Cordeiro, Tiago N; Teixeira, João M C; Pérez, Yolanda; Bernadó, Pau; Roche, Serge; Pons, Miquel

    2017-03-16

    The N-terminal regulatory region of c-Src including the SH4, Unique, and SH3 domains adopts a compact, yet highly dynamic, structure that can be described as an intramolecular fuzzy complex. Most of the long-range interactions within the Unique domain are also observed in constructs lacking the structured SH3, indicating a considerable degree of preorganization of the disordered Unique domain. Here we report that members of the Src family of kinases (SFK) share well-conserved sequence features involving aromatic residues in their Unique domains. This observation contrasts with the supposed lack of sequence homology implied by the name of these domains and suggests that the other members of SFK also have a regulatory region involving their Unique domains. We argue that the Unique domain of each SFK is sensitive to specific input signals, encoded by each specific sequence, but the entire family shares a common mechanism for connecting the disordered and structured domains.

  16. Clinical outcomes of advanced non-small-cell lung cancer patients with EGFR mutation, ALK rearrangement and EGFR/ALK co-alterations

    PubMed Central

    Chen, Hua-Jun; Zhou, Qing; Yan, Li-Xu; Xie, Zhi; Su, Jian; Chen, Zhi-Hong; Tu, Hai-Yan; Yan, Hong-Hong; Wang, Zhen; Xu, Chong-Rui; Jiang, Ben-Yuan; Wang, Bin-Chao; Bai, Xiao-Yan; Zhong, Wen-Zhao; Wu, Yi-Long; Yang, Jin-Ji

    2016-01-01

    The co-occurrence of epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) rearrangements constitutes a rare molecular subtype of non-small-cell lung cancer (NSCLC). Herein, we assessed the clinical outcomes and incidence of acquired resistance to tyrosine kinase inhibitors (TKIs) in this subtype. So we enrolled 118 advanced NSCLC treated with TKIs. EGFR mutations and ALK rearrangements were detected by DNA sequencing or Scorpion amplification refractory mutation system and fluorescence in situ hybridization respectively. Immunohistochemistry was used to evaluate the activation of associated proteins. We found that nine in ten patients with EGFR/ALK co-alterations had good response with first-line EGFR TKI, and the objective response rate (ORR) of EGFR TKIs was 80% (8/10) for EGFR/ALK co-altered and 65.5% (55/84) for EGFR-mutant (P = 0.57), with a median progression-free survival (PFS) of 11.2 and 13.2 months, (hazard ratio [HR]=0.95, 95% [CI], 0.49-1.84, P= 0.87). ORR of crizotinib was 40% (2/5) for EGFR/ALK co-altered and 73.9% (17/23) for ALK-rearranged (P= 0.29), with a median PFS of 1.9 and 6.9 months (hazard ratio [HR], 0.40; 95% [CI] 0.15-1.10, P = 0.08). The median overall survival (OS) was 21.3, 23.7, and 18.5 months in EGFR-mutant, ALK-rearranged, and EGFR/ALK co-altered (P= 0.06), and there existed a statistically significant difference in OS between ALK-rearranged and EGFR/ALK co-altered (P=0.03). Taken together, the first-line EGFR-TKI might be the reasonable care for advanced NSCLC harbouring EGFR/ALK co-alterations, whether or nor to use sequential crizotinib should be guided by the status of ALK rearrangement and the relative level of phospho-EGFR and phospho-ALK. PMID:27533086

  17. Purification, crystallization and preliminary X-ray diffraction analysis of the kinase domain of human tousled-like kinase 2

    SciTech Connect

    Garrote, Ana M.; Redondo, Pilar; Montoya, Guillermo; Muñoz, Inés G.

    2014-02-19

    The C-terminal kinase domain of TLK2 (a human tousled-like kinase) has been cloned and overexpressed in Escherichia coli followed by purification to homogeneity. Crystallization experiments in the presence of ATP-γ-S yielded crystals suitable for X-ray diffraction analysis belonging to two different space groups: tetragonal I4{sub 1}22 and cubic P2{sub 1}3. Tousled-like kinases (TLKs) are an evolutionarily conserved family of serine/threonine protein kinases involved in chromatin dynamics, including DNA replication and repair, transcription and chromosome segregation. The two members of the family reported in humans, namely TLK1 and TLK2, localize to the cell nucleus and are capable of forming homo- or hetero-oligomers by themselves. To characterize the role of TLK2, its C-terminal kinase domain was cloned and overexpressed in Escherichia coli followed by purification to homogeneity. Crystallization experiments in the presence of ATP-γ-S yielded crystals suitable for X-ray diffraction analysis belonging to two different space groups: tetragonal I4{sub 1}22 and cubic P2{sub 1}3. The latter produced the best diffracting crystal (3.4 Å resolution using synchrotron radiation), with unit-cell parameters a = b = c = 126.05 Å, α = β = γ = 90°. The asymmetric unit contained one protein molecule, with a Matthews coefficient of 4.59 Å{sup 3} Da{sup −1} and a solvent content of 73.23%.

  18. Uterine ALK3 is essential during the window of implantation

    PubMed Central

    Monsivais, Diana; Clementi, Caterina; Peng, Jia; Titus, Mary M.; Barrish, James P.; Creighton, Chad J.; Lydon, John P.; DeMayo, Francesco J.; Matzuk, Martin M.

    2016-01-01

    The window of implantation is defined by the inhibition of uterine epithelial proliferation, structural epithelial cell remodeling, and attenuated estrogen (E2) response. These changes occur via paracrine signaling between the uterine epithelium and stroma. Because implantation defects are a major cause of infertility in women, identifying these signaling pathways will improve infertility interventions. Bone morphogenetic proteins (BMPs) are TGF-β family members that regulate the postimplantation and midgestation stages of pregnancy. In this study, we discovered that signaling via activin-like kinase 3 (ALK3/BMPR1A), a BMP type 1 receptor, is necessary for blastocyst attachment. Conditional knockout (cKO) of ALK3 in the uterus was obtained by producing Alk3flox/flox-Pgr-cre–positive females. Alk3 cKO mice are sterile and have defects in the luminal uterine epithelium, including increased microvilli density and maintenance of apical cell polarity. Moreover, Alk3 cKO mice exhibit an elevated uterine E2 response and unopposed epithelial cell proliferation during the window of implantation. We determined that dual transcriptional regulation of Kruppel-like factor 15 (Klf15), by both the transforming growth factor β (TGF-β) transcription factor SMAD family member 4 (SMAD4) and progesterone receptor (PR), is necessary to inhibit uterine epithelial cell proliferation, a key step for embryo implantation. Our findings present a convergence of BMP and steroid hormone signaling pathways in the regulation of uterine receptivity. PMID:26721398

  19. Precision medicine in NSCLC and pathology: how does ALK fit in the pathway?

    PubMed

    Kerr, K M; López-Ríos, F

    2016-09-01

    The evolution of personalised medicine in lung cancer has dramatically impacted diagnostic pathology. Current challenges centre on the growing demands placed on small tissue samples by molecular diagnostic techniques. In this review, expert recommendations are provided regarding successful identification of anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC). Steps to correctly process and conserve tumour tissue during diagnostic testing are essential to ensure tissue availability. For example, storing extra tissue sections ready for molecular diagnostic steps allows faster testing and preserves tissue. Fluorescence in situ hybridisation (FISH) is commonly used to detect ALK rearrangements, with most laboratories favouring screening by immunohistochemistry followed by a confirmatory FISH assay. Reverse transcription-polymerase chain reaction can also identify ALK fusion gene mRNA transcripts but can be limited by the quality of RNA and the risk that rare fusion variants may not be captured. Next-generation sequencing (NGS) technology has recently provided an alternative method for detecting ALK rearrangements. While current experience is limited, NGS is set to become the most efficient approach as an increasing number of genetic abnormalities is required to be tested. Upfront, reflex testing for ALK gene rearrangement should become routine as ALK tyrosine kinase inhibitor therapy moves into the first-line setting. Guidelines recommend that EGFR and ALK tests are carried out in parallel on all confirmed and potential adenocarcinomas, and this is more efficient in terms of tissue usage and testing turnaround time for both of these actionable gene alterations. The practice of sequential testing is not recommended. Identification of ALK rearrangements is now essential for the diagnosis of NSCLC, underpinned by the benefits of ALK inhibitors. As scientific understanding and diagnostic technology develops, ALK testing will continue to be an

  20. Tackling ALK in non-small cell lung cancer: the role of novel inhibitors

    PubMed Central

    Facchinetti, Francesco; Di Maio, Massimo; Graziano, Paolo; Bria, Emilio; Rossi, Giulio; Novello, Silvia

    2016-01-01

    Crizotinib is an oral inhibitor of anaplastic lymphoma kinase (ALK) with remarkable clinical activity in patients suffering from ALK-rearranged non-small cell lung cancer (NSCLC), accounting to its superiority compared to chemotherapy. Unfortunately, virtually all ALK-rearranged tumors acquire resistance to crizotinib, frequently within one year since the treatment initiation. To date, therapeutic strategies to overcome crizotinib resistance have focused on the use of more potent and structurally different compounds. Second-generation ALK inhibitors such as ceritinib (LDK378), alectinib (CH5424802/RO5424802) and brigatinib (AP26113) have shown relevant clinical activity, consequently fostering their rapid clinical development and their approval by health agencies. The third-generation inhibitor lorlatinib (PF-06463922), selectively active against ALK and ROS1, harbors impressive biological potency; its efficacy in reversing resistance to crizotinib and to other ALK inhibitors is being proven by early clinical trials. The NTRK1-3 and ROS1 inhibitor entrectinib (RXDX-101) has been reported to act against NSCLC harboring ALK fusion proteins too. Despite the quick development of these novel agents, several issues remain to be discussed in the treatment of patients suffering from ALK-rearranged NSCLC. This position paper will discuss the development, the current evidence and approvals, as long as the future perspectives of new ALK inhibitors beyond crizotinib. Clinical behaviors of ALK-rearranged NSCLC vary significantly among patients and differential molecular events responsible of crizotinib resistance account for the most important quote of this heterogeneity. The precious availability of a wide range of active anti-ALK compounds should be approached in a critical and careful perspective, in order to develop treatment strategies tailored on the disease evolution of every single patient. PMID:27413712

  1. Completing the structural family portrait of the human EphB tyrosine kinase domains

    PubMed Central

    Overman, Ross C; Debreczeni, Judit E; Truman, Caroline M; McAlister, Mark S; Attwood, Teresa K

    2014-01-01

    The EphB receptors have key roles in cell morphology, adhesion, migration and invasion, and their aberrant action has been linked with the development and progression of many different tumor types. Their conflicting expression patterns in cancer tissues, combined with their high sequence and structural identity, present interesting challenges to those seeking to develop selective therapeutic molecules targeting this large receptor family. Here, we present the first structure of the EphB1 tyrosine kinase domain determined by X-ray crystallography to 2.5Å. Our comparative crystalisation analysis of the human EphB family kinases has also yielded new crystal forms of the human EphB2 and EphB4 catalytic domains. Unable to crystallize the wild-type EphB3 kinase domain, we used rational engineering (based on our new structures of EphB1, EphB2, and EphB4) to identify a single point mutation which facilitated its crystallization and structure determination to 2.2 Å. This mutation also improved the soluble recombinant yield of this kinase within Escherichia coli, and increased both its intrinsic stability and catalytic turnover, without affecting its ligand-binding profile. The partial ordering of the activation loop in the EphB3 structure alludes to a potential cis-phosphorylation mechanism for the EphB kinases. With the kinase domain structures of all four catalytically competent human EphB receptors now determined, a picture begins to emerge of possible opportunities to produce EphB isozyme-selective kinase inhibitors for mechanistic studies and therapeutic applications. PMID:24677421

  2. Dynamics of the Tec-family tyrosine kinase SH3 domains.

    PubMed

    Roberts, Justin M; Tarafdar, Sreya; Joseph, Raji E; Andreotti, Amy H; Smithgall, Thomas E; Engen, John R; Wales, Thomas E

    2016-04-01

    The Src Homology 3 (SH3) domain is an important regulatory domain found in many signaling proteins. X-ray crystallography and NMR structures of SH3 domains are generally conserved but other studies indicate that protein flexibility and dynamics are not. We previously reported that based on hydrogen exchange mass spectrometry (HX MS) studies, there is variable flexibility and dynamics among the SH3 domains of the Src-family tyrosine kinases and related proteins. Here we have extended our studies to the SH3 domains of the Tec family tyrosine kinases (Itk, Btk, Tec, Txk, Bmx). The SH3 domains of members of this family augment the variety in dynamics observed in previous SH3 domains. Txk and Bmx SH3 were found to be highly dynamic in solution by HX MS and Bmx was unstructured by NMR. Itk and Btk SH3 underwent a clear EX1 cooperative unfolding event, which was localized using pepsin digestion and mass spectrometry after hydrogen exchange labeling. The unfolding was localized to peptide regions that had been previously identified in the Src-family and related protein SH3 domains, yet the kinetics of unfolding were not. Sequence alignment does not provide an easy explanation for the observed dynamics behavior, yet the similarity of location of EX1 unfolding suggests that higher-order structural properties may play a role. While the exact reason for such dynamics is not clear, such motions can be exploited in intra- and intermolecular binding assays of proteins containing the domains.

  3. RANBP2-ALK fusion combined with monosomy 7 in acute myelomonocytic leukemia.

    PubMed

    Lim, Ji-Hun; Jang, Seongsoo; Park, Chan-Jeoung; Cho, Young-Uk; Lee, Je-Hwan; Lee, Kyoo-Hyung; Lee, Jin-Ok; Shin, Jong-Yeon; Kim, Jong-Il; Huh, Jooryung; Seo, Eul-Ju

    2014-01-01

    Anaplastic lymphoma receptor tyrosine kinase (ALK) is located on chromosome 2p23; the chromosomal rearrangements of this gene are common genetic alterations, resulting in the creation of multiple fusion genes involved in tumorigenesis. However, the presence of an ALK fusion in myeloid malignancies is extremely rare. We report a case of acute myelomonocytic leukemia in a 31-year-old woman with an unusual rearrangement between RAN-binding protein 2 (RANBP2) and ALK and a karyotype of 45,XX,inv(2)(p23q21),-7[20]. We detected an ALK rearrangement using fluorescence in situ hybridization, identified the ALK fusion partner by using RNA transcriptome sequencing, and demonstrated the RANBP2-ALK fusion transcript by reverse transcriptase--PCR and Sanger sequencing. Immunohistochemistry for ALK showed strong staining of the nuclear membrane in leukemic cells. The patient had an unfavorable clinical course. Our results, together with a literature review, suggest the RANBP2-ALK fusion combined with monosomy 7 may be related to a unique clonal hematologic disorder of childhood and adolescence, characterized by myelomonocytic leukemia and a poor prognosis.

  4. Crystal structure of the FLT3 kinase domain bound to the inhibitor quizartinib (AC220)

    SciTech Connect

    Zorn, Julie A.; Wang, Qi; Fujimura, Eric; Barros, Tiago; Kuriyan, John; Boggon, Titus J.

    2015-04-02

    More than 30% of acute myeloid leukemia (AML) patients possess activating mutations in the receptor tyrosine kinase FMS-like tyrosine kinase 3 or FLT3. A small-molecule inhibitor of FLT3 (known as quizartinib or AC220) that is currently in clinical trials appears promising for the treatment of AML. Here, we report the co-crystal structure of the kinase domain of FLT3 in complex with quizartinib. FLT3 with quizartinib bound adopts an “Abl-like” inactive conformation with the activation loop stabilized in the “DFG-out” orientation and folded back onto the kinase domain. This conformation is similar to that observed for the uncomplexed intracellular domain of FLT3 as well as for related receptor tyrosine kinases, except for a localized induced fit in the activation loop. The co-crystal structure reveals the interactions between quizartinib and the active site of FLT3 that are key for achieving its high potency against both wild-type FLT3 as well as a FLT3 variant observed in many AML patients. This co-complex further provides a structural rationale for quizartinib-resistance mutations.

  5. Crystal structure of the FLT3 kinase domain bound to the inhibitor quizartinib (AC220)

    DOE PAGES

    Zorn, Julie A.; Wang, Qi; Fujimura, Eric; ...

    2015-04-02

    More than 30% of acute myeloid leukemia (AML) patients possess activating mutations in the receptor tyrosine kinase FMS-like tyrosine kinase 3 or FLT3. A small-molecule inhibitor of FLT3 (known as quizartinib or AC220) that is currently in clinical trials appears promising for the treatment of AML. Here, we report the co-crystal structure of the kinase domain of FLT3 in complex with quizartinib. FLT3 with quizartinib bound adopts an “Abl-like” inactive conformation with the activation loop stabilized in the “DFG-out” orientation and folded back onto the kinase domain. This conformation is similar to that observed for the uncomplexed intracellular domain ofmore » FLT3 as well as for related receptor tyrosine kinases, except for a localized induced fit in the activation loop. The co-crystal structure reveals the interactions between quizartinib and the active site of FLT3 that are key for achieving its high potency against both wild-type FLT3 as well as a FLT3 variant observed in many AML patients. This co-complex further provides a structural rationale for quizartinib-resistance mutations.« less

  6. For staining of ALK protein, the novel D5F3 antibody demonstrates superior overall performance in terms of intensity and extent of staining in comparison to the currently used ALK1 antibody.

    PubMed

    Taheri, Diana; Zahavi, David J; Del Carmen Rodriguez, Maria; Meliti, Abdelrazak; Rezaee, Neda; Yonescu, Raluca; Ricardo, Bernardo F P; Dolatkhah, Shahaboddin; Ning, Yi; Bishop, Justin A; Netto, George J; Sharma, Rajni

    2016-09-01

    Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm. Approximately 50 % of IMTs show an anaplastic lymphoma kinase (ALK) gene fusion resulting in ALK overexpression on immunohistochemistry (IHC). A novel anti-ALK monoclonal antibody (D5F3) has been suggested to be of superior sensitivity to the ALK1 antibody which is currently used. We compared the performance of D5F3 in detecting ALK protein expression in IMTs from various anatomic sites compared to the currently utilized ALK1. We selected 25 IMTs from our surgical pathology files (2005-2015). The novel rabbit monoclonal anti-human CD246 (clone D5F3) and the currently used mouse monoclonal anti-human CD246 (clone ALK1) were used for immunohistochemical staining (IHC) in an automated slide stainer. The percentage of immunoreactive tumor cells (0, <5 %, 5-50 %, >50 %) and cytoplasmic staining intensity (graded 0-3) were assessed and compared between the two antibodies. Fluorescence in situ hybridization (FISH) studies for ALK gene rearrangement were performed on 11 tumors. D5F3 antibody stained 76 % and ALK1 antibody stained 72 % of IMTs (p = 0.747). Compared to staining with ALK1, D5F3 stained a higher proportion of cases extensively (>50 % cells) (76 vs. 28 %, p < 0.001) and with high intensity (grade 3 76 % vs 0; p < 0.001). FISH and IHC findings (for both antibodies) were concordant in 9/10 (90 %) IMTs, in which results were informative. The novel anti-ALK rabbit monoclonal antibody (D5F3 clone) demonstrates superior overall performance in term of intensity and extent of staining of ALK protein in IMT. We found IHC staining with both antibody clones to correlate equally well with FISH results for detection of ALK rearrangement.

  7. Structural Characterization of the Predominant Family of Histidine Kinase Sensor Domains

    SciTech Connect

    Zhang, Z.; Hendrickson, W

    2010-01-01

    Histidine kinase (HK) receptors are used ubiquitously by bacteria to monitor environmental changes, and they are also prevalent in plants, fungi, and other protists. Typical HK receptors have an extracellular sensor portion that detects a signal, usually a chemical ligand, and an intracellular transmitter portion that includes both the kinase domain itself and the site for histidine phosphorylation. While kinase domains are highly conserved, sensor domains are diverse. HK receptors function as dimers, but the molecular mechanism for signal transduction across cell membranes remains obscure. In this study, eight crystal structures were determined from five sensor domains representative of the most populated family, family HK1, found in a bioinformatic analysis of predicted sensor domains from transmembrane HKs. Each structure contains an inserted repeat of PhoQ/DcuS/CitA (PDC) domains, and similarity between sequence and structure is correlated across these and other double-PDC sensor proteins. Three of the five sensors crystallize as dimers that appear to be physiologically relevant, and comparisons between ligated structures and apo-state structures provide insights into signal transmission. Some HK1 family proteins prove to be sensors for chemotaxis proteins or diguanylate cyclase receptors, implying a combinatorial molecular evolution.

  8. Structural characterization of the predominant family of histidine kinase sensor domains.

    PubMed

    Zhang, Zhen; Hendrickson, Wayne A

    2010-07-16

    Histidine kinase (HK) receptors are used ubiquitously by bacteria to monitor environmental changes, and they are also prevalent in plants, fungi, and other protists. Typical HK receptors have an extracellular sensor portion that detects a signal, usually a chemical ligand, and an intracellular transmitter portion that includes both the kinase domain itself and the site for histidine phosphorylation. While kinase domains are highly conserved, sensor domains are diverse. HK receptors function as dimers, but the molecular mechanism for signal transduction across cell membranes remains obscure. In this study, eight crystal structures were determined from five sensor domains representative of the most populated family, family HK1, found in a bioinformatic analysis of predicted sensor domains from transmembrane HKs. Each structure contains an inserted repeat of PhoQ/DcuS/CitA (PDC) domains, and similarity between sequence and structure is correlated across these and other double-PDC sensor proteins. Three of the five sensors crystallize as dimers that appear to be physiologically relevant, and comparisons between ligated structures and apo-state structures provide insights into signal transmission. Some HK1 family proteins prove to be sensors for chemotaxis proteins or diguanylate cyclase receptors, implying a combinatorial molecular evolution.

  9. Characterisation of a plant 3-phosphoinositide-dependent protein kinase-1 homologue which contains a pleckstrin homology domain.

    PubMed

    Deak, M; Casamayor, A; Currie, R A; Downes, C P; Alessi, D R

    1999-05-28

    A plant homologue of mammalian 3-phosphoinositide-dependent protein kinase-1 (PDK1) has been identified in Arabidopsis and rice which displays 40% overall identity with human 3-phosphoinositide-dependent protein kinase-1. Like the mammalian 3-phosphoinositide-dependent protein kinase-1, Arabidopsis 3-phosphoinositide-dependent protein kinase-1 and rice 3-phosphoinositide-dependent protein kinase-1 possess a kinase domain at N-termini and a pleckstrin homology domain at their C-termini. Arabidopsis 3-phosphoinositide-dependent protein kinase-1 can rescue lethality in Saccharomyces cerevisiae caused by disruption of the genes encoding yeast 3-phosphoinositide-dependent protein kinase-1 homologues. Arabidopsis 3-phosphoinositide-dependent protein kinase-1 interacts via its pleckstrin homology domain with phosphatidic acid, PtdIns3P, PtdIns(3,4,5)P3 and PtdIns(3,4)P2 and to a lesser extent with PtdIns(4,5)P2 and PtdIns4P. Arabidopsis 3-phosphoinositide-dependent protein kinase-1 is able to activate human protein kinase B alpha (PKB/AKT) in the presence of PtdIns(3,4,5)P3. Arabidopsis 3-phosphoinositide-dependent protein kinase-1 is only the second plant protein reported to possess a pleckstrin homology domain and the first plant protein shown to bind 3-phosphoinositides.

  10. French multicentric validation of ALK rearrangement diagnostic in 547 lung adenocarcinomas.

    PubMed

    Lantuejoul, Sylvie; Rouquette, Isabelle; Blons, Hélène; Le Stang, Nolwenn; Ilie, Marius; Begueret, Hugues; Grégoire, Valerie; Hofman, Paul; Gros, Audrey; Garcia, Stephane; Monhoven, Nathalie; Devouassoux-Shisheboran, Mojgan; Mansuet-Lupo, Audrey; Thivolet, Françoise; Antoine, Martine; Vignaud, Jean-Michel; Penault-Llorca, Frederique; Galateau-Sallé, Françoise; McLeer-Florin, Anne

    2015-07-01

    Anaplastic lymphoma kinase (ALK) gene rearrangements in lung adenocarcinoma result in kinase activity targetable by crizotinib. Although fluorescence in situ hybridisation (FISH) is the reference diagnostic technique, immunohistochemistry (IHC) could be useful for pre-screening. Diagnostic yields of ALK IHC, FISH and quantitative reverse transcriptase PCR performed in 14 French pathology/molecular genetics platforms were compared. 547 lung adenocarcinoma specimens were analysed using 5A4 and D5F3 antibodies, two break-apart FISH probes and TaqMan kits. Clinicopathological data were recorded. 140 tumours were ALK rearranged (FISH with ≥15% of rearranged cells) and 400 were ALK FISH negative (<15%). FISH was not interpretable for seven cases. ALK patients were young (p=0.003), mostly females (p=0.007) and light/nonsmokers (p<0.0001). 13 cases were IHC negative but FISH ≥15%, including six cases with FISH between 15% and 20%; eight were IHC positive with FISH between 10% and 14%. Sensitivity and specificity for 5A4 and D5F3 were 87% and 92%, and 89% and 76%, respectively. False-negative IHC, observed in 2.4% of cases, dropped to 1.3% for FISH >20%. Variants were undetected in 36% of ALK tumours. Discordances predominated with FISH ranging from 10% to 20% of rearranged cells and were centre dependent. IHC remains a reliable pre-screening method for ALK rearrangement detection.

  11. Oncogenic ALK regulates EMT in non-small cell lung carcinoma through repression of the epithelial splicing regulatory protein 1

    PubMed Central

    Menotti, Matteo; Poggio, Teresa; Panizza, Elena; Wang, Qi; Minero, Valerio G.; Fagoonee, Sharmila; Compagno, Mara; Altruda, Fiorella; Monti, Stefano; Chiarle, Roberto

    2016-01-01

    A subset of Non-Small Cell Lung Carcinoma (NSCLC) carries chromosomal rearrangements involving the Anaplastic Lymphoma Kinase (ALK) gene. ALK-rearranged NSCLC are typically adenocarcinoma characterized by a solid signet-ring cell pattern that is frequently associated with a metastatic phenotype. Recent reports linked the presence of ALK rearrangement to an epithelial-mesenchymal transition (EMT) phenotype in NSCLC, but the extent and the mechanisms of an ALK-mediated EMT in ALK-rearranged NSCLC are largely unknown. We found that the ALK-rearranged H2228 and DFCI032, but not the H3122, cell lines displayed a mesenchymal phenotype. In these cell lines, oncogenic ALK activity dictated an EMT phenotype by directly suppressing E-cadherin and up-regulating vimentin expression, as well as expression of other genes involved in EMT. We found that the epithelial splicing regulatory protein 1 (ESRP1), a key regulator of the splicing switch during EMT, was repressed by EML4-ALK activity. The treatment of NSCLC cells with ALK tyrosine kinase inhibitors (TKIs) led to up-regulation of ESRP1 and E-cadherin, thus reverting the phenotype from mesenchymal to epithelial (MET). Consistently, ESRP1 knock-down impaired E-cadherin up-regulation upon ALK inhibition, whereas enforced expression of ESRP1 was sufficient to increase E-cadherin expression. These findings demonstrate an ALK oncogenic activity in the regulation of an EMT phenotype in a subset of NSCLC with potential implications for the biology of ALK-rearranged NSCLC in terms of metastatic propensity and resistance to therapy. PMID:27119231

  12. The bHLH transcription factor Hand is regulated by Alk in the Drosophila embryonic gut

    SciTech Connect

    Varshney, Gaurav K.; Palmer, Ruth H. . E-mail: Ruth.Palmer@ucmp.umu.se

    2006-12-29

    During embryonic development the midgut visceral muscle is formed by fusion of cells within the visceral mesoderm, a process initiated by the specification of a specialised cell type, the founder cell, within this tissue. Activation of the receptor tyrosine kinase Anaplastic lymphoma kinase (Alk) in the developing visceral muscle of Drosophila melanogaster initiates a signal transduction pathway required for muscle fusion. In this paper, we have investigated downstream components which are regulated by this novel signalling pathway. Here we show that Alk-mediated signal transduction drives the expression of the bHLH transcription factor Hand in vivo. Loss of Alk function results in a complete lack of Hand expression in this tissue, whereas Alk gain of function results in an expansion of Hand expression. Finally, we have investigated the process of muscle fusion in the gut of Hand mutant animals and can find no obvious defects in this process, suggesting that Hand is not critical for visceral muscle fusion per se.

  13. A ligand-induced switch in the periplasmic domain of sensor histidine kinase CitA.

    PubMed

    Sevvana, Madhumati; Vijayan, Vinesh; Zweckstetter, Markus; Reinelt, Stefan; Madden, Dean R; Herbst-Irmer, Regine; Sheldrick, George M; Bott, Michael; Griesinger, Christian; Becker, Stefan

    2008-03-21

    Sensor histidine kinases of two-component signal-transduction systems are essential for bacteria to adapt to variable environmental conditions. However, despite their prevalence, it is not well understood how extracellular signals such as ligand binding regulate the activity of these sensor kinases. CitA is the sensor histidine kinase in Klebsiella pneumoniae that regulates the transport and anaerobic metabolism of citrate in response to its extracellular concentration. We report here the X-ray structures of the periplasmic sensor domain of CitA in the citrate-free and citrate-bound states. A comparison of the two structures shows that ligand binding causes a considerable contraction of the sensor domain. This contraction may represent the molecular switch that activates transmembrane signaling in the receptor.

  14. Targeting autophagy enhances the anti-tumoral action of crizotinib in ALK-positive anaplastic large cell lymphoma

    PubMed Central

    Desquesnes, Aurore; Le Gonidec, Sophie; AlSaati, Talal; Beau, Isabelle; Lamant, Laurence; Meggetto, Fabienne; Espinos, Estelle; Codogno, Patrice; Brousset, Pierre; Giuriato, Sylvie

    2015-01-01

    Anaplastic Lymphoma Kinase-positive Anaplastic Large Cell Lymphomas (ALK+ ALCL) occur predominantly in children and young adults. Their treatment, based on aggressive chemotherapy, is not optimal since ALCL patients can still expect a 30% 2-year relapse rate. Tumor relapses are very aggressive and their underlying mechanisms are unknown. Crizotinib is the most advanced ALK tyrosine kinase inhibitor and is already used in clinics to treat ALK-associated cancers. However, crizotinib escape mechanisms have emerged, thus preventing its use in frontline ALCL therapy. The process of autophagy has been proposed as the next target for elimination of the resistance to tyrosine kinase inhibitors. In this study, we investigated whether autophagy is activated in ALCL cells submitted to ALK inactivation (using crizotinib or ALK-targeting siRNA). Classical autophagy read-outs such as autophagosome visualization/quantification by electron microscopy and LC3-B marker turn-over assays were used to demonstrate autophagy induction and flux activation upon ALK inactivation. This was demonstrated to have a cytoprotective role on cell viability and clonogenic assays following combined ALK and autophagy inhibition. Altogether, our results suggest that co-treatment with crizotinib and chloroquine (two drugs already used in clinics) could be beneficial for ALK-positive ALCL patients. PMID:26338968

  15. Domain Requirements of the JIL-1 Tandem Kinase for Histone H3 Serine 10 Phosphorylation and Chromatin Remodeling in Vivo*

    PubMed Central

    Li, Yeran; Cai, Weili; Wang, Chao; Yao, Changfu; Bao, Xiaomin; Deng, Huai; Girton, Jack; Johansen, Jørgen; Johansen, Kristen M.

    2013-01-01

    The JIL-1 kinase localizes to Drosophila polytene chromosome interbands and phosphorylates histone H3 at interphase, counteracting histone H3 lysine 9 dimethylation and gene silencing. JIL-1 can be divided into four main domains, including an NH2-terminal domain, two separate kinase domains, and a COOH-terminal domain. In this study, we characterize the domain requirements of the JIL-1 kinase for histone H3 serine 10 (H3S10) phosphorylation and chromatin remodeling in vivo. We show that a JIL-1 construct without the NH2-terminal domain is without H3S10 phosphorylation activity despite the fact that it localizes properly to polytene interband regions and that it contains both kinase domains. JIL-1 is a double kinase, and we demonstrate that both kinase domains of JIL-1 are required to be catalytically active for H3S10 phosphorylation to occur. Furthermore, we provide evidence that JIL-1 is phosphorylated at serine 424 and that this phosphorylation is necessary for JIL-1 H3S10 phosphorylation activity. Thus, these data are compatible with a model where the NH2-terminal domain of JIL-1 is required for chromatin complex interactions that position the kinase domain(s) for catalytic activity in the context of the state of higher order nucleosome packaging and chromatin structure and where catalytic H3S10 phosphorylation activity mediated by the first kinase domain is dependent on autophosphorylation of serine 424 by the second kinase domain. Furthermore, using a lacO repeat tethering system to target mutated JIL-1 constructs with or without catalytic activity, we show that the epigenetic H3S10 phosphorylation mark itself functions as a causative regulator of chromatin structure independently of any structural contributions from the JIL-1 protein. PMID:23723094

  16. SH2 domain proteins as high-affinity receptor tyrosine kinase substrates.

    PubMed

    Sierke, S L; Koland, J G

    1993-09-28

    Activation of a growth factor receptor tyrosine kinase (RTK) is accompanied by a rapid autophosphorylation of the receptor on tyrosine residues. Receptor activation has been shown to promote the association of signal-transducing proteins containing SH2 domains (second domain of src homology). These receptor-associated proteins can, in turn, be phosphorylated by the RTK, an event which presumably regulates their activities. It has been suggested that SH2 domains in signal-transducing proteins target these proteins as substrates of the activated RTK. To test this hypothesis, recombinant proteins were generated that contained tyrosine phosphorylation sites of the erbB3 receptor and/or the SH2 domain of c-src. Incorporation of the SH2 domain led to a decrease in KM and an increase in Vmax for the substrate. The KM determined for one chimeric SH2/erbB3 substrate was among the lowest reported for epidermal growth factor RTK substrates. Experiments with a truncated kinase lacking C-terminal autophosphorylation sites indicated that the reduction in KM for these substrates was mediated by interactions between the substrate SH2 domain and phosphotyrosine residues of the RTK. These interactions could also inhibit RTK activity. These results demonstrate that the SH2 domain can effectively target substrates to a RTK and that SH2 domain proteins can regulate RTK activity.

  17. Functional Characterization of the Receiver Domain for Phosphorelay Control in Hybrid Sensor Kinases.

    PubMed

    Kinoshita-Kikuta, Emiko; Kinoshita, Eiji; Eguchi, Yoko; Yanagihara, Shiho; Edahiro, Keisuke; Inoue, Yuki; Taniguchi, Momoka; Yoshida, Myu; Yamamoto, Kaneyoshi; Takahashi, Hirotaka; Sawasaki, Tatsuya; Utsumi, Ryutaro; Koike, Tohru

    2015-01-01

    Hybrid sensor kinase, which contains a histidine kinase (HK) domain, a receiver domain, and a histidine-containing phosphotransmitter (HPt) domain, conveys signals to its cognate response regulator by means of a His-Asp-His-Asp phosphorelay. We examined the multistep phosphorelay of a recombinant EvgAS system in Escherichia coli and performed in vitro quantitative analyses of phosphorylation by using Phos-tag SDS-PAGE. Replacement of Asp in the receiver domain of EvgS by Ala markedly promoted phosphorylation at His in the HK domain compared with that in wild-type EvgS. Similar Ala-substituted mutants of other hybrid sensor kinases BarA and ArcB showed similar characteristics. In the presence of sufficient ATP, autophosphorylation of the HK domain in the mutant progressed efficiently with nearly pseudo-first-order kinetics until the phosphorylation ratio reached a plateau value of more than 95% within 60 min, and the value was maintained until 180 min. However, both wild-type EvgS and the Ala-substituted mutant of His in the HPt domain showed a phosphorylation ratio of less than 25%, which gradually decreased after 10 min. These results showed that the phosphorylation level is regulated negatively by the receiver domain. Furthermore, our in vivo assays confirmed the existence of a similar hyperphosphorylation reaction in the HK domain of the EvgS mutant in which the Asp residue was replaced with Ala, confirming the validity of the control mechanism proposed from profiling of phosphorylation in vitro [corrected].

  18. Inhibitors of the Polo-Box Domain of Polo-Like Kinase 1.

    PubMed

    Berg, Angela; Berg, Thorsten

    2016-04-15

    Polo-like kinase 1 (Plk1), a key player in mitosis, is overexpressed in a wide range of tumor types and has been validated as a target for tumor therapy. In addition to its N-terminal kinase domain, Plk1 harbors a C-terminal protein-protein interaction domain, referred to as the polo-box domain (PBD). Because the PBD is unique to the five-member family of polo-like kinases, and its inhibition is sufficient to inhibit the enzyme, the Plk1 PBD is an attractive target for the inhibition of Plk1 function. Although peptide-based inhibitors are invaluable tools for elucidating the nature of the binding interface, small molecules are better suited for the induction of mitotic arrest and apoptosis in tumor cells by Plk1 inhibition. This review describes the considerable progress that has been made in developing small-molecule and peptide-based inhibitors of the Plk1 PBD.

  19. Purification, crystallization and preliminary X-ray diffraction analysis of the kinase domain of human tousled-like kinase 2

    PubMed Central

    Garrote, Ana M.; Redondo, Pilar; Montoya, Guillermo; Muñoz, Inés G.

    2014-01-01

    Tousled-like kinases (TLKs) are an evolutionarily conserved family of serine/threonine protein kinases involved in chromatin dynamics, including DNA replication and repair, transcription and chromosome segregation. The two members of the family reported in humans, namely TLK1 and TLK2, localize to the cell nucleus and are capable of forming homo- or hetero-oligomers by themselves. To characterize the role of TLK2, its C-terminal kinase domain was cloned and overexpressed in Escherichia coli followed by purification to homogeneity. Crystallization experiments in the presence of ATP-γ-S yielded crystals suitable for X-ray diffraction analysis belonging to two different space groups: tetragonal I4122 and cubic P213. The latter produced the best diffracting crystal (3.4 Å resolution using synchrotron radiation), with unit-cell parameters a = b = c = 126.05 Å, α = β = γ = 90°. The asymmetric unit contained one protein molecule, with a Matthews coefficient of 4.59 Å3 Da−1 and a solvent content of 73.23%. PMID:24598926

  20. A first generation inhibitor of human Greatwall kinase, enabled by structural and functional characterisation of a minimal kinase domain construct

    PubMed Central

    Ocasio, Cory A.; Rajasekaran, Mohan B.; Walker, Sarah; Le Grand, Darren; Spencer, John; Pearl, Frances M.G.; Ward, Simon E.; Savic, Velibor; Pearl, Laurence H.; Hochegger, Helfrid; Oliver, Antony W.

    2016-01-01

    MASTL (microtubule-associated serine/threonine kinase-like), more commonly known as Greatwall (GWL), has been proposed as a novel cancer therapy target. GWL plays a crucial role in mitotic progression, via its known substrates ENSA/ARPP19, which when phosphorylated inactivate PP2A/B55 phosphatase. When over-expressed in breast cancer, GWL induces oncogenic properties such as transformation and invasiveness. Conversely, down-regulation of GWL selectively sensitises tumour cells to chemotherapy. Here we describe the first structure of the GWL minimal kinase domain and development of a small-molecule inhibitor GKI-1 (Greatwall Kinase Inhibitor-1). In vitro, GKI-1 inhibits full-length human GWL, and shows cellular efficacy. Treatment of HeLa cells with GKI-1 reduces ENSA/ARPP19 phosphorylation levels, such that they are comparable to those obtained by siRNA depletion of GWL; resulting in a decrease in mitotic events, mitotic arrest/cell death and cytokinesis failure. Furthermore, GKI-1 will be a useful starting point for the development of more potent and selective GWL inhibitors. PMID:27563826

  1. Crystal structures of the S6K1 kinase domain in complexes with inhibitors.

    PubMed

    Niwa, Hideaki; Mikuni, Junko; Sasaki, Shunta; Tomabechi, Yuri; Honda, Keiko; Ikeda, Mariko; Ohsawa, Noboru; Wakiyama, Motoaki; Handa, Noriko; Shirouzu, Mikako; Honma, Teruki; Tanaka, Akiko; Yokoyama, Shigeyuki

    2014-09-01

    Ribosomal protein S6 kinase 1 (S6K1) is a serine/threonine protein kinase that plays an important role in the PIK3/mTOR signaling pathway, and is implicated in diseases including diabetes, obesity, and cancer. The crystal structures of the S6K1 kinase domain in complexes with staurosporine and the S6K1-specific inhibitor PF-4708671 have been reported. In the present study, five compounds (F108, F109, F176, F177, and F179) were newly identified by in silico screening of a chemical library and kinase assay. The crystal structures of the five inhibitors in complexes with the S6K1 kinase domain were determined at resolutions between 1.85 and 2.10 Å. All of the inhibitors bound to the ATP binding site, lying along the P-loop, while the activation loop stayed in the inactive form. Compound F179, with a carbonyl group in the middle of the molecule, altered the αC helix conformation by interacting with the invariant Lys123. Compounds F176 and F177 bound slightly distant from the hinge region, and their sulfoamide groups formed polar interactions with the protein. The structural features required for the specific binding of inhibitors are discussed.

  2. A transforming mutation enhances the activity of the c-Kit soluble tyrosine kinase domain.

    PubMed Central

    Lam, L P; Chow, R Y; Berger, S A

    1999-01-01

    An activating mutation (DY814) located in the catalytic domain of the c-Kit receptor has been found in mastocytomas from human, mouse and rat. We evaluated the enzymic properties of purified wild-type (WT) and DY814 tyrosine kinase domains expressed in Pichia pastoris. A linker encoding the Flag epitope was fused to c-Kit cDNA species, enabling affinity purification of the proteins with anti-Flag antibodies. Yeast lysates expressing DY814 contained multiple tyrosine-phosphorylated proteins, whereas WT lysates had no detectable tyrosine phosphorylation. Purification of the WT and mutant kinases in the presence of vanadate demonstrated that both enzymes undergo autophosphorylation. Kinetic analyses of WT and DY814 kinases indicated that at 20 nM enzyme concentration the mutation increases the specific activity 10-fold and decreases the apparent Km for ATP 9-fold. WT activity displayed a hyperbolic dependence on enzyme concentration, consistent with a requirement for dimerization or aggregation for activity. This activity was also enhanced by anti-Flag antibodies. In contrast, the dependence of DY814 activity on enzyme concentration was primarily linear and only marginally enhanced by anti-Flag antibodies. Gel-filtration analysis showed that the WT kinase migrated as a monomer, whereas the DY814 mutant migrated as a dimer. These results indicate that this point mutation promotes dimerization of the c-Kit kinase, potentially contributing to its transforming potential in mast cells. PMID:9931308

  3. A cell cycle kinase with tandem sensory PAS domains integrates cell fate cues

    PubMed Central

    Mann, Thomas H.; Seth Childers, W.; Blair, Jimmy A.; Eckart, Michael R.; Shapiro, Lucy

    2016-01-01

    All cells must integrate sensory information to coordinate developmental events in space and time. The bacterium Caulobacter crescentus uses two-component phospho-signalling to regulate spatially distinct cell cycle events through the master regulator CtrA. Here, we report that CckA, the histidine kinase upstream of CtrA, employs a tandem-PAS domain sensor to integrate two distinct spatiotemporal signals. Using CckA reconstituted on liposomes, we show that one PAS domain modulates kinase activity in a CckA density-dependent manner, mimicking the stimulation of CckA kinase activity that occurs on its transition from diffuse to densely packed at the cell poles. The second PAS domain interacts with the asymmetrically partitioned second messenger cyclic-di-GMP, inhibiting kinase activity while stimulating phosphatase activity, consistent with the selective inactivation of CtrA in the incipient stalked cell compartment. The integration of these spatially and temporally regulated signalling events within a single signalling receptor enables robust orchestration of cell-type-specific gene regulation. PMID:27117914

  4. Comprehensive Characterization of AMP-Activated Protein Kinase Catalytic Domain by Top-Down Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Yu, Deyang; Peng, Ying; Ayaz-Guner, Serife; Gregorich, Zachery R.; Ge, Ying

    2016-02-01

    AMP-activated protein kinase (AMPK) is a serine/threonine protein kinase that is essential in regulating energy metabolism in all eukaryotic cells. It is a heterotrimeric protein complex composed of a catalytic subunit (α) and two regulatory subunits (β and γ). C-terminal truncation of AMPKα at residue 312 yielded a protein that is active upon phosphorylation of Thr172 in the absence of β and γ subunits, which is refered to as the AMPK catalytic domain and commonly used to substitute for the AMPK heterotrimeric complex in in vitro kinase assays. However, a comprehensive characterization of the AMPK catalytic domain is lacking. Herein, we expressed a His-tagged human AMPK catalytic domin (denoted as AMPKΔ) in E. coli, comprehensively characterized AMPKΔ in its basal state and after in vitro phosphorylation using top-down mass spectrometry (MS), and assessed how phosphorylation of AMPKΔ affects its activity. Unexpectedly, we found that bacterially-expressed AMPKΔ was basally phosphorylated and localized the phosphorylation site to the His-tag. We found that AMPKΔ had noticeable basal activity and was capable of phosphorylating itself and its substrates without activating phosphorylation at Thr172. Moreover, our data suggested that Thr172 is the only site phosphorylated by its upstream kinase, liver kinase B1, and that this phosphorylation dramatically increases the kinase activity of AMPKΔ. Importantly, we demonstrated that top-down MS in conjunction with in vitro phosphorylation assay is a powerful approach for monitoring phosphorylation reaction and determining sequential order of phosphorylation events in kinase-substrate systems.

  5. Comprehensive Characterization of AMP-activated Protein Kinase Catalytic Domain by Top-down Mass Spectrometry

    PubMed Central

    Yu, Deyang; Peng, Ying; Ayaz-Guner, Serife; Gregorich, Zachery R.; Ge, Ying

    2015-01-01

    AMP-activated protein kinase (AMPK) is a serine/threonine protein kinase that is essential in regulating energy metabolism in all eukaryotic cells. It is a heterotrimeric protein complex composed of a catalytic subunit (α) and two regulatory subunits (β and γ. C-terminal truncation of AMPKα at residue 312 yielded a protein that is active upon phosphorylation of Thr172 in the absence of β and γ subunits, which is refered to as the AMPK catalytic domain and commonly used to substitute for the AMPK heterotrimeric complex in in vitro kinase assays. However, a comprehensive characterization of the AMPK catalytic domain is lacking. Herein, we expressed a His-tagged human AMPK catalytic domin (denoted as AMPKΔ) in E. coli, comprehensively characterized AMPKΔ in its basal state and after in vitro phosphorylation using top-down mass spectrometry (MS), and assessed how phosphorylation of AMPKΔ affects its activity. Unexpectedly, we found that bacterially-expressed AMPKΔ was basally phosphorylated and localized the phosphorylation site to the His-tag. We found that AMPKΔ has noticeable basal activity and was capable of phosphorylating itself and its substrates without activating phosphorylation at Thr172. Moreover, our data suggested that Thr172 is the only site phosphorylated by its upstream kinase, liver kinase B1, and that this phosphorylation dramatically increases the kinase activity of AMPKΔ. Importantly, we demonstrated that top-down MS in conjunction with in vitro phosphorylation assay is a powerful approach for monitoring phosphorylation reaction and determining sequential order of phosphorylation events in kinase-substrate systems. PMID:26489410

  6. Baculovirus protein PK2 subverts eIF2α kinase function by mimicry of its kinase domain C-lobe

    PubMed Central

    Li, John J.; Cao, Chune; Fixsen, Sarah M.; Young, Janet M.; Bando, Hisanori; Elde, Nels C.; Katsuma, Susumu; Dever, Thomas E.; Sicheri, Frank

    2015-01-01

    Phosphorylation of eukaryotic translation initiation factor 2α (eIF2α) by eIF2α family kinases is a conserved mechanism to limit protein synthesis under specific stress conditions. The baculovirus-encoded protein PK2 inhibits eIF2α family kinases in vivo, thereby increasing viral fitness. However, the precise mechanism by which PK2 inhibits eIF2α kinase function remains an enigma. Here, we probed the mechanism by which PK2 inhibits the model eIF2α kinase human RNA-dependent protein kinase (PKR) as well as native insect eIF2α kinases. Although PK2 structurally mimics the C-lobe of a protein kinase domain and possesses the required docking infrastructure to bind eIF2α, we show that PK2 directly binds the kinase domain of PKR (PKRKD) but not eIF2α. The PKRKD–PK2 interaction requires a 22-residue N-terminal extension preceding the globular PK2 body that we term the “eIF2α kinase C-lobe mimic” (EKCM) domain. The functional insufficiency of the N-terminal extension of PK2 implicates a role for the adjacent EKCM domain in binding and inhibiting PKR. Using a genetic screen in yeast, we isolated PK2-activating mutations that cluster to a surface of the EKCM domain that in bona fide protein kinases forms the catalytic cleft through sandwiching interactions with a kinase N-lobe. Interaction assays revealed that PK2 associates with the N- but not the C-lobe of PKRKD. We propose an inhibitory model whereby PK2 engages the N-lobe of an eIF2α kinase domain to create a nonfunctional pseudokinase domain complex, possibly through a lobe-swapping mechanism. Finally, we show that PK2 enhances baculovirus fitness in insect hosts by targeting the endogenous insect heme-regulated inhibitor (HRI)–like eIF2α kinase. PMID:26216977

  7. EML4-ALK induces epithelial–mesenchymal transition consistent with cancer stem cell properties in H1299 non-small cell lung cancer cells

    SciTech Connect

    Guo, Fuchun; Liu, Xiaoke Qing, Qin Sang, Yaxiong Feng, Chengjun Li, Xiaoyu Jiang, Li Su, Pei Wang, Yongsheng

    2015-04-10

    The echinoderm microtubule-associated protein-like 4(EML4) – anaplastic lymphoma kinase (ALK) fusion gene has been identified as a driver mutation in non-small-cell lung cancer (NSCLC). However, the role of EML4-ALK in malignant transformation is not entirely clear. Here, for the first time, we showed that H1299 NSCLC cells stably expressing EML4-ALK acquire EMT phenotype, associated with enhanced invasive migration and increased expression of EMT-inducing transcription factors. H1299-EML4-ALK cells also displayed cancer stem cell-like properties with a concomitant up-regulation of CD133 and enhanced ability of mammospheres formation. Moreover, we found that inhibition of ERK1/2 reversed EMT induced by EML4-ALK in H1299 cells. Taken together, these results suggested that EML4-ALK induced ERK activation is mechanistically associated with EMT phenotype. Thus, inhibition of ERK signaling pathway could be a potential strategy in treatment of NSCLC patients with EML4-ALK translocation. - Highlights: • EML4-ALK induced epithelial–mesenchymal transition in H1299 cells. • Expression of EML4-ALK promotes invasion and migration in vitro. • EML4-ALK enhanced sphere formation and stem cell-like properties in H1299 cells. • Blockage of ERK1/2 reverse Epithelial–Mesenchymal transition induced by EML4-ALK.

  8. Is membrane occupation and recognition nexus domain functional in plant phosphatidylinositol phosphate kinases?

    PubMed

    Mikami, Koji; Saavedra, Laura; Sommarin, Marianne

    2010-10-01

    Phosphatidylinositol phosphate kinase (PIPK) catalyzes a key step controlling cellular contents of phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P2], a critical intracellular messenger involved in vesicle trafficking and modulation of actin cytoskeleton and also a substrate of phospholipase C to produce the two intracellular messengers, diacylglycerol and inositol-1,4,5-trisphosphate. In addition to the conserved C-terminal PIPK catalytic domain, plant PIPKs contain a unique structural feature consisting of a repeat of membrane occupation and recognition nexus (MORN) motifs, called the MORN domain, in the N-terminal half. The MORN domain has previously been proposed to regulate plasma membrane localization and phosphatidic acid (PA)-inducible activation. Recently, the importance of the catalytic domain, but not the MORN domain, in these aspects was demonstrated. These conflicting data raise the question about the function of the MORN domain in plant PIPKs. We therefore performed analyses of PpPIPK1 from the moss Physcomitrella patens to elucidate the importance of the MORN domain in the control of enzymatic activity; however, we found no effect on either enzymatic activity or activation by PA. Taken together with our previous findings of lack of function in plasma membrane localization, there is no positive evidence indicating roles of the MORN domain in enzymatic and functional regulations of PpPIPK1. Therefore, further biochemical and reverse genetic analyses are necessary to understand the biological significance of the MORN domain in plant PIPKs.

  9. Identification of different ALK mutations in a pair of neuroblastoma cell lines established at diagnosis and relapse

    PubMed Central

    Chen, Lindi; Humphreys, Angharad; Turnbull, Lisa; Bellini, Angela; Schleiermacher, Gudrun; Salwen, Helen; Cohn, Susan L.; Bown, Nick; Tweddle, Deborah A.

    2016-01-01

    Anaplastic Lymphoma Kinase (ALK) is a transmembrane receptor kinase that belongs to the insulin receptor superfamily and has previously been shown to play a role in cell proliferation, migration and invasion in neuroblastoma. Activating ALK mutations are reported in both hereditary and sporadic neuroblastoma tumours, and several ALK inhibitors are currently under clinical evaluation as novel treatments for neuroblastoma. Overall, mutations at codons F1174, R1275 and F1245 together account for ∼85% of reported ALK mutations in neuroblastoma. NBLW and NBLW-R are paired cell lines originally derived from an infant with metastatic MYCN amplified Stage IVS (Evans Criteria) neuroblastoma, at diagnosis and relapse, respectively. Using both Sanger and targeted deep sequencing, this study describes the identification of distinct ALK mutations in these paired cell lines, including the rare R1275L mutation, which has not previously been reported in a neuroblastoma cell line. Analysis of the sensitivity of NBLW and NBLW-R cells to a panel of ALK inhibitors (TAE-684, Crizotinib, Alectinib and Lorlatinib) revealed differences between the paired cell lines, and overall NBLW-R cells with the F1174L mutation were more resistant to ALK inhibitor induced apoptosis compared with NBLW cells. This pair of cell lines represents a valuable pre-clinical model of clonal evolution of ALK mutations associated with neuroblastoma progression. PMID:27888620

  10. DSTYK kinase domain ablation impaired the mice capabilities of learning and memory in water maze test.

    PubMed

    Li, Kui; Liu, Ji-Wei; Zhu, Zhi-Chuan; Wang, Hong-Tao; Zu, Yong; Liu, Yong-Jie; Yang, Yan-Hong; Xiong, Zhi-Qi; Shen, Xu; Chen, Rui; Zheng, Jing; Hu, Ze-Lan

    2014-01-01

    DSTYK (Dual serine/threonine and tyrosine protein kinase) is a putative dual Ser/Thr and Tyr protein kinase with unique structural features. It is proposed that DSTYK may play important roles in brain because of its high expression in most brain areas. In the present study, a DSTYK knockout (KO) mouse line with the ablation of C-terminal of DSTYK including the kinase domain was generated to study the physiological function of DSTYK. The DSTYK KO mice are fertile and have no significant morphological defects revealed by Nissl staining compared with wildtype mice. Open field test and rotarod test showed there is no obvious difference in basic motor and balance capacity between the DSTYK homozygous KO mice and DSTYK heterozygous KO mice. In water maze test, however, the DSTYK homozygous KO mice show impaired capabilities of learning and memory compared with the DSTYK heterozygous KO mice.

  11. Phosphorylation of the Kinase Domain Regulates Autophosphorylation of Myosin IIIA and Its Translocation in Microvilli

    PubMed Central

    2015-01-01

    Motor activity of myosin III is regulated by autophosphorylation. To investigate the role of the kinase activity on the transporter function of myosin IIIA (Myo3A), we identified the phosphorylation sites of kinase domain (KD), which is responsible for the regulation of kinase activity and thus motor function. Using mass spectrometry, we identified six phosphorylation sites in the KD, which are highly conserved among class III myosins and Ste20-related misshapen (Msn) kinases. Two predominant sites, Thr184 and Thr188, in KD are important for phosphorylation of the KD as well as the motor domain, which regulates the affinity for actin. In the Caco2 cells, the full-length human Myo3A (hMyo3AFull) markedly enlarged the microvilli, although it did not show discrete localization within the microvilli. On the other hand, hMyo3AFull(T184A) and hMyo3AFull(T188A) both showed clear localization at the microvilli tips. Our results suggest that Myo3A induces large actin bundle formation to form microvilli, and phosphorylation of KD at Thr184 and Thr188 is critical for the kinase activity of Myo3A, and regulation of Myo3A translocation to the tip of microvilli. Retinal extracts potently dephosphorylate both KD and motor domain without IQ motifs (MDIQo), which was inhibited by okadaic acid (OA) with nanomolar range and by tautomycetin (TMC) with micromolar range. The results suggest that Myo3A phosphatase is protein phosphatase type 2A (PP2A). Supporting this result, recombinant PP2Ac potently dephosphorylates both KD and MDIQo. We propose that the phosphorylation–dephosphorylation mechanism plays an essential role in mediating the transport and actin bundle formation and stability functions of hMyo3A. PMID:25402663

  12. The Structural Basis for Activation and Inhibition of ZAP-70 Kinase Domain.

    PubMed

    Huber, Roland G; Fan, Hao; Bond, Peter J

    2015-10-01

    ZAP-70 (Zeta-chain-associated protein kinase 70) is a tyrosine kinase that interacts directly with the activated T-cell receptor to transduce downstream signals, and is hence a major player in the regulation of the adaptive immune response. Dysfunction of ZAP-70 causes selective T cell deficiency that in turn results in persistent infections. ZAP-70 is activated by a variety of signals including phosphorylation of the kinase domain (KD), and binding of its regulatory tandem Src homology 2 (SH2) domains to the T cell receptor. The present study investigates molecular mechanisms of activation and inhibition of ZAP-70 via atomically detailed molecular dynamics simulation approaches. We report microsecond timescale simulations of five distinct states of the ZAP-70 KD, comprising apo, inhibited and three phosphorylated variants. Extensive analysis of local flexibility and correlated motions reveal crucial transitions between the states, thus elucidating crucial steps in the activation mechanism of the ZAP-70 KD. Furthermore, we rationalize previously observed staurosporine-bound crystal structures, suggesting that whilst the KD superficially resembles an "active-like" conformation, the inhibitor modulates the underlying protein dynamics and restricts it in a compact, rigid state inaccessible to ligands or cofactors. Finally, our analysis reveals a novel, potentially druggable pocket in close proximity to the activation loop of the kinase, and we subsequently use its structure in fragment-based virtual screening to develop a pharmacophore model. The pocket is distinct from classical type I or type II kinase pockets, and its discovery offers promise in future design of specific kinase inhibitors, whilst mutations in residues associated with this pocket are implicated in immunodeficiency in humans.

  13. Automation of ALK gene rearrangement testing with fluorescence in situ hybridization (FISH): a feasibility study.

    PubMed

    Zwaenepoel, Karen; Merkle, Dennis; Cabillic, Florian; Berg, Erica; Belaud-Rotureau, Marc-Antoine; Grazioli, Vittorio; Herelle, Olga; Hummel, Michael; Le Calve, Michele; Lenze, Dido; Mende, Stefanie; Pauwels, Patrick; Quilichini, Benoit; Repetti, Elena

    2015-02-01

    In the past several years we have observed a significant increase in our understanding of molecular mechanisms that drive lung cancer. Specifically in the non-small cell lung cancer sub-types, ALK gene rearrangements represent a sub-group of tumors that are targetable by the tyrosine kinase inhibitor Crizotinib, resulting in significant reductions in tumor burden. Phase II and III clinical trials were performed using an ALK break-apart FISH probe kit, making FISH the gold standard for identifying ALK rearrangements in patients. FISH is often considered a labor and cost intensive molecular technique, and in this study we aimed to demonstrate feasibility for automation of ALK FISH testing, to improve laboratory workflow and ease of testing. This involved automation of the pre-treatment steps of the ALK assay using various protocols on the VP 2000 instrument, and facilitating automated scanning of the fluorescent FISH specimens for simplified enumeration on various backend scanning and analysis systems. The results indicated that ALK FISH can be automated. Significantly, both the Ikoniscope and BioView system of automated FISH scanning and analysis systems provided a robust analysis algorithm to define ALK rearrangements. In addition, the BioView system facilitated consultation of difficult cases via the internet.

  14. A novel Patient Derived Tumorgraft model with TRAF1-ALK Anaplastic Large Cell Lymphoma translocation

    PubMed Central

    Abate, Francesco; Todaro, Maria; van der Krogt, Jo-Anne; Boi, Michela; Landra, Indira; Machiorlatti, Rodolfo; Tabbo’, Fabrizio; Messana, Katia; Barreca, Antonella; Novero, Domenico; Gaudiano, Marcello; Aliberti, Sabrina; Di Giacomo, Filomena; Tousseyn, Thomas; Lasorsa, Elena; Crescenzo, Ramona; Bessone, Luca; Ficarra, Elisa; Acquaviva, Andrea; Rinaldi, Andrea; Ponzoni, Maurilio; Longo, Dario Livio; Aime, Silvio; Cheng, Mangeng; Ruggeri, Bruce; Piccaluga, Pier Paolo; Pileri, Stefano; Tiacci, Enrico; Falini, Brunangelo; Pera-Gresely, Benet; Cerchietti, Leandro; Iqbal, Javeed; Chan, Wing C; Shultz, Leonard D.; Kwee, Ivo; Piva, Roberto; Wlodarska, Iwona; Rabadan, Raul; Bertoni, Francesco; Inghirami, Giorgio

    2016-01-01

    Although Anaplastic Large Cell Lymphomas (ALCL) carrying Anaplastic Lymphoma Kinase (ALK) have a relatively good prognosis, aggressive forms exist. We have identified a novel translocation, causing the fusion of the TRAF1 and ALK genes, in one patient who presented with a leukemic ALK+ ALCL (ALCL-11). To uncover the mechanisms leading to high-grade ALCL, we developed a human Patient Derived Tumorgraft (hPDT) line. Molecular characterization of primary and PDT cells demonstrated the activation of ALK and of NFkB pathways. Genomic studies of ALCL-11 showed the TP53 loss and the in vivo subclonal expansion of lymphoma cells lacking PRDM1/Blimp-1 and with c-MYC gene amplification. The treatment with proteasome inhibitors of TRAF1-ALK cells led to down-regulation of p50/p52 and lymphoma growth inhibition. Moreover a NFkB gene set classifier stratified ALCL in distinct subsets with different clinical outcome. Moreover, a selective ALK inhibitor (CEP28122) resulted in a significant clinical response of hPDT mice, but the disease could not be eradicated. These data indicate that the activation of NFkB signaling contributes to the neoplastic phenotype of TRAF1-ALK ALCL. ALCL hPDTs are invaluable to validate the role of druggable molecules, predict therapeutic responses and are helpful tools for the implementation of patient specific therapies. PMID:25533804

  15. Critical role of the SPAK protein kinase CCT domain in controlling blood pressure

    PubMed Central

    Zhang, Jinwei; Siew, Keith; Macartney, Thomas; O'Shaughnessy, Kevin M.; Alessi, Dario R.

    2015-01-01

    The STE20/SPS1-related proline/alanine-rich kinase (SPAK) controls blood pressure (BP) by phosphorylating and stimulating the Na-Cl (NCC) and Na-K-2Cl (NKCC2) co-transporters, which regulate salt reabsorption in the kidney. SPAK possesses a conserved carboxy-terminal (CCT) domain, which recognises RFXV/I motifs present in its upstream activator [isoforms of the With-No-lysine (K) kinases (WNKs)] as well as its substrates (NCC and NKCC2). To define the physiological importance of the CCT domain, we generated knock-in mice in which the critical CCT domain Leu502 residue required for high affinity recognition of the RFXI/V motif was mutated to Alanine. The SPAK CCT domain defective knock-in animals are viable, and the Leu502Ala mutation abolished co-immunoprecipitation of SPAK with WNK1, NCC and NKCC2. The CCT domain defective animals displayed markedly reduced SPAK activity and phosphorylation of NCC and NKCC2 co-transporters at the residues phosphorylated by SPAK. This was also accompanied by a reduction in the expression of NCC and NKCC2 protein without changes in mRNA levels. The SPAK CCT domain knock-in mice showed typical features of Gitelman Syndrome with mild hypokalaemia, hypomagnesaemia, hypocalciuria and displayed salt wasting on switching to a low-Na diet. These observations establish that the CCT domain plays a crucial role in controlling SPAK activity and BP. Our results indicate that CCT domain inhibitors would be effective at reducing BP by lowering phosphorylation as well as expression of NCC and NKCC2. PMID:25994507

  16. Putting a bit into the polo-box domain of polo-like kinase 1.

    PubMed

    Park, Jung-Eun; Kim, Tae-Sung; Meng, Lingjun; Bang, Jeong K; Kim, Bo Y; Lee, Kyung S

    Polo-like kinase 1 (Plk1) plays key roles in regulating various mitotic processes that are critical for cellular proliferation. A growing body of evidence suggests that Plk1 overexpression is tightly associated with the development of human cancers. Interestingly, various types of cancer cells are shown to be addicted to a high level of Plk1, and the reversal of Plk1 addiction appears to be an effective strategy for selectively killing cancer cells, but not normal cells. Therefore, Plk1 is considered an attractive anticancer drug target. Over the years, a large number of inhibitors that target the catalytic activity of Plk1 have been developed. However, these inhibitors exhibit significant levels of cross-reactivity with related kinases, including Plk2 and Plk3. Consequently, as an alternative approach for developing anti-Plk1 therapeutics, substantial effort is under way to develop inhibitors that target the C-terminal protein-protein interaction domain of Plk1, called the polo-box domain (PBD). In this communication, I will discuss the pros and cons of targeting the PBD in comparison to those of targeting the ATP-binding site within the kinase domain.

  17. Crystal structure of the polo-box domain of polo-like kinase 2.

    PubMed

    Shan, Hong-Mei; Wang, Tao; Quan, Jun-Min

    2015-01-16

    Polo-like kinase 2 (PLK2) is a crucial regulator in cell cycle progression, DNA damage response, and neuronal activity. PLK2 is characterized by the conserved N-terminal kinase domain and the unique C-terminal polo-box domain (PBD). The PBD mediates diverse functions of PLK2 by binding phosphorylated Ser-pSer/pThr motifs of its substrates. Here, we report the first crystal structure of the PBD of PLK2. The overall structure of the PLK2 PBD is similar to that of the PLK1 PBD, which is composed by two polo boxes each contain β6α structures that form a 12-stranded β sandwich domain. The edge of the interface between the two polo boxes forms the phosphorylated Ser-pSer/pThr motifs binding cleft. On the hand, the peripheral regions around the core binding cleft of the PLK2 PBD is distinct from that of the PLK1 PBD, which might confer the substrate specificity of the PBDs of the polo-like kinase family.

  18. Real-time genomic profiling of histiocytoses identifies early-kinase domain BRAF alterations while improving treatment outcomes.

    PubMed

    Lee, Lynn H; Gasilina, Anjelika; Roychoudhury, Jayeeta; Clark, Jason; McCormack, Francis X; Pressey, Joseph; Grimley, Michael S; Lorsbach, Robert; Ali, Siraj; Bailey, Mark; Stephens, Philip; Ross, Jeffrey S; Miller, Vincent A; Nassar, Nicolas N; Kumar, Ashish R

    2017-02-09

    Many patients with histiocytic disorders such as Langerhans cell histiocytosis (LCH) or Erdheim-Chester disease (ECD) have treatment-refractory disease or suffer recurrences. Recent findings of gene mutations in histiocytoses have generated options for targeted therapies. We sought to determine the utility of prospective sequencing of select genes to further characterize mutations and identify targeted therapies for patients with histiocytoses. Biopsies of 72 patients with a variety of histiocytoses underwent comprehensive genomic profiling with targeted DNA and RNA sequencing. Fifteen patients (21%) carried the known BRAF V600E mutation, and 11 patients (15%) carried various mutations in MAP2K1, which we confirm induce constitutive activation of extracellular signal-regulated kinase (ERK) and were sensitive to inhibitors of mitogen-activated protein kinase kinase (MEK, the product of MAP2K1). We also identified recurring ALK rearrangements, and 4 LCH patients with an uncommon in-frame deletion in BRAF (N486_P490del or N486_T491>K), resulting in constitutive activation of ERK with resistance to V600E-specific inhibitors. We subsequently describe clinical cases where patients with aggressive multisystem LCH experience dramatic and sustained responses to monotherapy with either dabrafenib or trametinib. These findings support our conclusion that comprehensive genomic profiling should be regularly applied to these disorders at diagnosis, and can positively impact clinical care.

  19. Real-time genomic profiling of histiocytoses identifies early-kinase domain BRAF alterations while improving treatment outcomes

    PubMed Central

    Lee, Lynn H.; Gasilina, Anjelika; Roychoudhury, Jayeeta; McCormack, Francis X.; Pressey, Joseph; Lorsbach, Robert; Ali, Siraj; Bailey, Mark; Stephens, Philip; Ross, Jeffrey S.; Miller, Vincent A.; Nassar, Nicolas N.; Kumar, Ashish R.

    2017-01-01

    Many patients with histiocytic disorders such as Langerhans cell histiocytosis (LCH) or Erdheim-Chester disease (ECD) have treatment-refractory disease or suffer recurrences. Recent findings of gene mutations in histiocytoses have generated options for targeted therapies. We sought to determine the utility of prospective sequencing of select genes to further characterize mutations and identify targeted therapies for patients with histiocytoses. Biopsies of 72 patients with a variety of histiocytoses underwent comprehensive genomic profiling with targeted DNA and RNA sequencing. Fifteen patients (21%) carried the known BRAF V600E mutation, and 11 patients (15%) carried various mutations in MAP2K1, which we confirm induce constitutive activation of extracellular signal–regulated kinase (ERK) and were sensitive to inhibitors of mitogen-activated protein kinase kinase (MEK, the product of MAP2K1). We also identified recurring ALK rearrangements, and 4 LCH patients with an uncommon in-frame deletion in BRAF (N486_P490del or N486_T491>K), resulting in constitutive activation of ERK with resistance to V600E-specific inhibitors. We subsequently describe clinical cases where patients with aggressive multisystem LCH experience dramatic and sustained responses to monotherapy with either dabrafenib or trametinib. These findings support our conclusion that comprehensive genomic profiling should be regularly applied to these disorders at diagnosis, and can positively impact clinical care. PMID:28194436

  20. Activation of G Protein-Coupled Receptor Kinase 1 Involves Interactions between Its N-Terminal Region and Its Kinase Domain

    SciTech Connect

    Huang, Chih-chin; Orban, Tivadar; Jastrzebska, Beata; Palczewski, Krzysztof; Tesmer, John J.G.

    2012-03-16

    G protein-coupled receptor kinases (GRKs) phosphorylate activated G protein-coupled receptors (GPCRs) to initiate receptor desensitization. In addition to the canonical phosphoacceptor site of the kinase domain, activated receptors bind to a distinct docking site that confers higher affinity and activates GRKs allosterically. Recent mutagenesis and structural studies support a model in which receptor docking activates a GRK by stabilizing the interaction of its 20-amino acid N-terminal region with the kinase domain. This interaction in turn stabilizes a closed, more active conformation of the enzyme. To investigate the importance of this interaction for the process of GRK activation, we first validated the functionality of the N-terminal region in rhodopsin kinase (GRK1) by site-directed mutagenesis and then introduced a disulfide bond to cross-link the N-terminal region of GRK1 with its specific binding site on the kinase domain. Characterization of the kinetic and biophysical properties of the cross-linked protein showed that disulfide bond formation greatly enhances the catalytic efficiency of the peptide phosphorylation, but receptor-dependent phosphorylation, Meta II stabilization, and inhibition of transducin activation were unaffected. These data indicate that the interaction of the N-terminal region with the kinase domain is important for GRK activation but does not dictate the affinity of GRKs for activated receptors.

  1. Evaluation of the kinase domain of c-KIT in canine cutaneous mast cell tumors

    PubMed Central

    Webster, Joshua D; Kiupel, Matti; Yuzbasiyan-Gurkan, Vilma

    2006-01-01

    Background Mutations in the c-KIT proto-oncogene have been implicated in the progression of several neoplastic diseases, including gastrointestinal stromal tumors and mastocytosis in humans, and cutaneous mast cell tumors (MCTs) in canines. Mutations in human mastocytosis patients primarily occur in c-KIT exon 17, which encodes a portion of its kinase domain. In contrast, deletions and internal tandem duplication (ITD) mutations are found in the juxtamembrane domain of c-KIT in approximately 15% of canine MCTs. In addition, ITD c-KIT mutations are significantly associated with aberrant KIT protein localization in canine MCTs. However, some canine MCTs have aberrant KIT localization but lack ITD c-KIT mutations, suggesting that other mutations or other factors may be responsible for aberrant KIT localization in these tumors. Methods In order to characterize the prevalence of mutations in the phospho-transferase portion of c-KIT's kinase domain in canine MCTs exons 16–20 of 33 canine MCTs from 33 dogs were amplified and sequenced. Additionally, in order to determine if mutations in c-KIT exon 17 are responsible for aberrant KIT localization in MCTs that lack juxtamembrane domain c-KIT mutations, c-KIT exon 17 was amplified and sequenced from 18 canine MCTs that showed an aberrant KIT localization pattern but did not have ITD c-KIT mutations. Results No mutations or polymorphisms were identified in exons 16–20 of any of the MCTs examined. Conclusion In conclusion, mutations in the phospho-transferase portion of c-KIT's kinase domain do not play an important role in the progression of canine cutaneous MCTs, or in the aberrant localization of KIT in canine MCTs. PMID:16579858

  2. Novel ALK fusion partners in lung cancer.

    PubMed

    Iyevleva, Aglaya G; Raskin, Grigory A; Tiurin, Vladislav I; Sokolenko, Anna P; Mitiushkina, Natalia V; Aleksakhina, Svetlana N; Garifullina, Aigul R; Strelkova, Tatiana N; Merkulov, Valery O; Ivantsov, Alexandr O; Kuligina, Ekatherina Sh; Pozharisski, Kazimir M; Togo, Alexandr V; Imyanitov, Evgeny N

    2015-06-28

    Detection of ALK rearrangements in patients with non-small cell lung cancer (NSCLC) presents a significant technical challenge due to the existence of multiple translocation partners and break-points. To improve the performance of PCR-based tests, we utilized the combination of 2 assays, i.e. the variant-specific PCR for the 5 most common ALK rearrangements and the test for unbalanced 5'/3'-end ALK expression. Overall, convincing evidence for the presence of ALK translocation was obtained for 34/400 (8.5%) cases, including 14 EML4ex13/ALKex20, 12 EML4ex6/ALKex20, 3 EML4ex18/ALKex20, 2 EML4ex20/ALKex20 variants and 3 tumors with novel translocation partners. 386 (96.5%) out of 400 EGFR mutation-negative NSCLCs were concordant for both tests, being either positive (n = 26) or negative (n = 360) for ALK translocation; 49 of these samples (6 ALK+, 43 ALK-) were further evaluated by FISH, and there were no instances of disagreement. Among the 14 (3.5%) "discordant" tumors, 5 demonstrated ALK translocation by the first but not by the second PCR assay, and 9 had unbalanced ALK expression in the absence of known ALK fusion variants. 5 samples from the latter group were subjected to FISH, and the presence of translocation was confirmed in 2 cases. Next generation sequencing analysis of these 2 samples identified novel translocation partners, DCTN1 and SQSTM1; furthermore, the DCTN1/ALK fusion was also found in another NSCLC sample with unbalanced 5'/3'-end ALK expression, indicating a recurrent nature of this translocation. We conclude that the combination of 2 different PCR tests is a viable approach for the diagnostics of ALK rearrangements. Systematic typing of ALK fusions is likely to reveal new NSCLC-specific ALK partners.

  3. Structure of the GH1 domain of guanylate kinase-associated protein from Rattus norvegicus

    SciTech Connect

    Tong, Junsen; Yang, Huiseon; Eom, Soo Hyun; Chun, ChangJu; Im, Young Jun

    2014-09-12

    Graphical abstract: - Highlights: • The crystal structure of GKAP homology domain 1 (GH1) was determined. • GKAP GH1 is a three-helix bundle connected by short flexible loops. • The predicted helix α4 associates weakly with the helix α3, suggesting dynamic nature of the GH1 domain. - Abstract: Guanylate-kinase-associated protein (GKAP) is a scaffolding protein that links NMDA receptor-PSD-95 to Shank–Homer complexes by protein–protein interactions at the synaptic junction. GKAP family proteins are characterized by the presence of a C-terminal conserved GKAP homology domain 1 (GH1) of unknown structure and function. In this study, crystal structure of the GH1 domain of GKAP from Rattus norvegicus was determined in fusion with an N-terminal maltose-binding protein at 2.0 Å resolution. The structure of GKAP GH1 displays a three-helix bundle connected by short flexible loops. The predicted helix α4 which was not visible in the crystal structure associates weakly with the helix α3 suggesting dynamic nature of the GH1 domain. The strict conservation of GH1 domain across GKAP family members and the lack of a catalytic active site required for enzyme activity imply that the GH1 domain might serve as a protein–protein interaction module for the synaptic protein clustering.

  4. Structure of the catalytic domain of human polo-like kinase 1.

    PubMed

    Kothe, Michael; Kohls, Darcy; Low, Simon; Coli, Rocco; Cheng, Alan C; Jacques, Suzanne L; Johnson, Theresa L; Lewis, Cristina; Loh, Christine; Nonomiya, Jim; Sheils, Alissa L; Verdries, Kimberly A; Wynn, Thomas A; Kuhn, Cyrille; Ding, Yuan-Hua

    2007-05-22

    Polo-like kinase 1 (Plk1) is an attractive target for the development of anticancer agents due to its importance in regulating cell-cycle progression. Overexpression of Plk1 has been detected in a variety of cancers, and expression levels often correlate with poor prognosis. Despite high interest in Plk1-targeted therapeutics, there is currently no structure publicly available to guide structure-based drug design of specific inhibitors. We determined the crystal structures of the T210V mutant of the kinase domain of human Plk1 complexed with the nonhydrolyzable ATP analogue adenylylimidodiphosphate (AMPPNP) or the pyrrolo-pyrazole inhibitor PHA-680626 at 2.4 and 2.1 A resolution, respectively. Plk1 adopts the typical kinase domain fold and crystallized in a conformation resembling the active state of other kinases. Comparison of the kinetic parameters determined for the (unphosphorylated) wild-type enzyme, as well as the T210V and T210D mutants, shows that the mutations primarily affect the kcat of the reaction, with little change in the apparent Km for the protein or nucleotide substrates (kcat = 0.0094, 0.0376, and 0.0049 s-1 and Km(ATP) = 3.2, 4.0, and 3.0 microM for WT, T210D, and T210V, respectively). The structure highlights features of the active site that can be exploited to obtain Plk1-specific inhibitors with selectivity over other kinases and Plk isoforms. These include the presence of a phenylalanine at the bottom of the ATP pocket, combined with a cysteine (as opposed to the more commonly found leucine) in the roof of the binding site, a pocket created by Leu132 in the hinge region, and a cluster of positively charged residues in the solvent-exposed area outside of the adenine pocket adjacent to the hinge region.

  5. Novel Kinase Inhibitors Targeting the PH Domain of AKT for Preventing and Treating Cancer | NCI Technology Transfer Center | TTC

    Cancer.gov

    The National Cancer Institute's Medical Oncology Branch is seeking statements of capability or interest from parties interested in licensing and co-development collaborative research to further develop, evaluate, or commercialize novel kinase inhibitors targeting the PH domain of AKT.

  6. Three Years Sustained Complete Remission Achieved in a Primary Refractory ALK-Positive Anaplastic T Large Cell Lymphoma Treated with Crizotinib

    PubMed Central

    Mahuad, Carolina Valeria; Repáraz, María de los Ángeles Vicente; Zerga, Marta E.; Aizpurua, María Florencia; Casali, Claudia; Garate, Gonzalo

    2016-01-01

    The prognosis of the primary refractory anaplastic lymphoma kinase (ALK+) anaplastic T large cell lymphoma is ominous. The identification of molecular targets with potential to drive oncogenesis remains a cornerstone for the designing of new selective cancer therapies. Crizotinib is a selective ATP-competitive inhibitor for ALK, approved for its use in lung cancer with rearrangements on ALK gene. The reported cases describe the use of crizotinib as a bridging strategy prior to allotransplantation; there are no reported prolonged survivals under monotherapy with Crizotinib. We report a case of a primary refractory ALK+ anaplastic large-cell lymphoma that sustains complete response after 3 years of crizotinib monotherapy. PMID:27441079

  7. Sensing Domain Dynamics in Protein Kinase A-Iα Complexes by Solution X-ray Scattering*

    PubMed Central

    Cheng, Cecilia Y.; Yang, Jie; Taylor, Susan S.; Blumenthal, Donald K.

    2009-01-01

    The catalytic (C) and regulatory (R) subunits of protein kinase A are exceptionally dynamic proteins. Interactions between the R- and C-subunits are regulated by cAMP binding to the two cyclic nucleotide-binding domains in the R-subunit. Mammalian cells express four different isoforms of the R-subunit (RIα, RIβ, RIIα, and RIIβ) that all interact with the C-subunit in different ways. Here, we investigate the dynamic behavior of protein complexes between RIα and C-subunits using small angle x-ray scattering. We show that a single point mutation in RIα, R333K (which alters the cAMP-binding properties of Domain B) results in a compact shape compared with the extended shape of the wild-type R·C complex. A double mutant complex that disrupts the interaction site between the C-subunit and Domain B in RIα, RIαABR333K·C(K285P), results in a broader P(r) curve that more closely resembles the P(r) profiles of wild-type complexes. These results together suggest that interactions between RIα Domain B and the C-subunit in the RIα·C complex involve large scale dynamics that can be disrupted by single point mutations in both proteins. In contrast to RIα·C complexes. Domain B in the RIIβ·C heterodimer is not dynamic and is critical for both inhibition and complex formation. Our study highlights the functional differences of domain dynamics between protein kinase A isoforms, providing a framework for elucidating the global organization of each holoenzyme and the cross-talk between the R- and C-subunits. PMID:19837668

  8. Evaluation of EML4-ALK Fusion Proteins in Non-Small Cell Lung Cancer Using Small Molecule Inhibitors12

    PubMed Central

    Li, Yongjun; Ye, Xiaofen; Liu, Jinfeng; Zha, Jiping; Pei, Lin

    2011-01-01

    The echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) fusion gene resulting from an inversion within chromosome 2p occurs in approximately 5% of non-small cell lung cancer and is mutually exclusive with Ras and EGFR mutations. In this study, we have used a potent and selective ALK small molecule inhibitor, NPV-TAE684, to assess the oncogenic role of EML4-ALK in non-small cell lung cancer (NSCLC). We show here that TAE684 inhibits proliferation and induces cell cycle arrest, apoptosis, and tumor regression in two NSCLC models that harbor EML4-ALK fusions. TAE684 inhibits EML4-ALK activation and its downstream signaling including ERK, AKT, and STAT3. We used microarray analysis to carry out targeted pathway studies of gene expression changes in H2228 NSCLC xenograft model after TAE684 treatment and identified a gene signature of EML4-ALK inhibition. The gene signature represents 1210 known human genes, and the top biologic processes represented by these genes are cell cycle, DNA synthesis, cell proliferation, and cell death. We also compared the effect of TAE684 with PF2341066, a c-Met and ALK small molecule inhibitor currently in clinical trial in cancers harboring ALK fusions, and demonstrated that TAE684 is a much more potent inhibitor of EML4-ALK. Our data demonstrate that EML4-ALK plays an important role in the pathogenesis of a subset of NSCLC and provides insight into the mechanism of EML4-ALK inhibition by a small molecule inhibitor. PMID:21245935

  9. The JIL-1 Kinase Affects Telomere Expression in the Different Telomere Domains of Drosophila

    PubMed Central

    Silva-Sousa, Rute; Casacuberta, Elena

    2013-01-01

    In Drosophila, the non-LTR retrotransposons HeT-A, TART and TAHRE build a head-to-tail array of repetitions that constitute the telomere domain by targeted transposition at the end of the chromosome whenever needed. As a consequence, Drosophila telomeres have the peculiarity to harbor the genes in charge of telomere elongation. Understanding telomere expression is important in Drosophila since telomere homeostasis depends in part on the expression of this genomic compartment. We have recently shown that the essential kinase JIL-1 is the first positive regulator of the telomere retrotransposons. JIL-1 mediates chromatin changes at the promoter of the HeT-A retrotransposon that are necessary to obtain wild type levels of expression of these telomere transposons. With the present study, we show how JIL-1 is also needed for the expression of a reporter gene embedded in the telomere domain. Our analysis, using different reporter lines from the telomere and subtelomere domains of different chromosomes, indicates that JIL-1 likely acts protecting the telomere domain from the spreading of repressive chromatin from the adjacent subtelomere domain. Moreover, the analysis of the 4R telomere suggests a slightly different chromatin structure at this telomere. In summary, our results strongly suggest that the action of JIL-1 depends on which telomere domain, which chromosome and which promoter is embedded in the telomere chromatin. PMID:24244743

  10. HAMP Domain Rotation and Tilting Movements Associated with Signal Transduction in the PhoQ Sensor Kinase

    PubMed Central

    Matamouros, Susana; Hager, Kyle R.

    2015-01-01

    ABSTRACT HAMP domains are α-helical coiled coils that often transduce signals from extracytoplasmic sensing domains to cytoplasmic domains. Limited structural information has resulted in hypotheses that specific HAMP helix movement changes downstream enzymatic activity. These hypotheses were tested by mutagenesis and cysteine cross-linking analysis of the PhoQ histidine kinase, essential for resistance to antimicrobial peptides in a variety of enteric pathogens. These results support a mechanistic model in which periplasmic signals which induce an activation state generate a rotational movement accompanied by a tilt in α-helix 1 which activates kinase activity. Biochemical data and a high-confidence model of the PhoQ cytoplasmic domain indicate a possible physical interaction of the HAMP domain with the catalytic domain as necessary for kinase repression. These results support a model of PhoQ activation in which changes in the periplasmic domain lead to conformational movements in the HAMP domain helices which disrupt interaction between the HAMP and the catalytic domains, thus promoting increased kinase activity. PMID:26015499

  11. ALK Signaling and Target Therapy in Anaplastic Large Cell Lymphoma

    PubMed Central

    Tabbó, Fabrizio; Barreca, Antonella; Piva, Roberto; Inghirami, Giorgio

    2012-01-01

    The discovery by Morris et al. (1994) of the genes contributing to the t(2;5)(p23;q35) translocation has laid the foundation for a molecular based recognition of anaplastic large cell lymphoma and highlighted the need for a further stratification of T-cell neoplasia. Likewise the detection of anaplastic lymphoma kinase (ALK) genetic lesions among many human cancers has defined unique subsets of cancer patients, providing new opportunities for innovative therapeutic interventions. The objective of this review is to appraise the molecular mechanisms driving ALK-mediated transformation, and to maintain the neoplastic phenotype. The understanding of these events will allow the design and implementation of novel tailored strategies for a well-defined subset of cancer patients. PMID:22649787

  12. Structural Analysis of Sensor Domains from the TMAO-Responsive Histidine Kinase Receptor TorS.

    SciTech Connect

    Moore, J.; Hendrickson, W

    2009-01-01

    Histidine kinase receptors respond to diverse signals and mediate signal transduction across the plasma membrane in all prokaryotes and certain eukaryotes. Each receptor is part of a two-component system that regulates a particular cellular process. Organisms that use trimethylamine-N-oxide (TMAO) as a terminal electron acceptor typically control their anaerobic respiration through the TMAO reductase (Tor) pathway, which the TorS histidine kinase activates when sensing TMAO in the environment. We have determined crystal structures for the periplasmic sensor domains of TorS receptors from Escherichia coli and Vibrio parahaemolyticus. TorS sensor domains have a novel fold consisting of a membrane-proximal right-handed four-helical bundle and a membrane-distal left-handed four-helical bundle, but conformational dispositions differ significantly in the two structures. Isolated TorS sensor domains dimerize in solution; and from comparisons with dimeric NarX and Tar sensors, we postulate that signaling through TorS dimers involves a piston-type displacement between helices.

  13. Evolution of S-domain receptor-like kinases in land plants and origination of S-locus receptor kinases in Brassicaceae

    PubMed Central

    2013-01-01

    Background The S-domain serine/threonine receptor-like kinases (SRLKs) comprise one of the largest and most rapidly expanding subfamilies in the plant receptor-like/Pelle kinase (RLKs) family. The founding member of this subfamily, the S-locus receptor kinase (SRK), functions as the female determinant of specificity in the self-incompatibility (SI) responses of crucifers. Two classes of proteins resembling the extracellular S domain (designated S-domain receptor-like proteins, SRLPs) or the intracellular kinase domain (designated S-domain receptor-like cytoplasmic kinases, SRLCKs) of SRK are also ubiquitous in land plants, indicating that the SRLKs are composite molecules that originated by domain fusion of the two component proteins. Here, we explored the origin and diversification of SRLKs by phylogenomic methods. Results Based on the distribution patterns of SRLKs and SRLCKs in a reconciled species-domain tree, a maximum parsimony model was then established for simultaneously inferring and dating gene duplication/loss and fusion /fission events in SRLK evolution. Various SRK alleles from crucifer species were then included in our phylogenetic analyses to infer the origination of SRKs by identifying the proper outgroups. Conclusions Two gene fusion events were inferred and the major gene fusion event occurred in the common ancestor of land plants generated almost all of extant SRLKs. The functional diversification of duplicated SRLKs was illustrated by molecular evolution analyses of SRKs. Our findings support that SRKs originated as two ancient haplotypes derived from a pair of tandem duplicate genes through random regulatory neo-/sub- functionalization in the common ancestor of the Brassicaceae. PMID:23510165

  14. Binding partners of the kinase domains in Drosophila obscurin and their effect on the structure of the flight muscle.

    PubMed

    Katzemich, Anja; West, Ryan J H; Fukuzawa, Atsushi; Sweeney, Sean T; Gautel, Mathias; Sparrow, John; Bullard, Belinda

    2015-09-15

    Drosophila obscurin (Unc-89) is a titin-like protein in the M-line of the muscle sarcomere. Obscurin has two kinase domains near the C-terminus, both of which are predicted to be inactive. We have identified proteins binding to the kinase domains. Kinase domain 1 bound Bällchen (Ball, an active kinase), and both kinase domains 1 and 2 bound MASK (a 400-kDa protein with ankyrin repeats). Ball was present in the Z-disc and M-line of the indirect flight muscle (IFM) and was diffusely distributed in the sarcomere. MASK was present in both the M-line and the Z-disc. Reducing expression of Ball or MASK by siRNA resulted in abnormalities in the IFM, including missing M-lines and multiple Z-discs. Obscurin was still present, suggesting that the kinase domains act as a scaffold binding Ball and MASK. Unlike obscurin in vertebrate skeletal muscle, Drosophila obscurin is necessary for the correct assembly of the IFM sarcomere. We show that Ball and MASK act downstream of obscurin, and both are needed for development of a well defined M-line and Z-disc. The proteins have not previously been identified in Drosophila muscle.

  15. Definition of the interferon-alpha receptor-binding domain on the TYK2 kinase.

    PubMed

    Yan, H; Piazza, F; Krishnan, K; Pine, R; Krolewski, J J

    1998-02-13

    Interferons and cytokines modulate gene expression via a simple, direct signaling pathway containing receptors, JAK tyrosine kinases, and STAT transcription factors. The interferon-alpha pathway is a model for these cascades. Two receptors, IFNaR1 and IFNaR2, associate exclusively in a constitutive manner with two JAK proteins, TYK2 and JAK1, respectively. Defining the molecular interface between JAK proteins and their receptors is critical to understanding the signaling pathway and may contribute to the development of novel therapeutics. This report defines the IFNaR1 interaction domain on TYK2. In vitro binding studies demonstrate that the amino-terminal half of TYK2, which is approximately 600 amino acids long and contains JAK homology (JH) domains 3-7, comprises the maximal binding domain for IFNaR1. A fragment containing amino acids 171-601 (JH3-6) also binds IFNaR1, but with reduced affinity. Glutathione S-transferase-TYK2 fusion proteins approximating either the JH6 or JH3 domain affinity-precipitate IFNaR1, suggesting that these are major sites of interaction within the larger binding domain. TYK2 amino acids 1-601 act in a dominant manner to inhibit the transcription of an interferon-alpha-dependent reporter gene, presumably by displacing endogenous TYK2 from the receptor. This same fragment inhibits interferon-alpha-dependent tyrosine phosphorylation of TYK2, STAT1, and STAT2.

  16. Novel mutation in the tyrosine kinase domain of FGFR2 in a patient with Pfeiffer syndrome.

    PubMed

    Zankl, Andreas; Jaeger, Gudrun; Bonafé, Luisa; Boltshauser, Eugen; Superti-Furga, Andrea

    2004-12-15

    Mutations in the fibroblast growth factor receptor 2 (FGFR2) cause a variety of craniosynostosis syndromes. The mutational spectrum tends to be narrow with the majority of mutations occurring in either exon IIIa or IIIc or in the intronic sequence preceding exon IIIc. Mutations outside of this hotspot are uncommon and the few identified mutations have demonstrated wide clinical variability, making it difficult to establish a clear-cut genotype-phenotype correlation. To better delineate the clinical picture associated with these unusual mutations, we describe a severely affected patient with Pfeiffer syndrome and a missense mutation in the tyrosine kinase (TK) domain of FGFR2.

  17. Two Polo-like kinase 4 binding domains in Asterless perform distinct roles in regulating kinase stability

    PubMed Central

    Klebba, Joseph E.; Galletta, Brian J.; Nye, Jonathan; Plevock, Karen M.; Buster, Daniel W.; Hollingsworth, Natalie A.; Slep, Kevin C.

    2015-01-01

    Plk4 (Polo-like kinase 4) and its binding partner Asterless (Asl) are essential, conserved centriole assembly factors that induce centriole amplification when overexpressed. Previous studies found that Asl acts as a scaffolding protein; its N terminus binds Plk4’s tandem Polo box cassette (PB1-PB2) and targets Plk4 to centrioles to initiate centriole duplication. However, how Asl overexpression drives centriole amplification is unknown. In this paper, we investigated the Asl–Plk4 interaction in Drosophila melanogaster cells. Surprisingly, the N-terminal region of Asl is not required for centriole duplication, but a previously unidentified Plk4-binding domain in the C terminus is required. Mechanistic analyses of the different Asl regions revealed that they act uniquely during the cell cycle: the Asl N terminus promotes Plk4 homodimerization and autophosphorylation during interphase, whereas the Asl C terminus stabilizes Plk4 during mitosis. Therefore, Asl affects Plk4 in multiple ways to regulate centriole duplication. Asl not only targets Plk4 to centrioles but also modulates Plk4 stability and activity, explaining the ability of overexpressed Asl to drive centriole amplification. PMID:25688134

  18. Comparison and correlation of binding mode of ATP in the kinase domains of Hexokinase family

    PubMed Central

    Kumar, Yellapu Nanda; Kumar, Pasupuleti Santhosh; Sowjenya, Gopal; Rao, Valasani Koteswara; Yeswanth, Sthanikam; Prasad, Uppu Venkateswara; Pradeepkiran, Jangampalli Adi; Sarma, PVGK; Bhaskar, Matcha

    2012-01-01

    Hexokinases (HKs) are the enzymes that catalyses the ATP dependent phosphorylation of Hexose sugars to Hexose-6-Phosphate (Hex-6-P). There exist four different forms of HKs namely HK-I, HK-II, HK-III and HK-IV and all of them share a common ATP binding site core surrounded by more variable sequence that determine substrate affinities. Although they share a common binding site but they differ in their kinetic functions, hence the present study is aimed to analyze the binding mode of ATP. The analysis revealed that the four ATP binding domains are showing 13 identical, 7 similar and 6 dissimilar residues with similar structural conformation. Molecular docking of ATP into the kinase domains using Molecular Operating Environment (MOE) soft ware tool clearly showed the variation in the binding mode of ATP with variable docking scores. This probably explains the variable phosphorylation rates among hexokinases family. PMID:22829728

  19. ALK1 heterozygosity increases extracellular matrix protein expression, proliferation and migration in fibroblasts.

    PubMed

    Muñoz-Félix, José M; Perretta-Tejedor, Nuria; Eleno, Nélida; López-Novoa, José M; Martínez-Salgado, Carlos

    2014-06-01

    Fibrosis is a pathological situation in which excessive amounts of extracellular matrix (ECM) are deposited in the tissue. Myofibroblasts play a crucial role in the development and progress of fibrosis as they actively synthesize ECM components such as collagen I, fibronectin and connective tissue growth factor (CTGF) and cause organ fibrosis. Transforming growth factor beta 1 (TGF-β1) plays a major role in tissue fibrosis. Activin receptor-like kinase 1 (ALK1) is a type I receptor of TGF-β1 with an important role in angiogenesis whose function in cellular biology and TGF-β signaling is well known in endothelial cells, but its role in fibroblast biology and its contribution to fibrosis is poorly studied. We have recently demonstrated that ALK1 regulates ECM protein expression in a mouse model of obstructive nephropathy. Our aim was to evaluate the role of ALK1 in several processes involved in fibrosis such as ECM protein expression, proliferation and migration in ALK1(+/+) and ALK1(+/-) mouse embryonic fibroblasts (MEFs) after TGF-β1 stimulations and inhibitors. ALK1 heterozygous MEFs show increased expression of ECM proteins (collagen I, fibronectin and CTGF/CCN2), cell proliferation and migration due to an alteration of TGF-β/Smad signaling. ALK1 heterozygous disruption shows an increase of Smad2 and Smad3 phosphorylation that explains the increases in CTGF/CCN2, fibronectin and collagen I, proliferation and cell motility observed in these cells. Therefore, we suggest that ALK1 plays an important role in the regulation of ECM protein expression, proliferation and migration.

  20. Functional Analysis of the Cyclin-Dependent Kinase Inhibitor Pho81 Identifies a Novel Inhibitory Domain

    PubMed Central

    Huang, Sidong; Jeffery, Douglas A.; Anthony, Malcolm D.; O'Shea, Erin K.

    2001-01-01

    In response to phosphate limitation, Saccharomyces cerevisiae induces transcription of a set of genes important for survival. A phosphate-responsive signal transduction pathway mediates this response by controlling the activity of the transcription factor Pho4. Three components of this signal transduction pathway resemble those used to regulate the eukaryotic cell cycle: a cyclin-dependent kinase (CDK), Pho85; a cyclin, Pho80; and a CDK inhibitor (CKI), Pho81. Pho81 forms a stable complex with Pho80-Pho85 under both high- and low-phosphate conditions, but it only inhibits the kinase when cells are starved for phosphate. Pho81 contains six tandem repeats of the ankyrin consensus domain homologous to the INK4 family of mammalian CKIs. INK4 proteins inhibit kinase activity through an interaction of the ankyrin repeats and the CDK subunits. Surprisingly, we find that a region of Pho81 containing 80 amino acids C terminal to the ankyrin repeats is necessary and sufficient for Pho81's CKI function. The ankyrin repeats of Pho81 appear to have no significant role in Pho81 inhibition. Our results suggest that Pho81 inhibits Pho80-Pho85 with a novel motif. PMID:11533256

  1. Differential roles of the glycogen-binding domains of beta subunits in regulation of the Snf1 kinase complex.

    PubMed

    Mangat, Simmanjeet; Chandrashekarappa, Dakshayini; McCartney, Rhonda R; Elbing, Karin; Schmidt, Martin C

    2010-01-01

    Members of the AMP-activated protein kinase family, including the Snf1 kinase of Saccharomyces cerevisiae, are activated under conditions of nutrient stress. AMP-activated protein kinases are heterotrimeric complexes composed of a catalytic alpha subunit and regulatory beta and gamma subunits. In this study, the role of the beta subunits in the regulation of Snf1 activity was examined. Yeasts express three isoforms of the AMP-activated protein kinase consisting of Snf1 (alpha), Snf4 (gamma), and one of three alternative beta subunits, either Sip1, Sip2, or Gal83. The Gal83 isoform of the Snf1 complex is the most abundant and was analyzed in the greatest detail. All three beta subunits contain a conserved domain referred to as the glycogen-binding domain. The deletion of this domain from Gal83 results in a deregulation of the Snf1 kinase, as judged by a constitutive activity independent of glucose availability. In contrast, the deletion of this homologous domain from the Sip1 and Sip2 subunits had little effect on Snf1 kinase regulation. Therefore, the different Snf1 kinase isoforms are regulated through distinct mechanisms, which may contribute to their specialized roles in different stress response pathways. In addition, the beta subunits are subjected to phosphorylation. The responsible kinases were identified as being Snf1 and casein kinase II. The significance of the phosphorylation is unclear since the deletion of the region containing the phosphorylation sites in Gal83 had little effect on the regulation of Snf1 in response to glucose limitation.

  2. Differential Roles of the Glycogen-Binding Domains of β Subunits in Regulation of the Snf1 Kinase Complex▿

    PubMed Central

    Mangat, Simmanjeet; Chandrashekarappa, Dakshayini; McCartney, Rhonda R.; Elbing, Karin; Schmidt, Martin C.

    2010-01-01

    Members of the AMP-activated protein kinase family, including the Snf1 kinase of Saccharomyces cerevisiae, are activated under conditions of nutrient stress. AMP-activated protein kinases are heterotrimeric complexes composed of a catalytic α subunit and regulatory β and γ subunits. In this study, the role of the β subunits in the regulation of Snf1 activity was examined. Yeasts express three isoforms of the AMP-activated protein kinase consisting of Snf1 (α), Snf4 (γ), and one of three alternative β subunits, either Sip1, Sip2, or Gal83. The Gal83 isoform of the Snf1 complex is the most abundant and was analyzed in the greatest detail. All three β subunits contain a conserved domain referred to as the glycogen-binding domain. The deletion of this domain from Gal83 results in a deregulation of the Snf1 kinase, as judged by a constitutive activity independent of glucose availability. In contrast, the deletion of this homologous domain from the Sip1 and Sip2 subunits had little effect on Snf1 kinase regulation. Therefore, the different Snf1 kinase isoforms are regulated through distinct mechanisms, which may contribute to their specialized roles in different stress response pathways. In addition, the β subunits are subjected to phosphorylation. The responsible kinases were identified as being Snf1 and casein kinase II. The significance of the phosphorylation is unclear since the deletion of the region containing the phosphorylation sites in Gal83 had little effect on the regulation of Snf1 in response to glucose limitation. PMID:19897735

  3. Structural analysis of the polo-box domain of human Polo-like kinase 2.

    PubMed

    Kim, Ju Hee; Ku, Bonsu; Lee, Kyung S; Kim, Seung Jun

    2015-07-01

    Polo-like kinases (Plks) are the key regulators of cell cycle progression, the members of which share a kinase domain and a polo-box domain (PBD) that serves as a protein-binding module. While Plk1 is a promising target for antitumor therapy, Plk2 is regarded as a tumor suppressor even though the two Plks commonly recognize the S-pS/T-P motif through their PBD. Herein, we report the crystal structure of the PBD of Plk2 at 2.7 Å. Despite the overall structural similarity with that of Plk1 reflecting their high sequence homology, the crystal structure also contains its own features including the highly ordered loop connecting two subdomains and the absence of 310 -helices in the N-terminal region unlike the PBD of Plk1. Based on the three-dimensional structure, we furthermore could model its interaction with two types of phosphopeptides, one of which was previously screened as the optimal peptide for the PBD of Plk2.

  4. Fast kinase domain-containing protein 3 is a mitochondrial protein essential for cellular respiration

    SciTech Connect

    Simarro, Maria; Gimenez-Cassina, Alfredo; Kedersha, Nancy; Lazaro, Jean-Bernard; Adelmant, Guillaume O.; Marto, Jarrod A.; Rhee, Kirsten; Tisdale, Sarah; Danial, Nika; Benarafa, Charaf; Orduna, Anonio; Anderson, Paul

    2010-10-22

    Research highlights: {yields} Five members of the FAST kinase domain-containing proteins are localized to mitochondria in mammalian cells. {yields} The FASTKD3 interactome includes proteins involved in various aspects of mitochondrial metabolism. {yields} Targeted knockdown of FASTKD3 significantly reduces basal and maximal mitochondrial oxygen consumption. -- Abstract: Fas-activated serine/threonine phosphoprotein (FAST) is the founding member of the FAST kinase domain-containing protein (FASTKD) family that includes FASTKD1-5. FAST is a sensor of mitochondrial stress that modulates protein translation to promote the survival of cells exposed to adverse conditions. Mutations in FASTKD2 have been linked to a mitochondrial encephalomyopathy that is associated with reduced cytochrome c oxidase activity, an essential component of the mitochondrial electron transport chain. We have confirmed the mitochondrial localization of FASTKD2 and shown that all FASTKD family members are found in mitochondria. Although human and mouse FASTKD1-5 genes are expressed ubiquitously, some of them are most abundantly expressed in mitochondria-enriched tissues. We have found that RNA interference-mediated knockdown of FASTKD3 severely blunts basal and stress-induced mitochondrial oxygen consumption without disrupting the assembly of respiratory chain complexes. Tandem affinity purification reveals that FASTKD3 interacts with components of mitochondrial respiratory and translation machineries. Our results introduce FASTKD3 as an essential component of mitochondrial respiration that may modulate energy balance in cells exposed to adverse conditions by functionally coupling mitochondrial protein synthesis to respiration.

  5. Tyrosine kinase domain mutations of EGFR gene in head and neck squamous cell carcinoma

    PubMed Central

    Vatte, Chittibabu; Al Amri, Ali M; Cyrus, Cyril; Chathoth, Shahanas; Acharya, Sadananda; Hashim, Tariq Mohammad; Al Ali, Zhara; Alshreadah, Saleh Tawfeeq; Alsayyah, Ahmed; Al-Ali, Amein K

    2017-01-01

    Background Epidermal growth factor receptor (EGFR) is a commonly altered gene that is identified in various cancers, including head and neck squamous cell carcinoma (HNSCC). Therefore, EGFR is a promising molecular marker targeted by monoclonal antibodies and small molecule inhibitors targeting the tyrosine kinase (TK) domain. Objective The objective of this study was to investigate the spectrum of mutations in exons 18, 19, 20, and 21 of the EGFR gene in HNSCC patients. Materials and methods This retrospective study included 47 confirmed HNSCC cases. Mutations in the TK domain, exons 18, 19, 20, and 21 of the EGFR gene, were detected by Scorpion® chemistry and ARMS® technologies on Rotor-Gene Q real-time polymerase chain reaction. Results The tumors exhibited EGFR-TK domain mutations in 57% of cases. Four cases of T790M mutations were reported for the first time among HNSCC patients. Out of the total mutations, L861Q (exon 21), exon 20 insertions and deletions of exon 19 accounted for the majority of mutations (21%, 19%, and 17%, respectively). EGFR mutation status was correlated with the higher grade (P=0.026) and advanced stage (P=0.034) of HNSCC tumors. Conclusion Higher frequency of EGFR-TK domain mutations together with the presence of the T790M mutation suggests that identification of these mutations might streamline the therapy and provide a better prognosis in HNSCC cases. PMID:28352186

  6. Crystal Structure and Oligomeric State of the RetS Signaling Kinase Sensory Domain

    SciTech Connect

    Jing, X.; Jaw, J; Robinson, H; Schubot, F

    2010-01-01

    The opportunistic pathogen Pseudomonas aeruginosa may cause both acute and chronic-persistent infections in predisposed individuals. Acute infections require the presence of a functional type III secretion system (T3SS), whereas chronic P. aeruginosa infections are characterized by the formation of drug-resistant biofilms. The T3SS and biofilm formation are reciprocally regulated by the signaling kinases LadS, RetS, and GacS. RetS downregulates biofilm formation and upregulates expression of the T3SS through a unique mechanism. RetS forms a heterodimeric complex with GacS and thus prevents GacS autophosphorylation and downstream signaling. The signals that regulate RetS are not known but RetS possesses a distinctive periplasmic sensor domain that is believed to serve as receptor for the regulatory ligand. We have determined the crystal structure of the RetS sensory domain at 2.0 {angstrom} resolution. The structure closely resembles those of carbohydrate binding modules of other proteins, suggesting that the elusive ligands are likely carbohydrate moieties. In addition to the conserved beta-sandwich structure, the sensory domain features two alpha helices which create a unique surface topology. Protein-protein crosslinking and fluorescence energy transfer experiments also revealed that the sensory domain dimerizes with a dissociation constant of K{sub d} = 580 {+-} 50 nM, a result with interesting implications for our understanding of the underlying signaling mechanism.

  7. Concurrent EGFR Mutation and ALK Translocation in Non-Small Cell Lung Cancer

    PubMed Central

    Thomas, Sachdev; Bank, Bruce; Fishkin, Paul; Mooney, Colin; Salgia, Ravi

    2016-01-01

    Epidermal growth factor receptor (EGFR) mutations and anaplastic large-cell lymphoma kinase (ALK) rearrangements are now routine biomarkers that have been incorporated into the practice of managing non-small cell lung cancer (NSCLC). Historically, the two molecular alterations have been viewed as mutually exclusive, but recent identified cases suggest otherwise. In this report, we describe cases of lung cancer with concurrent EGFR mutation and ALK rearrangement and identify their clinical characteristics. Non-small cell lung cancer patients with multiple molecular alterations were retrospectively analyzed from an academic referral center from 2011–2013. An additional review was conducted of reported cases with dual alterations. Four cases of NSCLC with alterations in both EGFR and ALK were identified and evaluated with 16 published cases for a total of 20 cases. The age of patients ranged from 37 to 77 years. Nine patients were never smokers. The disease control rates in patients treated with EGFR inhibitors and ALK inhibitors were 46% (6/13) and 71% (5/7), respectively. This series highlights the importance of comprehensive molecular profiling of newly diagnosed lung cancer, as NSCLC may be driven by concurrent molecular alterations. EGFR- and ALK-targeted therapies appear to have modest activity in patients with tumors possessing both alterations. Dual-altered NSCLC patients may have distinct clinical characteristics warranting further study. Combination targeted therapy or novel multi-targeted tyrosine kinase inhibitors may prove important in these patients, though necessary studies remain ongoing. PMID:27026837

  8. Separate domains of the insulin receptor contain sites of autophosphorylation and tyrosine kinase activity

    SciTech Connect

    Goren, H.J.; White, M.F.; Khan, C.R.

    1987-04-21

    The authors have studied the structure and function of the solubilized insulin receptor before and after partial proteolytic digestion to define domains in the ..beta..-subunit that undergo autophosphorylation and contain the tyrosine kinase activity. Wheat germ agglutinin purified insulin receptor from Fao cells was digested briefly at 22/sup 0/C with low concentrations of trypsin, staphylococcal V8 protease, or elastase. Autophosphorylation of the ..beta..-subunit was carried out before and after digestion, and the (/sup 32/P)phosphoproteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, detected by autoradiography, and analyzed by tryptic peptide mapping by use of reverse-phase high-performance liquid chromatography. The 85-kDa fragment was not immunoprecipitated by an antibody directed against the C-terminal domain of the ..beta..-subunit (..cap alpha..Pep-1), indicating that this region of the receptor was lost. The 85-kDa fragment contained about half of the (/sup 32/P)phosphate originally found in the ..beta..-subunit, and tryptic peptide mapping showed that two major tryptic phosphopeptides (previously called pY2 and pY3) were removed. Three other tryptic phosphopeptides (pY1, pY1a, and pY4) were found in the 85- and 70-kDa fragments. To determined the structural requirements for kinase activity, the insulin receptor was subjected to tryptic digestion for 30 s-30 min, such that the receptor was composed exclusively of 85- and 70-kDa fragments of the ..beta..-subunit. The 85-kDa fragment exhibited autophosphorylation at pY1, pY1a, and pY4. Both the 85- and 70-kDa fragments phosphorylated tyrosine residues in a synthetic decapeptide that has the sequence of the C-terminal domain of the ..beta..-subunit of human insulin rare in the receptor.

  9. Fission yeast Cdk7 controls gene expression through both its CAK and C-terminal domain kinase activities.

    PubMed

    Devos, Maxime; Mommaerts, Elise; Migeot, Valerie; van Bakel, Harm; Hermand, Damien

    2015-05-01

    Cyclin-dependent kinase (Cdk) activation and RNA polymerase II transcription are linked by the Cdk7 kinase, which phosphorylates Cdks as a trimeric Cdk-activating kinase (CAK) complex, and serine 5 within the polymerase II (Pol II) C-terminal domain (CTD) as transcription factor TFIIH-bound CAK. However, the physiological importance of integrating these processes is not understood. Besides the Cdk7 ortholog Mcs6, fission yeast possesses a second CAK, Csk1. The two enzymes have been proposed to act redundantly to activate Cdc2. Using an improved analogue-sensitive Mcs6-as kinase, we show that Csk1 is not a relevant CAK for Cdc2. Further analyses revealed that Csk1 lacks a 20-amino-acid sequence required for its budding yeast counterpart, Cak1, to bind Cdc2. Transcriptome profiling of the Mcs6-as mutant in the presence or absence of the budding yeast Cak1 kinase, in order to uncouple the CTD kinase and CAK activities of Mcs6, revealed an unanticipated role of the CAK branch in the transcriptional control of the cluster of genes implicated in ribosome biogenesis and cell growth. The analysis of a Cdc2 CAK site mutant confirmed these data. Our data show that the Cdk7 kinase modulates transcription through its well-described RNA Pol II CTD kinase activity and also through the Cdc2-activating kinase activity.

  10. Fission Yeast Cdk7 Controls Gene Expression through both Its CAK and C-Terminal Domain Kinase Activities

    PubMed Central

    Devos, Maxime; Mommaerts, Elise; Migeot, Valerie; van Bakel, Harm

    2015-01-01

    Cyclin-dependent kinase (Cdk) activation and RNA polymerase II transcription are linked by the Cdk7 kinase, which phosphorylates Cdks as a trimeric Cdk-activating kinase (CAK) complex, and serine 5 within the polymerase II (Pol II) C-terminal domain (CTD) as transcription factor TFIIH-bound CAK. However, the physiological importance of integrating these processes is not understood. Besides the Cdk7 ortholog Mcs6, fission yeast possesses a second CAK, Csk1. The two enzymes have been proposed to act redundantly to activate Cdc2. Using an improved analogue-sensitive Mcs6-as kinase, we show that Csk1 is not a relevant CAK for Cdc2. Further analyses revealed that Csk1 lacks a 20-amino-acid sequence required for its budding yeast counterpart, Cak1, to bind Cdc2. Transcriptome profiling of the Mcs6-as mutant in the presence or absence of the budding yeast Cak1 kinase, in order to uncouple the CTD kinase and CAK activities of Mcs6, revealed an unanticipated role of the CAK branch in the transcriptional control of the cluster of genes implicated in ribosome biogenesis and cell growth. The analysis of a Cdc2 CAK site mutant confirmed these data. Our data show that the Cdk7 kinase modulates transcription through its well-described RNA Pol II CTD kinase activity and also through the Cdc2-activating kinase activity. PMID:25691663

  11. The RUN domain of rubicon is important for hVps34 binding, lipid kinase inhibition, and autophagy suppression.

    PubMed

    Sun, Qiming; Zhang, Jing; Fan, Weiliang; Wong, Kwun Ngok; Ding, Xiaojun; Chen, She; Zhong, Qing

    2011-01-07

    The class III phosphatidylinositol 3-kinase (PI3KC3) plays a central role in autophagy. Rubicon, a RUN domain-containing protein, is newly identified as a PI3KC3 subunit through its association with Beclin 1. Rubicon serves as a negative regulator of PI3KC3 and autophagosome maturation. The molecular mechanism underlying the PI3KC3 and autophagy inhibition by Rubicon is largely unknown. Here, we demonstrate that Rubicon interacts with the PI3KC3 catalytic subunit hVps34 via its RUN domain. The RUN domain contributes to the efficient inhibition of PI3KC3 lipid kinase activity by Rubicon. Furthermore, a Rubicon RUN domain deletion mutant fails to complement the autophagy deficiency in Rubicon-depleted cells. Hence, these results reveal a critical role of the Rubicon RUN domain in PI3KC3 and autophagy regulation.

  12. Identification of positive-acting domains in GCN2 protein kinase required for translational activation of GCN4 expression

    SciTech Connect

    Wek, R.C.; Ramirez, M.; Jackson, B.M.; Hinnebusch, A.G. )

    1990-06-01

    GCN4 is a transcriptional activator of amino acid-biosynthetic genes in the yeast {ital Saccharomyces cerevisiae}. GCN2, a translational activator of {ital GCN4} expression, contains a domain homologous to the catalytic subunit of eukaryotic protein kinases. Substitution of a highly conserved lysine residue in the kinase domain abolished GCN2 regulatory function in vivo and its ability to autophosphorylate in vitro, indicating that GCN2 acts as a protein kinase in stimulating {ital GCN4} expression. Elevated {ital GCN2} gene dosage led to depression of {ital GCN4} under nonstarvation conditions; however, the authors found that {ital GCN2} mRNA and protein levels did not increase in wild-type cells in response to amino acid starvation. Therefore, it appears that GCN2 protein kinase function is stimulated postranslationally in amino acid-starved cells. Three dominant-constitutive {ital GCN2} point mutations were isolated that led to derepressed {ital GCN4} expression under nonstarvation conditions. Two of the {ital GCN2}(Con) mutations mapped in the kinase domain itself. The third mapped just downstream from a carboxyl-terminal segment homologous to histidyl-tRNA synthetase (HisRS), which the authors suggest might function to detect uncharged tRNA in amino acid-starved cells and activate the adjacent protein kinase moiety.

  13. Intramolecular activation of a Ca(2+)-dependent protein kinase is disrupted by insertions in the tether that connects the calmodulin-like domain to the kinase

    NASA Technical Reports Server (NTRS)

    Vitart, V.; Christodoulou, J.; Huang, J. F.; Chazin, W. J.; Harper, J. F.; Evans, M. L. (Principal Investigator)

    2000-01-01

    Ca(2+)-dependent protein kinases (CDPK) have a calmodulin-like domain (CaM-LD) tethered to the C-terminal end of the kinase. Activation is proposed to involve intramolecular binding of the CaM-LD to a junction sequence that connects the CaM-LD to the kinase domain. Consistent with this model, a truncated CDPK (DeltaNC) in which the CaM-LD has been deleted can be activated in a bimolecular interaction with an isolated CaM-LD or calmodulin, similar to the activation of a calmodulin-dependent protein kinase (CaMK) by calmodulin. Here we provide genetic evidence that this bimolecular activation requires a nine-residue binding segment from F436 to I444 (numbers correspond to CPK-1 accession number L14771). Two mutations at either end of this core segment (F436/A and VI444/AA) severely disrupted bimolecular activation, whereas flanking mutations had only minor effects. Intramolecular activation of a full-length kinase was also disrupted by a VI444/AA mutation, but surprisingly not by a F436/A mutation (at the N-terminal end of the binding site). Interestingly, intramolecular but not bimolecular activation was disrupted by insertion mutations placed immediately downstream of I444. To show that mutant enzymes were not misfolded, latent kinase activity was stimulated through binding of an antijunction antibody. Results here support a model of intramolecular activation in which the tether (A445 to G455) that connects the CaM-LD to the kinase provides an important structural constraint and is not just a simple flexible connection.

  14. ALK oncoproteins in atypical inflammatory myofibroblastic tumours: novel RRBP1-ALK fusions in epithelioid inflammatory myofibroblastic sarcoma.

    PubMed

    Lee, Jen-Chieh; Li, Chien-Feng; Huang, Hsuan-Ying; Zhu, Mei-Jun; Mariño-Enríquez, Adrián; Lee, Chung-Ta; Ou, Wen-Bin; Hornick, Jason L; Fletcher, Jonathan A

    2017-02-01

    ALK oncogenic activation mechanisms were characterized in four conventional spindle-cell inflammatory myofibroblastic tumours (IMT) and five atypical IMT, each of which had ALK genomic perturbations. Constitutively activated ALK oncoproteins were purified by ALK immunoprecipitation and electrophoresis, and were characterized by mass spectrometry. The four conventional IMT had TPM3/4-ALK fusions (two cases) or DCTN1-ALK fusions (two cases), whereas two atypical spindle-cell IMT had TFG-ALK and TPM3-ALK fusion in one case each, and three epithelioid inflammatory myofibroblastic sarcomas had RANBP2-ALK fusions in two cases, and a novel RRBP1-ALK fusion in one case. The epithelioid inflammatory myofibroblastic sarcoma with RRBP1-ALK fusion had cytoplasmic ALK expression with perinuclear accentuation, different from the nuclear membranous ALK localization in epithelioid inflammatory myofibroblastic sarcomas with RANBP2-ALK fusions. Evaluation of three additional uncharacterized epithelioid inflammatory myofibroblastic sarcomas with ALK cytoplasmic/perinuclear- accentuation expression demonstrated RRBP1-ALK fusion in two cases. These studies show that atypical spindle-cell IMT can utilize the same ALK fusion mechanisms described previously in conventional IMT, whereas in clinically aggressive epithelioid inflammatory myofibroblastic sarcoma we identify a novel recurrent ALK oncogenic mechanism, resulting from fusion with the RRBP1 gene. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  15. Identification of green tea catechins as potent inhibitors of the polo-box domain of polo-like kinase 1.

    PubMed

    Shan, Hong-Mei; Shi, Yanxia; Quan, Junmin

    2015-01-01

    Polo-like kinase 1 (PLK1) plays crucial functions in multiple stages of mitosis and is considered to be a potential drug target for cancer therapy. The functions of PLK1 are mediated by its N-terminal kinase domain and C-terminal polo-box domain (PBD). Most inhibitors targeting the kinase domain of PLK1 have a selectivity issue because of a high degree of structural conservation within kinase domains of all protein kinases. Here, we combined virtual and experimental screenings to identify green tea catechins as potent inhibitors of the PLK1 PBD. Initially, (-)-epigallocatechin, one of the main components of green tea polyphenols, was found to significantly block the binding of fluorescein-labeled phosphopeptide to the PBD at a concentration of 10 μm. Next, additional catechins were evaluated for their dose-dependent inhibition of the PBD and preliminary structure-activity relationships were derived. Cellular analysis further showed that catechins interfere with the proper subcellular localization of PLK1, lead to cell-cycle arrest in the S and G2M phases, and induce growth inhibition of several human cancer cell types, such as breast adenocarcinoma (MCF7), lung adenocarcinoma (A549), and cervical adenocarcinoma (HeLa). Our data provides new insight into understanding the anticancer activities of green tea catechins.

  16. APS, an adapter protein with a PH and SH2 domain, is a substrate for the insulin receptor kinase.

    PubMed Central

    Ahmed, Z; Smith, B J; Kotani, K; Wilden, P; Pillay, T S

    1999-01-01

    APS (adapter protein with a PH and SH2 domain) is the newest member of a family of tyrosine kinase adapter proteins including SH2-B and Lnk. We previously identified SH2-B as an insulin-receptor-binding protein and substrate [Kotani, Wilden and Pillay (1998) Biochem J. 335, 103-109]. Here we show that APS interacts with the insulin receptor kinase activation loop through its SH2 domain and insulin stimulates the tyrosine-phosphorylation of APS. Furthermore, the phosphorylation of activation-loop tyrosine residues 1158 and 1162 are required for this interaction. PMID:10417330

  17. The pleiotrophin-ALK axis is required for tumorigenicity of glioblastoma stem cells.

    PubMed

    Koyama-Nasu, R; Haruta, R; Nasu-Nishimura, Y; Taniue, K; Katou, Y; Shirahige, K; Todo, T; Ino, Y; Mukasa, A; Saito, N; Matsui, M; Takahashi, R; Hoshino-Okubo, A; Sugano, H; Manabe, E; Funato, K; Akiyama, T

    2014-04-24

    Increasing evidence suggests that brain tumors arise from the transformation of neural stem/precursor/progenitor cells. Much current research on human brain tumors is focused on the stem-like properties of glioblastoma. Here we show that anaplastic lymphoma kinase (ALK) and its ligand pleiotrophin are required for the self-renewal and tumorigenicity of glioblastoma stem cells (GSCs). Furthermore, we demonstrate that pleiotrophin is transactivated directly by SOX2, a transcription factor essential for the maintenance of both neural stem cells and GSCs. We speculate that the pleiotrophin-ALK axis may be a promising target for the therapy of glioblastoma.

  18. ALK Positive Anaplastic Large Cell Lymphoma Presenting as Extensive Bone Involvement

    PubMed Central

    Gajendra, Smeeta; Lipi, Lipika; Goel, Shalini; Misra, Ruchira

    2015-01-01

    Anaplastic lymphoma kinase (ALK) positive Anaplastic large cell lymphoma (ALCL) represents approximately 2% of all Non-Hodgkin’s lymphomas that commonly involves nodal as well as a wide variety of extra nodal sites, as skin, soft tissue, bones and lungs, although primary or secondary involvement of bone is rare. Herein, we report a case of 14-year-old female child presented as extensive bony involvement with a clinical diagnosis of bone tumour/ small round cell tumour, which was proved to be ALK positive ALCL on histopathological examination. PMID:25738071

  19. Protein kinase C epsilon is localized to the Golgi via its zinc-finger domain and modulates Golgi function.

    PubMed Central

    Lehel, C; Olah, Z; Jakab, G; Anderson, W B

    1995-01-01

    Protein kinase C (PKC) is a multigene family of serine/threonine kinases that are central to many signal transduction pathways. Among the PKC isozymes, only PKC epsilon has been reported to exhibit full oncogenic potential. PKC epsilon also displays unique substrate specificity and intracellular localization. To examine the interrelationship between the biological effects and domain structure of PKC epsilon, NIH 3T3 cells were stably transfected to overexpress different epitope-tagged fragments of PKC epsilon. The overexpressed proteins each contain the epsilon-tag peptide at the C terminus to allow ready detection with an antibody specific for the tag. The holo-PKC epsilon was found to localize with the Golgi network and other compartments, whereas the zinc-finger domain localized exclusively at the Golgi. Golgi-specific glycosaminoglycan sulfation was strongly inhibited in cells overexpressing either holo-PKC epsilon or its zinc-finger domain, while the secretion of sulfated glycosaminoglycans into the medium was impaired in cells expressing the PKC epsilon zinc-finger domain. Thus, these results suggest that PKC epsilon may be involved in specifically regulating Golgi-related processes. Further, the results indicate that PKC epsilon domains other than the kinase domain may also have biological activity and that the zinc-finger domain may function as a subcellular localization signal. Images Fig. 1 Fig. 2 Fig. 3 PMID:7877991

  20. Sensory domain contraction in histidine kinase CitA triggers transmembrane signaling in the membrane-bound sensor

    PubMed Central

    Salvi, Michele; Schomburg, Benjamin; Giller, Karin; Graf, Sabrina; Unden, Gottfried; Becker, Stefan; Lange, Adam; Griesinger, Christian

    2017-01-01

    Bacteria use membrane-integral sensor histidine kinases (HK) to perceive stimuli and transduce signals from the environment to the cytosol. Information on how the signal is transmitted across the membrane by HKs is still scarce. Combining both liquid- and solid-state NMR, we demonstrate that structural rearrangements in the extracytoplasmic, citrate-sensing Per-Arnt-Sim (PAS) domain of HK CitA are identical for the isolated domain in solution and in a longer construct containing the membrane-embedded HK and lacking only the kinase core. We show that upon citrate binding, the PAS domain contracts, resulting in a shortening of the C-terminal β-strand. We demonstrate that this contraction of the PAS domain, which is well characterized for the isolated domain, is the signal transmitted to the transmembrane (TM) helices in a CitA construct in liposomes. Putting the extracytoplasmic PAS domain into context of the membrane-embedded CitA construct slows down citrate-binding kinetics by at least a factor of 60, confirming that TM helix motions are linked to the citrate-binding event. Our results are confirmation of a hallmark of the HK signal transduction mechanism with atomic resolution on a full-length construct lacking only the kinase core domain. PMID:28265100

  1. Sensory domain contraction in histidine kinase CitA triggers transmembrane signaling in the membrane-bound sensor.

    PubMed

    Salvi, Michele; Schomburg, Benjamin; Giller, Karin; Graf, Sabrina; Unden, Gottfried; Becker, Stefan; Lange, Adam; Griesinger, Christian

    2017-03-21

    Bacteria use membrane-integral sensor histidine kinases (HK) to perceive stimuli and transduce signals from the environment to the cytosol. Information on how the signal is transmitted across the membrane by HKs is still scarce. Combining both liquid- and solid-state NMR, we demonstrate that structural rearrangements in the extracytoplasmic, citrate-sensing Per-Arnt-Sim (PAS) domain of HK CitA are identical for the isolated domain in solution and in a longer construct containing the membrane-embedded HK and lacking only the kinase core. We show that upon citrate binding, the PAS domain contracts, resulting in a shortening of the C-terminal β-strand. We demonstrate that this contraction of the PAS domain, which is well characterized for the isolated domain, is the signal transmitted to the transmembrane (TM) helices in a CitA construct in liposomes. Putting the extracytoplasmic PAS domain into context of the membrane-embedded CitA construct slows down citrate-binding kinetics by at least a factor of 60, confirming that TM helix motions are linked to the citrate-binding event. Our results are confirmation of a hallmark of the HK signal transduction mechanism with atomic resolution on a full-length construct lacking only the kinase core domain.

  2. Sensitivity Analysis of the NPM-ALK Signalling Network Reveals Important Pathways for Anaplastic Large Cell Lymphoma Combination Therapy

    PubMed Central

    Buetti-Dinh, Antoine; O’Hare, Thomas

    2016-01-01

    A large subset of anaplastic large cell lymphoma (ALCL) patients harbour a somatic aberration in which anaplastic lymphoma kinase (ALK) is fused to nucleophosmin (NPM) resulting in a constitutively active signalling fusion protein, NPM-ALK. We computationally simulated the signalling network which mediates pathological cell survival and proliferation through NPM-ALK to identify therapeutically targetable nodes through which it may be possible to regain control of the tumourigenic process. The simulations reveal the predominant role of the VAV1-CDC42 (cell division control protein 42) pathway in NPM-ALK-driven cellular proliferation and of the Ras / mitogen-activated ERK kinase (MEK) / extracellular signal-regulated kinase (ERK) cascade in controlling cell survival. Our results also highlight the importance of a group of interleukins together with the Janus kinase 3 (JAK3) / signal transducer and activator of transcription 3 (STAT3) signalling in the development of NPM-ALK derived ALCL. Depending on the activity of JAK3 and STAT3, the system may also be sensitive to activation of protein tyrosine phosphatase-1 (SHP1), which has an inhibitory effect on cell survival and proliferation. The identification of signalling pathways active in tumourigenic processes is of fundamental importance for effective therapies. The prediction of alternative pathways that circumvent classical therapeutic targets opens the way to preventive approaches for countering the emergence of cancer resistance. PMID:27669408

  3. Intracellular catalytic domain of symbiosis receptor kinase hyperactivates spontaneous nodulation in absence of rhizobia.

    PubMed

    Saha, Sudip; Dutta, Ayan; Bhattacharya, Avisek; DasGupta, Maitrayee

    2014-12-01

    Symbiosis Receptor Kinase (SYMRK), a member of the Nod factor signaling pathway, is indispensible for both nodule organogenesis and intracellular colonization of symbionts in rhizobia-legume symbiosis. Here, we show that the intracellular kinase domain of a SYMRK (SYMRK-kd) but not its inactive or full-length version leads to hyperactivation of the nodule organogenic program in Medicago truncatula TR25 (symrk knockout mutant) in the absence of rhizobia. Spontaneous nodulation in TR25/SYMRK-kd was 6-fold higher than rhizobia-induced nodulation in TR25/SYMRK roots. The merged clusters of spontaneous nodules indicated that TR25 roots in the presence of SYMRK-kd have overcome the control over both nodule numbers and their spatial position. In the presence of rhizobia, SYMRK-kd could rescue the epidermal infection processes in TR25, but colonization of symbionts in the nodule interior was significantly compromised. In summary, ligand-independent deregulated activation of SYMRK hyperactivates nodule organogenesis in the absence of rhizobia, but its ectodomain is required for proper symbiont colonization.

  4. Expression, purification, stability optimization and characterization of human Aurora B kinase domain from E. coli.

    PubMed

    Sheth, Payal R; Ramanathan, Lata; Ranchod, Ashwin; Basso, Andrea D; Barrett, Dianah; Zhao, Jia; Gray, Kimberly; Liu, Yan-Hui; Zhang, Rumin; Le, Hung V

    2010-11-15

    Aurora B kinase plays a critical role in regulating mitotic progression, and its dysregulation has been linked to tumorigenesis. The structure of the kinase domain of human Aurora B and the complementary information of binding thermodynamics of known Aurora inhibitors is lacking. Towards that effort, we sought to identify a human Aurora B construct that would be amenable for large-scale protein production for biophysical and structural studies. Although the designed AurB(69-333) construct expressed at high levels in Escherichia coli, the purified protein was largely unstable and prone to aggregation. We employed thermal-shift assay for high-throughput screening of 192 conditions to identify optimal pH and salt conditions that increased the stability and minimized aggregation of AurB(69-333). Direct ligand binding analyses using temperature-dependent circular dichroism (TdCD) and TR-FRET-based Lanthascreen™ binding assay showed that the purified protein was folded and functional. The affinity rank-order obtained using TdCD and Lanthascreen™ binding assay correlated with enzymatic IC50 values measured using full-length Aurora B protein for all the inhibitors tested except for AZD1152. The direct binding results support the hypothesis that the purified human AurB(69-333) fragment is a good surrogate for its full-length counterpart for biophysical and structural analyses.

  5. Ligand-induced global transitions in the catalytic domain of protein kinase A

    PubMed Central

    Hyeon, Changbong; Jennings, Patricia A.; Adams, Joseph A.; Onuchic, José N.

    2009-01-01

    Conformational transitions play a central role in the phosphorylation mechanisms of protein kinase. To understand the nature of these transitions, we investigated the dynamics of nucleotide binding to the catalytic domain of PKA, a prototype for the protein kinase enzyme family. The open-to-closed transition in PKA was constructed as a function of ATP association by using available X-ray data and Brownian dynamics. Analyzing the multiple kinetic trajectories at the residue level, we find that the spatial rearrangement of the residues around the nucleotide-binding pocket, along with suppressed local fluctuations, controls the compaction of the entire molecule. In addition, to accommodate the stresses induced by ATP binding at the early transition stage, partial unfoldings (cracking) and reformations of several native contacts occur at the interfaces between the secondary structure motifs enveloping the binding pocket. This suggests that the enzyme experiences local structural deformations while reaching its functional, ATP-bound state. Our dynamical view of the ligand-induced transitions in PKA suggests that the kinetic hierarchy of local and global dynamics, the variable fluctuation of residues and the necessity of partial local unfolding may be fundamental components in other large scale allosteric transitions. PMID:19204278

  6. Alk5 inhibition increases delivery of macromolecular and protein-bound contrast agents to tumors

    PubMed Central

    Daldrup-Link, Heike E.; Mohanty, Suchismita; Ansari, Celina; Ito, Ken; Hong, Su Hyun; Hoffmann, Matthias; Pisani, Laura; Boudreau, Nancy; Gambhir, Sanjiv Sam; Coussens, Lisa M.

    2016-01-01

    Limited transendothelial permeability across tumor microvessels represents a significant bottleneck in the development of tumor-specific diagnostic agents and theranostic drugs. Here, we show an approach to increase transendothelial permeability of macromolecular and nanoparticle-based contrast agents via inhibition of the type I TGF-β receptor, activin-like kinase 5 (Alk5), in tumors. Alk5 inhibition significantly increased tumor contrast agent delivery and enhancement on imaging studies, while healthy organs remained relatively unaffected. Imaging data correlated with significantly decreased tumor interstitial fluid pressure, while tumor vascular density remained unchanged. This immediately clinically translatable concept involving Alk5 inhibitor pretreatment prior to an imaging study could be leveraged for improved tumor delivery of macromolecular and nanoparticle-based imaging probes and, thereby, facilitate development of more sensitive imaging tests for cancer diagnosis, enhanced tumor characterization, and personalized, image-guided therapies. PMID:27182558

  7. Tyrosine Kinase 2-mediated Signal Transduction in T Lymphocytes Is Blocked by Pharmacological Stabilization of Its Pseudokinase Domain*

    PubMed Central

    Tokarski, John S.; Zupa-Fernandez, Adriana; Tredup, Jeffrey A.; Pike, Kristen; Chang, ChiehYing; Xie, Dianlin; Cheng, Lihong; Pedicord, Donna; Muckelbauer, Jodi; Johnson, Stephen R.; Wu, Sophie; Edavettal, Suzanne C.; Hong, Yang; Witmer, Mark R.; Elkin, Lisa L.; Blat, Yuval; Pitts, William J.; Weinstein, David S.; Burke, James R.

    2015-01-01

    Inhibition of signal transduction downstream of the IL-23 receptor represents an intriguing approach to the treatment of autoimmunity. Using a chemogenomics approach marrying kinome-wide inhibitory profiles of a compound library with the cellular activity against an IL-23-stimulated transcriptional response in T lymphocytes, a class of inhibitors was identified that bind to and stabilize the pseudokinase domain of the Janus kinase tyrosine kinase 2 (Tyk2), resulting in blockade of receptor-mediated activation of the adjacent catalytic domain. These Tyk2 pseudokinase domain stabilizers were also shown to inhibit Tyk2-dependent signaling through the Type I interferon receptor but not Tyk2-independent signaling and transcriptional cellular assays, including stimulation through the receptors for IL-2 (JAK1- and JAK3-dependent) and thrombopoietin (JAK2-dependent), demonstrating the high functional selectivity of this approach. A crystal structure of the pseudokinase domain liganded with a representative example showed the compound bound to a site analogous to the ATP-binding site in catalytic kinases with features consistent with high ligand selectivity. The results support a model where the pseudokinase domain regulates activation of the catalytic domain by forming receptor-regulated inhibitory interactions. Tyk2 pseudokinase stabilizers, therefore, represent a novel approach to the design of potent and selective agents for the treatment of autoimmunity. PMID:25762719

  8. Characterization of the Catalytic and Nucleotide Binding Properties of the α-Kinase Domain of Dictyostelium Myosin-II Heavy Chain Kinase A*

    PubMed Central

    Yang, Yidai; Ye, Qilu; Jia, Zongchao; Côté, Graham P.

    2015-01-01

    The α-kinases are a widely expressed family of serine/threonine protein kinases that exhibit no sequence identity with conventional eukaryotic protein kinases. In this report, we provide new information on the catalytic properties of the α-kinase domain of Dictyostelium myosin-II heavy chain kinase-A (termed A-CAT). Crystallization of A-CAT in the presence of MgATP yielded structures with AMP or adenosine in the catalytic cleft together with a phosphorylated Asp-766 residue. The results show that the β- and α-phosphoryl groups are transferred either directly or indirectly to the catalytically essential Asp-766. Biochemical assays confirmed that A-CAT hydrolyzed ATP, ADP, and AMP with kcat values of 1.9, 0.6, and 0.32 min−1, respectively, and showed that A-CAT can use ADP to phosphorylate peptides and proteins. Binding assays using fluorescent 2′/3′-O-(N-methylanthraniloyl) analogs of ATP and ADP yielded Kd values for ATP, ADP, AMP, and adenosine of 20 ± 3, 60 ± 20, 160 ± 60, and 45 ± 15 μm, respectively. Site-directed mutagenesis showed that Glu-713, Leu-716, and Lys-645, all of which interact with the adenine base, were critical for nucleotide binding. Mutation of the highly conserved Gln-758, which chelates a nucleotide-associated Mg2+ ion, eliminated catalytic activity, whereas loss of the highly conserved Lys-722 and Arg-592 decreased kcat values for kinase and ATPase activities by 3–6-fold. Mutation of Asp-663 impaired kinase activity to a much greater extent than ATPase, indicating a specific role in peptide substrate binding, whereas mutation of Gln-768 doubled ATPase activity, suggesting that it may act to exclude water from the active site. PMID:26260792

  9. Structural insights into the recognition of β3 integrin cytoplasmic tail by the SH3 domain of Src kinase.

    PubMed

    Katyal, Priya; Puthenveetil, Robbins; Vinogradova, Olga

    2013-10-01

    Src kinase plays an important role in integrin signaling by regulating cytoskeletal organization and cell remodeling. Previous in vivo studies have revealed that the SH3 domain of c-Src kinase directly associates with the C-terminus of β3 integrin cytoplasmic tail. Here, we explore this binding interface with a combination of different spectroscopic and computational methods. Chemical shift mapping, PRE, transferred NOE and CD data were used to obtain a docked model of the complex. This model suggests a different binding mode from the one proposed through previous studies wherein, the C-terminal end of β3 spans the region in between the RT and n-Src loops of SH3 domain. Furthermore, we show that tyrosine phosphorylation of β3 prevents this interaction, supporting the notion of a constitutive interaction between β3 integrin and Src kinase.

  10. Structural insights into the recognition of β3 integrin cytoplasmic tail by the SH3 domain of Src kinase

    PubMed Central

    Katyal, Priya; Puthenveetil, Robbins; Vinogradova, Olga

    2013-01-01

    Src kinase plays an important role in integrin signaling by regulating cytoskeletal organization and cell remodeling. Previous in vivo studies have revealed that the SH3 domain of c-Src kinase directly associates with the C-terminus of β3 integrin cytoplasmic tail. Here, we explore this binding interface with a combination of different spectroscopic and computational methods. Chemical shift mapping, PRE, transferred NOE and CD data were used to obtain a docked model of the complex. This model suggests a different binding mode from the one proposed through previous studies wherein, the C-terminal end of β3 spans the region in between the RT and n-Src loops of SH3 domain. Furthermore, we show that tyrosine phosphorylation of β3 prevents this interaction, supporting the notion of a constitutive interaction between β3 integrin and Src kinase. PMID:23913837

  11. BMP9/ALK1 inhibits neovascularization in mouse models of age-related macular degeneration

    PubMed Central

    Ntumba, Kalonji; Akla, Naoufal; Oh, S. Paul; Eichmann, Anne; Larrivée, Bruno

    2016-01-01

    Age-related macular degeneration (AMD) is the leading cause of blindness in aging populations of industrialized countries. The drawbacks of inhibitors of vascular endothelial growth factor (VEGFs) currently used for the treatment of AMD, which include resistance and potential serious side-effects, require the identification of new therapeutic targets to modulate angiogenesis. BMP9 signaling through the endothelial Alk1 serine-threonine kinase receptor modulates the response of endothelial cells to VEGF and promotes vessel quiescence and maturation during development. Here, we show that BMP9/Alk1 signaling inhibits neovessel formation in mouse models of pathological ocular angiogenesis relevant to AMD. Activating Alk1 signaling in laser-induced choroidal neovascularization (CNV) and oxygen-induced retinopathy (OIR) inhibited neovascularization and reduced the volume of vascular lesions. Alk1 signaling was also found to interfere with VEGF signaling in endothelial cells whereas BMP9 potentiated the inhibitory effects of VEGFR2 signaling blockade, both in OIR and laser-induced CNV. Together, our data show that targeting BMP9/Alk1 efficiently prevents the growth of neovessels in AMD models and introduce a new approach to improve conventional anti-VEGF therapies. PMID:27517154

  12. A molecular dynamics investigation on the crizotinib resistance mechanism of C1156Y mutation in ALK

    SciTech Connect

    Sun, Hui-Yong; Ji, Feng-Qin

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer The study revealed the detailed resistance mechanism of the non-active mutation C1156Y in ALK. Black-Right-Pointing-Pointer C1156Y leads to crizotinib displacement and conformational changes in the binding cavity. Black-Right-Pointing-Pointer The conformations cause a decline in the vdW and electrostatic energy between crizotinib and ALK. -- Abstract: Crizotinib is an anaplastic lymphoma kinase (ALK) inhibitor that has recently been approved in the US for the treatment of non-small cell lung carcinoma (NSCLC). Despite its outstanding safety and efficacy, several resistant mutations against crizotinib have been detected in the treatment of NSCLC. However, in contrast to the widely accepted mechanism of steric hindrance by mutations at the active site, the mechanism by which the C1156Y non-active site mutation confers resistance against crizotinib remains unclear. In the present study, the resistance mechanism of C1156Y in ALK was investigated using molecular dynamics simulations. The results suggest that despite the non-active site mutation, C1156Y causes the dislocation of crizotinib as well as the indirect conformational changes in the binding cavity, which results in a marked decrease in the van der Waals and electrostatic interactions between crizotinib and ALK. The obtained results provide a detailed explanation of the resistance caused by C1156Y and may give a vital clue for the design of drugs to combat crizotinib resistance.

  13. Characterization of the PAS domain in the sensor-kinase BvgS: mechanical role in signal transmission

    PubMed Central

    2013-01-01

    Background In bacteria, signal-transduction two-component systems are major players for adaptation to environmental stimuli. The perception of a chemical or physical signal by a sensor-kinase triggers its autophosphorylation. The phosphoryl group is then transferred to the cognate response regulator, which mediates the appropriate adaptive response. Virulence of the whooping cough agent Bordetella pertussis is controlled by the two-component system BvgAS. Atypically, the sensor-kinase BvgS is active without specific stimuli at 37°C in laboratory conditions and is inactivated by the addition of negative chemical modulators. The structure of BvgS is complex, with two tandem periplasmic Venus flytrap domains and a cytoplasmic PAS domain that precedes the kinase domain, which is followed by additional phosphotransfer domains. PAS domains are small, ubiquitous sensing or regulatory domains. The function of the PAS domain in BvgS remains unknown. Results We showed that recombinant BvgS PAS proteins form dimers that are stabilized by α helical regions flanking the PAS core. A structural model of the PAS domain dimer was built and probed by site-directed mutagenesis and by biochemical and functional analyses. Although we found no ligands for the PAS domain cavity, its integrity is required for signaling. We also showed that the structural stability of the PAS core and its proper coupling to its flanking N- and C-terminal α helices are crucial for BvgS activity. Conclusions We propose that a major function of the BvgS PAS domain is to maintain conformational signals arising from mechanical strain generated by the periplasmic domain. The tight structure of the PAS core and its connections with the upstream and downstream helices ensure signaling to the kinase domain, which determines BvgS activity. Many mild substitutions that map to the PAS domain keep BvgS active but make it unresponsive to negative modulators, supporting that modulation increases conformational strain

  14. Characterization of the sensor domain of QseE histidine kinase from Escherichia coli.

    PubMed

    Yeo, Kwon Joo; Park, Jin-Wan; Kim, Eun-Hee; Jeon, Young Ho; Hwang, Kwang Yeon; Cheong, Hae-Kap

    2016-10-01

    In enterohemorrhagic Escherichia coli (EHEC), the QseEF two-component system causes attaching and effacing (AE) lesion on epithelial cells. QseE histidine kinase senses the host hormone epinephrine, sulfate, and phosphate; it also regulates QseF response regulator, which activates LEE gene that encodes AE lesion. In order to understand the recognition of ligand molecules and signal transfer mechanism in pathogenic bacteria, structural studies of the sensor domain of QseE of Escherichia coli should be conducted. In this study, we describe the overexpression, purification, and structural and biophysical properties of the sensor domain of QseE. The fusion protein had a 6×His tag at its N-terminus; this protein was overexpressed as inclusion bodies in E. coli BL21 (DE3). The protein was denatured in 7M guanidine hydrochloride and refolded by dialysis. The purification of the refolded protein was carried out using Ni-NTA affinity column and size-exclusion chromatography. Thereafter, the characteristics of the refolded protein were determined from NMR, CD, and MALS spectroscopies. In a pH range of 7.4-5.0, the folded protein existed in a monomeric form with a predominantly helical structure. (1)H-(15)N HSQC NMR spectra shows that approximately 93% backbone amide peaks are detected at pH 5.0, suggesting that the number of backbone signals is sufficient for NMR studies. These data might provide an opportunity for structural and functional studies of the sensor domain of QseE.

  15. Methylatable Signaling Helix Coordinated Inhibitory Receiver Domain in Sensor Kinase Modulates Environmental Stress Response in Bacillus Cereus

    PubMed Central

    Chen, Jung-Chi; Liu, Jyung-Hurng; Hsu, Duen-Wei; Shu, Jwu-Ching; Chen, Chien-Yen; Chen, Chien-Cheng

    2015-01-01

    σB, an alternative transcription factor, controls the response of the cell to a variety of environmental stresses in Bacillus cereus. Previously, we reported that RsbM negatively regulates σB through the methylation of RsbK, a hybrid sensor kinase, on a signaling helix (S-helix). However, RsbK comprises a C-terminal receiver (REC) domain whose function remains unclear. In this study, deletion of the C-terminal REC domain of RsbK resulted in high constitutive σB expression independent of environmental stimuli. Thus, the REC domain may serve as an inhibitory element. Mutagenic substitution was employed to modify the putative phospho-acceptor residue D827 in the REC domain of RsbK. The expression of RsbKD827N and RsbKD827E exhibited high constitutive σB, indicating that D827, if phosphorylatable, possibly participates in σB regulation. Bacterial two-hybrid analyses demonstrated that RsbK forms a homodimer and the REC domain interacts mainly with the histidine kinase (HK) domain and partly with the S-helix. In particular, co-expression of RsbM strengthens the interaction between the REC domain and the S-helix. Consistently, our structural model predicts a significant interaction between the HK and REC domains of the RsbK intradimer. Here, we demonstrated that coordinated the methylatable S-helix and the REC domain of RsbK is functionally required to modulate σB-mediated stress response in B. cereus and maybe ubiquitous in microorganisms encoded RsbK-type sensor kinases. PMID:26379238

  16. Structural and functional studies of the HAMP domain of EnvZ, an osmosensing transmembrane histidine kinase in Escherichia coli.

    PubMed

    Kishii, Ryuta; Falzon, Liliana; Yoshida, Takeshi; Kobayashi, Hiroshi; Inouye, Masayori

    2007-09-07

    The HAMP domain plays an essential role in signal transduction not only in histidine kinase but also in a number of other signal-transducing receptor proteins. Here we expressed the EnvZ HAMP domain (Arg(180)-Thr(235)) with the R218K mutation (termed L(RK)) or with L(RK) connected with domain A (Arg(180)-Arg(289)) (termed LA(RK)) of EnvZ, an osmosensing transmembrane histidine kinase in Escherichia coli, by fusing it with protein S. The L(RK) and LA(RK) proteins were purified after removing protein S. The CD analysis of the isolated L protein revealed that it consists of a random structure or is unstructured. This suggests that the EnvZ HAMP domain by itself is unable to form a stable structure and that this structural fragility may be important for its role in signal transduction. Interestingly the substitution of Ala(193) in the EnvZ HAMP domain with valine or leucine in Tez1A1, a chimeric protein of Tar and EnvZ, caused a constitutive OmpC phenotype. The CD analysis of LA(RK)(A193L) revealed that this mutated HAMP domain possesses considerable secondary structures and that the thermostability of this entire LA(RK)(A193L) became substantially lower than that of LA(RK) or just domain A, indicating that the structure of the HAMP domain with the A193L mutation affects the stability of downstream domain A. This results in cooperative thermodenaturation of domain A with the mutated HAMP domain. These results are discussed in light of the recently solved NMR structure of the HAMP domain from a thermophilic bacterium (Hulko, M., Berndt, F., Gruber, M., Linder, J. U., Truffault, V., Schultz, A., Martin, J., Schultz, J. E., Lupas, A. N., and Coles, M. (2006) Cell 126, 929-940).

  17. Targeting Neuroblastoma Cell Surface Proteins: Recommendations for Homology Modeling of hNET, ALK, and TrkB

    PubMed Central

    Haddad, Yazan; Heger, Zbyněk; Adam, Vojtech

    2017-01-01

    Targeted therapy is a promising approach for treatment of neuroblastoma as evident from the large number of targeting agents employed in clinical practice today. In the absence of known crystal structures, researchers rely on homology modeling to construct template-based theoretical structures for drug design and testing. Here, we discuss three candidate cell surface proteins that are suitable for homology modeling: human norepinephrine transporter (hNET), anaplastic lymphoma kinase (ALK), and neurotrophic tyrosine kinase receptor 2 (NTRK2 or TrkB). When choosing templates, both sequence identity and structure quality are important for homology modeling and pose the first of many challenges in the modeling process. Homology modeling of hNET can be improved using template models of dopamine and serotonin transporters instead of the leucine transporter (LeuT). The extracellular domains of ALK and TrkB are yet to be exploited by homology modeling. There are several idiosyncrasies that require direct attention throughout the process of model construction, evaluation and refinement. Shifts/gaps in the alignment between the template and target, backbone outliers and side-chain rotamer outliers are among the main sources of physical errors in the structures. Low-conserved regions can be refined with loop modeling method. Residue hydrophobicity, accessibility to bound metals or glycosylation can aid in model refinement. We recommend resolving these idiosyncrasies as part of “good modeling practice” to obtain highest quality model. Decreasing physical errors in protein structures plays major role in the development of targeting agents and understanding of chemical interactions at the molecular level. PMID:28163672

  18. The Extracellular Domain of the Saccharomyces cerevisiae Sln1p Membrane Osmolarity Sensor Is Necessary for Kinase Activity

    PubMed Central

    Ostrander, Darin B.; Gorman, Jessica A.

    1999-01-01

    The function of the extracellular domain (ECD) of Sln1p, a plasma membrane two-transmembrane domain (TMD) sensor of the high-osmolarity glycerol (HOG) response pathway, has been studied in the yeast Saccharomyces cerevisiae. Truncations of SLN1 that retain an intact kinase domain are capable of complementing the lethality of an sln1Δ strain. By observing levels of Hog1p phosphorylation as well as the phosphorylation state of Sln1p, the kinase activities of various SLN1 constructions were determined. In derivatives that do not contain the first TMD, Sln1p activity was no longer dependent on medium osmolarity but appeared to be constitutively active even under conditions of high osmolarity. Removal of the first TMD (ΔTMD1 construct) gave a protein that was strongly phosphorylated whereas Hog1p was largely dephosphorylated, as expected if the active form of Sln1p is phosphorylated. When both TMDs as well as the ECD were deleted, so that the kinase domain is cytosolic, Sln1p was not phosphorylated whereas Hog1p became constitutively hyperphosphorylated. Surprisingly, this hyperactivity of the HOG mitogen-activated protein kinase signaling pathway was not sufficient to result in cell lethality. When the ECD of the ΔTMD1 construct was replaced with a leucine zipper motif, Sln1p was hyperactive, so that Hog1p became mostly unphosphorylated. In contrast, when the Sln1p/leucine zipper construct was crippled by a mutation of one of the internal leucines, the Sln1 kinase was inactive. These experiments are consistent with the hypothesis that the ECD of Sln1p functions as a dimerization and activation domain but that osmotic regulation of activity requires the presence of the first TMD. PMID:10198019

  19. Crizotinib for the Treatment of ALK-Rearranged Non-Small Cell Lung Cancer: A Success Story to Usher in the Second Decade of Molecular Targeted Therapy in Oncology

    PubMed Central

    Bartlett, Cynthia Huang; Mino-Kenudson, Mari; Cui, Jean; Iafrate, A. John

    2012-01-01

    Crizotinib, an ALK/MET/ROS1 inhibitor, was approved by the U.S. Food and Drug Administration for the treatment of anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) in August 2011, merely 4 years after the first publication of ALK-rearranged NSCLC. The crizotinib approval was accompanied by the simultaneous approval of an ALK companion diagnostic fluorescent in situ hybridization assay for the detection of ALK-rearranged NSCLC. Crizotinib continued to be developed as an ALK and MET inhibitor in other tumor types driven by alteration in ALK and MET. Crizotinib has recently been shown to be an effective ROS1 inhibitor in ROS1-rearranged NSCLC, with potential future clinical applications in ROS1-rearranged tumors. Here we summarize the heterogeneity within the ALK- and ROS1-rearranged molecular subtypes of NSCLC. We review the past and future clinical development of crizotinib for ALK-rearranged NSCLC and the diagnostic assays to detect ALK-rearranged NSCLC. We highlight how the success of crizotinib has changed the paradigm of future drug development for targeted therapies by targeting a molecular-defined subtype of NSCLC despite its rarity and affected the practice of personalized medicine in oncology, emphasizing close collaboration between clinical oncologists, pathologists, and translational scientists. PMID:22989574

  20. Regulation of protein kinase Cmu by basic peptides and heparin. Putative role of an acidic domain in the activation of the kinase.

    PubMed

    Gschwendt, M; Johannes, F J; Kittstein, W; Marks, F

    1997-08-15

    Protein kinase Cmu is a novel member of the protein kinase C (PKC) family that differs from the other isoenzymes in structural and enzymatic properties. No substrate proteins of PKCmu have been identified as yet. Moreover, the regulation of PKCmu activity remains obscure, since a structural region corresponding to the pseudosubstrate domains of other PKC isoenzymes has not been found for PKCmu. Here we show that aldolase is phosphorylated by PKCmu in vitro. Phosphorylation of aldolase and of two substrate peptides by PKCmu is inhibited by various proteins and peptides, including typical PKC substrates such as histone H1, myelin basic protein, and p53. This inhibitory activity seems to depend on clusters of basic amino acids in the protein/peptide structures. Moreover, in contrast to other PKC isoenzymes PKCmu is activated by heparin and dextran sulfate. Maximal activation by heparin is about twice and that by dextran sulfate four times as effective as maximal activation by phosphatidylserine plus 12-O-tetradecanoylphorbol-13-acetate, the conventional activators of c- and nPKC isoforms. We postulate that PKCmu contains an acidic domain, which is involved in the formation and stabilization of an active state and which, in the inactive enzyme, is blocked by an intramolecular interaction with a basic domain. This intramolecular block is thought to be released by heparin and possibly also by 12-O-tetradecanoylphorbol-13-acetate/phosphatidylserine, whereas basic peptides and proteins inhibit PKCmu activity by binding to the acidic domain of the active enzyme.

  1. ANKRD54 preferentially selects Bruton's Tyrosine Kinase (BTK) from a Human Src-Homology 3 (SH3) domain library.

    PubMed

    Gustafsson, Manuela O; Mohammad, Dara K; Ylösmäki, Erkko; Choi, Hyunseok; Shrestha, Subhash; Wang, Qing; Nore, Beston F; Saksela, Kalle; Smith, C I Edvard

    2017-01-01

    Bruton's Tyrosine Kinase (BTK) is a cytoplasmic protein tyrosine kinase with a fundamental role in B-lymphocyte development and activation. The nucleocytoplasmic shuttling of BTK is specifically modulated by the Ankyrin Repeat Domain 54 (ANKRD54) protein and the interaction is known to be exclusively SH3-dependent. To identify the spectrum of the ANKRD54 SH3-interactome, we applied phage-display screening of a library containing all the 296 human SH3 domains. The BTK-SH3 domain was the prime interactor. Quantitative western blotting analysis demonstrated the accuracy of the screening procedure. Revealing the spectrum and specificity of ANKRD54-interactome is a critical step toward functional analysis in cells and tissues.

  2. DIFFERENT REQUIREMENTS OF THE KINASE AND UHM DOMAINS OF KIS FOR ITS NUCLEAR LOCALIZATION AND BINDING TO SPLICING FACTORS

    PubMed Central

    Manceau, Valérie; Kielkopf, Clara L.; Sobel, André; Maucuer, Alexandre

    2008-01-01

    Summary The protein kinase KIS is made by the juxtaposition of a unique kinase domain and a C-terminal domain with a U2AF Homology Motif (UHM), a sequence motif for protein interaction initially identified in the heterodimeric pre-mRNA splicing factor U2AF. This domain of KIS is closely related to the C-terminal UHM domain of the U2AF large subunit, U2AF65. KIS phosphorylates the splicing factor SF1, which in turn enhances SF1 binding to U2AF65 and the 3′ splice site, an event known to take place at an early step of spliceosome assembly. Here, the analysis of the subcellular localization of mutated forms of KIS indicates that the kinase domain of KIS is the necessary domain for its nuclear localization. As in the case of U2AF65, the UHM containing C-terminal domain of KIS is required for binding to the splicing factors SF1 and SF3b155. The efficiency of KIS binding to SF1 and SF3b155 is similar to that of U2AF65 in pull-down assays. These results further support the functional link of KIS with splicing factors. Interestingly, when compared to other UHM containing proteins, KIS presents a different specificity for the UHM docking sites that are present in the N-terminal region of SF3b155, thus providing a new insight into the variety of interactions mediated by UHM domains. PMID:18588901

  3. The SNF1 Kinase Ubiquitin-associated Domain Restrains Its Activation, Activity, and the Yeast Life Span.

    PubMed

    Jiao, Rubin; Postnikoff, Spike; Harkness, Troy A; Arnason, Terra G

    2015-06-19

    The enzyme family of heterotrimeric AMP-dependent protein kinases is activated upon low energy states, conferring a switch toward energy-conserving metabolic pathways through immediate kinase actions on enzyme targets and delayed alterations in gene expression through its nuclear relocalization. This family is evolutionarily conserved, including the presence of a ubiquitin-associated (UBA) motif in most catalytic subunits. The potential for the UBA domain to promote protein associations or direct subcellular location, as seen in other UBA-containing proteins, led us to query whether the UBA domain within the yeast AMP-dependent protein kinase ortholog, SNF1 kinase, was important in these aspects of its regulation. Here, we demonstrate that conserved UBA motif mutations significantly alter SNF1 kinase activation and biological activity, including enhanced allosteric subunit associations and increased oxidative stress resistance and life span. Significantly, the enhanced UBA-dependent longevity and oxidative stress response are at least partially dependent on the Fkh1 and Fkh2 stress response transcription factors, which in turn are shown to influence Snf1 gene expression.

  4. EGFR kinase domain mutation positive lung cancers are sensitive to intrapleural perfusion with hyperthermic chemotherapy (IPHC) complete treatment.

    PubMed

    Zhang, Hongjuan; Zhan, Cheng; Ke, Ji; Xue, Zhiqiang; Zhang, Aiqun; Xu, Kaifeng; Shen, Zhirong; Yu, Lei; Chen, Liang

    2016-01-19

    Lung cancer is the global leading cause of cancer-related deaths. A significant portion of lung cancer patients harbor kinase domain mutations in the epidermal growth factor receptor (EGFR). While EGFR tyrosine kinase inhibitors (TKI) effectively shrink tumors harboring mutant EGFR, clinical efficacy is limited by the development of TKI resistance. Effective alternatives are desperately needed in clinic for treating EGFR kinase domain mutation positive lung cancer. In our clinic in treating M1a lung cancer patients through intrapleural perfusion with hyperthermic chemotherapy (IPHC) followed by cycles of systemic chemotherapy (we termed this procedure IPHC complete treatment, IPHC-CT), we found dramatic tumor shrinkage in mutant EGFR-positive patients. We further confirmed the sensitivity of EGFR mutation-positive lung cancer cell lines derived from patients to HC (hyperthermic chemotherapy) treatment. We found that hyperthermia promoted accumulation of cisplatin in lung cancer cells. Hyperthermia and cisplatin synergistically downregulated the EGFR protein level, leading to quenching of signal from EGFR and induction of apoptosis. Our work therefore showed IPHC-CT is an effective treatment for EGFR kinase domain mutation positive lung cancer patients.

  5. An SH2 domain-based tyrosine kinase assay using biotin ligase modified with a terbium(III) complex.

    PubMed

    Sueda, Shinji; Shinboku, Yuki; Kusaba, Takeshi

    2013-01-01

    Src homology 2 (SH2) domains are modules of approximately 100 amino acids and are known to bind phosphotyrosine-containing sequences with high affinity and specificity. In the present work, we developed an SH2 domain-based assay for Src tyrosine kinase using a unique biotinylation reaction from archaeon Sulfolobus tokodaii. S. tokodaii biotinylation has a unique property that biotin protein ligase (BPL) forms a stable complex with its biotinylated substrate protein (BCCP). Here, an SH2 domain from lymphocyte-specific tyrosine kinase was genetically fused to a truncated BCCP, and the resulting fusion protein was labeled through biotinylation with BPL carrying multiple copies of a luminescent Tb(3+) complex. The labeled SH2 fusion proteins were employed to detect a phosphorylated peptide immobilized on the surface of the microtiter plate, where the phosphorylated peptide was produced by phosphorylation to the substrate peptide by Src tyrosine kinase. Our assay allows for a reliable determination of the activity of Src kinase lower than 10 pg/μL by a simple procedure.

  6. Cyclic di-GMP mediates a histidine kinase/phosphatase switch by noncovalent domain cross-linking

    PubMed Central

    Dubey, Badri N.; Lori, Christian; Ozaki, Shogo; Fucile, Geoffrey; Plaza-Menacho, Ivan; Jenal, Urs; Schirmer, Tilman

    2016-01-01

    Histidine kinases are key components of regulatory networks in bacteria. Although many of these enzymes are bifunctional, mediating both phosphorylation and dephosphorylation of downstream targets, the molecular details of this central regulatory switch are unclear. We showed recently that the universal second messenger cyclic di–guanosine monophosphate (c-di-GMP) drives Caulobacter crescentus cell cycle progression by forcing the cell cycle kinase CckA from its default kinase into phosphatase mode. We use a combination of structure determination, modeling, and functional analysis to demonstrate that c-di-GMP reciprocally regulates the two antagonistic CckA activities through noncovalent cross-linking of the catalytic domain with the dimerization histidine phosphotransfer (DHp) domain. We demonstrate that both c-di-GMP and ADP (adenosine diphosphate) promote phosphatase activity and propose that c-di-GMP stabilizes the ADP-bound quaternary structure, which allows the receiver domain to access the dimeric DHp stem for dephosphorylation. In silico analyses predict that c-di-GMP control is widespread among bacterial histidine kinases, arguing that it can replace or modulate canonical transmembrane signaling. PMID:27652341

  7. Development of natural product-derived receptor tyrosine kinase inhibitors based on conservation of protein domain fold.

    PubMed

    Kissau, Lars; Stahl, Petra; Mazitschek, Ralph; Giannis, Athannasios; Waldmann, Herbert

    2003-07-03

    Receptor tyrosine kinases (RTKs) such as Tie-2, IGF1R, Her-2/Neu, EGFR, and VEGFR1-3 play crucial roles in the control of cell growth and differentiation. Inhibition of such RTKs has become a major focus of current anticancer drug development, and therefore the discovery of new classes of inhibitors for these signal-transducing proteins is of prime importance. We have recently proposed a novel concept for improving the hit-finding process by employing natural products as biologically validated starting points in structural space for compound library development. In this concept, natural products are regarded as evolutionary chosen ligands for protein domains which are structurally conserved yet genetically mobile. Here we report on the discovery of novel and highly selective VEGFR-2 and -3, Tie-2, and IGF1R inhibitors derived from the naturally occurring Her-2/Neu kinase inhibitor nakijiquinone C and developed on the basis of this concept. Based on the structure of the natural product, a small library (74 members) was synthesized and investigated for inhibition of kinases with highly similar ATP-binding domains. The library yielded inhibitors with IC(50)s in the low micromolar range with high frequency (7 out of 74). In particular, four inhibitors of Tie-2 were found, a kinase critically involved in the formation of new blood vessels from preexisting ones (angiogenesis) and believed to be a new promising target in antitumor therapy. These results support the "domain concept". To advance the development of improved inhibitors, extensive molecular modeling studies were undertaken, including the construction of new homology models for VEGFR-2 and Tie-2. These studies revealed residues in the kinase structure which are crucial to the development of tailor-made receptor tyrosine kinase inhibitors.

  8. Interactions between the S-Domain Receptor Kinases and AtPUB-ARM E3 Ubiquitin Ligases Suggest a Conserved Signaling Pathway in Arabidopsis1[W][OA

    PubMed Central

    Samuel, Marcus A.; Mudgil, Yashwanti; Salt, Jennifer N.; Delmas, Frédéric; Ramachandran, Shaliny; Chilelli, Andrea; Goring, Daphne R.

    2008-01-01

    The Arabidopsis (Arabidopsis thaliana) genome encompasses multiple receptor kinase families with highly variable extracellular domains. Despite their large numbers, the various ligands and the downstream interacting partners for these kinases have been deciphered only for a few members. One such member, the S-receptor kinase, is known to mediate the self-incompatibility (SI) response in Brassica. S-receptor kinase has been shown to interact and phosphorylate a U-box/ARM-repeat-containing E3 ligase, ARC1, which, in turn, acts as a positive regulator of the SI response. In an effort to identify conserved signaling pathways in Arabidopsis, we performed yeast two-hybrid analyses of various S-domain receptor kinase family members with representative Arabidopsis plant U-box/ARM-repeat (AtPUB-ARM) E3 ligases. The kinase domains from S-domain receptor kinases were found to interact with ARM-repeat domains from AtPUB-ARM proteins. These kinase domains, along with M-locus protein kinase, a positive regulator of SI response, were also able to phosphorylate the ARM-repeat domains in in vitro phosphorylation assays. Subcellular localization patterns were investigated using transient expression assays in tobacco (Nicotiana tabacum) BY-2 cells and changes were detected in the presence of interacting kinases. Finally, potential links to the involvement of these interacting modules to the hormone abscisic acid (ABA) were investigated. Interestingly, AtPUB9 displayed redistribution to the plasma membrane of BY-2 cells when either treated with ABA or coexpressed with the active kinase domain of ARK1. As well, T-DNA insertion mutants for ARK1 and AtPUB9 lines were altered in their ABA sensitivity during germination and acted at or upstream of ABI3, indicating potential involvement of these proteins in ABA responses. PMID:18552232

  9. Crystal structure of the kinase domain of human protein tyrosine kinase 6 (PTK6) at 2.33 Å resolution.

    PubMed

    Thakur, Manish Kumar; Kumar, Amit; Birudukota, Swarnakumari; Swaminathan, Srinivasan; Tyagi, Rajiv; Gosu, Ramachandraiah

    2016-09-16

    Human Protein tyrosine kinase 6 (PTK6) (EC:2.7.10.2), also known as the breast tumor kinase (BRK), is an intracellular non-receptor Src-related tyrosine kinase expressed in a majority of human breast tumors and breast cancer cell lines, but its expression is low or completely absent in normal mammary glands. In the recent past, several studies have suggested that PTK6 is a potential therapeutic target in cancer. To understand its structural and functional properties, the PTK6 kinase domain (PTK6-KD) gene was cloned, overexpressed in a baculo-insect cell system, purified and crystallized at room temperature. X-ray diffraction data to 2.33 Å resolution was collected on a single PTK6-KD crystal, which belonged to the triclinic space group P1. The Matthews coefficient calculation suggested the presence of four protein molecules per asymmetric unit, with a solvent content of ∼50%.The structure has been solved by molecular replacement and crystal structure data submitted to the protein data bank under the accession number 5D7V. This is the first report of apo PTK6-KD structure crystallized in DFG-in and αC-helix-out conformation.

  10. Structure of the two-domain hexameric APS kinase from Thiobacillus denitrificans: structural basis for the absence of ATP sulfurylase activity

    SciTech Connect

    Gay, Sean C.; Segel, Irwin H.; Fisher, Andrew J.

    2009-10-01

    APS kinase from Thiobacillus denitrificans contains an inactive N-terminal ATP sulfurylase domain. The structure presented unveils the first hexameric assembly for an APS kinase, and reveals that structural changes in the N-terminal domain disrupt the ATP sulfurylase active site thus prohibiting activity. The Tbd-0210 gene of the chemolithotrophic bacterium Thiobacillus denitrificans is annotated to encode a 60.5 kDa bifunctional enzyme with ATP sulfurylase and APS kinase activity. This putative bifunctional enzyme was cloned, expressed and structurally characterized. The 2.95 Å resolution X-ray crystal structure reported here revealed a hexameric assembly with D{sub 3} symmetry. Each subunit contains a large N-terminal sulfurylase-like domain and a C-terminal APS kinase domain reminiscent of the two-domain fungal ATP sulfurylases of Penicillium chrysogenum and Saccharomyces cerevisiae, which also exhibit a hexameric assembly. However, the T. denitrificans enzyme exhibits numerous structural and sequence differences in the N-terminal domain that render it inactive with respect to ATP sulfurylase activity. Surprisingly, the C-terminal domain does indeed display APS kinase activity, indicating that this gene product is a true APS kinase. Therefore, these results provide the first structural insights into a unique hexameric APS kinase that contains a nonfunctional ATP sulfurylase-like domain of unknown function.

  11. ALK- anaplastic large-cell lymphoma is clinically and immunophenotypically different from both ALK+ ALCL and peripheral T-cell lymphoma, not otherwise specified: report from the International Peripheral T-Cell Lymphoma Project.

    PubMed

    Savage, Kerry J; Harris, Nancy Lee; Vose, Julie M; Ullrich, Fred; Jaffe, Elaine S; Connors, Joseph M; Rimsza, Lisa; Pileri, Stefano A; Chhanabhai, Mukesh; Gascoyne, Randy D; Armitage, James O; Weisenburger, Dennis D

    2008-06-15

    The International Peripheral T-Cell Lymphoma Project is a collaborative effort designed to gain better understanding of peripheral T-cell and natural killer (NK)/T-cell lymphomas (PTCLs). A total of 22 institutions in North America, Europe, and Asia submitted clinical and pathologic information on PTCLs diagnosed and treated at their respective centers. Of the 1314 eligible patients, 181 had anaplastic large-cell lymphoma (ALCL; 13.8%) on consensus review: One hundred fifty-nine had systemic ALCL (12.1%) and 22 had primary cutaneous ALCL (1.7%). Patients with anaplastic lymphoma kinase-positive (ALK(+)) ALCL had a superior outcome compared with those with ALK(-) ALCL (5-year failure-free survival [FFS], 60% vs 36%; P = .015; 5-year overall survival [OS], 70% vs 49%; P = .016). However, contrary to prior reports, the 5-year FFS (36% vs 20%; P = .012) and OS (49% vs 32%; P = .032) were superior for ALK(-) ALCL compared with PTCL, not otherwise specified (PTCL-NOS). Patients with primary cutaneous ALCL had a very favorable 5-year OS (90%), but with a propensity to relapse (5-year FFS, 55%). In summary, ALK(-) ALCL should continue to be separated from both ALK(+) ALCL and PTCL-NOS. Although the prognosis of ALK(-) ALCL appears to be better than that for PTCL-NOS, it is still unsatisfactory and better therapies are needed. Primary cutaneous ALCL is associated with an indolent course.

  12. L1198F Mutation Resensitizes Crizotinib to ALK by Altering the Conformation of Inhibitor and ATP Binding Sites

    PubMed Central

    Li, Jian; Sun, Rong; Wu, Yuehong; Song, Mingzhu; Li, Jia; Yang, Qianye; Chen, Xiaoyi; Bao, Jinku; Zhao, Qi

    2017-01-01

    The efficacy of anaplastic lymphoma kinase (ALK) positive non-small-cell lung cancer (NSCLC) treatment with small molecule inhibitors is greatly challenged by acquired resistance. A recent study reported the newest generation inhibitor resistant mutation L1198F led to the resensitization to crizotinib, which is the first Food and Drug Administration (FDA) approved drug for the treatment of ALK-positive NSCLC. It is of great importance to understand how this extremely rare event occurred for the purpose of overcoming the acquired resistance of such inhibitors. In this study, we exploited molecular dynamics (MD) simulation to dissect the molecular mechanisms. Our MD results revealed that L1198F mutation of ALK resulted in the conformational change at the inhibitor site and altered the binding affinity of ALK to crizotinib and lorlatinib. L1198F mutation also affected the autoactivation of ALK as supported by the identification of His1124 and Tyr1278 as critical amino acids involved in ATP binding and phosphorylation. Our findings are valuable for designing more specific and potent inhibitors for the treatment of ALK-positive NSCLC and other types of cancer. PMID:28245558

  13. Prediction of the repeat domain structures and impact of parkinsonism-associated variations on structure and function of all functional domains of leucine-rich repeat kinase 2 (LRRK2).

    PubMed

    Mills, Ryan D; Mulhern, Terrence D; Liu, Fei; Culvenor, Janetta G; Cheng, Heung-Chin

    2014-04-01

    Genetic variations of leucine-rich repeat kinase 2 (LRRK2) are the major cause of dominantly inherited Parkinson disease (PD). LRRK2 protein contains seven predicted domains: a tandem Ras-like GTPase (ROC) domain and C-terminal of Roc (COR) domain, a protein kinase domain, and four repeat domains. PD-causative variations arise in all domains, suggesting that aberrant functioning of any domain can contribute to neurotoxic mechanisms of LRRK2. Determination of the three-dimensional structure of LRRK2 is one of the best avenues to decipher its neurotoxic mechanism. However, with the exception of the Roc domain, the three-dimensional structures of the functional domains of LRRK2 have yet to be determined. Based on the known three-dimensional structures of repeat domains of other proteins, the tandem Roc-COR domains of the Chlorobium tepidum Rab family protein, and the kinase domain of the Dictyostelium discoideum Roco4 protein, we predicted (1) the motifs essential for protein-protein interactions in all domains, (2) the motifs critical for catalysis and substrate recognition in the tandem Roc-COR and kinase domains, and (3) the effects of some PD-associated missense variations on the neurotoxic action of LRRK2. Results of our analysis provide a conceptual framework for future investigation into the regulation and the neurotoxic mechanism of LRRK2.

  14. Ethanol activates midkine and anaplastic lymphoma kinase signaling in neuroblastoma cells and in the brain.

    PubMed

    He, Donghong; Chen, Hu; Muramatsu, Hisako; Lasek, Amy W

    2015-11-01

    Alcohol engages signaling pathways in the brain. Midkine (MDK) is a neurotrophic factor that is over-expressed in the prefrontal cortex of alcoholics. MDK and one of its receptors, anaplastic lymphoma kinase (ALK), also regulate behavioral responses to ethanol in mice. The goal of this study was to determine whether MDK and ALK expression and signaling are activated by ethanol. We found that ethanol treatment of neuroblastoma cells increased MDK and ALK expression. We also assessed activation of ALK by ethanol in cells and found that ALK and ALK-dependent extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription 3 (STAT3) phosphorylation increased rapidly with ethanol exposure. Similarly, treatment of cells with recombinant MDK protein increased ALK, ERK and STAT3 phosphorylation, suggesting that ethanol may utilize MDK to activate ALK signaling. In support of this, transfection of cells with MDK siRNAs attenuated ALK signaling in response to ethanol. Ethanol also activates ERK signaling in the brain. We found that inhibition of ALK or knockout of MDK attenuated ethanol-induced ERK phosphorylation in mouse amygdala. These results demonstrate that ethanol engages MDK and ALK signaling, which has important consequences for alcohol-induced neurotoxicity and the regulation of behaviors related to alcohol abuse.

  15. OsBRI1 Activates BR Signaling by Preventing Binding between the TPR and Kinase Domains of OsBSK3 via Phosphorylation1

    PubMed Central

    Wang, Xiaolong; Zhao, Zhiying; Wang, Ruiju; Huang, Xiahe; Zhu, Yali; Yuan, Li; Wang, Yingchun; Burlingame, Alma L.; Gao, Yingjie

    2016-01-01

    Many plant receptor kinases transduce signals through receptor-like cytoplasmic kinases (RLCKs); however, the molecular mechanisms that create an effective on-off switch are unknown. The receptor kinase BR INSENSITIVE1 (BRI1) transduces brassinosteroid (BR) signal by phosphorylating members of the BR-signaling kinase (BSK) family of RLCKs, which contain a kinase domain and a C-terminal tetratricopeptide repeat (TPR) domain. Here, we show that the BR signaling function of BSKs is conserved in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa) and that the TPR domain of BSKs functions as a “phospho-switchable” autoregulatory domain to control BSKs’ activity. Genetic studies revealed that OsBSK3 is a positive regulator of BR signaling in rice, while in vivo and in vitro assays demonstrated that OsBRI1 interacts directly with and phosphorylates OsBSK3. The TPR domain of OsBSK3, which interacts directly with the protein’s kinase domain, serves as an autoinhibitory domain to prevent OsBSK3 from interacting with bri1-SUPPRESSOR1 (BSU1). Phosphorylation of OsBSK3 by OsBRI1 disrupts the interaction between its TPR and kinase domains, thereby increasing the binding between OsBSK3’s kinase domain and BSU1. Our results not only demonstrate that OsBSK3 plays a conserved role in regulating BR signaling in rice, but also provide insight into the molecular mechanism by which BSK family proteins are inhibited under basal conditions but switched on by the upstream receptor kinase BRI1. PMID:26697897

  16. Chimeric Plant Calcium/Calmodulin-Dependent Protein Kinase Gene with a Neural Visinin-Like Calcium-Binding Domain

    NASA Technical Reports Server (NTRS)

    Patil, Shameekumar; Takezawa, D.; Poovaiah, B. W.

    1995-01-01

    Calcium, a universal second messenger, regulates diverse cellular processes in eukaryotes. Ca-2(+) and Ca-2(+)/calmodulin-regulated protein phosphorylation play a pivotal role in amplifying and diversifying the action of Ca-2(+)- mediated signals. A chimeric Ca-2(+)/calmodulin-dependent protein kinase (CCaMK) gene with a visinin-like Ca-2(+)- binding domain was cloned and characterized from lily. The cDNA clone contains an open reading frame coding for a protein of 520 amino acids. The predicted structure of CCaMK contains a catalytic domain followed by two regulatory domains, a calmodulin-binding domain and a visinin-like Ca-2(+)-binding domain. The amino-terminal region of CCaMK contains all 11 conserved subdomains characteristic of serine/threonine protein kinases. The calmodulin-binding region of CCaMK has high homology (79%) to alpha subunit of mammalian Ca-2(+)/calmodulin-dependent protein kinase. The calmodulin-binding region is fused to a neural visinin-like domain that contains three Ca-2(+)-binding EF-hand motifs and a biotin-binding site. The Escherichia coli-expressed protein (approx. 56 kDa) binds calmodulin in a Ca-2(+)-dependent manner. Furthermore, Ca-45-binding assays revealed that CCaMK directly binds Ca-2(+). The CCaMK gene is preferentially expressed in developing anthers. Southern blot analysis revealed that CCaMK is encoded by a single gene. The structural features of the gene suggest that it has multiple regulatory controls and could play a unique role in Ca-2(+) signaling in plants.

  17. Discovery of Novel Polo-Like Kinase 1 Polo-Box Domain Inhibitors to Induce Mitotic Arrest in Tumor Cells.

    PubMed

    Qin, Tan; Chen, Fangjin; Zhuo, Xiaolong; Guo, Xiao; Yun, Taikangxiang; Liu, Ying; Zhang, Chuanmao; Lai, Luhua

    2016-08-11

    Polo-like kinase 1(Plk1) is vital for cell mitosis and has been identified as anticancer target. Its polo-box domain (PBD) mediates substrate binding, blocking of which may offer selective Plk1 inhibition compared to kinase domain inhibitors. Although several PBD inhibitors were reported, most of them suffer from low cell activity. Here, we report the discovery of novel inhibitors to induce mitotic arrest in HeLa cells by virtual screening with Plk1 PBD and cellular activity testing. Of the 81 compounds tested in the cell assay, 10 molecules with diverse chemical scaffolds are potent to induce mitotic arrest of HeLa at low micromolar concentrations. The best compound induces mitotic arrest of HeLa cells with an EC50 of 4.4 μM. The cellular active inhibitors showed binding to Plk1 PBD and compete with PBD substrate in microscale thermophoresis analysis.

  18. The SH3 regulatory domain of the hematopoietic cell kinase Hck binds ELMO via its polyproline motif

    PubMed Central

    Awad, Rida; Marion, Sévajol; Isabel, Ayala; Anne, Chouquet; Philippe, Frachet; Pierre, Gans; Jean-Baptiste, Reiser; Jean-Philippe, Kleman

    2015-01-01

    Eukaryotic EnguLfment and cell MOtility (ELMO) proteins form an evolutionary conserved family of regulators involved in small GTPase dependent actin remodeling processes that regulates the guanine exchange factor activity of some of the Downstream Of CrK (DOCK) family members. Gathered data strongly suggest that DOCK activation by ELMO and the subsequent signaling result from a subtle balance in the binding of partners to ELMO. Among its putative upward modulators, the Hematopoietic cell kinase (Hck), a member of the Src kinase superfamily, has been identified as a binding partner and a specific tyrosine kinase for ELMO1. Indeed, Hck is implicated in distinct molecular signaling pathways governing phagocytosis, cell adhesion, and migration of hematopoietic cells. Although ELMO1 has been shown to interact with the regulatory Src Homology 3 (SH3) domain of Hck, no direct evidence indicating the mode of interaction between Hck and ELMO1 have been provided in the literature. In the present study, we report convergent pieces of evidence that demonstrate the specific interaction between the SH3 domain of Hck and the polyproline motif of ELMO1. Our results also suggest that the tyrosine-phosphorylation state of ELMO1 tail might act as a putative modulator of Hck kinase activity towards ELMO1 that in turn participates in DOCK180 activation and further triggers subsequent signaling towards actin remodeling. PMID:25737835

  19. A large, single-center, real-world study of clinicopathological characteristics and treatment in advanced ALK-positive non-small-cell lung cancer.

    PubMed

    Chen, Gang; Chen, Xi; Zhang, Yaxiong; Yan, Fang; Fang, Wenfeng; Yang, Yunpeng; Hong, Shaodong; Miao, Siyu; Wu, Manli; Huang, Xiaodan; Luo, Youli; Zhou, Cong; Gong, Run; Huang, Yan; Zhou, Ningning; Zhao, Hongyun; Zhang, Li

    2017-04-04

    Crizotinib has achieved astonishing success in advanced non-small-cell lung cancer (NSCLC) patients harboring anaplastic lymphoma kinase (ALK) rearrangement. However, no real-world studies described the clinicopathological characteristics and treatment of such patients in China. Patients were consecutively collected from Sun Yat-sen University Cancer Center. Chi-square test was applied to explore the relationship between ALK fusion status and metastasis sites. Kaplan-Meier methods and multivariable analyses were used to estimate progression-free survival (PFS). A total of 291 advanced NSCLC patients (ALK (+), N = 97; both ALK & epidermal growth factor receptor (EGFR) (-), N = 194) were enrolled. The occurrence of brain metastasis in ALK-positive patients was significantly higher than double-negative ones both at baseline (26.5% vs. 16.5%, P = 0.038) and during treatment (25.8% vs. 11.9%, P = 0.003), but opposite for pleural effusion (6.2% vs. 26.9%, P < 0.001 at baseline; 3.1% vs. 10.3%, P = 0.031 during treatment). ALK-positive patients of 53.6% used crizotinib, whereas others only received chemotherapy (37.1%) or supportive care (9.3%). Usage of crizotinib prolonged PFS compared with chemotherapy in ALK-positive patients (median PFS 17.6 m vs. 4.8 m, P < 0.001). ALK-positive NSCLC had more brain metastasis and less pleural effusion than double-negative ones. Crizotinib showed better PFS than chemotherapy in advanced ALK-positive NSCLC at any line. However, half advanced ALK-positive patients never received crizotinib, which was grim and need improving.

  20. ALK-positive anaplastic large cell lymphoma limited to the skin: clinical, histopathological and molecular analysis of 6 pediatric cases. A report from the ALCL99 study.

    PubMed

    Oschlies, Ilske; Lisfeld, Jasmin; Lamant, Laurence; Nakazawa, Atsuko; d'Amore, Emanuele S G; Hansson, Ulrika; Hebeda, Konnie; Simonitsch-Klupp, Ingrid; Maldyk, Jadwiga; Müllauer, Leonhard; Tinguely, Marianne; Stücker, Markus; Ledeley, Marie-Cecile; Siebert, Reiner; Reiter, Alfred; Brugières, Laurence; Klapper, Wolfram; Woessmann, Wilhelm

    2013-01-01

    Anaplastic large cell lymphomas are peripheral T-cell lymphomas that are characterized by a proliferation of large anaplastic blasts expressing CD30. In children, systemic anaplastic large cell lymphomas often present at advanced clinical stage and harbor translocations involving the anaplastic lymphoma kinase (ALK) gene leading to the expression of chimeric anaplastic lymphoma kinase (ALK)-fusion proteins. Primary cutaneous anaplastic large cell lymphoma is regarded as an ALK-negative variant confined to the skin and is part of the spectrum of primary cutaneous CD30-positive T-cell lymphoproliferative disorders. Thirty-three of 487 pediatric patients registered within the Anaplastic Large Cell Lymphoma-99 trial (1999 to 2006) presented with a skin limited CD30-positive lympho-proliferative disorder. In 23 of the 33 patients, material for international histopathological review was available, and the cases were studied for histopathological, immunophenotypical and clinical features as well as for breaks within the ALK gene. Five of 23 cases and one additional case (identified after closure of the trial) expressed ALK-protein. Complete staging excluded any other organ involvement in all children. Expression of ALK proteins was demonstrated by immunohistochemistry in all cases and the presence of breaks of the ALK gene was genetically confirmed in 5 evaluable cases. The histopathological and clinical picture of these skin-restricted ALK-positive lymphomas was indistinguishable from that of cutaneous anaplastic large cell lymphoma. Five children presented with a single skin lesion that was completely resected in 4 and incompletely resected in one. Three of these patients received no further therapy, 2 additional local radiotherapy, and one chemotherapy. All children remain in complete remission with a median follow up of seven years (range 1-8 years). We present 6 pediatric cases of ALK-positive primary cutaneous anaplastic large cell lymphomas. After thorough

  1. Anaplastic lymphoma kinase: role in cancer pathogenesis and small-molecule inhibitor development for therapy

    PubMed Central

    Webb, Thomas R; Slavish, Jake; George, Rani E; Look, A Thomas; Xue, Liquan; Jiang, Qin; Cui, Xiaoli; Rentrop, Walter B; Morris, Stephan W

    2009-01-01

    Anaplastic lymphoma kinase (ALK), a receptor tyrosine kinase in the insulin receptor superfamily, was initially identified in constitutively activated oncogenic fusion forms – the most common being nucleophosmin-ALK – in anaplastic large-cell lymphomas, and subsequent studies have identified ALK fusions in diffuse large B-cell lymphomas, systemic histiocytosis, inflammatory myofibroblastic tumors, esophageal squamous cell carcinomas and non-small-cell lung carcinomas. More recently, genomic DNA amplification and protein overexpression, as well as activating point mutations, of ALK have been described in neuroblastomas. In addition to those cancers for which a causative role for aberrant ALK activity is well validated, more circumstantial links implicate the full-length, normal ALK receptor in the genesis of other malignancies – including glioblastoma and breast cancer – via a mechanism of receptor activation involving autocrine and/or paracrine growth loops with the reported ALK ligands, pleiotrophin and midkine. This review summarizes normal ALK biology, the confirmed and putative roles of ALK in the development of human cancers and efforts to target ALK using small-molecule kinase inhibitors. PMID:19275511

  2. In vivo binding properties of SH2 domains from GTPase-activating protein and phosphatidylinositol 3-kinase.

    PubMed Central

    Cooper, J A; Kashishian, A

    1993-01-01

    We have used a transient expression system and mutant platelet-derived growth factor (PDGF) receptors to study the binding specificities of the Src homology 2 (SH2) regions of the Ras GTPase-activator protein (GAP) and the p85 alpha subunit of phosphatidylinositol 3-kinase (PI3 kinase). A number of fusion proteins, each tagged with an epitope allowing recognition by a monoclonal antibody, were expressed at levels comparable to those of endogenous GAP. Fusion proteins containing the central SH2-SH3-SH2 region of GAP or the C-terminal region of p85 alpha, which includes two SH2 domains, bound to PDGF receptors in response to PDGF stimulation. Both fusion proteins showed the same requirements for tyrosine phosphorylation sites in the PDGF receptor as the full-length proteins from which they were derived, i.e., binding of the GAP fusion protein was reduced by mutation of Tyr-771, and binding of the p85 fusion protein was reduced by mutation of Tyr-740, Tyr-751, or both residues. Fusion proteins containing single SH2 domains from either GAP or p85 alpha did not bind detectably to PDGF receptors in this system, suggesting that two SH2 domains in a single polypeptide cooperate to raise the affinity of binding. The sequence specificities of individual SH2 domains were deduced from the binding properties of fusion proteins containing one SH2 domain from GAP and another from p85. The results suggest that the C-terminal GAP SH2 domain specifies binding to Tyr-771, the C-terminal p85 alpha SH2 domain binds to either Tyr-740 or Tyr-751, and each protein's N-terminal SH2 domain binds to unidentified phosphorylation sites.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:8382774

  3. PB1 Domain-Dependent Signaling Complex Is Required for Extracellular Signal-Regulated Kinase 5 Activation

    PubMed Central

    Nakamura, Kazuhiro; Uhlik, Mark T.; Johnson, Nancy L.; Hahn, Klaus M.; Johnson, Gary L.

    2006-01-01

    MEKK2, MEK5, and extracellular signal-regulated kinase 5 (ERK5) are members of a three-kinase cascade for the activation of ERK5. MEK5 is the only MAP2K to express a PB1 domain, and we have shown that it heterodimerizes with the PB1 domain of MEKK2. Here we demonstrate the MEK5 PB1 domain is a scaffold that also binds ERK5, functionally forming a MEKK2-MEK5-ERK5 complex. Reconstitution assays and CFP/YFP imaging (fluorescence resonance energy transfer [FRET]) measuring YFP-MEKK2/CFP-MEK5 and CFP-MEK5/YFP-ERK5 interactions define distinct MEK5 PB1 domain binding sites for MEKK2 and ERK5, with a C-terminal extension of the PB1 domain contributing to ERK5 binding. Stimulus-dependent CFP/YFP FRET in combination with mutational analysis was used to define MEK5 PB1 domain residues critical for the interaction of MEKK2/MEK5 and MEK5/ERK5 required for activation of the ERK5 pathway in living cells. Fusion of the MEK5 PB1 domain to the N terminus of MEK1 confers ERK5 regulation by a MAP2K normally regulating only ERK1/2. The MEK5 PB1 domain confers stringent MAP3K regulation of ERK5 relative to more promiscuous MAP3K control of ERK1/2, JNK, and p38. PMID:16507987

  4. Biochemical characterization of the protein tyrosine kinase homology domain of the ErbB3 (HER3) receptor protein.

    PubMed

    Sierke, S L; Cheng, K; Kim, H H; Koland, J G

    1997-03-15

    The putative protein tyrosine kinase domain (TKD) of the ErbB3 (HER3) receptor protein was generated as a histidine-tagged recombinant protein (hisTKD-B3) and characterized enzymologically. CD spectroscopy indicated that the hisTKD-B3 protein assumed a native conformation with a secondary structure similar to that of the epidermal growth factor (EGF) receptor TKD. However, when compared with the EGF receptor-derived protein, hisTKD-B3 exhibited negligible intrinsic protein tyrosine kinase activity. Immune complex kinase assays of full-length ErbB3 proteins also yielded no evidence of catalytic activity. A fluorescence assay previously used to characterize the nucleotide-binding properties of the EGF receptor indicated that the ErbB3 protein was unable to bind nucleotide. The hisTKD-B3 protein was subsequently found to be an excellent substrate for the EGF receptor protein tyrosine kinase, which suggested that in vivo phosphorylation of ErbB3 in response to EGF could be attributed to a direct cross-phosphorylation by the EGF receptor protein tyrosine kinase.

  5. Biochemical characterization of the protein tyrosine kinase homology domain of the ErbB3 (HER3) receptor protein.

    PubMed Central

    Sierke, S L; Cheng, K; Kim, H H; Koland, J G

    1997-01-01

    The putative protein tyrosine kinase domain (TKD) of the ErbB3 (HER3) receptor protein was generated as a histidine-tagged recombinant protein (hisTKD-B3) and characterized enzymologically. CD spectroscopy indicated that the hisTKD-B3 protein assumed a native conformation with a secondary structure similar to that of the epidermal growth factor (EGF) receptor TKD. However, when compared with the EGF receptor-derived protein, hisTKD-B3 exhibited negligible intrinsic protein tyrosine kinase activity. Immune complex kinase assays of full-length ErbB3 proteins also yielded no evidence of catalytic activity. A fluorescence assay previously used to characterize the nucleotide-binding properties of the EGF receptor indicated that the ErbB3 protein was unable to bind nucleotide. The hisTKD-B3 protein was subsequently found to be an excellent substrate for the EGF receptor protein tyrosine kinase, which suggested that in vivo phosphorylation of ErbB3 in response to EGF could be attributed to a direct cross-phosphorylation by the EGF receptor protein tyrosine kinase. PMID:9148746

  6. A frequent kinase domain mutation that changes the interaction between PI3K[alpha] and the membrane

    SciTech Connect

    Mandelker, Diana; Gabelli, Sandra B.; Schmidt-Kittler, Oleg; Zhu, Jiuxiang; Cheong, Ian; Huang, Chuan-Hsiang; Kinzler, Kenneth W.; Vogelstein, Bert; Amzel, L. Mario

    2009-12-01

    Mutations in oncogenes often promote tumorigenesis by changing the conformation of the encoded proteins, thereby altering enzymatic activity. The PIK3CA oncogene, which encodes p110{alpha}, the catalytic subunit of phosphatidylinositol 3-kinase alpha (PI3K{alpha}), is one of the two most frequently mutated oncogenes in human cancers. We report the structure of the most common mutant of p110{alpha} in complex with two interacting domains of its regulatory partner (p85{alpha}), both free and bound to an inhibitor (wortmannin). The N-terminal SH2 (nSH2) domain of p85{alpha} is shown to form a scaffold for the entire enzyme complex, strategically positioned to communicate extrinsic signals from phosphopeptides to three distinct regions of p110{alpha}. Moreover, we found that Arg-1047 points toward the cell membrane, perpendicular to the orientation of His-1047 in the WT enzyme. Surprisingly, two loops of the kinase domain that contact the cell membrane shift conformation in the oncogenic mutant. Biochemical assays revealed that the enzymatic activity of the p110{alpha} His1047Arg mutant is differentially regulated by lipid membrane composition. These structural and biochemical data suggest a previously undescribed mechanism for mutational activation of a kinase that involves perturbation of its interaction with the cellular membrane.

  7. Mutations in the Kinase Domain of the HER2/ERBB2 Gene Identified in a Wide Variety of Human Cancers.

    PubMed

    Wen, Wenhsiang; Chen, Wangjuh Sting; Xiao, Nick; Bender, Ryan; Ghazalpour, Anatole; Tan, Zheng; Swensen, Jeffrey; Millis, Sherri Z; Basu, Gargi; Gatalica, Zoran; Press, Michael F

    2015-09-01

    The HER2 (official name ERBB2) gene encodes a membrane receptor in the epidermal growth factor receptor family amplified and overexpressed in adenocarcinoma. Activating mutations also occur in several cancers. We report mutation analyses of the HER2 kinase domain in 7497 histologically diverse cancers. Forty-five genes, including the kinase domain of HER2 with HER2 IHC and dual in situ hybridization, were analyzed in tumors from 7497 patients with cancer, including 850 breast, 770 colorectal, 910 non-small cell lung, 823 uterine or cervical, 1372 ovarian, and 297 pancreatic cancers, as well as 323 melanomas and 2152 other solid tumors. Sixty-nine HER2 kinase domain mutations were identified in tumors from 68 patients (approximately 1% of all cases, ranging from absent in sarcomas to 4% in urothelial cancers), which included previously published activating mutations and 13 novel mutations. Fourteen cases with coexisting HER2 mutation and amplification and/or overexpression were identified. Fifty-two of 68 patients had additional mutations in other analyzed genes, whereas 16 patients (23%) had HER2 mutations identified as the sole driver mutation. HER2 mutations coexisted with HER2 gene amplification and overexpression and with mutations in other functionally important genes. HER2 mutations were identified as the only driver mutation in a significant proportion of solid cancers. Evaluation of anti-HER2 therapies in nonamplified, HER2-mutated cancers is warranted.

  8. Autophosphorylation of the C2 domain inhibits translocation of the novel protein kinase C (nPKC) Apl II.

    PubMed

    Farah, Carole A; Lindeman, Amanda A; Siu, Vincent; Gupta, Micaela Das; Sossin, Wayne S

    2012-11-01

    Protein kinase Cs (PKCs) are critical signaling molecules controlled by complex regulatory pathways. Herein, we describe an important regulatory role for C2 domain phosphorylation. Novel PKCs (nPKCs) contain an N-terminal C2 domain that cannot bind to calcium. Previously, we described an autophosphorylation site in the Aplysia novel PKC Apl II that increased the binding of the C2 domain to lipids. In this study, we show that the function of this phosphorylation is to inhibit PKC translocation. Indeed, a phosphomimetic serine-glutamic acid mutation reduced translocation of PKC Apl II while blocking phosphorylation with a serine-alanine mutation enhanced translocation and led to the persistence of the kinase at the membrane longer after the end of the stimulation. Consistent with a role for autophosphorylation in regulating kinase translocation, inhibiting PKC activity using bisindolymaleimide 1 increased physiological translocation of PKC Apl II, whereas inhibiting phosphatase activity using calyculin A inhibited physiological translocation of PKC Apl II in neurons. Our results suggest a major role for autophosphorylation-dependent regulation of translocation.

  9. BRAF Kinase Domain Mutations are Common in RASwt Chronic Myelomonocytic Leukemia

    PubMed Central

    Zhang, Liping; Singh, Rajesh R.; Patel, Keyur P.; Stingo, Francesco; Routbort, Mark; You, M. James; Miranda, Roberto N.; Kantarjian, Hagop M.; Medeiros, L. Jeffrey; Luthra, Raja; Khoury, Joseph D.

    2014-01-01

    Purpose The frequency of RAS mutations in chronic myelomonocytic leukemia (CMML) suggests that activation of the MAPK pathway is important in CMML pathogenesis. Accordingly, we hypothesized that mutations in other members of the MAPK pathway might be overrepresented in RASwt CMML. Methods We performed next generation sequencing analysis on 70 CMML patients with known RAS mutation status using the TruSeq Amplicon Cancer Panel kit (Illumina, San Diego, CA). Results The study group included 37 men and 33 women with a median age of 67.8 years (range, 28–86 years). Forty patients were RASwt and 30 were RASmut; the latter included KRAS=17; NRAS=12; KRAS+NRAS=1. Next-generation sequencing showed 5 patients (7.1% of total group; 12.5% of RASwt group) with RASwt who had BRAF mutations. All BRAFmut patients had CMML-1; 2 (40%) with MPN-CMML and 3 with MDS-CMML. The BRAF mutations were of missense type and involved exon 11 in 1 patient and exon 15 in 4 patients. All BRAFmut patients had CMML-1 with low-risk cytogenetic findings, and none of the BRAFmut CMML cases were therapy-related. Two (40%) of the 5 patients with BRAFmut patients transformed to acute myeloid leukemia during follow up. Multivariate Cox proportional hazard regression modeling suggests that BRAFmut status is associated with overall survival (p=0.04). Additionally, the RASmut group tended to have worse OS compared to the RASwt group. Conclusion In summary, we demonstrate that a subset of patients with RASwt CMML harbors BRAF kinase domain mutations that are potentially capable of activating the MAPK signaling pathway. PMID:24446311

  10. Solution structure of the focal adhesion adaptor PINCH LIM1 domain and characterization of its interaction with the integrin-linked kinase ankyrin repeat domain.

    PubMed

    Velyvis, A; Yang, Y; Wu, C; Qin, J

    2001-02-16

    PINCH is a recently identified adaptor protein that comprises an array of five LIM domains. PINCH functions through LIM-mediated protein-protein interactions that are involved in cell adhesion, growth, and differentiation. The LIM1 domain of PINCH interacts with integrin-linked kinase (ILK), thereby mediating focal adhesions via a specific integrin/ILK signaling pathway. We have solved the NMR structure of the PINCH LIM1 domain and characterized its binding to ILK. LIM1 contains two contiguous zinc fingers of the CCHC and CCCH types and adopts a global fold similar to that of functionally distinct LIM domains from cysteine-rich protein and cysteine-rich intestinal protein families with CCHC and CCCC zinc finger types. Gel-filtration and NMR experiments demonstrated a 1:1 complex between PINCH LIM1 and the ankyrin repeat domain of ILK. A chemical shift mapping experiment identified regions in PINCH LIM1 that are important for interaction with ILK. Comparison of surface features between PINCH LIM1 and other functionally different LIM domains indicated that the LIM motif might have a highly variable mode in recognizing various target proteins.

  11. Genetic and biochemical dissection of a HisKA domain identifies residues required exclusively for kinase and phosphatase activities.

    PubMed

    Willett, Jonathan W; Kirby, John R

    2012-01-01

    Two-component signal transduction systems, composed of histidine kinases (HK) and response regulators (RR), allow bacteria to respond to diverse environmental stimuli. The HK can control both phosphorylation and subsequent dephosphorylation of its cognate RR. The majority of HKs utilize the HisKA subfamily of dimerization and histidine phosphotransfer (DHp) domains, which contain the phospho-accepting histidine and directly contact the RR. Extensive genetics, biochemistry, and structural biology on several prototypical TCS systems including NtrB-NtrC and EnvZ-OmpR have provided a solid basis for understanding the function of HK-RR signaling. Recently, work on NarX, a HisKA_3 subfamily protein, indicated that two residues in the highly conserved region of the DHp domain are responsible for phosphatase activity. In this study we have carried out both genetic and biochemical analyses on Myxococcus xanthus CrdS, a member of the HisKA subfamily of bacterial HKs. CrdS is required for the regulation of spore formation in response to environmental stress. Following alanine-scanning mutagenesis of the α1 helix of the DHp domain of CrdS, we determined the role for each mutant protein for both kinase and phosphatase activity. Our results indicate that the conserved acidic residue (E372) immediately adjacent to the site of autophosphorylation (H371) is specifically required for kinase activity but not for phosphatase activity. Conversely, we found that the conserved Thr/Asn residue (N375) was required for phosphatase activity but not for kinase activity. We extended our biochemical analyses to two CrdS homologs from M. xanthus, HK1190 and HK4262, as well as Thermotoga maritima HK853. The results were similar for each HisKA family protein where the conserved acidic residue is required for kinase activity while the conserved Thr/Asn residue is required for phosphatase activity. These data are consistent with conserved mechanisms for kinase and phosphatase activities in the

  12. Artocarpus altilis CG-901 alters critical nodes in the JH1-kinase domain of Janus kinase 2 affecting upstream JAK/STAT3 signaling.

    PubMed

    Nash, Oyekanmi; Omotuyi, Olaposi; Lee, Joonku; Kwon, Byoung-Mog; Ogbadu, Lucy

    2015-11-01

    As a key step in achieving low-cost, easily accessible anti-cancer therapy for low- and middle-income countries, we recently established the scientific basis for the folkloric use of Artocarpus altilis for the treatment of cancer by investigating the geranyl dihydrochalcone (CG-901) content and its interference with signal transducer and activator of transcription 3 (STAT3) phosphorylation and blockage of further downstream signaling. In the current study, the CG-901 upstream target was queried by chemical fingerprinting similarity assessment, semi-empirical (PM6ESCF) QMMM and molecular dynamics (MD) simulation. Moderate (∼0.4) to high (∼0.7) Tanimoto scores were found when the CG-901 scaffold was compared to ligands co-crystallized with Janus kinases (JAK) 1-3. High negative energy values were obtained when the CG-901 was treated semi-empirically (PM6ESCF) within the classical field of JAK (1-3). Multiple nanosecond MD simulations showed that CG-901 did not cause any large structural perturbations in the nucleotide-binding, activation and catalytic loops within the kinase (JH1) domain of JAK (1-3); however, it reduced the energy required to attain metastability along the path to energy minima conformation. In comparison to JAK1 and Apo-state JAK2, JAK2-bound CG-901 exhibited a highly re-organized key intra-domain protein network; indicating atomic level interference with inter-residue communication. In conclusion, CG-901 isolated from A. altilis represents a broad-spectrum JAK inhibitor, which may underlie the mechanism of STAT3 phosphorylation blockage. Graphical abstract Upper panel Janus kinase 2 upstream signaling pathway. Lower panel Apo-JAK2 (left) and CG-901-bound JAK2 (right).

  13. Kinase inhibitor-responsive genotypes in EGFR mutated lung adenocarcinomas: moving past common point mutations or indels into uncommon kinase domain duplications and rearrangements

    PubMed Central

    2016-01-01

    The most frequent epidermal growth factor receptor (EGFR) mutations found by traditional or comprehensive molecular profiling of lung adenocarcinomas include indels of exon 19 (the exon 19 deletion delE746_A750 being the most common) and the exon 21 L858R point mutation. The current approval labels for first line palliative gefitinib 250 mg/day, erlotinib 150 mg/day and afatinib 40 mg/day for advanced lung cancers require the presence of the aforementioned classical/sensitizing EGFR mutations. Other gefitinib, erlotinib and afatinib sensitizing mutations include exon 18 indels, G719X, exon 19 insertions, A763_Y764insFQEA, S768I and L861Q; for which off-label EGFR kinase inhibitor use is generally agreed upon by thoracic oncologists. The main biological mechanism of resistance to approved first line EGFR inhibitors is the selection/acquisition of EGFR-T790M that in itself can be inhibited by osimertinib 80 mg/day, a 3rd generation EGFR inhibitor that is bypassed by EGFR-C797X mutations. Another class of de novo inhibitor insensitive mutation includes EGFR exon 20 insertions. More recently, the dichotomy of only point mutations or indels explaining aberrant kinase activation of EGFR plus inhibitor response has been shattered by the discovery of uncommon (<0.5% of all EGFR mutations) genomic events involving exon 18–25 kinase domain duplications (KDD) and rearrangements (EGFR-RAD51 or EGFR-PURB). The latter lead to oncogene addiction, enhanced sensitivity to kinase inhibitors in vitro and clinical responses to approved EGFR inhibitors. The enhanced landscape of EGFR inhibitor-responsive genotypes highlights that comprehensive molecular profiling may be necessary to maximize the identification of all cases that can benefit from precision oncology. PMID:27413714

  14. Kinase inhibitor-responsive genotypes in EGFR mutated lung adenocarcinomas: moving past common point mutations or indels into uncommon kinase domain duplications and rearrangements.

    PubMed

    Costa, Daniel B

    2016-06-01

    The most frequent epidermal growth factor receptor (EGFR) mutations found by traditional or comprehensive molecular profiling of lung adenocarcinomas include indels of exon 19 (the exon 19 deletion delE746_A750 being the most common) and the exon 21 L858R point mutation. The current approval labels for first line palliative gefitinib 250 mg/day, erlotinib 150 mg/day and afatinib 40 mg/day for advanced lung cancers require the presence of the aforementioned classical/sensitizing EGFR mutations. Other gefitinib, erlotinib and afatinib sensitizing mutations include exon 18 indels, G719X, exon 19 insertions, A763_Y764insFQEA, S768I and L861Q; for which off-label EGFR kinase inhibitor use is generally agreed upon by thoracic oncologists. The main biological mechanism of resistance to approved first line EGFR inhibitors is the selection/acquisition of EGFR-T790M that in itself can be inhibited by osimertinib 80 mg/day, a 3(rd) generation EGFR inhibitor that is bypassed by EGFR-C797X mutations. Another class of de novo inhibitor insensitive mutation includes EGFR exon 20 insertions. More recently, the dichotomy of only point mutations or indels explaining aberrant kinase activation of EGFR plus inhibitor response has been shattered by the discovery of uncommon (<0.5% of all EGFR mutations) genomic events involving exon 18-25 kinase domain duplications (KDD) and rearrangements (EGFR-RAD51 or EGFR-PURB). The latter lead to oncogene addiction, enhanced sensitivity to kinase inhibitors in vitro and clinical responses to approved EGFR inhibitors. The enhanced landscape of EGFR inhibitor-responsive genotypes highlights that comprehensive molecular profiling may be necessary to maximize the identification of all cases that can benefit from precision oncology.

  15. Plant chimeric Ca2+/Calmodulin-dependent protein kinase. Role of the neural visinin-like domain in regulating autophosphorylation and calmodulin affinity

    NASA Technical Reports Server (NTRS)

    Sathyanarayanan, P. V.; Cremo, C. R.; Poovaiah, B. W.

    2000-01-01

    Chimeric Ca(2+)/calmodulin-dependent protein kinase (CCaMK) is characterized by a serine-threonine kinase domain, an autoinhibitory domain, a calmodulin-binding domain and a neural visinin-like domain with three EF-hands. The neural visinin-like Ca(2+)-binding domain at the C-terminal end of the CaM-binding domain makes CCaMK unique among all the known calmodulin-dependent kinases. Biological functions of the plant visinin-like proteins or visinin-like domains in plant proteins are not well known. Using EF-hand deletions in the visinin-like domain, we found that the visinin-like domain regulated Ca(2+)-stimulated autophosphorylation of CCaMK. To investigate the effects of Ca(2+)-stimulated autophosphorylation on the interaction with calmodulin, the equilibrium binding constants of CCaMK were measured by fluorescence emission anisotropy using dansylated calmodulin. Binding was 8-fold tighter after Ca(2+)-stimulated autophosphorylation. This shift in affinity did not occur in CCaMK deletion mutants lacking Ca(2+)-stimulated autophosphorylation. A variable calmodulin affinity regulated by Ca(2+)-stimulated autophosphorylation mediated through the visinin-like domain is a new regulatory mechanism for CCaMK activation and calmodulin-dependent protein kinases. Our experiments demonstrate the existence of two functional molecular switches in a protein kinase regulating the kinase activity, namely a visinin-like domain acting as a Ca(2+)-triggered switch and a CaM-binding domain acting as an autophosphorylation-triggered molecular switch.

  16. A malignant inflammatory myofibroblastic tumor of the hypopharynx harboring the 3a/b variants of the EML4-ALK fusion gene

    PubMed Central

    Muscarella, Lucia Anna; Rossi, Giulio; Trombetta, Domenico; La Torre, Annamaria; Di Candia, Leonarda; Mengoli, Maria Cecilia; Sparaneo, Angelo; Fazio, Vito Michele; Graziano, Paolo

    2017-01-01

    Inflammatory myofibroblastic tumors (IMT) in the head and neck region are rare neoplasms that generally mimic benign/low-grade neoplasms. Overexpression of anaplastic lymphoma kinase (ALK) has been reported in 50% of IMT cases, secondary to ALK activation by structural rearrangements in the ALK gene, which results in a fusion protein with echinoderm microtubule associated protein like 4 (EML4) in ~20% of cases. The present study describes a case of a 74-year-old woman with a malignant IMT in the right posterior hypopharynx harboring a previously unreported chromosomal rearrangement resulting in EML4 and ALK gene fusion. Strong ALK immunoreactivity was observed in neoplastic cells, while fluorescent in situ hybridization combined with fluorescent fragment analysis and direct sequencing identified the first case of the 3a/b variants of the EML4-ALK fusion gene in IMT. The results of the current study highlight the uncommon occurrence of ALK-positive IMT in the head/neck region and demonstrate the importance of integrating different molecular methodologies to identify unequivocal gene fusion characterization. PMID:28356934

  17. EML4-ALK induces epithelial-mesenchymal transition consistent with cancer stem cell properties in H1299 non-small cell lung cancer cells.

    PubMed

    Guo, Fuchun; Liu, Xiaoke; Qing, Qin; Sang, Yaxiong; Feng, Chengjun; Li, Xiaoyu; Jiang, Li; Su, Pei; Wang, Yongsheng

    2015-04-10

    The echinoderm microtubule-associated protein-like 4(EML4)--anaplastic lymphoma kinase (ALK) fusion gene has been identified as a driver mutation in non-small-cell lung cancer (NSCLC). However, the role of EML4-ALK in malignant transformation is not entirely clear. Here, for the first time, we showed that H1299 NSCLC cells stably expressing EML4-ALK acquire EMT phenotype, associated with enhanced invasive migration and increased expression of EMT-inducing transcription factors. H1299-EML4-ALK cells also displayed cancer stem cell-like properties with a concomitant up-regulation of CD133 and enhanced ability of mammospheres formation. Moreover, we found that inhibition of ERK1/2 reversed EMT induced by EML4-ALK in H1299 cells. Taken together, these results suggested that EML4-ALK induced ERK activation is mechanistically associated with EMT phenotype. Thus, inhibition of ERK signaling pathway could be a potential strategy in treatment of NSCLC patients with EML4-ALK translocation.

  18. Stimulation of the midkine/ALK axis renders glioma cells resistant to cannabinoid antitumoral action

    PubMed Central

    Lorente, M; Torres, S; Salazar, M; Carracedo, A; Hernández-Tiedra, S; Rodríguez-Fornés, F; García-Taboada, E; Meléndez, B; Mollejo, M; Campos-Martín, Y; Lakatosh, S A; Barcia, J; Guzmán, M; Velasco, G

    2011-01-01

    Identifying the molecular mechanisms responsible for the resistance of gliomas to anticancer treatments is an issue of great therapeutic interest. Δ9-Tetrahydrocannabinol (THC), the major active ingredient of marijuana, and other cannabinoids inhibit tumor growth in animal models of cancer, including glioma, an effect that relies, at least in part, on the stimulation of autophagy-mediated apoptosis in tumor cells. Here, by analyzing the gene expression profile of a large series of human glioma cells with different sensitivity to cannabinoid action, we have identified a subset of genes specifically associated to THC resistance. One of these genes, namely that encoding the growth factor midkine (Mdk), is directly involved in the resistance of glioma cells to cannabinoid treatment. We also show that Mdk mediates its protective effect via the anaplastic lymphoma kinase (ALK) receptor and that Mdk signaling through ALK interferes with cannabinoid-induced autophagic cell death. Furthermore, in vivo Mdk silencing or ALK pharmacological inhibition sensitizes cannabinod-resistant tumors to THC antitumoral action. Altogether, our findings identify Mdk as a pivotal factor involved in the resistance of glioma cells to THC pro-autophagic and antitumoral action, and suggest that selective targeting of the Mdk/ALK axis could help to improve the efficacy of antitumoral therapies for gliomas. PMID:21233844

  19. An Unusual Case of Systemic Inflammatory Myofibroblastic Tumor with Successful Treatment with ALK-Inhibitor

    PubMed Central

    Jacob, Sanjivini V.; Reith, John D.; Kojima, Angerika Y.; Williams, William D.; Liu, Chen; Vila Duckworth, Lizette

    2014-01-01

    Systemic inflammatory myofibroblastic tumor is an exceedingly rare entity. A 45-year-old Hispanic female presented with a 6-month history of left-sided thigh pain, low back pain, and generalized weakness. PET/CT scan revealed abnormal activity in the liver, adrenal gland, and pancreas. MRI of the abdomen demonstrated two 6-7 cm masses in the liver. MRI of the lumbar spine demonstrated lesions in the L2 to L4 spinous processes, paraspinal muscles, and subcutaneous tissues, as well as an 8 mm enhancing intradural lesion at T11, all thought to be metastatic disease. A biopsy of the liver showed portal tract expansion by a spindle cell proliferation rich in inflammation. Tumor cells showed immunoreactivity for smooth muscle actin and anaplastic lymphoma kinase 1 (ALK1). Tissue from the L5 vertebra showed a process histologically identical to that seen in the liver. FISH analysis of these lesions demonstrated an ALK (2p23) gene rearrangement. The patient was successfully treated with an ALK-inhibitor, Crizotinib, and is now in complete remission. We present the first reported case, to our knowledge, of inflammatory myofibroblastic tumor with systemic manifestations and ALK translocation. This case is a prime example of how personalized medicine has vastly improved patient care through the use of molecular-targeted therapy. PMID:25045570

  20. Genome-wide RNAi screen reveals ALK1 mediates LDL uptake and transcytosis in endothelial cells

    PubMed Central

    Kraehling, Jan R.; Chidlow, John H.; Rajagopal, Chitra; Sugiyama, Michael G.; Fowler, Joseph W.; Lee, Monica Y.; Zhang, Xinbo; Ramírez, Cristina M.; Park, Eon Joo; Tao, Bo; Chen, Keyang; Kuruvilla, Leena; Larriveé, Bruno; Folta-Stogniew, Ewa; Ola, Roxana; Rotllan, Noemi; Zhou, Wenping; Nagle, Michael W.; Herz, Joachim; Williams, Kevin Jon; Eichmann, Anne; Lee, Warren L.; Fernández-Hernando, Carlos; Sessa, William C.

    2016-01-01

    In humans and animals lacking functional LDL receptor (LDLR), LDL from plasma still readily traverses the endothelium. To identify the pathways of LDL uptake, a genome-wide RNAi screen was performed in endothelial cells and cross-referenced with GWAS-data sets. Here we show that the activin-like kinase 1 (ALK1) mediates LDL uptake into endothelial cells. ALK1 binds LDL with lower affinity than LDLR and saturates only at hypercholesterolemic concentrations. ALK1 mediates uptake of LDL into endothelial cells via an unusual endocytic pathway that diverts the ligand from lysosomal degradation and promotes LDL transcytosis. The endothelium-specific genetic ablation of Alk1 in Ldlr-KO animals leads to less LDL uptake into the aortic endothelium, showing its physiological role in endothelial lipoprotein metabolism. In summary, identification of pathways mediating LDLR-independent uptake of LDL may provide unique opportunities to block the initiation of LDL accumulation in the vessel wall or augment hepatic LDLR-dependent clearance of LDL. PMID:27869117

  1. AKAP (A-kinase anchoring protein) domains: beads of structure-function on the necklace of G-protein signalling.

    PubMed

    Malbon, C C; Tao, J; Shumay, E; Wang, H-Y

    2004-11-01

    AKAPs (A-kinase anchoring proteins) are members of a diverse family of scaffold proteins that minimally possess a characteristic binding domain for the RI/RII regulatory subunit of protein kinase A and play critical roles in establishing spatial constraints for multivalent signalling assemblies. Especially for G-protein-coupled receptors, the AKAPs provide an organizing centre about which various protein kinases and phosphatases can be assembled to create solid-state signalling devices that can signal, be modulated and trafficked within the cell. The structure of AKAP250 (also known as gravin or AKAP12), based on analyses of milligram quantities of recombinant protein expressed in Escherichia coli, suggests that the AKAP is probably an unordered scaffold, acting as a necklace on which 'jewels' of structure-function (e.g. the RII-binding domain) that provide docking sites on which signalling components can be assembled. Recent results suggest that AKAP250 provides not only a 'tool box' for assembling signalling elements, but may indeed provide a basis for spatial constraint observed for many signalling paradigms. The spatial dimension of the integration of cell signalling will probably reflect many functions performed by members of the AKAP family.

  2. Bruton's tyrosine kinase activity is negatively regulated by Sab, the Btk-SH3 domain-binding protein.

    PubMed

    Yamadori, T; Baba, Y; Matsushita, M; Hashimoto, S; Kurosaki, M; Kurosaki, T; Kishimoto, T; Tsukada, S

    1999-05-25

    Bruton's tyrosine kinase (Btk) is a cytoplasmic tyrosine kinase that is crucial for human and murine B cell development, and its deficiency causes human X-linked agammaglobulinemia and murine X-linked immunodeficiency. In this report, we describe the function of the Btk-binding protein Sab (SH3-domain binding protein that preferentially associates with Btk), which we reported previously as a newly identified Src homology 3 domain-binding protein. Sab was shown to inhibit the auto- and transphosphorylation activity of Btk, which prompted us to propose that Sab functions as a transregulator of Btk. Forced overexpression of Sab in B cells led to the reduction of B cell antigen receptor-induced tyrosine phosphorylation of Btk and significantly reduced both early and late B cell antigen receptor-mediated events, including calcium mobilization, inositol 1, 4,5-trisphosphate production, and apoptotic cell death, where the involvement of Btk activity has been demonstrated previously. Together, these results indicate the negative regulatory role of Sab in the B cell cytoplasmic tyrosine kinase pathway.

  3. Bruton’s tyrosine kinase activity is negatively regulated by Sab, the Btk-SH3 domain-binding protein

    PubMed Central

    Yamadori, Tomoki; Baba, Yoshihiro; Matsushita, Masato; Hashimoto, Shoji; Kurosaki, Mari; Kurosaki, Tomohiro; Kishimoto, Tadamitsu; Tsukada, Satoshi

    1999-01-01

    Bruton’s tyrosine kinase (Btk) is a cytoplasmic tyrosine kinase that is crucial for human and murine B cell development, and its deficiency causes human X-linked agammaglobulinemia and murine X-linked immunodeficiency. In this report, we describe the function of the Btk-binding protein Sab (SH3-domain binding protein that preferentially associates with Btk), which we reported previously as a newly identified Src homology 3 domain-binding protein. Sab was shown to inhibit the auto- and transphosphorylation activity of Btk, which prompted us to propose that Sab functions as a transregulator of Btk. Forced overexpression of Sab in B cells led to the reduction of B cell antigen receptor-induced tyrosine phosphorylation of Btk and significantly reduced both early and late B cell antigen receptor-mediated events, including calcium mobilization, inositol 1,4,5-trisphosphate production, and apoptotic cell death, where the involvement of Btk activity has been demonstrated previously. Together, these results indicate the negative regulatory role of Sab in the B cell cytoplasmic tyrosine kinase pathway. PMID:10339589

  4. Responses to crizotinib in patients with ALK-positive lung adenocarcinoma who tested immunohistochemistry (IHC)-positive and fluorescence in situ hybridization (FISH)-negative

    PubMed Central

    Yang, Lin; Mu, Xinlin; Wang, Yan; Zhao, Xinming; Li, Junling; Lin, Dongmei

    2016-01-01

    Although the Ventana immunohistochemistry (IHC) platform for detecting anaplastic lymphoma kinase gene (ALK) (D5F3) expression was recently approved by the US Food and Drugs Administration (FDA), fluorescence in situ hybridization (FISH) is still the “gold-standard” method recommended by the US National Comprehensive Cancer Network (NCCN) guideline for NSCLC. We evaluated 6 ALK-positive lung adenocarcinoma patients who tested Ventana IHC-positive and FISH-negative and assessed their clinical responses to the ALK tyrosine kinase inhibitor (TKI) crizotinib. Histologic and cytologic specimens from the 6 patients were stained with Ventana anti-ALK(D5F3) rabbit monoclonal primary antibody using the OptiView™ DAB IHC detection kit and OptiView™ amplification kit on a Ventana BenchMark XT processor. In addition, they were also tested by FISH, qRT-PCR, next-generation sequencing (NGS), and RNAscope ISH analysis. All patients received crizotinib treatment and their follow-up clinical data were recorded. The objective response rate achieved with crizotinib therapy was 66.7% (4/6 partial responses and 2/6 stable disease). One patient in whom a new fusion type (EML4->EXOC6B->ALK fusion) was identified obtained a partial response. These findings indicate that patients with ALK-positive lung adenocarcinoma who test Ventana IHC-positive and FISH-negative may still respond to crizotinib therapy. PMID:27418132

  5. Crystal structure of designed PX domain from cytokine-independent survival kinase and implications on evolution-based protein engineering.

    PubMed

    Shultis, David; Dodge, Gregory; Zhang, Yang

    2015-08-01

    The Phox homology domain (PX domain) is a phosphoinositide-binding structural domain that is critical in mediating protein and cell membrane association and has been found in more than 100 eukaryotic proteins. The abundance of PX domains in nature offers an opportunity to redesign the protein using EvoDesign, a computational approach to design new sequences based on structure profiles of multiple evolutionarily related proteins. In this study, we report the X-ray crystallographic structure of a designed PX domain from the cytokine-independent survival kinase (CISK), which has been implicated as functioning in parallel with PKB/Akt in cell survival and insulin responses. Detailed data analysis of the designed CISK-PX protein demonstrates positive impacts of knowledge-based secondary structure and solvation predictions and structure-based sequence profiles on the efficiency of the evolutionary-based protein design method. The structure of the designed CISK-PX domain is close to the wild-type (1.54 Å in Cα RMSD), which was accurately predicted by I-TASSER based fragment assembly simulations (1.32 Å in Cα RMSD). This study represents the first successfully designed conditional peripheral membrane protein fold and has important implications in the examination and experimental validation of the evolution-based protein design approaches.

  6. Crystal structure of shikimate kinase from Mycobacterium tuberculosis reveals the dynamic role of the LID domain in catalysis.

    PubMed

    Gu, Yijun; Reshetnikova, Ludmila; Li, Yue; Wu, Yan; Yan, Honggao; Singh, Shivendra; Ji, Xinhua

    2002-06-07

    Shikimate kinase (SK) and other enzymes in the shikimate pathway are potential targets for developing non-toxic antimicrobial agents, herbicides, and anti-parasite drugs, because the pathway is essential in the above species but is absent from mammals. The crystal structure of Mycobacterium tuberculosis SK (MtSK) in complex with MgADP has been determined at 1.8 A resolution, revealing critical information for the structure-based design of novel anti-M. tuberculosis agents. MtSK, with a five-stranded parallel beta-sheet flanked by eight alpha-helices, has three domains: the CORE domain, the shikimate-binding domain (SB), and the LID domain. The ADP molecule is bound with its adenine moiety sandwiched between the side-chains of Arg110 and Pro155, its beta-phosphate group in the P-loop, and the alpha and beta-phosphate groups hydrogen bonded to the guanidinium group of Arg117. Arg117 is located in the LID domain, is strictly conserved in SK sequences, is observed for the first time to interact with any bound nucleotide, and appears to be important in both substrate binding and catalysis. The crystal structure of MtSK (this work) and that of Erwinia chrysanthemi SK suggest a concerted conformational change of the LID and SB domains upon nucleotide binding.

  7. The Drosophila midkine/pleiotrophin homologues Miple1 and Miple2 affect adult lifespan but are dispensable for alk signaling during embryonic gut formation.

    PubMed

    Hugosson, Fredrik; Sjögren, Camilla; Birve, Anna; Hedlund, Ludmilla; Eriksson, Therese; Palmer, Ruth H

    2014-01-01

    Midkine (MDK) and Pleiotrophin (PTN) are small heparin-binding cytokines with closely related structures. The Drosophila genome harbours two genes encoding members of the MDK/PTN family of proteins, known as miple1 and miple2. We have investigated the role of Miple proteins in vivo, in particular with regard to their proposed role as ligands for the Alk receptor tyrosine kinase (RTK). Here we show that Miple proteins are neither required to drive Alk signaling during Drosophila embryogenesis, nor are they essential for development in the fruit fly. Additionally we show that neither MDK nor PTN can activate hALK in vivo when ectopically co-expressed in the fly. In conclusion, our data suggest that Alk is not activated by MDK/PTN related growth factors Miple1 and Miple 2 in vivo.

  8. Neuronal leucine-rich repeat 1 negatively regulates anaplastic lymphoma kinase in neuroblastoma

    PubMed Central

    Satoh, Shunpei; Takatori, Atsushi; Ogura, Atsushi; Kohashi, Kenichi; Souzaki, Ryota; Kinoshita, Yoshiaki; Taguchi, Tomoaki; Hossain, Md. Shamim; Ohira, Miki; Nakamura, Yohko; Nakagawara, Akira

    2016-01-01

    In neuroblastoma (NB), one of the most common paediatric solid tumours, activation of anaplastic lymphoma kinase (ALK) is often associated with poor outcomes. Although genetic studies have identified copy number alteration and nonsynonymous mutations of ALK, the regulatory mechanism of ALK signalling at protein levels is largely elusive. Neuronal leucine-rich repeat 1 (NLRR1) is a type 1 transmembrane protein that is highly expressed in unfavourable NB and potentially influences receptor tyrosine kinase signalling. Here, we showed that NLRR1 and ALK exhibited a mutually exclusive expression pattern in primary NB tissues by immunohistochemistry. Moreover, dorsal root ganglia of Nlrr1+/+ and Nlrr1−/− mice displayed the opposite expression patterns of Nlrr1 and Alk. Of interest, NLRR1 physically interacted with ALK in vitro through its extracellular region. Notably, the NLRR1 ectodomain impaired ALK phosphorylation and proliferation of ALK-mutated NB cells. A newly identified cleavage of the NLRR1 ectodomain also supported NLRR1-mediated ALK signal regulation in trans. Thus, we conclude that NLRR1 appears to be an extracellular negative regulator of ALK signalling in NB and neuronal development. Our findings may be beneficial to comprehend NB heterogeneity and to develop a novel therapy against unfavourable NB. PMID:27604320

  9. Reduced mural cell coverage and impaired vessel integrity after angiogenic stimulation in the Alk1-deficient brain

    PubMed Central

    Chen, Wanqiu; Guo, Yi; Walker, Espen J.; Shen, Fanxia; Jun, Kristine; Oh, S. Paul; Degos, Vincent; Lawton, Michael T.; Tihan, Tarik; Davalos, Dimitrios; Akassoglou, Katerina; Nelson, Jeffrey; Pile-Spellman, John; Su, Hua; Young, William L.

    2013-01-01

    Objective Vessels in brain arteriovenous malformations (bAVM) are prone to rupture. The underlying pathogenesis is not clear. Hereditary hemorrhagic telangiectasia type 2 (HHT2) patients with activin receptor-like kinase 1 (Alk1) mutation have a higher incidence of bAVM than the general population. We tested the hypothesis that vascular endothelial growth factor (VEGF) impairs vascular integrity in the Alk1-deficient brain through reduction of mural cell-coverage. Methods and Results Adult Alk11f/2f mice (loxP sites flanking exons 4-6) and wild-type (WT) mice were injected with 2×107 PFU Ad-Cre and 2×109 genome copies of AAV-VEGF to induce focal homozygous Alk1 deletion (in Alk11f/2f mice) and angiogenesis. Brain vessels were analyzed eight weeks later. Compared to WT mice, the Alk1-deficient brain had more fibrin (99±30×103 pixels/mm2 vs. 40±13×103, P=0.001), iron deposition (508±506 pixels/mm2 vs. 6 ±49, P=0.04), and Iba1+ microglia/macrophage infiltration (888±420 Iba1+ cells/mm2 vs. 240±104 Iba1+, P=0.001) after VEGF stimulation. In the angiogenic foci, the Alk1-deficient brain had more α-SMA- vessels (52±9% vs. 12±7%, P<0.001), fewer vascular associated pericytes (503±179/mm2 vs. 931±115, P<0.001), and reduced PDGFR-β expression (26±9%, P<0.001). Conclusion Reduction of mural cell coverage in response to VEGF stimulation is a potential mechanism for the impairment of vessel wall integrity in HHT2-associated bAVM. PMID:23241407

  10. microRNA classifiers are powerful diagnostic/prognostic tools in ALK-, EGFR-, and KRAS-driven lung cancers.

    PubMed

    Gasparini, Pierluigi; Cascione, Luciano; Landi, Lorenza; Carasi, Stefania; Lovat, Francesca; Tibaldi, Carmelo; Alì, Greta; D'Incecco, Armida; Minuti, Gabriele; Chella, Antonio; Fontanini, Gabriella; Fassan, Matteo; Cappuzzo, Federico; Croce, Carlo M

    2015-12-01

    microRNAs (miRNAs) can act as oncosuppressors or oncogenes, induce chemoresistance or chemosensitivity, and are major posttranscriptional gene regulators. Anaplastic lymphoma kinase (ALK), EGF receptor (EGFR), and V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) are major drivers of non-small cell lung cancer (NSCLC). The aim of this study was to assess the miRNA profiles of NSCLCs driven by translocated ALK, mutant EGFR, or mutant KRAS to find driver-specific diagnostic and prognostic miRNA signatures. A total of 85 formalin-fixed, paraffin-embedded samples were considered: 67 primary NSCLCs and 18 matched normal lung tissues. Of the 67 primary NSCLCs, 17 were echinoderm microtubule-associated protein-like 4-ALK translocated (ALK(+)) lung cancers; the remaining 50 were not (ALK(-)). Of the 50 ALK(-) primary NSCLCs, 24 were EGFR and KRAS mutation-negative (i.e., WT; triple negative); 11 were mutant EGFR (EGFR(+)), and 15 were mutant KRAS (KRAS(+)). We developed a diagnostic classifier that shows how miR-1253, miR-504, and miR-26a-5p expression levels can classify NSCLCs as ALK-translocated, mutant EGFR, or mutant KRAS versus mutation-free. We also generated a prognostic classifier based on miR-769-5p and Let-7d-5p expression levels that can predict overall survival. This classifier showed better performance than the commonly used classifiers based on mutational status. Although it has several limitations, this study shows that miRNA signatures and classifiers have great potential as powerful, cost-effective next-generation tools to improve and complement current genetic tests. Further studies of these miRNAs can help define their roles in NSCLC biology and in identifying best-performing chemotherapy regimens.

  11. Cloning, overexpression, purification and preliminary X-ray analysis of the protein kinase domain of enhanced disease resistance 1 (EDR1) from Arabidopsis thaliana

    PubMed Central

    Kaljunen, Heidi; Panneerselvam, Saravanan; Mueller-Dieckmann, Jochen

    2014-01-01

    Enhanced disease resistance 1 is a member of the Raf-like mitogen-activated protein kinase kinase kinase (MAPKKK) family that negatively regulates disease resistance, ethylene-induced senescence and programmed cell death in response to both abiotic and biotic stresses. A catalytically inactive form of the EDR1 kinase domain was successfully cloned, expressed, purified and crystallized. Crystallization was conducted in the presence of the ATP analogue AMP-PNP. The crystals belonged to space group P3221 and contained two molecules in the asymmetric unit. The crystals diffracted X-rays to 2.55 Å resolution. PMID:25005098

  12. Role of a Novel PH-Kinase Domain Interface in PKB/Akt Regulation: Structural Mechanism for Allosteric Inhibition

    PubMed Central

    Parker, Peter J; Larijani, Banafshé

    2009-01-01

    Protein kinase B (PKB/Akt) belongs to the AGC superfamily of related serine/threonine protein kinases. It is a key regulator downstream of various growth factors and hormones and is involved in malignant transformation and chemo-resistance. Full-length PKB protein has not been crystallised, thus studying the molecular mechanisms that are involved in its regulation in relation to its structure have not been simple. Recently, the dynamics between the inactive and active conformer at the molecular level have been described. The maintenance of PKB's inactive state via the interaction of the PH and kinase domains prevents its activation loop to be phosphorylated by its upstream activator, phosphoinositide-dependent protein kinase-1 (PDK1). By using a multidisciplinary approach including molecular modelling, classical biochemical assays, and Förster resonance energy transfer (FRET)/two-photon fluorescence lifetime imaging microscopy (FLIM), a detailed model depicting the interaction between the different domains of PKB in its inactive conformation was demonstrated. These findings in turn clarified the molecular mechanism of PKB inhibition by AKT inhibitor VIII (a specific allosteric inhibitor) and illustrated at the molecular level its selectivity towards different PKB isoforms. Furthermore, these findings allude to the possible function of the C-terminus in sustaining the inactive conformer of PKB. This study presents essential insights into the quaternary structure of PKB in its inactive conformation. An understanding of PKB structure in relation to its function is critical for elucidating its mode of activation and discovering how to modulate its activity. The molecular mechanism of inhibition of PKB activation by the specific drug AKT inhibitor VIII has critical implications for determining the mechanism of inhibition of other allosteric inhibitors and for opening up opportunities for the design of new generations of modulator drugs. PMID:19166270

  13. Both synchronous and asynchronous muscle isoforms of projectin (the Drosophila bent locus product) contain functional kinase domains

    PubMed Central

    1995-01-01

    In Drosophila, the large muscle protein, projectin, has very different localizations in synchronous and asynchronous muscles, suggesting that projectin has different functions in different muscle types. The multiple projectin isoforms are encoded by a single gene; however they differ significantly in size (as detected by gel mobility) and show differences in some peptide fragments, presumably indicating alternative splicing or termination. We now report additional sequence of the projectin gene, showing a kinase domain and flanking regions highly similar to equivalent regions of twitchin, including a possible autoinhibitory region. In spite of apparent differences in function, all isoforms of projectin have the kinase domain and all are capable of autophosphorylation in vitro. The projectin gene is in polytene region 102C/D where the bentD phenotype maps. The recessive lethality of bentD is associated with a breakpoint that removes sequence of the projectin kinase domain. We find that different alleles of the highly mutable recessive lethal complementation group, l(4)2, also have defects in different parts of the projectin sequence, both NH2-terminal and COOH- terminal to the bentD breakpoint. These alleles are therefore renamed as alleles of the bent locus. Adults heterozygous for projectin mutations show little, if any, effect of one defective gene copy, but homozygosity for any of the defects is lethal. The times of death can vary with allele. Some alleles kill the embryos, others are larval lethal. These molecular studies begin to explain why genetic studies suggested that l(4)2 was a complex (or pseudoallelic) locus. PMID:7844153

  14. Alectinib induced CNS radiation necrosis in an ALK+NSCLC patient with a remote (7 years) history of brain radiation.

    PubMed

    Ou, Sai-Hong Ignatius; Weitz, Michael; Jalas, John R; Kelly, Daniel F; Wong, Vanessa; Azada, Michele C; Quines, Oliver; Klempner, Samuel J

    2016-06-01

    Alectinib is a second generation ALK inhibitor that has significant clinical activity in central nervous system (CNS) metastases in anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC). Pseudoprogression (PsP) due to radiation necrosis during alecitnib treatment of central nervous system (CNS) metastases from ALK-rearranged NSCLC as been reported. Hence, distinguishing radiation-related PsP from alectinib-induced radiographic changes is important to avoid erroneous early trial discontinuation and abandonment of an effective treatment. However, it remains difficult to assess casuality of radiation necrosis is related to recent direct radiation or induced by alectinib treatment or both. It is also unknown how long from previous radiation can alectinib still induce radiation necrosis. Here we reported a crizotinib-refractory ALK-positive NSCLC patient who develop radiation necrosis in one of his metastatic CNS lesions after approximately 12 months of alectinib treatment who otherwise had on-going CNS response on alectinib. His most recent radiation to his CNS metastases was 7 years prior to the start of alectinib. This case illustrates that in the setting of pror CNS radiation, given the significant clinical activity of alectinib in CNS metastases in ALK-positive NSCLC patients the risk of CNS radiation necrosis remains long after previous radiation to the CNS metastases has been completed and can occur after durable response of treatment.

  15. Assembly of the transmembrane domain of E. coli PhoQ histidine kinase: implications for signal transduction from molecular simulations.

    PubMed

    Lemmin, Thomas; Soto, Cinque S; Clinthorne, Graham; DeGrado, William F; Dal Peraro, Matteo

    2013-01-01

    The PhoQP two-component system is a signaling complex essential for bacterial virulence and cationic antimicrobial peptide resistance. PhoQ is the histidine kinase chemoreceptor of this tandem machine and assembles in a homodimer conformation spanning the bacterial inner membrane. Currently, a full understanding of the PhoQ signal transduction is hindered by the lack of a complete atomistic structure. In this study, an atomistic model of the key transmembrane (TM) domain is assembled by using molecular simulations, guided by experimental cross-linking data. The formation of a polar pocket involving Asn202 in the lumen of the tetrameric TM bundle is crucial for the assembly and solvation of the domain. Moreover, a concerted displacement of the TM helices at the periplasmic side is found to modulate a rotation at the cytoplasmic end, supporting the transduction of the chemical signal through a combination of scissoring and rotational movement of the TM helices.

  16. PAS-MEDIATED DIMERIZATION OF SOLUBLE GUANYLYL CYCLASE REVEALED BY SIGNAL TRANSDUCTION HISTIDINE KINASE DOMAIN CRYSTAL STRUCTURE

    PubMed Central

    Ma, Xiaolei; Sayed, Nazish; Baskaran, Padmamalini; Beuve, Annie; van den Akker, Focco

    2010-01-01

    Signal transduction histidine kinases (STHK) are key for sensing environmental stresses, crucial for cell survival, and attain their sensing ability using small molecule binding domains. The N-terminal domain in an STHK from Nostoc punctiforme is of unknown function yet is homologous to the central region in soluble guanylyl cyclase (sGC), the main receptor for nitric oxide (NO). This domain is termed H-NOXA (or H-NOBA) since it is often associated with the heme-nitric-oxide/oxygen binding (H-NOX) domain. A structure-function approach was taken to investigate the role of H-NOXA in STHK and sGC. We report the 2.1 Å resolution crystal structure of the dimerized H-NOXA domain of STHK, which reveals a Per-Arnt-Sim (PAS) fold. The H-NOXA monomers dimerize in a parallel arrangement juxtaposing their N-terminal helices and preceding residues. Such PAS-dimerization is similar to that previously observed for EcDOS, AvNifL, and RmFixL. Deletion of 7 N-terminal residues affected dimer organization. Alanine scanning mutagenesis in sGC indicates that the H-NOXA domains of sGC could adopt a similar dimer organization. Although most putative interface mutations did decrease sGCβ1 H-NOXA homodimerization, heterodimerization of full length heterodimeric sGC was mostly unaffected likely due to sGC’s additional dimerization contacts in the coiled-coil and catalytic domains. Exceptions are mutations sGC-α1 F285A and -β1 F217A which each caused a drastic drop in NO stimulated activity and mutations sGCα1 Q368A and -β1 Q309A which resulted in both a complete lack of activity and heterodimerization. Our structural and mutational results provide new insights into sGC and STHK dimerization and overall architecture. PMID:18006497

  17. A novel mutation leading to a deletion in the SH3 domain of Bruton's tyrosine kinase.

    PubMed

    Mesci, Lütfiye; Ozdag, Hilal; Turul, Tuba; Ersoy, Fügen; Tezcan, Ilhan; Sanal, Ozden

    2006-01-01

    X-linked agammaglobulinemia (XLA) is a primary B cell immunodeficiency disorder, caused by a defect in the Bruton tyrosine kinase (BTK) gene. Here, we describe a novel four base pair mutation (838delGAGT) in intron 9 of the BTK gene leading to the skipping of exon 9 in a 2.5-year-old boy with this disorder.

  18. Therapeutic efficacy of the bromodomain inhibitor OTX015/MK-8628 in ALK-positive anaplastic large cell lymphoma: an alternative modality to overcome resistant phenotypes

    PubMed Central

    Vurchio, Valentina; Yang, Shao Ning; Moon, John; Kwee, Ivo; Rinaldi, Andrea; Pan, Heng; Crescenzo, Ramona; Cheng, Mangeng; Cerchietti, Leandro; Elemento, Olivier; Riveiro, Maria E.; Cvitkovic, Esteban; Bertoni, Francesco; Inghirami, Giorgio

    2016-01-01

    Anaplastic large cell lymphomas (ALCL) represent a peripheral T-cell lymphoma subgroup, stratified based on the presence or absence of anaplastic lymphoma kinase (ALK) chimeras. Although ALK-positive ALCLs have a more favorable outcome than ALK-negative ALCL, refractory and/or relapsed forms are common and novel treatments are needed. Here we investigated the therapeutic potential of a novel bromodomain inhibitor, OTX015/MK-8628 in ALK-positive ALCLs. The effects of OTX015 on a panel of ALK+ ALCL cell lines was evaluated in terms of proliferation, cell cycle and downstream signaling, including gene expression profiling analyses. Synergy was tested with combination targeted therapies. Bromodomain inhibition with OTX015 led primarily to ALCL cell cycle arrest in a dose-dependent manner, along with downregulation of MYC and its downstream regulated genes. MYC overexpression did not compensate this OTX015-mediated phenotype. Transcriptomic analysis of OTX015-treated ALCL cells identified a gene signature common to various hematologic malignancies treated with bromodomain inhibitors, notably large cell lymphoma. OTX015-modulated genes included transcription factors (E2F2, NFKBIZ, FOS, JUNB, ID1, HOXA5 and HOXC6), members of multiple signaling pathways (ITK, PRKCH, and MKNK2), and histones (clusters 1-3). Combination of OTX015 with the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib led to cell cycle arrest then cell death, and combination with suboptimal doses of the ALK inhibitor CEP28122 caused cell cycle arrest. When OTX015 was associated with GANT61, a selective GLI1/2 inhibitor, C1156Y-resistant ALK ALCL growth was impaired. These findings support OTX015 clinical trials in refractory ALCL in combination with inhibitors of interleukin-2-inducible kinase or SHH/GLI1. PMID:27793034

  19. Analyses of Compact Trichinella Kinomes Reveal a MOS-Like Protein Kinase with a Unique N-Terminal Domain

    PubMed Central

    Stroehlein, Andreas J.; Young, Neil D.; Korhonen, Pasi K.; Chang, Bill C. H.; Sternberg, Paul W.; La Rosa, Giuseppe; Pozio, Edoardo; Gasser, Robin B.

    2016-01-01

    Parasitic worms of the genus Trichinella (phylum Nematoda; class Enoplea) represent a complex of at least twelve taxa that infect a range of different host animals, including humans, around the world. They are foodborne, intracellular nematodes, and their life cycles differ substantially from those of other nematodes. The recent characterization of the genomes and transcriptomes of all twelve recognized taxa of Trichinella now allows, for the first time, detailed studies of their molecular biology. In the present study, we defined, curated, and compared the protein kinase complements (kinomes) of Trichinella spiralis and T. pseudospiralis using an integrated bioinformatic workflow employing transcriptomic and genomic data sets. We examined how variation in the kinome might link to unique aspects of Trichinella morphology, biology, and evolution. Furthermore, we utilized in silico structural modeling to discover and characterize a novel, MOS-like kinase with an unusual, previously undescribed N-terminal domain. Taken together, the present findings provide a basis for comparative investigations of nematode kinomes, and might facilitate the identification of Enoplea-specific intervention and diagnostic targets. Importantly, the in silico modeling approach assessed here provides an exciting prospect of being able to identify and classify currently unknown (orphan) kinases, as a foundation for their subsequent structural and functional investigation. PMID:27412987

  20. The structure of the periplasmic ligand-binding domain of the sensor kinase CitA reveals the first extracellular PAS domain.

    PubMed

    Reinelt, Stefan; Hofmann, Eckhard; Gerharz, Tanja; Bott, Michael; Madden, Dean R

    2003-10-03

    The integral membrane sensor kinase CitA of Klebsiella pneumoniae is part of a two-component signal transduction system that regulates the transport and metabolism of citrate in response to its environmental concentration. Two-component systems are widely used by bacteria for such adaptive processes, but the stereochemistry of periplasmic ligand binding and the mechanism of signal transduction across the membrane remain poorly understood. The crystal structure of the CitAP periplasmic sensor domain in complex with citrate reveals a PAS fold, a versatile ligand-binding structural motif that has not previously been observed outside the cytoplasm or implicated in the transduction of conformational signals across the membrane. Citrate is bound in a pocket that is shared among many PAS domains but that shows structural variation according to the nature of the bound ligand. In CitAP, some of the citrate contact residues are located in the final strand of the central beta-sheet, which is connected to the C-terminal transmembrane helix. These secondary structure elements thus provide a potential conformational link between the periplasmic ligand binding site and the cytoplasmic signaling domains of the receptor.

  1. Phosphopeptide analysis reveals two discrete clusters of phosphorylation in the N-terminus and the Roc domain of the Parkinson-disease associated protein kinase LRRK2.

    PubMed

    Gloeckner, Christian Johannes; Boldt, Karsten; von Zweydorf, Felix; Helm, Sandra; Wiesent, Ludwig; Sarioglu, Hakan; Ueffing, Marius

    2010-04-05

    Mutations in leucine-rich repeat kinase 2 (LRRK2) that increase its kinase activity associate with familial forms of Parkinson disease (PD). As phosphorylation determines the functional state of most protein kinases, we systematically mapped LRRK2 phosphorylation sites by mass spectrometry. Our analysis revealed a high degree of constitutive phosphorylation in a narrow serine-rich region preceding the LRR-domain. Allowing de novo autophosphorylation of purified LRRK2 in an in vitro autokinase assay prior to mass spectrometric analysis, we discovered multiple sites of autophosphorylation. Solely serine and threonine residues were found phosphorylated suggesting LRRK2 as a true serine threonine kinase. Autophosphorylation mainly targets the ROC GTPase domain and its clustering around the GTP binding pocket of ROC suggests cross-regulatory activity between kinase and Roc domain. In conclusion, the phosphoprotein LRRK2 functions as an autocatalytically active serine threonine kinase. Clustering of phosphosites within two discrete domains suggest that phosphorylation may regulate its biological functions in a yet unknown fashion.

  2. Identification of a novel Polo-like kinase 1 inhibitor that specifically blocks the functions of Polo-Box domain

    PubMed Central

    Li, Dongsheng; Jiang, Jiandong; Wang, Yanchang; Si, Shuyi

    2017-01-01

    Polo-like kinase 1 (Plk1) is a promising target for cancer therapy due to its essential role in cell division. In addition to a highly conserved kinase domain, Plk1 also contains a Polo-Box domain (PBD), which is essential for Plk1's subcellular localization and mitotic functions. We adopted a fluorescence polarization assay and identified a new Plk1 PBD inhibitor T521 from a small-molecule compound library. T521 specifically inhibits the PBD of Plk1, but not those of Plk2-3. T521 exhibits covalent binding to some lysine residues of Plk1 PBD, which causes significant changes in the secondary structure of Plk1 PBD. Using a cell-based assay, we showed that T521 impedes the interaction between Plk1 and Bub1, a mitotic checkpoint protein. Moreover, HeLa cells treated with T521 exhibited dramatic mitotic defects. Importantly, T521 suppresses the growth of A549 cells in xenograft nude mice. Taken together, we have identified a novel Plk1 inhibitor that specifically disrupts the functions of Plk1 PBD and shows anticancer activity. PMID:27902479

  3. S cysteine-rich (SCR) binding domain analysis of the Brassica self-incompatibility S-locus receptor kinase.

    PubMed

    Kemp, Benjamin P; Doughty, James

    2007-01-01

    Brassica self-incompatibility, a highly discriminating outbreeding mechanism, has become a paradigm for the study of plant cell-cell communications. When self-pollen lands on a stigma, the male ligand S cysteine-rich (SCR), which is present in the pollen coat, is transmitted to the female receptor, S-locus receptor kinase (SRK). SRK is a membrane-spanning serine/threonine receptor kinase present in the stigmatic papillar cell membrane. Haplotype-specific binding of SCR to SRK brings about pollen rejection. The extracellular receptor domain of SRK (eSRK) is responsible for binding SCR. Based on sequence homology, eSRK can be divided into three subdomains: B lectin-like, hypervariable, and PAN. Biochemical analysis of these subdomains showed that the hypervariable subdomain is responsible for most of the SCR binding capacity of eSRK, whereas the B lectin-like and PAN domains have little, if any, affinity for SCR. Fine mapping of the SCR binding region of SRK using a peptide array revealed a region of the hypervariable subdomain that plays a key role in binding the SCR molecule. We show that residues within the hypervariable subdomain define SRK binding and are likely to be involved in defining haplotype specificity.

  4. Identification of a novel Polo-like kinase 1 inhibitor that specifically blocks the functions of Polo-Box domain.

    PubMed

    Chen, Yunyu; Zhang, Jing; Li, Dongsheng; Jiang, Jiandong; Wang, Yanchang; Si, Shuyi

    2017-01-03

    Polo-like kinase 1 (Plk1) is a promising target for cancer therapy due to its essential role in cell division. In addition to a highly conserved kinase domain, Plk1 also contains a Polo-Box domain (PBD), which is essential for Plk1's subcellular localization and mitotic functions. We adopted a fluorescence polarization assay and identified a new Plk1 PBD inhibitor T521 from a small-molecule compound library. T521 specifically inhibits the PBD of Plk1, but not those of Plk2-3. T521 exhibits covalent binding to some lysine residues of Plk1 PBD, which causes significant changes in the secondary structure of Plk1 PBD. Using a cell-based assay, we showed that T521 impedes the interaction between Plk1 and Bub1, a mitotic checkpoint protein. Moreover, HeLa cells treated with T521 exhibited dramatic mitotic defects. Importantly, T521 suppresses the growth of A549 cells in xenograft nude mice. Taken together, we have identified a novel Plk1 inhibitor that specifically disrupts the functions of Plk1 PBD and shows anticancer activity.

  5. Regulated intramembrane proteolysis of the AXL receptor kinase generates an intracellular domain that localizes in the nucleus of cancer cells

    PubMed Central

    Lu, Yinzhong; Wan, Jun; Yang, Zhifeng; Lei, Xiling; Niu, Qi; Jiang, Lanxin; Passtoors, Willemijn M.; Zang, Aiping; Fraering, Patrick C.; Wu, Fang

    2017-01-01

    Deregulation of the TAM (TYRO3, AXL, and MERTK) family of receptor tyrosine kinases (RTKs) has recently been demonstrated to predominately promote survival and chemoresistance of cancer cells. Intramembrane proteolysis mediated by presenilin/γ-secretase is known to regulate the homeostasis of some RTKs. In the present study, we demonstrate that AXL, but not TYRO3 or MERTK, is efficiently and sequentially cleaved by α- and γ-secretases in various types of cancer cell lines. Proteolytic processing of AXL redirected signaling toward a secretase-mediated pathway, away from the classic, well-known, ligand-dependent canonical RTK signaling pathway. The AXL intracellular domain cleavage product, but not full-length AXL, was further shown to translocate into the nucleus via a nuclear localization sequence that harbored a basic HRRKK motif. Of interest, we found that the γ-secretase–uncleavable AXL mutant caused an elevated chemoresistance in non–small-cell lung cancer cells. Altogether, our findings suggest that AXL can undergo sequential processing mediated by various proteases kept in a homeostatic balance. This newly discovered post-translational processing of AXL may provide an explanation for the diverse functions of AXL, especially in the context of drug resistance in cancer cells.—Lu, Y., Wan, J., Yang, Z., Lei, X., Niu, Q., Jiang, L., Passtoors, W. M., Zang, A., Fraering, P. C., Wu, F. Regulated intramembrane proteolysis of the AXL receptor kinase generates an intracellular domain that localizes in the nucleus of cancer cells. PMID:28034848

  6. Chaperone-Like Effect of the Linker on the Isolated C-Terminal Domain of Rabbit Muscle Creatine Kinase

    PubMed Central

    Chen, Zhe; Chen, Xiang-Jun; Xia, Mengdie; He, Hua-Wei; Wang, Sha; Liu, Huihui; Gong, Haipeng; Yan, Yong-Bin

    2012-01-01

    Intramolecular chaperones (IMCs), which are specific domains/segments encoded in the primary structure of proteins, exhibit chaperone-like activity against the aggregation of the other domains in the same molecule. In this research, we found that the truncation of the linker greatly promoted the thermal aggregation of the isolated C-terminal domain (CTD) of rabbit muscle creatine kinase (RMCK). Either the existence of the linker covalently linked to CTD or the supply of the synthetic linker peptide additionally could successfully protect the CTD of RMCK against aggregation in a concentration-dependent manner. Truncated fragments of the linker also behaved as a chaperone-like effect with lower efficiency, revealing the importance of its C-terminal half in the IMC function of the linker. The aggregation sites in the CTD of RMCK were identified by molecular dynamics simulations. Mutational analysis of the three key hydrophobic residues resulted in opposing effects on the thermal aggregation between the CTD with intact or partial linker, confirming the role of linker as a lid to protect the hydrophobic residues against exposure to solvent. These observations suggested that the linkers in multidomain proteins could act as IMCs to facilitate the correct folding of the aggregation-prone domains. Furthermore, the intactness of the IMC linker after proteolysis modulates the production of off-pathway aggregates, which may be important to the onset of some diseases caused by the toxic effects of aggregated proteolytic fragments. PMID:22947872

  7. Phosphorylation Regulates Interaction of 210-kDa Myosin Light Chain Kinase N-terminal Domain with Actin Cytoskeleton.

    PubMed

    Vilitkevich, E L; Khapchaev, A Y; Kudryashov, D S; Nikashin, A V; Schavocky, J P; Lukas, T J; Watterson, D M; Shirinsky, V P

    2015-10-01

    High molecular weight myosin light chain kinase (MLCK210) is a multifunctional protein involved in myosin II activation and integration of cytoskeletal components in cells. MLCK210 possesses actin-binding regions both in the central part of the molecule and in its N-terminal tail domain. In HeLa cells, mitotic protein kinase Aurora B was suggested to phosphorylate MLCK210 N-terminal tail at serine residues (Dulyaninova, N. G., and Bresnick, A. R. (2004) Exp. Cell Res., 299, 303-314), but the functional significance of the phosphorylation was not established. We report here that in vitro, the N-terminal actin-binding domain of MLCK210 is located within residues 27-157 (N27-157, avian MLCK210 sequence) and is phosphorylated by cAMP-dependent protein kinase (PKA) and Aurora B at serine residues 140/149 leading to a decrease in N27-157 binding to actin. The same residues are phosphorylated in a PKA-dependent manner in transfected HeLa cells. Further, in transfected cells, phosphomimetic mutants of N27-157 showed reduced association with the detergent-stable cytoskeleton, whereas in vitro, the single S149D mutation reduced N27-157 association with F-actin to a similar extent as that achieved by N27-157 phosphorylation. Altogether, our results indicate that phosphorylation of MLCK210 at distinct serine residues, mainly at S149, attenuates the interaction of MLCK210 N-terminus with the actin cytoskeleton and might serve to regulate MLCK210 microfilament cross-linking activity in cells.

  8. A novel lead compound CM-118: antitumor activity and new insight into the molecular mechanism and combination therapy strategy in c-Met- and ALK-dependent cancers.

    PubMed

    Meng, Lanfang; Shu, Mengjun; Chen, Yaqing; Yang, Dexiao; He, Qun; Zhao, Hui; Feng, Zhiyong; Liang, Chris; Yu, Ker

    2014-06-01

    The anaplastic lymphoma kinase (ALK) and the c-Met receptor tyrosine kinase play essential roles in the pathogenesis in multiple human cancers and present emerging targets for cancer treatment. Here, we describe CM-118, a novel lead compound displaying low nanomolar biochemical potency against both ALK and c-Met with selectivity over>90 human kinases. CM-118 potently abrogated hepatocyte growth factor (HGF)-induced c-Met phosphorylation and cell migration, phosphorylation of ALK, EML4-ALK, and ALK resistance mutants in transfected cells. CM-118 inhibited proliferation and/or induced apoptosis in multiple c-Met- and ALK-addicted cancer lines with dose response profile correlating target blockade. We show that the CM-118-induced apoptosis in c-Met-amplified H1993 NSCLC cells involved a rapid suppression of c-Met activity and c-Met-to-EGFR cross-talk, and was profoundly potentiated by EGFR inhibitors as shown by the increased levels of apoptotic proteins cleaved-PARP and Bim as well as reduction of the survival protein Mcl-1. Bim-knockdown or Mcl-1 overexpression each significantly attenuated apoptosis. We also revealed a key role by mTOR in mediating CM-118 action against the EML4-ALK-dependent NSCLC cells. Abrogation of EML4-ALK in H2228 cells profoundly reduced signaling capacity of the rapamycin-sensitive mTOR pathway leading to G 1 cell cycle arrest and mitochondrial hyperpolarization, a metabolic perturbation linked to mTOR inhibition. Depletion of mTOR or mTORC1 inhibited H2228 cell growth, and mTOR inhibitors potentiated CM-118's antitumor activity in vitro and in vivo. Oral administration of CM-118 at a wide range of well tolerated dosages diminished c-Met- and ALK phosphorylation in vivo, and caused tumor regression or growth inhibition in multiple c-Met- and ALK-dependent tumor xenografts in mice. CM-118 exhibits favorable pharmacokinetic and drug metabolism properties hence presents a candidate for clinical evaluation.

  9. Bacillus subtilis Two-Component System Sensory Kinase DegS Is Regulated by Serine Phosphorylation in Its Input Domain

    PubMed Central

    Jers, Carsten; Kobir, Ahasanul; Søndergaard, Elsebeth Oline; Jensen, Peter Ruhdal; Mijakovic, Ivan

    2011-01-01

    Bacillus subtilis two-component system DegS/U is well known for the complexity of its regulation. The cytosolic sensory kinase DegS does not receive a single predominant input signal like most two-component kinases, instead it integrates a wide array of metabolic inputs that modulate its activity. The phosphorylation state of the response regulator DegU also does not confer a straightforward “on/off” response; it is fine-tuned and at different levels triggers different sub-regulons. Here we describe serine phosphorylation of the DegS sensing domain, which stimulates its kinase activity. We demonstrate that DegS phosphorylation can be carried out by at least two B. subtilis Hanks-type kinases in vitro, and this stimulates the phosphate transfer towards DegU. The consequences of this process were studied in vivo, using phosphomimetic (Ser76Asp) and non-phosphorylatable (Ser76Ala) mutants of DegS. In a number of physiological assays focused on different processes regulated by DegU, DegS S76D phosphomimetic mutant behaved like a strain with intermediate levels of DegU phosphorylation, whereas DegS S76A behaved like a strain with lower levels of DegU phophorylation. These findings suggest a link between DegS phosphorylation at serine 76 and the level of DegU phosphorylation, establishing this post-translational modification as an additional trigger for this two-component system. PMID:21304896

  10. Alteration of Substrate Specificity: The Variable N-Terminal Domain of Tobacco Ca2+-Dependent Protein Kinase Is Important for Substrate Recognition[W

    PubMed Central

    Ito, Takeshi; Nakata, Masaru; Fukazawa, Jutarou; Ishida, Sarahmi; Takahashi, Yohsuke

    2010-01-01

    Protein kinases are major signaling molecules that are involved in a variety of cellular processes. However, the molecular mechanisms whereby protein kinases discriminate specific substrates are still largely unknown. Ca2+-dependent protein kinases (CDPKs) play central roles in Ca2+ signaling in plants. Previously, we found that a tobacco (Nicotiana tabacum) CDPK1 negatively regulated the transcription factor REPRESSION OF SHOOT GROWTH (RSG), which is involved in gibberellin feedback regulation. Here, we found that the variable N-terminal domain of CDPK1 is necessary for the recognition of RSG. A mutation (R10A) in the variable N-terminal domain of CDPK1 reduced both RSG binding and RSG phosphorylation while leaving kinase activity intact. Furthermore, the R10A mutation suppressed the in vivo function of CDPK1. The substitution of the variable N-terminal domain of an Arabidopsis thaliana CDPK, At CPK9, with that of Nt CDPK1 conferred RSG kinase activities. This chimeric CDPK behaved according to the identity of the variable N-terminal domain in transgenic plants. Our results open the possibility of engineering the substrate specificity of CDPK by manipulation of the variable N-terminal domain, enabling a rational rewiring of cellular signaling pathways. PMID:20442373

  11. OSI-930: a novel selective inhibitor of Kit and kinase insert domain receptor tyrosine kinases with antitumor activity in mouse xenograft models.

    PubMed

    Garton, Andrew J; Crew, Andrew P A; Franklin, Maryland; Cooke, Andrew R; Wynne, Graham M; Castaldo, Linda; Kahler, Jennifer; Winski, Shannon L; Franks, April; Brown, Eric N; Bittner, Mark A; Keily, John F; Briner, Paul; Hidden, Chris; Srebernak, Mary C; Pirrit, Carrie; O'Connor, Matthew; Chan, Anna; Vulevic, Bojana; Henninger, Dwight; Hart, Karen; Sennello, Regina; Li, An-Hu; Zhang, Tao; Richardson, Frank; Emerson, David L; Castelhano, Arlindo L; Arnold, Lee D; Gibson, Neil W

    2006-01-15

    OSI-930 is a novel inhibitor of the receptor tyrosine kinases Kit and kinase insert domain receptor (KDR), which is currently being evaluated in clinical studies. OSI-930 selectively inhibits Kit and KDR with similar potency in intact cells and also inhibits these targets in vivo following oral dosing. We have investigated the relationships between the potency observed in cell-based assays in vitro, the plasma exposure levels achieved following oral dosing, the time course of target inhibition in vivo, and antitumor activity of OSI-930 in tumor xenograft models. In the mutant Kit-expressing HMC-1 xenograft model, prolonged inhibition of Kit was achieved at oral doses between 10 and 50 mg/kg and this dose range was associated with antitumor activity. Similarly, prolonged inhibition of wild-type Kit in the NCI-H526 xenograft model was observed at oral doses of 100 to 200 mg/kg, which was the dose level associated with significant antitumor activity in this model as well as in the majority of other xenograft models tested. The data suggest that antitumor activity of OSI-930 in mouse xenograft models is observed at dose levels that maintain a significant level of inhibition of the molecular targets of OSI-930 for a prolonged period. Furthermore, pharmacokinetic evaluation of the plasma exposure levels of OSI-930 at these effective dose levels provides an estimate of the target plasma concentrations that may be required to achieve prolonged inhibition of Kit and KDR in humans and which would therefore be expected to yield a therapeutic benefit in future clinical evaluations of OSI-930.

  12. The anaplastic lymphoma kinase testing conundrum.

    PubMed

    Conde, Esther; Taniere, Philippe; Lopez-Rios, Fernando

    2015-02-01

    Given the excellent results of the clinical trials with anaplastic lymphoma kinase (ALK) inhibitors, the importance of accurately identifying ALK-positive lung carcinoma patients has never been greater. It brings with it a pressing need for harmonized development of companion diagnostics, for economic, scientific and medical reasons. Therefore, it is crucial that ALK testing assays become more standardized both in performance (analytical phase) and interpretation (post-analytical phase). We find that both methods currently recommended by College of American Pathologists/International Association for the Study of Lung Cancer/Association for Molecular Pathology guidelines (FISH and Immunohistochemistry) are reasonable approaches for primary routine ALK testing, if at least 50 tumor cells are scored and protocols are strictly followed. Moreover, due to the high demand to study multiple predictive biomarkers on different assay platforms, quick and reliable approaches to achieve this are essential to guide treatment decisions.

  13. Comparison of small biopsy specimens and surgical specimens for the detection of EGFR mutations and EML4-ALK in non-small-cell lung cancer

    PubMed Central

    Xiao, DeSheng; Lu, Can; Zhu, Wei; He, QiuYan; Li, Yong; Fu, ChunYan; Zhou, JianHua; Liu, Shuang; Tao, YongGuang

    2016-01-01

    Epidermal growth factor receptor (EGFR) mutations and anaplastic lymphoma kinase (ALK) fusion genes represent novel oncogenes that are associated with non–small-cell lung cancers (NSCLC). The feasibility of detecting EGFR mutations and ALK fusion genes in small biopsy specimens or surgical specimens was determined. Of the 721 NSCLC patients, a total of 305 cases were positive for EGFR mutations (42.3%). The rate of EGFR mutations in women was significantly higher than that in men. Histologically, the EGFR mutation rate in adenocarcinomas was significantly higher than that in squamous cell carcinomas. No difference in the EGFR mutation rate was observed between surgical specimens (42.1%) and small biopsy specimens (42.4%), which indicated that the EGFR mutation ratios in surgical specimens and small biopsy specimens were not different. In 385 NSCLC patients, 26 cases were positive for EML4-ALK (6.8%). However, 11.7% of the surgical specimens were EML4-ALK-positive, whereas the positive proportion in the small biopsy specimens was only 4.7%, which indicated that EML4-ALK-positive rate in the surgical specimens was significantly higher than that in the small biopsy specimens. Detection of EGFR gene mutations was feasible in small biopsy specimens, and screening for EML4-ALK expression in small biopsy specimens can be used to guide clinical treatments. PMID:27322143

  14. Light-induced movement of the LOV2 domain in an Asp720Asn mutant LOV2-kinase fragment of Arabidopsis phototropin 2.

    PubMed

    Takayama, Yuki; Nakasako, Masayoshi; Okajima, Koji; Iwata, Aya; Kashojiya, Sachiko; Matsui, Yuka; Tokutomi, Satoru

    2011-02-22

    Phototropin, a blue-light receptor protein of plants, triggers phototropic responses, chloroplast relocation, and opening of stomata to maximize the efficiency of photosynthesis. Phototropin is composed of two light-oxygen-voltage sensing domains (LOV1 and LOV2) that absorb blue light and a serine/theroine kinase domain responsible for light-dependent autophosphorylation leading to cellular signaling cascades. Although the light-activated LOV2 domain is primarily responsible for subsequent activation of the kinase domain, it is unclear how conformational changes in the former transmit to the latter. To understand this molecular mechanism in Arabidopsis phototropin 2, we performed small-angle X-ray scattering analysis on a fragment composed of the LOV2 and kinase domains, which contained an Asp720Asn mutation that led to an absence of ATP binding activity. The scattering data were collected up to a resolution of 25 Å. The apparent molecular weight of the fragment estimated from scattering intensities demonstrated that the fragment existed in a monomeric form in solution. The fragment exhibited photoreversible changes in the scattering profiles, and the radii of gyration under dark and blue-light irradiation conditions were 32.4 and 34.8 Å, respectively. In the dark, the molecular shape restored from the scattering profile appeared as an elongated shape of 110 Å in length and 45 Å in width. The homology modeled LOV2 and kinase domains could be fitted to the molecular shape and appeared to make slight contact. However, under blue-light irradiation, a more extended molecular shape was observed. The changes in the molecular shape and radius of gyration were interpreted as a light-dependent positional shift of the LOV2 domain of approximately 13 Å from the kinase domain. Because the region connecting the LOV2 and kinase domains was categorized as a naturally unfolded polypeptide, we propose that the light-activated LOV2 domain triggers conformational changes in the

  15. P-glycoprotein Mediates Ceritinib Resistance in Anaplastic Lymphoma Kinase-rearranged Non-small Cell Lung Cancer

    PubMed Central

    Katayama, Ryohei; Sakashita, Takuya; Yanagitani, Noriko; Ninomiya, Hironori; Horiike, Atsushi; Friboulet, Luc; Gainor, Justin F.; Motoi, Noriko; Dobashi, Akito; Sakata, Seiji; Tambo, Yuichi; Kitazono, Satoru; Sato, Shigeo; Koike, Sumie; John Iafrate, A.; Mino-Kenudson, Mari; Ishikawa, Yuichi; Shaw, Alice T.; Engelman, Jeffrey A.; Takeuchi, Kengo; Nishio, Makoto; Fujita, Naoya

    2015-01-01

    The anaplastic lymphoma kinase (ALK) fusion oncogene is observed in 3%–5% of non-small cell lung cancer (NSCLC). Crizotinib and ceritinib, a next-generation ALK tyrosine kinase inhibitor (TKI) active against crizotinib-refractory patients, are clinically available for the treatment of ALK-rearranged NSCLC patients, and multiple next-generation ALK-TKIs are currently under clinical evaluation. These ALK-TKIs exhibit robust clinical activity in ALK-rearranged NSCLC patients; however, the emergence of ALK-TKI resistance restricts the therapeutic effect. To date, various secondary mutations or bypass pathway activation-mediated resistance have been identified, but large parts of the resistance mechanism are yet to be identified. Here, we report the discovery of p-glycoprotein (P-gp/ABCB1) overexpression as a ceritinib resistance mechanism in ALK-rearranged NSCLC patients. P-gp exported ceritinib and its overexpression conferred ceritinib and crizotinib resistance, but not to PF-06463922 or alectinib, which are next-generation ALK inhibitors. Knockdown of ABCB1 or P-gp inhibitors sensitizes the patient-derived cancer cells to ceritinib, in vitro and in vivo. P-gp overexpression was identified in three out of 11 cases with in ALK-rearranged crizotinib or ceritinib resistant NSCLC patients. Our study suggests that alectinib, PF-06463922, or P-gp inhibitor with ceritinib could overcome the ceritinib or crizotinib resistance mediated by P-gp overexpression. PMID:26870817

  16. Entrectinib, a Pan-TRK, ROS1, and ALK Inhibitor with Activity in Multiple Molecularly Defined Cancer Indications.

    PubMed

    Ardini, Elena; Menichincheri, Maria; Banfi, Patrizia; Bosotti, Roberta; De Ponti, Cristina; Pulci, Romana; Ballinari, Dario; Ciomei, Marina; Texido, Gemma; Degrassi, Anna; Avanzi, Nilla; Amboldi, Nadia; Saccardo, Maria Beatrice; Casero, Daniele; Orsini, Paolo; Bandiera, Tiziano; Mologni, Luca; Anderson, David; Wei, Ge; Harris, Jason; Vernier, Jean-Michel; Li, Gang; Felder, Eduard; Donati, Daniele; Isacchi, Antonella; Pesenti, Enrico; Magnaghi, Paola; Galvani, Arturo

    2016-04-01

    Activated ALK and ROS1 tyrosine kinases, resulting from chromosomal rearrangements, occur in a subset of non-small cell lung cancers (NSCLC) as well as other tumor types and their oncogenic relevance as actionable targets has been demonstrated by the efficacy of selective kinase inhibitors such as crizotinib, ceritinib, and alectinib. More recently, low-frequency rearrangements of TRK kinases have been described in NSCLC, colorectal carcinoma, glioblastoma, and Spitzoid melanoma. Entrectinib, whose discovery and preclinical characterization are reported herein, is a novel, potent inhibitor of ALK, ROS1, and, importantly, of TRK family kinases, which shows promise for therapy of tumors bearing oncogenic forms of these proteins. Proliferation profiling against over 200 human tumor cell lines revealed that entrectinib is exquisitely potent in vitro against lines that are dependent on the drug's pharmacologic targets. Oral administration of entrectinib to tumor-bearing mice induced regression in relevant human xenograft tumors, including the TRKA-dependent colorectal carcinoma KM12, ROS1-driven tumors, and several ALK-dependent models of different tissue origins, including a model of brain-localized lung cancer metastasis. Entrectinib is currently showing great promise in phase I/II clinical trials, including the first documented objective responses to a TRK inhibitor in colorectal carcinoma and in NSCLC. The drug is, thus, potentially suited to the therapy of several molecularly defined cancer settings, especially that of TRK-dependent tumors, for which no approved drugs are currently available. Mol Cancer Ther; 15(4); 628-39. ©2016 AACR.

  17. Pleckstrin Homology Domain of Akt Kinase: A Proof of Principle for Highly Specific and Effective Non-Enzymatic Anti-Cancer Target

    PubMed Central

    Joh, Eun-Ha; Hollenbaugh, Joseph A.; Kim, Baek; Kim, Dong-Hyun

    2012-01-01

    While pharmacological inhibition of Akt kinase has been regarded as a promising anti-cancer strategy, most of the Akt inhibitors that have been developed are enzymatic inhibitors that target the kinase active site of Akt. Another key cellular regulatory event for Akt activation is the translocation of Akt kinase to the cell membrane from the cytoplasm, which is accomplished through the pleckstrin homology (PH) domain of Akt. However, compounds specifically interacting with the PH domain of Akt to inhibit Akt activation are currently limited. Here we identified a compound, lancemaside A (LAN-A), which specifically binds to the PH domain of Akt kinase. First, our mass spectra analysis of cellular Akt kinase isolated from cells treated with LAN-A revealed that LAN-A specifically binds to the PH domain of cellular Akt kinase. Second, we observed that LAN-A inhibits the translocation of Akt kinase to the membrane and thus Akt activation, as examined by the phosphorylation of various downstream targets of Akt such as GSK3β, mTOR and BAD. Third, in a co-cultured cell model containing human lung epithelial cancer cells (A549) and normal human primary lung fibroblasts, LAN-A specifically restricts the growth of the A549 cells. LAN-A also displayed anti-proliferative effects on various human cancer cell lines. Finally, in the A549-luciferase mouse transplant model, LAN-A effectively inhibited A549 cell growth with little evident cytotoxicity. Indeed, the therapeutic index of LAN-A in this mouse model was >250, supporting that LAN-A is a potential lead compound for PH domain targeting as a safe anti-cancer Akt inhibitor. PMID:23189201

  18. Anaplastic lymphoma kinase aberrations correlate with metastatic features in pediatric rhabdomyosarcoma

    PubMed Central

    Villa, Raffaella; Collini, Paola; Alaggio, Rita; Zin, Angelica; Bonvini, Paolo; Antonescu, Cristina R; Boldrini, Renata; Caserini, Roberto; Moro, Massimo; Centonze, Giovanni; Meazza, Cristina; Massimino, Maura; Bergamaschi, Luca; Luksch, Roberto; Chiaravalli, Stefano; Bisogno, Gianni; Zaffaroni, Nadia; Daidone, MariaGrazia

    2016-01-01

    Rhabdomyosarcoma (RMS) is the most frequent soft tissue tumor in childhood and arises from immature mesenchymal cells committed to skeletal muscle differentiation. Anaplastic Lymphoma Kinase (ALK) is a receptor tyrosine kinase aberrantly expressed in several cancers. Moreover, ALK full-length receptor protein has been observed in RMS, although its clinical and functional significance is yet controversial. The role of ALK and its clinical relevance were investigated in a selected cohort of 74 FFPE pediatric RMS and a panel of RMS cell lines, evaluating its gene and protein status, utilizing Fluorescent In Situ Hybridization (FISH), immunohistochemistry (IHC) and Western blot approaches. Moreover, to get insight into its possible therapeutic relevance, effects of ALK silencing on cell proliferation, invasion and apoptosis were studied in RMS cells. ALK IHC positivity was significantly correlated with gene copy number gain, the alveolar subtype, PAX3/7-FOXO1 rearrangements, the presence of metastasis at diagnosis and a worse overall outcome. Furthermore, EML4-ALK fusion gene associated with higher protein expression was identified in an embryonal RMS. ALK silencing in RH30 ALK positive cells strongly inhibited invasion capability. Overall, our data suggest a potential role of ALK in pediatric RMS. PMID:27385213

  19. Trafficking of Lyn through the Golgi caveolin involves the charged residues on αE and αI helices in the kinase domain

    PubMed Central

    Kasahara, Kousuke; Nakayama, Yuji; Ikeda, Kikuko; Fukushima, Yuka; Matsuda, Daisuke; Horimoto, Shinya; Yamaguchi, Naoto

    2004-01-01

    Src-family kinases, known to participate in signaling pathways of a variety of surface receptors, are localized to the cytoplasmic side of the plasma membrane through lipid modification. We show here that Lyn, a member of the Src-family kinases, is biosynthetically transported to the plasma membrane via the Golgi pool of caveolin along the secretory pathway. The trafficking of Lyn from the Golgi apparatus to the plasma membrane is inhibited by deletion of the kinase domain or Csk-induced “closed conformation” but not by kinase inactivation. Four residues (Asp346 and Glu353 on αE helix, and Asp498 and Asp499 on αI helix) present in the C-lobe of the kinase domain, which can be exposed to the molecular surface through an “open conformation,” are identified as being involved in export of Lyn from the Golgi apparatus toward the plasma membrane but not targeting to the Golgi apparatus. Thus, the kinase domain of Lyn plays a role in Lyn trafficking besides catalysis of substrate phosphorylation. PMID:15173188

  20. The carboxy-terminal domains of erbB-2 and epidermal growth factor receptor exert different regulatory effects on intrinsic receptor tyrosine kinase function and transforming activity.

    PubMed Central

    Di Fiore, P P; Segatto, O; Lonardo, F; Fazioli, F; Pierce, J H; Aaronson, S A

    1990-01-01

    The erbB-2 gene product, gp185erbB-2, displays a potent transforming effect when overexpressed in NIH 3T3 cells. In addition, it possesses constitutively high levels of tyrosine kinase activity in the absence of exogenously added ligand. In this study, we demonstrate that its carboxy-terminal domain exerts an enhancing effect on erbB-2 kinase and transforming activities. A premature termination mutant of the erbB-2 protein, lacking the entire carboxy-terminal domain (erbB-2 delta 1050), showed a 40-fold reduction in transforming ability and a lowered in vivo kinase activity for intracellular substrates. When the carboxy-terminal domain of erbB-2 was substituted for its analogous region in the epidermal growth factor receptor (EGFR) (EGFR/erbB-2COOH chimera), it conferred erbB-2-like properties to the EGFR, including transforming ability in the absence of epidermal growth factor, elevated constitutive autokinase activity in vivo and in vitro, and constitutive ability to phosphorylate phospholipase C-gamma. Conversely, a chimeric erbB-2 molecule bearing an EGFR carboxy-terminal domain (erbB-2/EGFRCOOH chimera) showed reduced transforming and kinase activity with respect to the wild-type erbB-2 and was only slightly more efficient than the erbB-2 delta 1050 mutant. Thus, we conclude that the carboxy-terminal domains of erbB-2 and EGFR exert different regulatory effects on receptor kinase function and biological activity. The up regulation of gp185erbB-2 enzymatic activity exerted by its carboxy-terminal domain can explain, at least in part, its constitutive level of kinase activity. Images PMID:2188097

  1. Protein Kinase C Phosphorylation of a γ-Protocadherin C-terminal Lipid Binding Domain Regulates Focal Adhesion Kinase Inhibition and Dendrite Arborization.

    PubMed

    Keeler, Austin B; Schreiner, Dietmar; Weiner, Joshua A

    2015-08-21

    The γ-protocadherins (γ-Pcdhs) are a family of 22 adhesion molecules with multiple critical developmental functions, including the proper formation of dendritic arbors by forebrain neurons. The γ-Pcdhs bind to and inhibit focal adhesion kinase (FAK) via a constant C-terminal cytoplasmic domain shared by all 22 proteins. In cortical neurons lacking the γ-Pcdhs, aberrantly high activity of FAK and of PKC disrupts dendrite arborization. Little is known, however, about how γ-Pcdh function is regulated by other factors. Here we show that PKC phosphorylates a serine residue situated within a phospholipid binding motif at the shared γ-Pcdh C terminus. Western blots using a novel phospho-specific antibody against this site suggest that a portion of γ-Pcdh proteins is phosphorylated in the cortex in vivo. We find that PKC phosphorylation disrupts both phospholipid binding and the γ-Pcdh inhibition of (but not binding to) FAK. Introduction of a non-phosphorylatable (S922A) γ-Pcdh construct into wild-type cortical neurons significantly increases dendrite arborization. This same S922A construct can also rescue dendrite arborization defects in γ-Pcdh null neurons cell autonomously. Consistent with these data, introduction of a phosphomimetic (S/D) γ-Pcdh construct or treatment with a PKC activator reduces dendrite arborization in wild-type cortical neurons. Together, these data identify a novel mechanism through which γ-Pcdh control of a signaling pathway important for dendrite arborization is regulated.

  2. Spotlight on crizotinib in the first-line treatment of ALK-positive advanced non-small-cell lung cancer: patients selection and perspectives

    PubMed Central

    Leprieur, Etienne Giroux; Fallet, Vincent; Cadranel, Jacques; Wislez, Marie

    2016-01-01

    Around 4% of advanced non-small-cell lung cancers (NSCLCs) have an ALK rearrangement at the time of diagnosis. This molecular feature is more frequent in young patients, with no/light smoking habit and with adenocarcinoma pathological subtype. Crizotinib is a tyrosine kinase inhibitor, targeting ALK, ROS1, RON, and MET. The preclinical efficacy results led to a fast-track clinical development. The US Food and Drug Administration (FDA) approval was achieved after the Phase I clinical trial in 2011 in ALK-rearranged advanced NSCLC progressing after a first-line treatment. In 2013, the randomized Phase III trial PROFILE-1007 confirmed the efficacy of crizotinib in ALK-rearranged NSCLC, compared to cytotoxic chemotherapy, in second-line setting or more. In 2014, the PROFILE-1014 trial showed the superiority of crizotinib in the first-line setting compared to the pemetrexed platinum doublet chemotherapy. The response rate was 74%, and the progression-free survival was 10.9 months with crizotinib. Based on these results, crizotinib received approval from the FDA and European Medicines Agency for first-line treatment of ALK-rearranged NSCLC. The various molecular mechanisms at the time of the progression (ALK mutations or amplification, ALK-independent mechanisms) encourage performing re-biopsy at the time of progression under crizotinib. The best treatment strategy at the progression (crizotinib continuation beyond progression, switch to second-generation tyrosine kinase inhibitors, or cytotoxic chemotherapy) depends on the phenotype of the progression, the molecular status, and the physical condition of the patient. PMID:28210164

  3. Functional characterization of a StyS sensor kinase reveals distinct domains associated with intracellular and extracellular sensing of styrene in P. putida CA-3.

    PubMed

    O'Leary, Niall D; Mooney, Aisling; O'Mahony, Mark; Dobson, Alan Dw

    2014-01-01

    Bacterial two-component systems (TCSs) are of vital importance in the translation of rapidly changing environmental conditions into appropriate cellular regulatory responses enabling adaptation, growth, and survival. The diverse range of environmental signals that TCSs can process, coupled with discrete modular domains within TCS proteins, offers considerable potential for the rational design of bio-sensor and/or bio-reporter strains. In this study we functionally characterize the multi-domain StyS sensor kinase associated with sensing of the aromatic pollutant styrene by Pseudomonas putida CA-3. Deletion analysis of discrete domains was performed and the ability of the truncated StyS sensor proteins to activate a cognate reporter system in an E. coli host assessed. The essential histidine kinase and PAS input domains were identified for StyS dependent activation of the reporter system. However, co-expression of an ABC-transporter protein StyE, previously linked to styrene transport in P. putida CA-3, enabled activation of the reporter system with a StyS construct containing a non-essential PAS input domain, suggesting a novel role for intracellular detection and/or activation. Site directed mutagenesis and amino acid deletions were employed to further characterize the PAS sensing domains of both input regions. The potential implications of these findings in the use of multi-domain sensor kinases in rational design strategies and the potential link between transport and intracellular sensing are discussed.

  4. Functional characterization of a StyS sensor kinase reveals distinct domains associated with intracellular and extracellular sensing of styrene in P. putida CA-3

    PubMed Central

    O'Leary, Niall D; Mooney, Aisling; O'Mahony, Mark; Dobson, Alan DW

    2014-01-01

    Bacterial two-component systems (TCSs) are of vital importance in the translation of rapidly changing environmental conditions into appropriate cellular regulatory responses enabling adaptation, growth, and survival. The diverse range of environmental signals that TCSs can process, coupled with discrete modular domains within TCS proteins, offers considerable potential for the rational design of bio-sensor and/or bio-reporter strains. In this study we functionally characterize the multi-domain StyS sensor kinase associated with sensing of the aromatic pollutant styrene by Pseudomonas putida CA-3. Deletion analysis of discrete domains was performed and the ability of the truncated StyS sensor proteins to activate a cognate reporter system in an E. coli host assessed. The essential histidine kinase and PAS input domains were identified for StyS dependent activation of the reporter system. However, co-expression of an ABC-transporter protein StyE, previously linked to styrene transport in P. putida CA-3, enabled activation of the reporter system with a StyS construct containing a non-essential PAS input domain, suggesting a novel role for intracellular detection and/or activation. Site directed mutagenesis and amino acid deletions were employed to further characterize the PAS sensing domains of both input regions. The potential implications of these findings in the use of multi-domain sensor kinases in rational design strategies and the potential link between transport and intracellular sensing are discussed. PMID:24637704

  5. Interaction between the tRNA-Binding and C-Terminal Domains of Yeast Gcn2 Regulates Kinase Activity In Vivo

    PubMed Central

    Lageix, Sebastien; Zhang, Jinwei; Rothenburg, Stefan; Hinnebusch, Alan G.

    2015-01-01

    The stress-activated protein kinase Gcn2 regulates protein synthesis by phosphorylation of translation initiation factor eIF2α. Gcn2 is activated in amino acid-deprived cells by binding of uncharged tRNA to the regulatory domain related to histidyl-tRNA synthetase, but the molecular mechanism of activation is unclear. We used a genetic approach to identify a key regulatory surface in Gcn2 that is proximal to the predicted active site of the HisRS domain and likely remodeled by tRNA binding. Mutations leading to amino acid substitutions on this surface were identified that activate Gcn2 at low levels of tRNA binding (Gcd- phenotype), while other substitutions block kinase activation (Gcn- phenotype), in some cases without altering tRNA binding by Gcn2 in vitro. Remarkably, the Gcn- substitutions increase affinity of the HisRS domain for the C-terminal domain (CTD), previously implicated as a kinase autoinhibitory segment, in a manner dampened by HisRS domain Gcd- substitutions and by amino acid starvation in vivo. Moreover, tRNA specifically antagonizes HisRS/CTD association in vitro. These findings support a model wherein HisRS-CTD interaction facilitates the autoinhibitory function of the CTD in nonstarvation conditions, with tRNA binding eliciting kinase activation by weakening HisRS-CTD association with attendant disruption of the autoinhibitory KD-CTD interaction. PMID:25695491

  6. Multiple isoforms of Arabidopsis casein kinase I combine conserved catalytic domains with variable carboxyl-terminal extensions.

    PubMed Central

    Klimczak, L J; Farini, D; Lin, C; Ponti, D; Cashmore, A R; Giuliano, G

    1995-01-01

    Three cDNA clones encoding isoforms of casein kinase I (CKI) were isolated from Arabidopsis thaliana. One full-length clone, designated CKI1, contained an open reading frame of 1371 bp encoding a protein of 51,949 D with an isoelectric point of 9.7. In addition to the highly conserved catalytic domain (of about 300 amino acids), the Arabidopsis CKI isoforms contain 150 to 180 amino acid carboxyl-terminal extensions, which show among themselves a lower level of sequence conservation. These extensions do not show any sequence similarity to nonplant CKI isoforms, such as rat testis CKI delta, which is their closest isolated homolog, or to yeast CKI isoforms. Three additional isoforms of Arabidopsis CKI were found in the data bases of expressed sequence tags and/or were isolated serendipitously in nonspecific screening procedures by others. One of them also shows a carboxyl-terminal extension, but of only 80 amino acids. Casein kinase activity was detected in the soluble fraction of Escherichia coli strains expressing the CKI1 protein. This activity showed the crucial properties of CKI, including the ability to phosphorylate the D4 peptide, a specific substrate of CKI, and inhibition by N-(2-aminoethyl)-5-chloroisoquinoline-8-sulfonamide, a specific CKI inhibitor. Like several recombinant CKI isoforms from yeast, CKI1 was able to phosphorylate tyrosine-containing acidic polymers. PMID:7480353

  7. Flavonol Activation Defines an Unanticipated Ligand-Binding Site in the Kinase-RNase Domain of IRE1

    SciTech Connect

    Wiseman, R. Luke; Zhang, Yuhong; Lee, Kenneth P.K.; Harding, Heather P.; Haynes, Cole M.; Price, Joshua; Sicheri, Frank; Ron, David

    2010-08-18

    Signaling in the most conserved branch of the endoplasmic reticulum (ER) unfolded protein response (UPR) is initiated by sequence-specific cleavage of the HAC1/XBP1 mRNA by the ER stress-induced kinase-endonuclease IRE1. We have discovered that the flavonol quercetin activates yeast IRE1's RNase and potentiates activation by ADP, a natural activating ligand that engages the IRE1 nucleotide-binding cleft. Enzyme kinetics and the structure of a cocrystal of IRE1 complexed with ADP and quercetin reveal engagement by quercetin of an unanticipated ligand-binding pocket at the dimer interface of IRE1's kinase extension nuclease (KEN) domain. Analytical ultracentrifugation and crosslinking studies support the preeminence of enhanced dimer formation in quercetin's mechanism of action. These findings hint at the existence of endogenous cytoplasmic ligands that may function alongside stress signals from the ER lumen to modulate IRE1 activity and at the potential for the development of drugs that modify UPR signaling from this unanticipated site.

  8. Isolation and characterization of signermycin B, an antibiotic that targets the dimerization domain of histidine kinase WalK.

    PubMed

    Watanabe, Takafumi; Igarashi, Masayuki; Okajima, Toshihide; Ishii, Eiji; Kino, Hirokazu; Hatano, Masaki; Sawa, Ryuichi; Umekita, Maya; Kimura, Tomoyuki; Okamoto, Sho; Eguchi, Yoko; Akamatsu, Yuzuru; Utsumi, Ryutaro

    2012-07-01

    The WalK (histidine kinase)/WalR (response regulator) two-component signal transduction system is a master regulatory system for cell wall metabolism and growth. This system is conserved in low G+C Gram-positive bacteria, including Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, and Streptococcus mutans. In this study, we found the first antibiotic that functions as a WalK inhibitor (signermycin B) by screening 10,000 Streptomyces extracts. The chemical structure (C(23)H(35)NO(4); molecular weight, 389.5) comprises a tetramic acid moiety and a decalin ring. Signermycin B exhibited antimicrobial activity, with MIC values ranging from 3.13 μg/ml (8 μM) to 6.25 μg/ml (16 μM) against Gram-positive bacteria that possess the WalK/WalR two-component signal transduction system, including the drug-resistant bacteria methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis. The half-maximal inhibitory concentrations of signermycin B against WalK in these organisms ranged from 37 to 61 μM. To determine the mechanism of action of signermycin B, surface plasmon resonance response analysis with the two WalK domains of Bacillus subtilis and competition assay with ATP were performed. The results showed that signermycin B binds to the dimerization domain but not the ATP-binding domain of WalK. In the presence of the cross-linker glutaraldehyde, signermycin B did not cause protein aggregation but interfered with the cross-linking of WalK dimers. These results suggest that signermycin B targets the conserved dimerization domain of WalK to inhibit autophosphorylation. In Bacillus subtilis and Staphylococcus aureus, signermycin B preferentially controlled the WalR regulon, thereby inhibiting cell division. These phenotypes are consistent with those of cells starved for the WalK/WalR system.

  9. Isolation and Characterization of Signermycin B, an Antibiotic That Targets the Dimerization Domain of Histidine Kinase WalK

    PubMed Central

    Watanabe, Takafumi; Igarashi, Masayuki; Okajima, Toshihide; Ishii, Eiji; Kino, Hirokazu; Hatano, Masaki; Sawa, Ryuichi; Umekita, Maya; Kimura, Tomoyuki; Okamoto, Sho; Eguchi, Yoko; Akamatsu, Yuzuru

    2012-01-01

    The WalK (histidine kinase)/WalR (response regulator) two-component signal transduction system is a master regulatory system for cell wall metabolism and growth. This system is conserved in low G+C Gram-positive bacteria, including Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, and Streptococcus mutans. In this study, we found the first antibiotic that functions as a WalK inhibitor (signermycin B) by screening 10,000 Streptomyces extracts. The chemical structure (C23H35NO4; molecular weight, 389.5) comprises a tetramic acid moiety and a decalin ring. Signermycin B exhibited antimicrobial activity, with MIC values ranging from 3.13 μg/ml (8 μM) to 6.25 μg/ml (16 μM) against Gram-positive bacteria that possess the WalK/WalR two-component signal transduction system, including the drug-resistant bacteria methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis. The half-maximal inhibitory concentrations of signermycin B against WalK in these organisms ranged from 37 to 61 μM. To determine the mechanism of action of signermycin B, surface plasmon resonance response analysis with the two WalK domains of Bacillus subtilis and competition assay with ATP were performed. The results showed that signermycin B binds to the dimerization domain but not the ATP-binding domain of WalK. In the presence of the cross-linker glutaraldehyde, signermycin B did not cause protein aggregation but interfered with the cross-linking of WalK dimers. These results suggest that signermycin B targets the conserved dimerization domain of WalK to inhibit autophosphorylation. In Bacillus subtilis and Staphylococcus aureus, signermycin B preferentially controlled the WalR regulon, thereby inhibiting cell division. These phenotypes are consistent with those of cells starved for the WalK/WalR system. PMID:22526318

  10. Binding of Drosophila Polo kinase to its regulator Matrimony is noncanonical and involves two separate functional domains.

    PubMed

    Bonner, Amanda M; Hughes, Stacie E; Chisholm, Jennifer A; Smith, S Kendall; Slaughter, Brian D; Unruh, Jay R; Collins, Kimberly A; Friederichs, Jennifer M; Florens, Laurence; Swanson, Selene K; Pelot, Marissa C; Miller, Danny E; Washburn, Michael P; Jaspersen, Sue L; Hawley, R Scott

    2013-03-26

    Drosophila melanogaster Polo kinase physically interacts with, and is repressed by, the Matrimony (Mtrm) protein during oogenesis. Females heterozygous for a deletion of the mtrm gene display defects in chromosome segregation at meiosis I. However, a complete absence of Mtrm results in both meiotic catastrophe and female sterility. We show that three phosphorylated residues in an N-terminal region in Mtrm are required for Mtrm::Polo binding. However, this binding is noncanonical; it does not require either a complete S-pS/pT-P motif in Mtrm or key residues in the Polo-box domain of Polo that allow Polo to bind phosphorylated substrates. By using fluorescence cross-correlation spectroscopy to characterize the Mtrm::Polo interaction in vivo, we show that a sterile α-motif (SAM) domain located at the C terminus of Mtrm increases the stability of Mtrm::Polo binding. Although Mtrm's C-terminal SAM domain is not required to rescue the chromosome segregation defects observed in mtrm/+ females, it is essential to prevent both meiotic catastrophe and the female sterility observed in mtrm/mtrm females. We propose that Polo's interaction with the cluster of phosphorylated residues alone is sufficient to rescue the meiosis I defect. However, the strengthening of Mtrm::Polo binding mediated by the SAM domain is necessary to prevent meiotic catastrophe and ensure female fertility. Characterization of the Mtrm::Polo interaction, as well as that of other Polo regulators, may assist in the design of a new class of Polo inhibitors to be used as targeted anticancer therapeutic agents.

  11. Genetic obesity alters recruitment of TANK-binding kinase 1 and AKT into hypothalamic lipid rafts domains.

    PubMed

    Delint-Ramirez, Ilse; Maldonado Ruiz, Roger; Torre-Villalvazo, Ivan; Fuentes-Mera, Lizeth; Garza Ocañas, Lourdes; Tovar, Armando; Camacho, Alberto

    2015-01-01

    Lipid rafts (LRs) are membrane subdomains enriched in cholesterol, glycosphingolipids and sphingolipids containing saturated fatty acid. Signaling proteins become concentrated in these microdomains mainly by saturated fatty acid modification, thus facilitating formation of protein complexes and activation of specific signaling pathways. High intake of saturated fatty acids promotes inflammation and insulin resistance, in part by disrupting insulin signaling pathway. Here we investigate whether lipid-induced toxicity in obesity correlates with altered composition of insulin signaling proteins in LRs in the brain. Our results showed that insulin receptor (IR) is highly concentrated in LRs fraction in comparison with soluble or postsynaptic density (PSD) fractions. Analysis of LRs domains from hippocampus of obese mouse showed a significant decrease of IR and its downstream signaling protein AKT, while in the PSD fraction we detected partial decrease of AKT and no changes in the IR concentration. No changes were shown in the soluble extract. In hypothalamus, genetic obesity also decreases interaction of AKT, but we did not detect changes in the IR distribution. However, in this structure genetic obesity increases recruitment of the IR negative regulator TANK-binding kinase 1 (TBK1) into LRs and PSD fraction. No changes of AKT, IR and TBK1 were found in soluble fractions of obese in comparison with lean mice. In vitro studies showed that incubation with saturated palmitic acid but not with unsaturated docosahexaenoic acid (DHA) or palmitoleic acid decreases association of IR and AKT and increases TBK1 recruitment into LRs and PSD domains, emulating what happens in the obese mice. TBK1 recruitment to insoluble domains correlates with decreases of IR tyrosine phosphorylation and ser473 AKT phosphorylation, markers of insulin resistance. These data support the hypothesis that hyperlipidemia associated with genetic obesity alters targeting of TBK1 and insulin signaling

  12. ATP forms a stable complex with the essential histidine kinase WalK (YycG) domain

    SciTech Connect

    Celikel, Reha; Veldore, Vidya Harini; Mathews, Irimpan; Devine, Kevin M.; Varughese, Kottayil I.

    2012-07-01

    The histidine WalK (YycG) plays a crucial role in coordinating murein synthesis with cell division and the crystal structure of its ATP binding domain has been determined. Interestingly the bound ATP was not hydrolyzed during crystallization and remains intact in the crystal lattice. In Bacillus subtilis, the WalRK (YycFG) two-component system coordinates murein synthesis with cell division. It regulates the expression of autolysins that function in cell-wall remodeling and of proteins that modulate autolysin activity. The transcription factor WalR is activated upon phosphorylation by the histidine kinase WalK, a multi-domain homodimer. It autophosphorylates one of its histidine residues by transferring the γ-phosphate from ATP bound to its ATP-binding domain. Here, the high-resolution crystal structure of the ATP-binding domain of WalK in complex with ATP is presented at 1.61 Å resolution. The bound ATP remains intact in the crystal lattice. It appears that the strong binding interactions and the nature of the binding pocket contribute to its stability. The triphosphate moiety of ATP wraps around an Mg{sup 2+} ion, providing three O atoms for coordination in a near-ideal octahedral geometry. The ATP molecule also makes strong interactions with the protein. In addition, there is a short contact between the exocyclic O3′ of the sugar ring and O2B of the β-phosphate, implying an internal hydrogen bond. The stability of the WalK–ATP complex in the crystal lattice suggests that such a complex may exist in vivo poised for initiation of signal transmission. This feature may therefore be part of the sensing mechanism by which the WalRK two-component system is so rapidly activated when cells encounter conditions conducive for growth.

  13. Development of potent ALK inhibitor and its molecular inhibitory mechanism against NSCLC harboring EML4-ALK proteins

    SciTech Connect

    Kang, Chung Hyo; Yun, Jeong In; Lee, Kwangho; Lee, Chong Ock; Lee, Heung Kyoung; Yun, Chang-Soo; Hwang, Jong Yeon; Cho, Sung Yun; Jung, Heejung; Kim, Pilho; Ha, Jae Du; Jeon, Jeong Hee; Choi, Sang Un; Jeong, Hye Gwang; Kim, Hyoung Rae; Park, Chi Hoon

    2015-08-28

    Here, we show the newly synthesized and potent ALK inhibitor having similar scaffold to KRCA-0008, which was reported previously, and its molecular mechanism against cancer cells harboring EML4-ALK fusion protein. Through ALK wild type enzyme assay, we selected two compounds, KRCA-0080 and KRCA-0087, which have trifluoromethyl instead of chloride in R2 position. We characterized these newly synthesized compounds by in vitro and in vivo assays. Enzyme assay shows that KRCA-0080 is more potent against various ALK mutants, including L1196M, G1202R, T1151-L1152insT, and C1156Y, which are seen in crizotinib-resistant patients, than KRCA-0008 is. Cell based assays demonstrate our compounds downregulate the cellular signaling, such as Akt and Erk, by suppressing ALK activity to inhibit the proliferation of the cells harboring EML4-ALK. Interestingly, our compounds induced strong G1/S arrest in H3122 cells leading to the apoptosis, which is proved by PARP-1 cleavage. In vivo H3122 xenograft assay, we found that KRCA-0080 shows significant reduction in tumor size compared to crizotinib and KRCA-0008 by 15–20%. Conclusively, we report a potent ALK inhibitor which shows significant in vivo efficacy as well as excellent inhibitory activity against various ALK mutants. - Highlights: • We synthesized KRCA-0008 derivatives having trifluoromethyl instead of chloride. • KRCA-0080 shows superior activity against several ALK mutants to KRCA-0008. • Cellular assays show our ALK inhibitors suppress only EML4-ALK positive cells. • Our ALK inhibitors induce G1/S arrest to lead apoptosis in H3122 cells. • KRCA-0080 has superior in vivo efficacy to crizotinib and KRCA-0008 by 15–20%.

  14. Fatal Haemoptysis Associated with Dramatic Response to Crizotinib in an ALK-Rearranged Lung Adenocarcinoma

    PubMed Central

    Mussat, Elodie; Giraud, Violaine; Julie, Catherine; Chinet, Thierry

    2016-01-01

    The presence of an ALK (Anaplastic Lymphoma Kinase) rearrangement is a rare molecular feature in Non-Small Cell Lung Carcinoma (NSCLC), and concerns mainly non- or light smokers, young patients, with adenocarcinoma histological type. These tumours are particularly sensitive to Alk-targeted therapies, as crizotinib. Crizotinib is usually well-tolerated. We report a case of fatal haemoptysis associated with dramatic response to crizotinib in a patient with an ALK-rearranged lung adenocarcinoma. The patient presented a mediastinal invasion with tracheal involvement and compression of the right pulmonary artery. The initial evolution under crizotinib was good with tumour response. At 6 weeks of crizotinib the patient presented a massive haemoptysis with a tracheobronchial fistula and pneumomediastinum. She died of acute respiratory failure. Our case is the first to report a fatal effect of crizotinib associated with tumour necrosis and good tumour response on a massive mediastinal infiltration. Precautions are recommended with the use of crizotinib in proximal lung tumours with vascular invasion. PMID:27134984

  15. Uncommon features of surgically resected ALK-positive cavitary lung adenocarcinoma: a case report.

    PubMed

    Takamori, Shinkichi; Yamaguchi, Masafumi; Taguchi, Kenichi; Edagawa, Makoto; Shimamatsu, Shinichiro; Toyozawa, Ryo; Nosaki, Kaname; Hirai, Fumihiko; Seto, Takashi; Takenoyama, Mitsuhiro; Ichinose, Yukito

    2017-12-01

    Some features found on chest computed tomography (CT), such as central tumor location, large pleural effusion, and the absence of a pleural tail, and a patient age of less than 60 years, have been suggested to be useful in predicting anaplastic lymphoma kinase (ALK) rearrangement in patients with non-small cell lung cancer (NSCLC).A 68-year-old female patient with a history of gynecological treatment was found to have a cavitary mass in the right lower lobe on an annual chest roentgenogram. The tumor was located in the peripheral area with a pleural tail showing no pleural effusion. In addition, two pure ground-glass-opacity nodules (p-GGNs) in the right upper lobe of the lung were detected on consecutive chest CT scans. The patient underwent right lower lobectomy, partial resection of the right upper lobe, and hilar mediastinal lymph node dissection for complete resection of each tumor. The pathological diagnosis was invasive mucinous adenocarcinoma with signet-ring cells for the cavitary mass in the right lower lobe and invasive adenocarcinoma for the rest of the p-GGNs; subcarinal lymph node metastasis was also detected. The ALK rearrangement was detected by fluorescence in situ hybridization from the cavitary mass. The patient underwent four cycles of cisplatin and vinorelbine chemotherapy as standard adjuvant chemotherapy for pStage III NSCLC. The ALK fusion gene status of NSCLC with atypical CT features should also be investigated.

  16. Determination and validation of mTOR kinase-domain 3D structure by homology modeling.

    PubMed

    Lakhlili, Wiame; Chevé, Gwénaël; Yasri, Abdelaziz; Ibrahimi, Azeddine

    2015-01-01

    The AKT/mammalian target of rapamycin (mTOR) pathway is considered as one of the commonly activated and deregulated signaling pathways in human cancer. mTOR is associated with other proteins in two molecular complexes: mTOR complex 1/Raptor and the mTOR complex 2/Rictor. Using the crystal structure of the related lipid kinase PI3Kγ, we built a model of the catalytic region of mTOR. The modeling of the three-dimensional (3D) structure of the mTOR was performed by homology modeling program SWISS-MODEL. The quality and validation of the obtained model were performed using PROCHECK and PROVE softwares. The overall stereochemical property of the protein was assessed by the Ramachandran plot. The model validation was also done by docking of known inhibitors. In this paper, we describe and validate a 3D model for the mTOR catalytic site.

  17. Alectinib's activity against CNS metastases from ALK-positive non-small cell lung cancer: a single institution case series.

    PubMed

    Metro, Giulio; Lunardi, Gianluigi; Bennati, Chiara; Chiarini, Pietro; Sperduti, Isabella; Ricciuti, Biagio; Marcomigni, Luca; Costa, Cinzia; Crinò, Lucio; Floridi, Piero; Gori, Stefania; Chiari, Rita

    2016-09-01

    In the present study we assessed the activity of the next-generation anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitor (-TKI) alectinib, in patients with ALK-postive, advanced non-small cell lung cancer (NSCLC) and central nervous system (CNS) metastases. NSCLCs with ALK-positive disease, as assessed by fluorescence in situ hybridization, and CNS metastases were treated with alectinib 600 mg BID. Included patients were followed prospectively in order to evaluate the efficacy of the drug, with particular emphasis on activity in the CNS. Eleven consecutive patients were enrolled. The majority of them were pretreated with crizotinib (n = 10, 90.9 %), and cranial radiotherapy (n = 8, 72.7 %). Six of the seven patients with measurable CNS disease experienced a CNS response, including three patients who were naïve for cranial radiation. Median duration of response was 8 months. For the whole population, median CNS-progression-free survival (-PFS), systemic-PFS, overall-PFS, overall survival, and 1-year survival were 8, 11, 8, 13 months, and 31.1 %, respectively. Two patients experiencing a CNS response were assessed for alectinib's concentrations in serum and cerebro-spinal fluid (CSF), and showed a CSF-to-serum ratio ranging from 0.001 to 0.003 ng/mL. Alectinib is highly active against CNS metastases from ALK-positive NSCLCs, irrespective of prior treatment(s) with ALK-TKI(s) and/or cranial radiotherapy. The low CSF-to-serum ratio of alectinib suggests that measuring the concentrations of the drug in the CSF may not be a reliable surrogate of its distribution into the CNS.

  18. Genotype-driven therapies for non-small cell lung cancer: focus on EGFR, KRAS and ALK gene abnormalities.

    PubMed

    Gaughan, Elizabeth M; Costa, Daniel B

    2011-05-01

    Non-small cell lung cancers (NSCLCs) are heterogeneous cancers. In 2004, the identification of epidermal growth factor receptor (EGFR) somatic mutations provided the first glimpse of a clinically relevant NSCLC oncogene. Approximately 70% of NSCLCs with EGFR mutations (exon 19 deletions or the exon 21 L858R) attain responses to EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib, with improved response rate (RR), progression-free survival (PFS) and in some reports overall survival (OS) when compared with EGFR wildtype (WT) cases. Three randomized trials of gefitinib versus chemotherapy (IPASS, WJTOG3405, NEJ002) in stage IV NSCLC have consistently demonstrated better RR and PFS (hazard ratios of 0.48 [IPASS], 0.49 [WJTOG3405] and 0.30 [NEJ002]) for EGFR-mutated NSCLCs treated with gefitinib. Novel irreversible EGFR TKIs (afatinib, XL647, PF00299804) show similar activity in EGFR-mutated patients. A translocation involving the anaplastic lymphoma kinase (ALK) gene with EML4, identified in 2007, is the most recent oncogene found in NSCLC. Crizotinib (PF02341066), an ALK TKI, has shown impressive activity against ALK translocated NSCLC in an expanded cohort of a phase I trial (NCT00585195). Over 80 patients have been treated and the RR is ∼60% with the 6-month PFS rate exceeding 70%. A registration phase III trial of crizotinib versus second-line chemotherapy (pemetrexed/docetaxel) is underway (PROFILE 1007, NCT00932893). KRAS, EGFR mutations and ALK translocations are mutually exclusive and few EGFR WT NSCLCs respond to EGFR TKIs. The promising results of EGFR and ALK TKIs in molecular subgroups of NSCLCs herald a new age of drug and clinical trial development for patients with NSCLC.

  19. AlkB homolog 3-mediated tRNA demethylation promotes protein synthesis in cancer cells

    PubMed Central

    Ueda, Yuko; Ooshio, Ikumi; Fusamae, Yasuyuki; Kitae, Kaori; Kawaguchi, Megumi; Jingushi, Kentaro; Hase, Hiroaki; Harada, Kazuo; Hirata, Kazumasa; Tsujikawa, Kazutake

    2017-01-01

    The mammalian AlkB homolog (ALKBH) family of proteins possess a 2-oxoglutarate- and Fe(II)-dependent oxygenase domain. A similar domain in the Escherichia coli AlkB protein catalyzes the oxidative demethylation of 1-methyladenine (1-meA) and 3-methylcytosine (3-meC) in both DNA and RNA. AlkB homolog 3 (ALKBH3) was also shown to demethylate 1-meA and 3-meC (induced in single-stranded DNA and RNA by a methylating agent) to reverse the methylation damage and retain the integrity of the DNA/RNA. We previously reported the high expression of ALKBH3 in clinical tumor specimens and its involvement in tumor progression. In this study, we found that ALKBH3 effectively demethylated 1-meA and 3-meC within endogenously methylated RNA. Moreover, using highly purified recombinant ALKBH3, we identified N6-methyladenine (N6-meA) in mammalian transfer RNA (tRNA) as a novel ALKBH3 substrate. An in vitro translation assay showed that ALKBH3-demethylated tRNA significantly enhanced protein translation efficiency. In addition, ALKBH3 knockdown in human cancer cells impaired cellular proliferation and suppressed the nascent protein synthesis that is usually accompanied by accumulation of the methylated RNAs. Thus, our data highlight a novel role for ALKBH3 in tumor progression via RNA demethylation and subsequent protein synthesis promotion. PMID:28205560

  20. BMP type I receptor ALK2 is required for angiotensin II-induced cardiac hypertrophy.

    PubMed

    Shahid, Mohd; Spagnolli, Ester; Ernande, Laura; Thoonen, Robrecht; Kolodziej, Starsha A; Leyton, Patricio A; Cheng, Juan; Tainsh, Robert E T; Mayeur, Claire; Rhee, David K; Wu, Mei X; Scherrer-Crosbie, Marielle; Buys, Emmanuel S; Zapol, Warren M; Bloch, Kenneth D; Bloch, Donald B

    2016-04-15

    Bone morphogenetic protein (BMP) signaling contributes to the development of cardiac hypertrophy. However, the identity of the BMP type I receptor involved in cardiac hypertrophy and the underlying molecular mechanisms are poorly understood. By using quantitative PCR and immunoblotting, we demonstrated that BMP signaling increased during phenylephrine-induced hypertrophy in cultured neonatal rat cardiomyocytes (NRCs), as evidenced by increased phosphorylation of Smads 1 and 5 and induction of Id1 gene expression. Inhibition of BMP signaling with LDN193189 or noggin, and silencing of Smad 1 or 4 using small interfering RNA diminished the ability of phenylephrine to induce hypertrophy in NRCs. Conversely, activation of BMP signaling with BMP2 or BMP4 induced hypertrophy in NRCs. Luciferase reporter assay further showed that BMP2 or BMP4 treatment of NRCs repressed atrogin-1 gene expression concomitant with an increase in calcineurin protein levels and enhanced activity of nuclear factor of activated T cells, providing a mechanism by which BMP signaling contributes to cardiac hypertrophy. In a model of cardiac hypertrophy, C57BL/6 mice treated with angiotensin II (A2) had increased BMP signaling in the left ventricle. Treatment with LDN193189 attenuated A2-induced cardiac hypertrophy and collagen deposition in left ventricles. Cardiomyocyte-specific deletion of BMP type I receptor ALK2 (activin-like kinase 2), but not ALK1 or ALK3, inhibited BMP signaling and mitigated A2-induced cardiac hypertrophy and left ventricular fibrosis in mice. The results suggest that BMP signaling upregulates the calcineurin/nuclear factor of activated T cell pathway via BMP type I receptor ALK2, contributing to cardiac hypertrophy and fibrosis.

  1. Expression, purification and crystallization of a BH domain from the GTPase regulatory protein associated with focal adhesion kinase.

    PubMed

    Sheffield, P J; Derewenda, U; Taylor, J; Parsons, T J; Derewenda, Z S

    1999-01-01

    Signaling by small GTPases is down-regulated by GTPase activating proteins (GAPs) which enhance the rate of GTP hydrolysis. The activity of GAPs specific for Rho GTPases resides in the BH domain, many homologues of which are found in any mammalian genome. One of them was identified in the GTPase regulator associated with focal-adhesion kinase (GRAF). It shares approximately 20% sequence identity with p50RhoGAP. This GAP activates RhoA and Cdc42Hs, but not Rac. In order to dissect the molecular basis of this specificity, a 231-residue-long fragment corresponding to the BH domain of GRAF has been expressed, purified and crystallized. Trigonal crystals, of space group P3(1)21 or P3(2)21, with unit-cell dimensions a = b = 63.5, c = 90.38 A were grown from solutions of PEG 6000. Data to 2.15 A were collected from a flash-frozen sample on an R-AXIS IV imaging-plate detector mounted on a rotating anode X-ray generator.

  2. Genetic and mechanistic analyses of the periplasmic domain of the enterohemorrhagic E. coli (EHEC) QseC histidine sensor kinase.

    PubMed

    Parker, Christopher T; Russell, Regan; Njoroge, Jacqueline W; Jimenez, Angel G; Taussig, Ron; Sperandio, Vanessa

    2017-01-30

    The histidine sensor kinase (HK) QseC, senses autoinducer-3 (AI-3), and the adrenergic hormones epinephrine and norepinephrine. Upon sensing these signals, QseC acts through three response regulators (RRs) to regulate expression of virulence genes in enterohemorrhagic E. coli (EHEC). The QseB, QseF and KdpE RRs that are phosphorylated by QseC constitute a tripartite signaling cascade having different and overlapping targets, including flagella and motility, the type three secretion system encoded by the locus of enterocyte effacement (LEE), and Shiga toxin. We modeled the tertiary structure of QseC's periplasmic sensing domain, and also aligned these sequences from 12 different species to identify the most conserved amino acids. We selected eight conserved aminoacids in all of these QseC homologs. These QseC site directed mutants were expressed and still able to autophosphorylate, albeit four mutants depicted increased basal level of phosphorylation. These mutants have differential flagella and motility, LEE and Shiga toxin expression phenotypes. We selected four mutants for more in depth analyses and found that they differed in their ability to phosphorylate QseB, KdpE and QseF. This suggests that these mutations in the periplasmic sensing domain affected the downstream of the QseC signaling cascade, and therefore, can influence which pathway QseC regulates.

  3. Absence of catalytic domain in a putative protein kinase C (PkcA) suppresses tip dominance in Dictyostelium discoideum.

    PubMed

    Mohamed, Wasima; Ray, Sibnath; Brazill, Derrick; Baskar, Ramamurthy

    2015-09-01

    A number of organisms possess several isoforms of protein kinase C but little is known about the significance of any specific isoform during embryogenesis and development. To address this we characterized a PKC ortholog (PkcA; DDB_G0288147) in Dictyostelium discoideum. pkcA expression switches from prestalk in mound to prespore in slug, indicating a dynamic expression pattern. Mutants lacking the catalytic domain of PkcA (pkcA(-)) did not exhibit tip dominance. A striking phenotype of pkcA- was the formation of an aggregate with a central hollow, and aggregates later fragmented to form small mounds, each becoming a fruiting body. Optical density wave patterns of cAMP in the late aggregates showed several cAMP wave generation centers. We attribute these defects in pkcA(-) to impaired cAMP signaling, altered cell motility and decreased expression of the cell adhesion molecules - CadA and CsaA. pkcA(-) slugs showed ectopic expression of ecmA in the prespore region. Further, the use of a PKC-specific inhibitor, GF109203X that inhibits the activity of catalytic domain phenocopied pkcA(-).

  4. Absence of catalytic domain in a putative protein kinase C (PkcA) suppresses tip dominance in Dictyostelium discoideum

    PubMed Central

    Mohamed, Wasima; Ray, Sibnath; Brazill, Derrick; Baskar, Ramamurthy

    2017-01-01

    A number of organisms possess several isoforms of protein kinase C but little is known about the significance of any specific isoform during embryogenesis and development. To address this we characterized a PKC ortholog (PkcA; DDB_G0288147) in Dictyostelium discoideum. pkcA expression switches from prestalk in mound to prespore in slug, indicating a dynamic expression pattern. Mutants lacking the catalytic domain of PkcA (pkcA−) did not exhibit tip dominance. A striking phenotype of pkcA− was the formation of an aggregate with a central hollow, and aggregates later fragmented to form small mounds, each becoming a fruiting body. Optical density wave patterns of cAMP in the late aggregates showed several cAMP wave generation centers. We attribute these defects in pkcA− to impaired cAMP signaling, altered cell motility and decreased expression of the cell adhesion molecules – CadA and CsaA. pkcA− slugs showed ectopic expression of ecmA in the prespore region. Further, the use of a PKC-specific inhibitor, GF109203X that inhibits the activity of catalytic domain phenocopied pkcA−. PMID:26183108

  5. Identification and characterization of a novel SH3-domain binding protein, Sab, which preferentially associates with Bruton's tyrosine kinase (BtK).

    PubMed

    Matsushita, M; Yamadori, T; Kato, S; Takemoto, Y; Inazawa, J; Baba, Y; Hashimoto, S; Sekine, S; Arai, S; Kunikata, T; Kurimoto, M; Kishimoto, T; Tsukada, S

    1998-04-17

    Protein interaction cloning method was used to identify a novel molecule, Sab, which binds to the SH3 domain of Bruton's tyrosine kinase (Btk), the deficient cytoplasmic tyrosine kinase in human X-linked agammaglobulinemia and murine X-linked immunodeficiency. Immunoprecipitation using the anti-Sab antibody identified the protein product of the gene as a 70 kDa molecule. While Sab does not have a proline-rich sequence, it was shown to bind to Btk through the commonly conserved structure among SH3 domains. Remarkably, Sab exhibited a high preference for binding to Btk rather than to other cytoplasmic tyrosine kinases, which suggests a unique role of Sab in the Btk signal transduction pathway.

  6. Identification and Analysis of a Novel Dimerization Domain Shared by Various Members of c-Jun N-terminal Kinase (JNK) Scaffold Proteins*

    PubMed Central

    Cohen-Katsenelson, Ksenya; Wasserman, Tanya; Darlyuk-Saadon, Ilona; Rabner, Alona; Glaser, Fabian; Aronheim, Ami

    2013-01-01

    Mitogen-activated protein kinases (MAPKs) form a kinase tier module in which MAPK, MAP2K, and MAP3K are held by scaffold proteins. The scaffold proteins serve as a protein platform for selective and spatial kinase activation. The precise mechanism by which the scaffold proteins function has not yet been fully explained. WDR62 is a novel scaffold protein of the c-Jun N-terminal kinase (JNK) pathway. Recessive mutations within WDR62 result in severe cerebral cortical malformations. One of the WDR62 mutant proteins found in a patient with microcephaly encodes a C-terminal truncated protein that fails to associate efficiently with JNK and MKK7β1. The present article shows that the WDR62 C-terminal region harbors a novel dimerization domain composed of a putative loop-helix domain that is necessary and sufficient for WDR62 dimerization and is critical for its scaffolding function. The loop-helix domain is highly conserved between orthologues and is also shared by the JNK scaffold protein, JNKBP1/MAPKBP1. Based on the high sequence conservation of the loop-helix domain, our article shows that MAPKBP1 homodimerizes and heterodimerizes with WDR62. Endogenous WDR62 and MAPKBP1 co-localize to stress granules following arsenite treatment, but not during mitosis. This study proposes another layer of complexity, in which coordinated activation of signaling pathways is mediated by the association between the different JNK scaffold proteins depending on their biological function. PMID:23341463

  7. Transient receptor potential melastatin 7 is involved in oestrogen receptor-negative metastatic breast cancer cells migration through its kinase domain.

    PubMed

    Guilbert, A; Gautier, M; Dhennin-Duthille, I; Rybarczyk, P; Sahni, J; Sevestre, H; Scharenberg, A M; Ouadid-Ahidouch, H

    2013-11-01

    Oestrogen receptor negative (ER(-)) invasive ductal carcinoma (IDC) represents a significant clinical challenge and therefore prompts the discovery of novel biomarkers. Transient receptor potential melastatin 7 (TRPM7), a channel protein that also contains a regulatory kinase domain, is overexpressed in IDC and regulates migration. However, the molecular mechanism remains poorly defined. Here, we examined whether TRPM7 regulates migration by its channel function or by its kinase domain. A Magnesium Inhibited Cation current was recorded in two ER(-) highly metastatic breast cancer cell lines. Down-regulation of TRPM7 neither affected Ca(2+)-, nor Mg(2+)-homoeostasis but significantly reduced cell migration via a Ca(2+)-independent pathway. Notably, the overexpression of the truncated kinase domain form of TRPM7 decreased cell migration, while the overexpression of the wild-type form strongly increased it. Concomitantly, TRPM7 silencing reduced the myosin IIA heavy chain phosphorylation. Furthermore, we found higher TRPM7 expression in ER(-) IDC tissues and lymph nodes than in the non-invasive tumoural samples. In conclusion, TRPM7 plays a critical role in breast cancer cell migration through its kinase domain, and our data support the consideration of using TRPM7 as a novel biomarker and a potential therapeutic target in the treatment of human ER(-) IDC.

  8. Dynamic coupling between the LID and NMP domain motions in the catalytic conversion of ATP and AMP to ADP by adenylate kinase.

    PubMed

    Jana, Biman; Adkar, Bharat V; Biswas, Rajib; Bagchi, Biman

    2011-01-21

    The catalytic conversion of adenosine triphosphate (ATP) and adenosine monophosphate (AMP) to adenosine diphosphate (ADP) by adenylate kinase (ADK) involves large amplitude, ligand induced domain motions, involving the opening and the closing of ATP binding domain (LID) and AMP binding domain (NMP) domains, during the repeated catalytic cycle. We discover and analyze an interesting dynamical coupling between the motion of the two domains during the opening, using large scale atomistic molecular dynamics trajectory analysis, covariance analysis, and multidimensional free energy calculations with explicit water. Initially, the LID domain must open by a certain amount before the NMP domain can begin to open. Dynamical correlation map shows interesting cross-peak between LID and NMP domain which suggests the presence of correlated motion between them. This is also reflected in our calculated two-dimensional free energy surface contour diagram which has an interesting elliptic shape, revealing a strong correlation between the opening of the LID domain and that of the NMP domain. Our free energy surface of the LID domain motion is rugged due to interaction with water and the signature of ruggedness is evident in the observed root mean square deviation variation and its fluctuation time correlation functions. We develop a correlated dynamical disorder-type theoretical model to explain the observed dynamic coupling between the motion of the two domains in ADK. Our model correctly reproduces several features of the cross-correlation observed in simulations.

  9. SH2 domain-containing phosphatase 1 regulates pyruvate kinase M2 in hepatocellular carcinoma

    PubMed Central

    Tai, Wei-Tien; Hung, Man-Hsin; Chu, Pei-Yi; Chen, Yao-Li; Chen, Li-Ju; Tsai, Ming-Hsien; Chen, Min-Husan; Shiau, Chung-Wai; Boo, Yin-Pin; Chen, Kuen-Feng

    2016-01-01

    Pyruvate kinase M2 (PKM2) is known to promote tumourigenesis through dimer formation of p-PKM2Y105. Here, we investigated whether SH2-containing protein tyrosine phosphatase 1 (SHP-1) decreases p-PKM2Y105 expression and, thus, determines the sensitivity of sorafenib through inhibiting the nuclear-related function of PKM2. Immunoprecipitation and immunoblot confirmed the effect of SHP-1 on PKM2Y105 dephosphorylation. Lactate production was assayed in cells and tumor samples to determine whether sorafenib reversed the Warburg effect. Clinical hepatocellular carcinoma (HCC) tumor samples were assessed for PKM2 expression. SHP-1 directly dephosphorylated PKM2 at Y105 and further decreased the proliferative activity of PKM2; similar effects were found in sorafenib-treated HCC cells. PKM2 was also found to determine the sensitivity of targeted drugs, such as sorafenib, brivanib, and sunitinib, by SHP-1 activation. Significant sphere-forming activity was found in HCC cells stably expressing PKM2. Clinical findings suggest that PKM2 acts as a predicting factor of early recurrence in patients with HCC, particularly those without known risk factors (63.6%). SHP-1 dephosphorylates PKM2 at Y105 to inhibit nuclear function of PKM2 and determines the efficacy of targeted drugs. Targeting PKM2 by SHP-1 might provide new therapeutic insights for patients with HCC. PMID:26959741

  10. Crystallization and preliminary crystallographic analysis of the kinase-recruitment domain of the PP2C-type phosphatase RsbU.

    PubMed

    Dutta, Sujit; Lewis, Richard J

    2003-01-01

    The general stress response of Bacillus subtilis provides a protective resistance to a variety of pressures. The key molecule is a subunit of RNA polymerase, sigma(B), which confers promoter specificity and is regulated by two signalling modules. Each module comprises protein kinases and phosphatases and 'switch' protein substrates for the kinase and phosphatase. The phosphorylation state of the switch molecules indirectly controls the activity of sigma(B). The binding of the kinase RsbT to the phosphatase RsbU stimulates its enzymatic activity towards its substrate, phosphorylated RsbV. To understand how these enzymes interact, thus regulating transcription, crystallization of the kinase-recruitment domain of RsbU in a form suitable for high-resolution structure determination is reported.

  11. PGE2 induces angiogenesis via MT1-MMP-mediated activation of the TGFbeta/Alk5 signaling pathway.

    PubMed

    Alfranca, Arántzazu; López-Oliva, Juan Manuel; Genís, Laura; López-Maderuelo, Dolores; Mirones, Isabel; Salvado, Dolores; Quesada, Antonio J; Arroyo, Alicia G; Redondo, Juan Miguel

    2008-08-15

    The development of a new vascular network is essential for the onset and progression of many pathophysiologic processes. Cyclooxygenase-2 displays a proangiogenic activity in in vitro and in vivo models, mediated principally through its metabolite prostaglandin E(2) (PGE(2)). Here, we provide evidence for a novel signaling route through which PGE(2) activates the Alk5-Smad3 pathway in endothelial cells. PGE(2) induces Alk5-dependent Smad3 nuclear translocation and DNA binding, and the activation of this pathway involves the release of active TGFbeta from its latent form through a process mediated by the metalloproteinase MT1-MMP, whose membrane clustering is promoted by PGE(2). MT1-MMP-dependent transforming growth factor beta (TGFbeta) signaling through Alk5 is also required for PGE(2)-induced endothelial cord formation in vitro, and Alk5 kinase activity is required for PGE(2)-induced neovascularization in vivo. These findings identify a novel signaling pathway linking PGE(2) and TGFbeta, 2 effectors involved in tumor growth and angiogenesis, and reveal potential targets for the treatment of angiogenesis-related disorders.

  12. Management of crizotinib therapy for ALK-rearranged non-small cell lung carcinoma: an expert consensus.

    PubMed

    Cappuzzo, Federico; Moro-Sibilot, Denis; Gautschi, Oliver; Boleti, Ekaterini; Felip, Enriqueta; Groen, Harry J M; Germonpré, Paul; Meldgaard, Peter; Arriola, Edurne; Steele, Nicola; Fox, Jesme; Schnell, Patrick; Engelsberg, Arne; Wolf, Jürgen

    2015-02-01

    Within 4 years of the discovery of anaplastic lymphoma kinase (ALK) rearrangements in non-small cell lung cancer (NSCLC), the ALK inhibitor crizotinib gained US and European approval for the treatment of advanced ALK-positive NSCLC. This was due to the striking response data observed with crizotinib in phase I and II trials in patients with ALK-positive NSCLC, as well as the favorable tolerability and safety profile observed. Recently published phase III data established crizotinib as a new standard of care for this NSCLC molecular subset. A consequence of such rapid approval, however, is the limited clinical experience and relative paucity of information concerning optimal therapy management. In this review, we discuss the development of crizotinib and the clinical relevance of its safety profile, examining crizotinib-associated adverse events in detail and making specific management recommendations. Crizotinib-associated adverse events were mostly mild to moderate in severity in clinical studies, and appropriate monitoring and supportive therapies are considered effective in avoiding the need for dose interruption or reduction in most cases. Therapy management of patients following disease progression on crizotinib is also discussed. Based on available clinical data, it is evident that patients may have prolonged benefit from crizotinib after Response Evaluation Criteria in Solid Tumors-defined disease progression, and crizotinib should be continued for as long as the patient derives benefit.

  13. Combating autophagy is a strategy to increase cytotoxic effects of novel ALK inhibitor entrectinib in neuroblastoma cells

    PubMed Central

    Aveic, Sanja; Pantile, Marcella; Seydel, Anke; Esposito, Maria Rosaria; Zanon, Carlo; Li, Gary; Tonini, Gian Paolo

    2016-01-01

    Neuroblastoma (NB) is a threatening childhood malignancy. Its prognosis is affected by several morphological, and biological characteristics, including the constitutive expression of ALK tyrosine kinase. In this study we examined the therapeutic potential of a novel ALK inhibitor, entrectinib, in obliterating NB tumor cells. Entrectinib showed the growth-inhibitory effects on NB cells with a 50% inhibitory concentration range of 0.03–5 μM. In the ALK-dependent cells, entrectinib mediated G1-arrest, which was associated with modified expression of multiple cell-cycle regulators. Down-regulation of Ki-67, and attenuated phosphorylation of ERK1/2, and STAT3, correlated with observed antiproliferative capacity of entrectinib. Initial cytostatic activity of entrectinib was followed by concentration-dependent apoptotic cell death, and Caspase-3 activation. However, we delineated a reduced sensitivity of ALK mutated NB cells to entrectinib, and demonstrated strong activation of autophagy in SH-SY5YF1174L NB cell line. Abrogation of autophagy by chloroquine increased significantly the toxicity of entrectinib, as confirmed by enhanced death rate, and PARP protein cleavage in SH-SY5YF1174L cells. In aggregate, our data show that entrectinib inhibits proliferation, and induces G1-arrest, and apoptosis in NB cells. We propose entrectinib for further consideration in treatment of NB, and recommend pharmacological inhibition of autophagy to be explored for a combined therapeutic approach in NB patients that might develop resistance to entrectinib. PMID:26735175

  14. Novel tetracyclic benzo[b]carbazolones as highly potent and orally bioavailable ALK inhibitors: design, synthesis, and structure-activity relationship study.

    PubMed

    Jiang, Xiaolong; Zhou, Ji; Ai, Jing; Song, Zilan; Peng, Xia; Xing, Li; Xi, Yong; Guo, Junfeng; Yao, Qizheng; Ding, Jian; Geng, Meiyu; Zhang, Ao

    2015-11-13

    Four series of tetracyclic benzo[b]carbazolone compounds possessing more rotatable bonds and higher molecular flexibility were designed by either inserting a linker within the C8-side chain or by opening the middle ketone ring on the basis of compound 5 (Alectinib, CH5424802). Compound 15b was identified showing nearly identical high potency against both wild-type and the gatekeeper mutant ALK kinase (3.4 vs 3.9 nM). This compound has favorable PK profile with an oral bioavailability of 67.1% in rats. Moreover, compound 15b showed significant growth inhibition against ALK driven cancer cells and KARPAS-299 xenograft model.

  15. Role of FAST Kinase Domains 3 (FASTKD3) in Post-transcriptional Regulation of Mitochondrial Gene Expression.

    PubMed

    Boehm, Erik; Zornoza, María; Jourdain, Alexis A; Delmiro Magdalena, Aitor; García-Consuegra, Inés; Torres Merino, Rebeca; Orduña, Antonio; Martín, Miguel A; Martinou, Jean-Claude; De la Fuente, Miguel A; Simarro, María

    2016-12-09

    The Fas-activated serine/threonine kinase (FASTK) family of proteins has recently emerged as a central regulator of mitochondrial gene expression through the function of an unusual RNA-binding domain named RAP (for RNA-binding domain abundant in Apicomplexans), shared by all six members of the family. Here we describe the role of one of the less characterized members, FASTKD3, in mitochondrial RNA metabolism. First, we show that, in contrast to FASTK, FASTKD2, and FASTKD5, FASTKD3 does not localize in mitochondrial RNA granules, which are sites of processing and maturation of mtRNAs and ribosome biogenesis. Second, we generated FASTKD3 homozygous knock-out cell lines by homologous recombination and observed that the absence of FASTKD3 resulted in increased steady-state levels and half-lives of a subset of mature mitochondrial mRNAs: ND2, ND3, CYTB, COX2, and ATP8/6. No aberrant processing of RNA precursors was observed. Rescue experiments demonstrated that RAP domain is required for FASTKD3 function in mRNA stability. Besides, we describe that FASTKD3 is required for efficient COX1 mRNA translation without altering mRNA levels, which results in a decrease in the steady-state levels of COX1 protein. This finding is associated with reduced mitochondrial complex IV assembly and activity. Our observations suggest that the function of this family of proteins goes beyond RNA processing and ribosome assembly and includes RNA stability and translation regulation within mitochondria.

  16. Insertion element analysis and mapping of the Pseudomonas plasmid alk regulon.

    PubMed Central

    Fennewald, M; Benson, S; Oppici, M; Shapiro, J

    1979-01-01

    We characterized and mapped new mutations of the alk (alkane utilization) genes found on Pseudomonas plasmids of the Inc P-2 group. These mutations were isolated after (i) nitrosoguanidine mutagenesis, (ii) transposition of the Tn7 trimethoprim and streptomycin resistance determinant, and (iii) reversion of polarity effects of alk::Tn7 insertion mutations. Our results indicate the existence of two alk loci not previously described--alkD, whose product is required for synthesis of membrane alkane-oxidizing activities, and alkE, whose product is required for synthesis of inducible membrane alcohol dehydrogenase activity. Polarity of alk::Tn7 insertion mutations indicates the existence of an alkBAE operon. Mapping of alk loci by transduction in P. aeruginosa shows that there are at least three alk clusters in the CAM-OCT plasmid--alkRD, containing regulatory genes; alkBAE, containing genes for specific biochemical activities; and alkC, containing one or more genes needed for normal synthesis of membrane alcohol dehydrogenase. The alkRD and alkBAE clusters are linked but separated by about 42 kilobases. The alkC cluster is not linked to either of the other two alk regions. Altogether, these results indicate a complex genetic control of the alkane utilization phenotype in P. putida and P. aeruginosa involving at least six separate genes. Images PMID:479111

  17. Phosphatidylinositol 3-kinase activation is mediated by high-affinity interactions between distinct domains within the p110 and p85 subunits.

    PubMed Central

    Holt, K H; Olson, L; Moye-Rowley, W S; Pessin, J E

    1994-01-01

    Domains of interaction between the p85 and p110 subunits of phosphatidylinositol 3-kinase (PI 3-kinase) were studied with the yeast two-hybrid expression system. A gene fusion between the GAL4 transactivation domain and p85 activated transcription from a GAL1-lacZ reporter gene when complemented with a gene fusion between the GAL4 DNA binding domain and p110. To define subdomains responsible for this interaction, a series of p85 deletion mutants were analyzed. A 192-amino-acid inter-SH2 (IS) fragment (residues 429 to 621) was the smallest determinant identified that specifically associated with p110. In analogous experiments, the subdomain within p110 responsible for interaction with p85 was localized to an EcoRI fragment encoding the amino-terminal 127 residues. Expression of these two subdomains [p85(IS) with p110RI] resulted in 100-fold greater reporter activity than that obtained with full-length p85 and p110. Although the p85(IS) domain conferred a strong interaction with the p110 catalytic subunit, this region was not sufficient to impart phosphotyrosine peptide stimulation of PI 3-kinase activity. In contrast, coexpression of the p110 subunit with full-length p85 or with constructs containing the IS sequences flanked by both SH2 domains of p85 [p85(n/cSH2)] or either of the individual SH2 domains [p85(nSH2+IS) or p85(IS+cSH2)] resulted in PI 3-kinase activity that was activated by a phosphotyrosine peptide. These data suggest that phosphotyrosine peptide binding to either SH2 domain generates an intramolecular signal propagated through the IS region to allosterically activate p110. Images PMID:8264609

  18. Alk1 and Alk5 inhibition by Nrp1 controls vascular sprouting downstream of Notch

    PubMed Central

    Aspalter, Irene Maria; Gordon, Emma; Dubrac, Alexandre; Ragab, Anan; Narloch, Jarek; Vizán, Pedro; Geudens, Ilse; Collins, Russell Thomas; Franco, Claudio Areias; Abrahams, Cristina Luna; Thurston, Gavin; Fruttiger, Marcus; Rosewell, Ian; Eichmann, Anne; Gerhardt, Holger

    2015-01-01

    Sprouting angiogenesis drives blood vessel growth in healthy and diseased tissues. Vegf and Dll4/Notch signalling cooperate in a negative feedback loop that specifies endothelial tip and stalk cells to ensure adequate vessel branching and function. Current concepts posit that endothelial cells default to the tip-cell phenotype when Notch is inactive. Here we identify instead that the stalk-cell phenotype needs to be actively repressed to allow tip-cell formation. We show this is a key endothelial function of neuropilin-1 (Nrp1), which suppresses the stalk-cell phenotype by limiting Smad2/3 activation through Alk1 and Alk5. Notch downregulates Nrp1, thus relieving the inhibition of Alk1 and Alk5, thereby driving stalk-cell behaviour. Conceptually, our work shows that the heterogeneity between neighbouring endothelial cells established by the lateral feedback loop of Dll4/Notch utilizes Nrp1 levels as the pivot, which in turn establishes differential responsiveness to TGF-β/BMP signalling. PMID:26081042

  19. The Utility of Thyroid Transcription Factor 1 (TTF-1), Napsin A, Excision Repair Cross-Complementing 1 (ERCC1), Anaplastic Lymphoma Kinase (ALK) and the Epidermal Growth Factor Receptor (EGFR) Expression in Small Biopsy in Prognosis of Patients with Lung Adenocarcinoma – A Retrograde Single-Center Study from Croatia

    PubMed Central

    Burazer, Marina Piljić; Mladinov, Suzana; Ćapkun, Vesna; Kuret, Sendi; Durdov, Merica Glavina

    2017-01-01

    Background The present study was carried out in order to evaluate our institutional experience with small biopsy in diagnosis and molecular testing of lung adenocarcinoma. Few specific and predictive markers have been evaluated and correlated with clinicopathologic characteristics and survival in patients with lung adenocarcinoma who received platinum-based chemotherapy. There have not been such reports from Croatia. Material/Methods A total of 142 cases of lung adenocarcinoma were retrospectively investigated in small biopsies for the immunohistochemical expression of TTF-1, napsin A, ERCC1, ALK, and the EGFR mutation by real-time polymerase chain reaction (rtPCR). Results TTF-1, napsin A, and ERCC1 expression was found in 81%, 78%, and 69% of patients, respectively, and the expressions were not significantly associated with subtype. Expression of ALK was found in 4% and EGFR mutation in 10% of patients. Exon 19 deletions were the most common. Longer survival was significantly associated with TTF-1 positivity (p=0.007) and napsin A positivity (p=0.026). Higher relative risk of death significantly correlated with positive expression of ERCC1 (p=0.041). Conclusions Positive TTF-1 and napsin A expressions in lung adenocarcinoma tissues were useful diagnostic and favorable prognostic parameters. Positive ERCC1 expression was identified as a negative prognostic marker in patients treated with platinum-based chemotherapy. The percentages of EGFR and ALK mutations corresponded to those in previously published reports for Caucasians. PMID:28128193

  20. Expression, purification, characterization and crystallization of non- and phosphorylated states of JAK2 and JAK3 kinase domain

    SciTech Connect

    Hall, Troii; Emmons, Thomas L.; Chrencik, Jill E.; Gormley, Jennifer A.; Weinberg, Robin A.; Leone, Joseph W.; Hirsch, Jeffrey L.; Saabye, Matthew J.; Schindler, John F.; Day, Jacqueline E.; Williams, Jennifer M.; Kiefer, James R.; Lightle, Sandra A.; Harris, Melissa S.; Guru, Siradanahalli; Fischer, H. David; Tomasselli, Alfredo G.

    2012-05-29

    Janus-associated kinases (JAKs) play critical roles in cytokine signaling, and have emerged as viable therapeutic targets in inflammation and oncology related diseases. To date, targeting JAK proteins with highly selective inhibitor compounds have remained elusive. We have expressed the active kinase domains for both JAK2 and JAK3 and devised purification protocols to resolve the non-, mono- (Y1007) and diphosphorylated (Y1007 and Y1008) states of JAK2 and non- and monophosphorylated states of JAK3 (Y980). An optimal purified protein yield of 20, 29 and 69 mg per 20 L cell culture was obtained for the three JAK2 forms, respectively, and 12.2 and 2.3 mg per 10 L fermentation for the two JAK3 forms allowing detailed biochemical and biophysical studies. To monitor the purification process we developed a novel HPLC activity assay where a sequential order of phosphorylation was observed whereby the first tyrosine residue was completely phosphorylated prior to phosphorylation of the tandem tyrosine residue. A Caliper-based microfluidics assay was used to determine the kinetic parameters (K{sub m} and k{sub cat}) for each phosphorylated state, showing that monophosphorylated (Y1007) JAK2 enzyme activity increased 9-fold over that of the nonphosphorylated species, and increased an additional 6-fold for the diphosphorylated (Y1007/Y1008) species, while phosphorylation of JAK3 resulted in a negligible increase in activity. Moreover, crystal structures have been generated for each isolated state of JAK2 and JAK3 with resolutions better than 2.4 {angstrom}. The generation of these reagents has enabled kinetic and structural characterization to inform the design of potent and selective inhibitors of the JAK family.

  1. Activation of a Ca(2+)-dependent protein kinase involves intramolecular binding of a calmodulin-like regulatory domain

    NASA Technical Reports Server (NTRS)

    Huang, J. F.; Teyton, L.; Harper, J. F.; Evans, M. L. (Principal Investigator)

    1996-01-01

    Ca(2+)-dependent protein kinases (CDPKs) are regulated by a C-terminal calmodulin-like domain (CaM-LD). The CaM-LD is connected to the kinase by a short junction sequence which contains a pseudosubstrate autoinhibitor. To understand how the CaM-LD regulates a CDPK, a recombinant CDPK (isoform CPK-1 from Arabidopsis, accession no. L14771) was made as a fusion protein in Escherichia coli. We show here that a truncated CDPK lacking a CaM-LD (e.g. mutant delta NC-26H) can be activated by exogenous calmodulin or an isolated CaM-LD (Kact approximately 2 microM). We propose that Ca2+ activation of a CDPK normally occurs through intramolecular binding of the CaM-LD to the junction. When the junction and CaM-LD are made as two separate polypeptides, the CaM-LD can bind the junction in a Ca(2+)-dependent fashion with a dissociation constant (KD) of 6 x 10(-6) M, as determined by kinetic binding analyses. When the junction and CaM-LD are tethered in a single polypeptide (e.g. in protein JC-1), their ability to engage in bimolecular binding is suppressed (e.g. the tethered CaM-LD cannot bind a separate junction). A mutation which disrupts the putative CaM-LD binding sequence (e.g. substitution LRV-1444 to DLPG) appears to block intramolecular binding, as indicated by the restored ability of a tethered CaM-LD to engage in bimolecular binding. This mutation, in the context of a full-length enzyme (mutant KJM46H), appears to block Ca2+ activation. Thus, a disruption of intramolecular binding correlates with a disruption of the Ca2+ activation mechanism. CDPKs provide the first example of a member of the calmodulin superfamily where a target binding sequence is located within the same polypeptide.

  2. Domain Analysis of ArcS, the Hybrid Sensor Kinase of the Shewanella oneidensis MR-1 Arc Two-Component System, Reveals Functional Differentiation of Its Two Receiver Domains

    PubMed Central

    Bubendorfer, Sebastian

    2013-01-01

    In all species of the genus Shewanella, the redox-sensing Arc two-component system consists of the response regulator ArcA, the sensor kinase ArcS, and the separate phosphotransfer protein HptA. Compared to its counterpart ArcB in Escherichia coli, ArcS has a significantly different domain structure. Resequencing and reannotation revealed that in the N-terminal part, ArcS possesses a periplasmic CaChe-sensing domain bracketed by two transmembrane domains and, moreover, that ArcS has two cytoplasmic PAS-sensing domains and two receiver domains, compared to a single one of each in ArcB. Here, we used a combination of in vitro phosphotransfer studies on purified proteins and phenotypic in vivo mutant analysis to determine the roles of the different domains in ArcS function. The analysis revealed that phosphotransfer occurs from and toward the response regulator ArcA and involves mainly the C-terminal RecII domain. However, RecI also can receive a phosphate from HptA. In addition, the PAS-II domain, located upstream of the histidine kinase domain, is crucial for function. The results support a model in which phosphorylation of RecI stimulates histidine kinase activity of ArcS in order to maintain an appropriate level of phosphorylated ArcA according to environmental conditions. In addition, the study reveals some fundamental mechanistic differences between ArcS/HptA and ArcB with respect to signal perception and phosphotransfer despite functional conservation of the Arc system in Shewanella and E. coli. PMID:23161031

  3. ANKRD54 preferentially selects Bruton’s Tyrosine Kinase (BTK) from a Human Src-Homology 3 (SH3) domain library

    PubMed Central

    Mohammad, Dara K.; Ylösmäki, Erkko; Choi, Hyunseok; Shrestha, Subhash; Wang, Qing; Nore, Beston F.; Saksela, Kalle; Smith, C. I. Edvard

    2017-01-01

    Bruton’s Tyrosine Kinase (BTK) is a cytoplasmic protein tyrosine kinase with a fundamental role in B-lymphocyte development and activation. The nucleocytoplasmic shuttling of BTK is specifically modulated by the Ankyrin Repeat Domain 54 (ANKRD54) protein and the interaction is known to be exclusively SH3-dependent. To identify the spectrum of the ANKRD54 SH3-interactome, we applied phage-display screening of a library containing all the 296 human SH3 domains. The BTK-SH3 domain was the prime interactor. Quantitative western blotting analysis demonstrated the accuracy of the screening procedure. Revealing the spectrum and specificity of ANKRD54-interactome is a critical step toward functional analysis in cells and tissues. PMID:28369144

  4. Classic phenotype of Coffin-Lowry syndrome in a female with stimulus-induced drop episodes and a genotype with preserved N-terminal kinase domain.

    PubMed

    Rojnueangnit, Kitiwan; Jones, Julie R; Basehore, Monica J; Robin, Nathaniel H

    2014-02-01

    An adolescent female presented with intellectual disability, stimulus-induced drop episodes (SIDEs), facial characteristics that include wide set eyes, short nose with wide columella, full and everted lips with wide mouth and progressive skeletal changes: scoliosis, spondylolisthesis and pectus excavatum. These findings were suggestive of Coffin-Lowry syndrome (CLS), and this was confirmed by the identification of a novel mutation in RPS6KA3, a heterozygous one basepair duplication at nucleotide 1570 (c.1570dupA). This mutation occurs within the C-terminal kinase domain of the protein, and, therefore contradicts the previous report that SIDEs is only associated with premature truncation of the protein in the N-terminal kinase domain or upstream of this domain. As CLS is X-linked, it is unusual for a female to have such a classic phenotype.

  5. Nuclear localization of lymphocyte-specific protein tyrosine kinase (Lck) and its role in regulating LIM domain only 2 (Lmo2) gene

    SciTech Connect

    Venkitachalam, Srividya; Chueh, Fu-Yu; Yu, Chao-Lan

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer Lmo2 expression is elevated in Lck-transformed cells. Black-Right-Pointing-Pointer Both endogenous and exogenous Lck localize in the nucleus. Black-Right-Pointing-Pointer Nuclear Lck is active in Lck-transformed cells. Black-Right-Pointing-Pointer Lck binds to the promoter region of Lmo2 gene in vivo. Black-Right-Pointing-Pointer In contrast to JAK2, Lck does not increase histone H3 phosphorylation on Tyr 41. -- Abstract: LIM domain only protein 2 (Lmo2) is a transcription factor that plays a critical role in the development of T-acute lymphoblastic leukemia (T-ALL). A previous report established a link between Lmo2 expression and the nuclear presence of oncogenic Janus kinase 2 (JAK2), a non-receptor protein tyrosine kinase. The oncogenic JAK2 kinase phosphorylates histone H3 on Tyr 41 that leads to the relief of Lmo2 promoter repression and subsequent gene expression. Similar to JAK2, constitutive activation of lymphocyte-specific protein tyrosine kinase (Lck) has been implicated in lymphoid malignancies. However, it is not known whether oncogenic Lck regulates Lmo2 expression through a similar mechanism. We show here that Lmo2 expression is significantly elevated in T cell leukemia LSTRA overexpressing active Lck kinase and in HEK 293 cells expressing oncogenic Y505FLck kinase. Nuclear localization of active Lck kinase was confirmed in both Lck-transformed cells by subcellular fractionation and immunofluorescence microscopy. More importantly, in contrast to oncogenic JAK2, oncogenic Lck kinase does not result in significant increase in histone H3 phosphorylation on Tyr 41. Instead, chromatin immunoprecipitation experiment shows that oncogenic Y505FLck kinase binds to the Lmo2 promoter in vivo. This result raises the possibility that oncogenic Lck may activate Lmo2 promoter through direct interaction.

  6. Fluorescence in situ hybridization analysis of the ALK gene in 2,045 non-small cell lung cancer patients from North-Western Spain (Galicia).

    PubMed

    Sánchez-Ares, María; Cameselle-Teijeiro, José M; Vázquez-Estévez, Sergio; Lázaro-Quintela, Martín; Vázquez-Boquete, Ángel; Afonso-Afonso, Francisco J; Casal-Rubio, Joaquín; González-Piñeiro, Ana L; Rico-Rodríguez, Yolanda; Fírvida-Pérez, José L; Ruíz-Bañobre, Juan; Couso, Elena; Santomé, Lucía; Pérez-Becerra, Raquel; García-Campelo, Rosario; Amenedo, Margarita; Azpitarte-Raposeiras, Cristina; Antúnez, José; Abdulkader, Ihab

    2016-08-01

    Identification of anaplastic lymphoma receptor tyrosine kinase (ALK) gene rearrangements is a standard diagnostic test in patients with advanced non-small cell lung cancer (NSCLC). The current study describes the experience of ALK rearrangement detection of a referral center in the public health care system of Galicia in North-Western Spain. The fluorescence in situ hybridization (FISH) patterns of the ALK gene and the clinical and pathological features of these patients are reported. This study is also of interest for comparative purposes due to the relative geographical isolation of the area, which could have contributed to particular genetic features. A total of 2,045 tissue samples from NSCLC patients were collected between October 2010 and July 2015 and tested for ALK rearrangements by FISH. Examination of 1,686 paraffin-embedded tissue specimens and 395 cytological samples (306 cell block preparations and 53 cytological smears) was conducted, and any associations between the FISH results and clinicopathological features were assessed. The rate of successful evaluation was marginally higher in tissue samples than in cytological samples (92.9% vs. 84.1%); this difference was not significant. ALK rearrangements were identified in 82 patients(4%): 65 (79.3%) in tissue specimens, 15 (18.3%) in cell block samples and 2 (2.4%) in cytological smears. This genetic translocation appeared to be associated with a non-smoking history, younger age, female gender, stage IV and adenocarcinoma histological type. The findings demonstrate that ALK evaluation by FISH is feasible in tissue and cytological samples. The clinical and pathological features of the ALK-positive series of patients are similar to those previously reported in the literature.

  7. The cytoplasmic PASC domain of the sensor kinase DcuS of Escherichia coli: role in signal transduction, dimer formation, and DctA interaction

    PubMed Central

    Monzel, Christian; Degreif-Dünnwald, Pia; Gröpper, Christina; Griesinger, Christian; Unden, Gottfried

    2013-01-01

    The cytoplasmic PASC domain of the fumarate responsive sensor kinase DcuS of Escherichia coli links the transmembrane to the kinase domain. PASC is also required for interaction with the transporter DctA serving as a cosensor of DcuS. Earlier studies suggested that PASC functions as a hinge and transmits the signal to the kinase. Reorganizing the PASC dimer interaction and, independently, removal of DctA, converts DcuS to the constitutive ON state (active without fumarate stimulation). ON mutants were categorized with respect to these two biophysical interactions and the functional state of DcuS: type I-ON mutations grossly reorganize the homodimer, and decrease interaction with DctA. Type IIA-ON mutations create the ON state without grossly reorganizing the homodimer, whereas interaction with DctA is decreased. The type IIB-ON mutations were neither in PASC/PASC, nor in DctA/DcuS interaction affected, similar to fumarate activated wild-typic DcuS. OFF mutations never affected dimer stability. The ON mutations provide novel mechanistic insight: PASC dimerization is essential to silence the kinase. Reorganizing the homodimer and its interaction with DctA activate the kinase. The study suggests a novel ON homo-dimer conformation (type IIB) and an OFF conformation for PASC. Type IIB-ON corresponds to the fumarate induced wild-type conformation, representing an interesting target for structural biology. PMID:24039243

  8. Mutation of the PDK1 PH Domain Inhibits Protein Kinase B/Akt, Leading to Small Size and Insulin Resistance▿ †

    PubMed Central

    Bayascas, Jose R.; Wullschleger, Stephan; Sakamoto, Kei; García-Martínez, Juan M.; Clacher, Carol; Komander, David; van Aalten, Daan M. F.; Boini, Krishna M.; Lang, Florian; Lipina, Christopher; Logie, Lisa; Sutherland, Calum; Chudek, John A.; van Diepen, Janna A.; Voshol, Peter J.; Lucocq, John M.; Alessi, Dario R.

    2008-01-01

    PDK1 activates a group of kinases, including protein kinase B (PKB)/Akt, p70 ribosomal S6 kinase (S6K), and serum and glucocorticoid-induced protein kinase (SGK), that mediate many of the effects of insulin as well as other agonists. PDK1 interacts with phosphoinositides through a pleckstrin homology (PH) domain. To study the role of this interaction, we generated knock-in mice expressing a mutant of PDK1 incapable of binding phosphoinositides. The knock-in mice are significantly small, insulin resistant, and hyperinsulinemic. Activation of PKB is markedly reduced in knock-in mice as a result of lower phosphorylation of PKB at Thr308, the residue phosphorylated by PDK1. This results in the inhibition of the downstream mTOR complex 1 and S6K1 signaling pathways. In contrast, activation of SGK1 or p90 ribosomal S6 kinase or stimulation of S6K1 induced by feeding is unaffected by the PDK1 PH domain mutation. These observations establish the importance of the PDK1-phosphoinositide interaction in enabling PKB to be efficiently activated with an animal model. Our findings reveal how reduced activation of PKB isoforms impinges on downstream signaling pathways, causing diminution of size as well as insulin resistance. PMID:18347057

  9. Ser360 and Ser364 in the Kinase Domain of Tomato SlMAPKKKα are Critical for Programmed Cell Death Associated with Plant Immunity

    PubMed Central

    Hwang, In Sun; Brady, Jen; Martin, Gregory B.; Oh, Chang-Sik

    2017-01-01

    SlMAPKKKα, a tomato (Solanum lycopersicum) mitogen-activated protein kinase kinase kinase, is a positive regulator of Pto-mediated effector-triggered immunity, which elicits programmed cell death (PCD) in plants. In this study, we examined whether putative phosphorylation sites in the conserved activation segment of the SlMAPKKKα kinase domain are critical for eliciting PCD. Three amino acids, threonine353, serine360 (Ser360), or serine364 (Ser364), in the conserved activation segment of SlMAPKKKα kinase domain were substituted to alanine (T353A, S360A, or S364A), and these variants were transiently expressed in tomato and Nicotiana benthamiana plants. Two alanine substitutions, S360A and S364A, completely abolished SlMAPKKKα PCD-eliciting activity in both plants, while T353A substitution did not affect its PCD-eliciting activity. SlMAPKKKα wild type and variant proteins accumulated to similar levels in plant leaves. However, SlMAPKKKα protein with the largest size was missed when either S360A or S364A substitutions were expressed, whereas proteins with the smaller masses were more accumulated than those of full-length of SIMAPKKKα and T353A. These results suggest that phosphorylation of SlMAPKKKα at Ser360 and Ser364 is critical for PCD elicitation in plants. PMID:28381963

  10. Crystal structures of apo and inhibitor-bound TGFβR2 kinase domain: insights into TGFβR isoform selectivity

    SciTech Connect

    Tebben, Andrew J.; Ruzanov, Maxim; Gao, Mian; Xie, Dianlin; Kiefer, Susan E.; Yan, Chunhong; Newitt, John A.; Zhang, Liping; Kim, Kyoung; Lu, Hao; Kopcho, Lisa M.; Sheriff, Steven

    2016-04-26

    The cytokine TGF-β modulates a number of cellular activities and plays a critical role in development, hemostasis and physiology, as well as in diseases including cancer and fibrosis. TGF-β signals through two transmembrane serine/threonine kinase receptors: TGFβR1 and TGFβR2. Multiple structures of the TGFβR1 kinase domain are known, but the structure of TGFβR2 remains unreported. Wild-type TGFβR2 kinase domain was refractory to crystallization, leading to the design of two mutated constructs: firstly, a TGFβR1 chimeric protein with seven ATP-site residues mutated to their counterparts in TGFβR2, and secondly, a reduction of surface entropy through mutation of six charged residues on the surface of the TGFβR2 kinase domain to alanines. These yielded apo and inhibitor-bound crystals that diffracted to high resolution (<2 Å). Comparison of these structures with those of TGFβR1 reveal shared ligand contacts as well as differences in the ATP-binding sites, suggesting strategies for the design of pan and selective TGFβR inhibitors.

  11. Structural and mechanistic insight into alkane hydroxylation by Pseudomonas putida AlkB.

    PubMed

    Alonso, Hernan; Kleifeld, Oded; Yeheskel, Adva; Ong, Poh C; Liu, Yu C; Stok, Jeanette E; De Voss, James J; Roujeinikova, Anna

    2014-06-01

    Pseudomonas putida GPo1 alkane hydroxylase (AlkB) is an integral membrane protein that catalyses the hydroxylation of medium-chain alkanes (C3-C12). 1-Octyne irreversibly inhibits this non-haem di-iron mono-oxygenase under turnover conditions, suggesting that it acts as a mechanism-based inactivator. Upon binding to the active site, 1-octyne is postulated to be oxidized to an oxirene that rapidly rearranges to a reactive ketene which covalently acylates nearby residues, resulting in enzyme inactivation. In analysis of inactivated AlkB by LC-MS/MS, several residues exhibited a mass increase of 126.1 Da, corresponding to the octanoyl moiety derived from oxidative activation of 1-octyne. Mutagenesis studies of conserved acylated residues showed that Lys18 plays a critical role in enzyme function, as a single-point mutation of Lys18 to alanine (K18A) completely abolished enzymatic activity. Finally, we present a computational 3D model structure of the transmembrane domain of AlkB, which revealed the overall packing arrangement of the transmembrane helices within the lipid bilayer and the location of the active site mapped by the 1-octyne modifications.

  12. Tyrosine phosphorylation of the BRI1 receptor kinase occurs via a posttranslational modification and is activated by the juxtamembrane domain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In metazoans, receptor kinases control many essential processes related to growth and development and response to the environment. The receptor kinases in plants and animals are structurally similar but evolutionarily distinct from one another, and thus while most animal receptor kinases are tyrosin...

  13. Phosphorylation by cAMP-dependent protein kinase causes a conformational change in the R domain of the cystic fibrosis transmembrane conductance regulator.

    PubMed

    Dulhanty, A M; Riordan, J R

    1994-04-05

    Individuals with cystic fibrosis have a defect in the CFTR protein, a chloride channel regulated by cAMP-dependent protein kinase (PKA). The majority of the phosphorylation sites of PKA are located in the R domain of CFTR. It has been postulated that this domain may act as a gate for the chloride channel. Of the many possible mechanisms whereby the R domain could gate the channel, including interdomain interactions, charge distribution, or conformational change, we investigated the possibility that phosphorylation leads to conformational changes in the R domain. To test this hypothesis, a protocol for purification of human R domain peptide synthesized in a bacterial expression system was developed. Purified R domain was phosphorylated by PKA, and CD spectra were obtained. As a result of phosphorylation by PKA, a significant spectral change, indicative of a reduction in the alpha-helical content, was found. CD spectra of the R domain of a shark homologue of CFTR indicated similar changes in conformation as a result of phosphorylation by PKA. In contrast, phosphorylation of the human R domain by PKC, which has only a small influence on CFTR channel activity, failed to elicit CD spectral changes, indicating no conformational change comparable to those induced by PKA phosphorylation. These observations provide the first structural characterization of the R domain and suggest that the gating of the CFTR chloride channel by PKA may involve a conformational change in the R domain.

  14. The second immunoglobulin-like domain of the VEGF tyrosine kinase receptor Flt-1 determines ligand binding and may initiate a signal transduction cascade.

    PubMed Central

    Davis-Smyth, T; Chen, H; Park, J; Presta, L G; Ferrara, N

    1996-01-01

    Vascular endothelial growth factor (VEGF) is an angiogenic inducer that mediates its effects through two high affinity receptor tyrosine kinases, Flt-1 and KDR. Flt-1 is required for endothelial cell morphogenesis whereas KDR is involved primarily in mitogenesis. Flt-1 has an alternative ligand, placenta growth factor (PlGF). Both Flt-1 and KDR have seven immunoglobulin (Ig)-like domains in the extracellular domain. The significance and function of these domains for ligand binding and receptor activation are unknown. Here we show that deletion of the second domain of Flt-1 completely abolishes the binding of VEGF. Introduction of the second domain of KDR into an Flt-1 mutant lacking the homologous domain restored VEGF binding. However, the ligand specificity was characteristic of the KDR receptor. We then created chimeric receptors where the first three or just the second Ig-like domains of Flt-1 replaced the corresponding domains in Flt-4, a receptor that does not bind VEGF, and analyzed their ability to bind VEGF. Both swaps conferred upon Flt-4 the ability to bind VEGF with an affinity nearly identical to that of wild-type Flt-1. Furthermore, transfected cells expressing these chimeric Flt-4 receptors exhibited increased DNA synthesis in response to VEGF or PlGF. These results demonstrate that a single Ig-like domain is the major determinant for VEGF-PlGF interaction and that binding to this domain may initiate a signal transduction cascade. Images PMID:8890165

  15. The NMR structure of the sensory domain of the membranous two-component fumarate sensor (histidine protein kinase) DcuS of Escherichia coli.

    PubMed

    Pappalardo, Lucia; Janausch, Ingo G; Vijayan, Vinesh; Zientz, Eva; Junker, Jochen; Peti, Wolfgang; Zweckstetter, Markus; Unden, Gottfried; Griesinger, Christian

    2003-10-03

    The structure of the water-soluble, periplasmic domain of the fumarate sensor DcuS (DcuS-pd) has been determined by NMR spectroscopy in solution. DcuS is a prototype for a sensory histidine kinase with transmembrane signal transfer. DcuS belongs to the CitA family of sensors that are specific for sensing di- and tricarboxylates. The periplasmic domain is folded autonomously and shows helices at the N and the C terminus, suggesting direct linking or connection to helices in the two transmembrane regions. The structure constitutes a novel fold. The nearest structural neighbor is the Per-Arnt-Sim domain of the photoactive yellow protein that binds small molecules covalently. Residues Arg107, His110, and Arg147 are essential for fumarate sensing and are found clustered together. The structure constitutes the first periplasmic domain of a two component sensory system and is distinctly different from the aspartate sensory domain of the Tar chemotaxis sensor.

  16. Synergistic activity of ALK and mTOR inhibitors for the treatment of NPM-ALK positive lymphoma

    PubMed Central

    Redaelli, Sara; Ceccon, Monica; Antolini, Laura; Rigolio, Roberta; Pirola, Alessandra; Peronaci, Marco; Gambacorti-Passerini, Carlo; Mologni, Luca

    2016-01-01

    ALK-positive Anaplastic Large Cell Lymphoma (ALCL) represents a subset of Non-Hodgkin Lymphoma whose treatment benefited from crizotinib development, a dual ALK/MET inhibitor. Crizotinib blocks ALK-triggered pathways such as PI3K/AKT/mTOR, indispensable for survival of ALK-driven tumors. Despite the positive impact of targeted treatment in ALCL, resistant clones are often selected during therapy. Strategies to overcome resistance include the design of second generation drugs and the use of combined therapies that simultaneously target multiple nodes essential for cells survival. We investigated the effects of combined ALK/mTOR inhibition. We observed a specific synergistic effect of combining ALK inhibitors with an mTOR inhibitor (temsirolimus), in ALK+ lymphoma cells. The positive cooperation resulted in an increased inhibition of mTOR effectors, compared to single treatments, a block in G0/G1 phase and induction of apoptosis. The combination was able to prevent the selection of resistant clones, while long-term exposure to single agents led to the establishment of resistant cell lines, with either ALK inhibitor or temsirolimus. In vivo, mice injected with Karpas 299 cells and treated with low dose combination showed complete regression of tumors, while only partial inhibition was obtained in single agents-treated mice. Upon treatment stop the combination was able to significantly delay tumor relapses. Re-challenge of relapsed tumors at a higher dose led to full regression of xenografts in the combination group, but not in mice treated with lorlatinib alone. In conclusion, our data suggest that the combination of ALK and mTOR inhibitors could be a valuable therapeutic option for ALK+ ALCL patients. PMID:27662658

  17. Identification, activity, and structural studies of peptides incorporating the phorbol ester-binding domain of protein kinase C.

    PubMed Central

    Wender, P A; Irie, K; Miller, B L

    1995-01-01

    The family of homologous enzymes known as protein kinase C (PKC) has been the object of intense interest because of its crucial role in cellular signal transduction. Although considerable information about the activation of PKC has been gained through structure-activity, molecular modeling, and synthetic studies of both natural and designed activators, information about the structure of PKC itself has been limited by its large size and requirement for phospholipid cofactors. Additionally, difficulties in the purification of truncated mutants of PKC have thus far prevented their analysis by nuclear magnetic resonance (NMR) or x-ray crystallographic methods. We describe the identification, synthesis, ligand-binding analysis, cofactor requirements, and preliminary NMR evaluation of two subdomains (peptides B and C) of the regulatory domain of PKC-gamma. Peptides B and C bind [3H]phorbol 12,13-dibutyrate with good affinity (Kd = 6.4 microM and 414 nM, respectively) in the presence of phosphatidylserine. In comparison, the binding affinity of [3H]phorbol 12,13-dibutyrate for PKC was found to be 2.6 nM. Like PKC itself, these peptides also recognize other PKC activators, including dioctanoylglycerol and teleocidin B-4, and exhibit an ability to differentiate phorbol ester from its C-4 epimer. NMR studies of PKC subdomains are also described, indicating that both peptides B and C are well behaved in solution and do not exhibit any concentration-dependent changes. Finally, these studies reveal that peptide B becomes conformationally ordered only in the presence of phospholipid, suggesting that the regulatory domain of PKC itself might be organized for activation only when associated with the lipid bilayer, where its activator (diacylglycerol) is encountered. PMID:7816824

  18. PIK3CA mutations in the kinase domain (exon 20) of uterine endometrial adenocarcinomas are associated with adverse prognostic parameters.

    PubMed

    Catasus, Lluis; Gallardo, Alberto; Cuatrecasas, Miriam; Prat, Jaime

    2008-02-01

    Mutations of the oncogene PIK3CA occur frequently in endometrial carcinomas, but their prognostic significance is unclear. To determine the clinicopathological and molecular implications of these mutations, PIK3CA status was investigated in 109 endometrial (102 endometrioid and 7 mixed) carcinomas and the results were compared with clinicopathological parameters associated with prognosis. Tumors were also investigated for microsatellite instability and PTEN, beta-catenin gene (CTNNB1), K-RAS, and B-RAF mutations. We found 35 PIK3CA somatic missense mutations in 32 (29%) endometrial carcinomas. Eighteen mutations occurred in exon 20 (kinase domain), and 17 in exon 9 (helical domain). Almost all mutated tumors were pure endometrioid adenocarcinomas. All tumors with PIK3CA mutations exhibited myometrial invasion (P=0.032). Lymphovascular invasion was found more frequently in mutated (28%) than nonmutated carcinomas (18%). Histological grade varied significantly according to the location of the PIK3CA mutations whether in exon 9 or exon 20 (P=0.033). The frequency of exon 9 mutations was higher in grade 1 carcinomas (57%) than in grade 2 (29%) or grade 3 (14%) tumors. Conversely, mutations in exon 20 were more common in grade 3 (60%) than in grade 2 (20%) or grade 1 (20%) carcinomas. None of the tumors confined to the endometrium (stage IA) had PIK3CA mutations. Furthermore, whereas 64% of adenocarcinomas with exon 9 mutations had invaded < or =(1/2) of the myometrial thickness (stage IB), 73% of tumors with exon 20 mutations had either deeper myometrial invasion (stage IC) or cervical involvement (stage II) (P=0.045). PIK3CA mutations coexisted with microsatellite instability and mutations in PTEN, CTNNB1, K-RAS, and B-RAF genes. These results favor that PIK3CA mutations are associated with myometrial invasion and, moreover, that tumors harboring PIK3CA mutations in exon 20 are frequently high-grade, deeply invasive endometrial carcinomas that tend to exhibit

  19. Regulation of Yersinia Protein Kinase A (YpkA) Kinase Activity by Multisite Autophosphorylation and Identification of an N-terminal Substrate-binding Domain in YpkA*

    PubMed Central

    Pha, Khavong; Wright, Matthew E.; Barr, Tasha M.; Eigenheer, Richard A.; Navarro, Lorena

    2014-01-01

    The serine/threonine protein kinase YpkA is an essential virulence factor produced by pathogenic Yersinia species. YpkA is delivered into host mammalian cells via a type III secretion system and localizes to the inner side of the plasma membrane. We have previously shown that YpkA binds to and phosphorylates the α subunit of the heterotrimeric G protein complex, Gαq, resulting in inhibition of Gαq signaling. To identify residues in YpkA involved in substrate binding activity we generated GFP-YpkA N-terminal deletion mutants and performed coimmunoprecipitation experiments. We located a substrate-binding domain on amino acids 40–49 of YpkA, which lies within the previously identified membrane localization domain on YpkA. Deletion of amino acids 40–49 on YpkA interfered with substrate binding, substrate phosphorylation and substrate inhibition. Autophosphorylation regulates the kinase activity of YpkA. To dissect the mechanism by which YpkA transmits signals, we performed nano liquid chromatography coupled to tandem mass spectrometry to map in vivo phosphorylation sites. Multiple serine phosphorylation sites were identified in the secretion/translocation region, kinase domain, and C-terminal region of YpkA. Using site-directed mutagenesis we generated multiple YpkA constructs harboring specific serine to alanine point mutations. Our results demonstrate that multiple autophosphorylation sites within the N terminus regulate YpkA kinase activation, whereas mutation of serine to alanine within the C terminus of YpkA had no effect on kinase activity. YpkA autophosphorylation on multiple sites may be a strategy used by pathogenic Yersinia to prevent inactivation of this important virulence protein by host proteins. PMID:25086045

  20. Consequences of heat shock protein 72 (Hsp72) expression and activity on stress-induced apoptosis in CD30+ NPM-ALK+ anaplastic large-cell lymphomas.

    PubMed

    Bonvini, P; Zorzi, E; Mussolin, L; Pillon, M; Romualdi, C; Peron, M; d'Amore, E S G; Lamant, L; Rosolen, A

    2012-06-01

    Understanding the mechanisms that control stress-induced apoptosis is critical to explain how tumours respond to treatment, as cancer cells frequently escape drug toxicity by regulating stress response through heat shock protein (HSP) expression. The overexpression of Hsp72, in particular, results in increased incidence of cell transformation, and correlates with poor prognosis in a wide range of cancers. We have shown that Hsp72 assists folding of oncogenic NPM-ALK kinase in anaplastic large-cell lymphomas (ALCLs), but its role in the maintenance of the malignant phenotype remains uncertain. Therefore, we assessed Hsp72 expression in ALCLs, investigating more in detail the mechanisms that regulate its status and activity. We found that Hsp72 is unique among the HSPs involved in tumourigenesis to be overexpressed in ALK(+) tumours and cell lines and to be induced by stress. Different from other HSPs, Hsp72 prevents cell injury, Bax activation and death by apoptosis in ALK(+) cells, acting both upstream and downstream of mitochondria. Conversely, Hsp72 is underexpressed in ALK(-) ALCL cells, and it is unable to protect cells from apoptosis under stress. Moreover, when Hsp72 expression is reduced following NPM-ALK inhibition, lymphoma cells undergo apoptosis, demonstrating the importance of Hsp72 in regulating ALCL stress response and drug sensitivity.

  1. Three-Year Follow-Up of an Alectinib Phase I/II Study in ALK-Positive Non-Small-Cell Lung Cancer: AF-001JP.

    PubMed

    Tamura, Tomohide; Kiura, Katsuyuki; Seto, Takashi; Nakagawa, Kazuhiko; Maemondo, Makoto; Inoue, Akira; Hida, Toyoaki; Yoshioka, Hiroshige; Harada, Masao; Ohe, Yuichiro; Nogami, Naoyuki; Murakami, Haruyasu; Kuriki, Hiroshi; Shimada, Tadashi; Tanaka, Tomohiro; Takeuchi, Kengo; Nishio, Makoto

    2017-03-15

    Purpose Alectinib is an anaplastic lymphoma kinase (ALK) -specific kinase inhibitor that seems to be effective against non-small-cell lung cancer (NSCLC) with a variety of ALK mutations. The primary analysis of AF-001JP reported a promising overall response rate. To assess progression-free survival (PFS) and overall survival (OS), patients from the phase II part of AF-001JP were followed up for approximately 3 years. Patients and Methods Oral alectinib 300 mg was administered twice per day to patients with ALK inhibitor-naïve, ALK-positive NSCLC who had progressed after one or more regimens of previous chemotherapy. In this long-term follow-up, efficacy (PFS, OS), correlation between tumor shrinkage and PFS, safety of alectinib, and relief of cancer symptoms were evaluated. Results At the updated data cutoff (September 10, 2015; first patient in August 30, 2011, last patient in April 18, 2012), 25 of 46 phase II patients were still receiving alectinib. Disease progression was confirmed in 18 patients (39%); median PFS was not reached (3-year PFS rate, 62%; 95% CI, 45 to 75). Fourteen patients had brain metastases at baseline; of these, 6 remained in the study without CNS and systemic progression. Tumor shrinkage and PFS showed no correlation. The 3-year OS rate was 78% (13 events). The most common treatment-related adverse event (all grades) was increased blood bilirubin (36.2%). Most cancer symptoms were relieved early, and medication for symptoms was dramatically decreased during alectinib therapy. Conclusion Alectinib was effective in this 3-year follow-up with a favorable safety profile over a long administration period in ALK-positive NSCLC without previous ALK inhibitor treatment.

  2. Fluoride Regulate Osteoblastic Transforming Growth Factor-β1 Signaling by Mediating Recycling of the Type I Receptor ALK5

    PubMed Central

    Yang, Chen; Wang, Yan; Xu, Hui

    2017-01-01

    This study aimed to preliminary investigate the role of activin receptor-like kinase (ALK) 5 as one of TGF-βR1 subtypes in bone turnover and osteoblastic differentiation induced by fluoride. We analyzed bone mineral density and the expression of genes related with transforming growth factor-β1(TGF-β1) signaling and bone turnover in rats treated by different concentrations of fluoride with or without SB431542 in vivo. Moreover, MTT assay, alkaline phosphatase staining, RT-PCR, immunocytochemical analysis and western blot analysis were used to detect the influence on bone marrow stem cells (BMSC) after stimulating by varying concentration of fluoride with or without SB431542 in vitro. The in vivo study showed SB431542 treatment affected bone density and gene expression of rats, which indicated TGF-β1 and ALK5 might take part in fluoride-induced bone turnover and bone formation. The in vitro study showed low concentration of fluoride improved BMSC cells viability, alkaline phosphatase activity, and osteocalcin protein expression which were inhibited by high concentration of fluoride. The gene expression of Runx2 and ALK5 in cells increased after low concentration fluoride treatment which was also inhibited by high concentration of fluoride. Fluoride treatment inhibited gene and protein expression of Samd3 (except 1 mgF-/L). Compared with fluoride treatment alone, cells differentiation was inhibited with SB431542 treatment. Moreover, the expression of Runx2, ALK5 and Smad3 were influenced by SB431542 treatment. In conclusion, this preliminary study indicated that fluoride regulated osteoblastic TGFβ1 signaling in bone turnover and cells differentiation via ALK5. PMID:28125630

  3. Decoding Tumor Phenotypes for ALK, ROS1, and RET Fusions in Lung Adenocarcinoma Using a Radiomics Approach

    PubMed Central

    Yoon, Hyun Jung; Sohn, Insuk; Cho, Jong Ho; Lee, Ho Yun; Kim, Jae-Hun; Choi, Yoon-La; Kim, Hyeseung; Lee, Genehee; Lee, Kyung Soo; Kim, Jhingook

    2015-01-01

    Abstract Quantitative imaging using radiomics can capture distinct phenotypic differences between tumors and may have predictive power for certain phenotypes according to specific genetic mutations. We aimed to identify the clinicoradiologic predictors of tumors with ALK (anaplastic lymphoma kinase), ROS1 (c-ros oncogene 1), or RET (rearranged during transfection) fusions in patients with lung adenocarcinoma. A total of 539 pathologically confirmed lung adenocarcinomas were included in this retrospective study. The baseline clinicopathologic characteristics were retrieved from the patients’ medical records and the ALK/ROS1/RET fusion status was reviewed. Quantitative computed tomography (CT) and positron emission tomography imaging characteristics were evaluated using a radiomics approach. Significant features for the fusion-positive tumor prediction model were extracted from all of the clinicoradiologic features, and were used to calculate diagnostic performance for predicting 3 fusions’ positivity. The clinicoradiologic features were compared between ALK versus ROS1/RET fusion-positive tumors to identify the clinicoradiologic similarity between the 2 groups. The fusion-positive tumor prediction model was a combination of younger age, advanced tumor stage, solid tumor on CT, higher values for SUVmax and tumor mass, lower values for kurtosis and inverse variance on 3-voxel distance than those of fusion-negative tumors (sensitivity and specificity, 0.73 and 0.70, respectively). ALK fusion-positive tumors were significantly different in tumor stage, central location, SUVmax, homogeneity on 1-, 2-, and 3-voxel distances, and sum mean on 2-voxel distance compared with ROS1/RET fusion-positive tumors. ALK/ROS1/RET fusion-positive lung adenocarcinomas possess certain clinical and imaging features that enable good discrimination of fusion-positive from fusion-negative lung adenocarcinomas. PMID:26469915

  4. Decoding Tumor Phenotypes for ALK, ROS1, and RET Fusions in Lung Adenocarcinoma Using a Radiomics Approach.

    PubMed

    Yoon, Hyun Jung; Sohn, Insuk; Cho, Jong Ho; Lee, Ho Yun; Kim, Jae-Hun; Choi, Yoon-La; Kim, Hyeseung; Lee, Genehee; Lee, Kyung Soo; Kim, Jhingook

    2015-10-01

    Quantitative imaging using radiomics can capture distinct phenotypic differences between tumors and may have predictive power for certain phenotypes according to specific genetic mutations. We aimed to identify the clinicoradiologic predictors of tumors with ALK (anaplastic lymphoma kinase), ROS1 (c-ros oncogene 1), or RET (rearranged during transfection) fusions in patients with lung adenocarcinoma.A total of 539 pathologically confirmed lung adenocarcinomas were included in this retrospective study. The baseline clinicopathologic characteristics were retrieved from the patients' medical records and the ALK/ROS1/RET fusion status was reviewed. Quantitative computed tomography (CT) and positron emission tomography imaging characteristics were evaluated using a radiomics approach. Significant features for the fusion-positive tumor prediction model were extracted from all of the clinicoradiologic features, and were used to calculate diagnostic performance for predicting 3 fusions' positivity. The clinicoradiologic features were compared between ALK versus ROS1/RET fusion-positive tumors to identify the clinicoradiologic similarity between the 2 groups.The fusion-positive tumor prediction model was a combination of younger age, advanced tumor stage, solid tumor on CT, higher values for SUV(max) and tumor mass, lower values for kurtosis and inverse variance on 3-voxel distance than those of fusion-negative tumors (sensitivity and specificity, 0.73 and 0.70, respectively). ALK fusion-positive tumors were significantly different in tumor stage, central location, SUV(max), homogeneity on 1-, 2-, and 3-voxel distances, and sum mean on 2-voxel distance compared with ROS1/RET fusion-positive tumors.ALK/ROS1/RET fusion-positive lung adenocarcinomas possess certain clinical and imaging features that enable good discrimination of fusion-positive from fusion-negative lung adenocarcinomas.

  5. Modulation of Pantothenate Kinase 3 Activity by Small Molecules that Interact with the Substrate/Allosteric Regulatory Domain

    SciTech Connect

    Leonardi, Roberta; Zhang, Yong-Mei; Yun, Mi-Kyung; Zhou, Ruobing; Zeng, Fu-Yue; Lin, Wenwei; Cui, Jimmy; Chen, Taosheng; Rock, Charles O.; White, Stephen W.; Jackowski, Suzanne

    2010-09-27

    Pantothenate kinase (PanK) catalyzes the rate-controlling step in coenzyme A (CoA) biosynthesis. PanK3 is stringently regulated by acetyl-CoA and uses an ordered kinetic mechanism with ATP as the leading substrate. Biochemical analysis of site-directed mutants indicates that pantothenate binds in a tunnel adjacent to the active site that is occupied by the pantothenate moiety of the acetyl-CoA regulator in the PanK3 acetyl-CoA binary complex. A high-throughput screen for PanK3 inhibitors and activators was applied to a bioactive compound library. Thiazolidinediones, sulfonylureas and steroids were inhibitors, and fatty acyl-amides and tamoxifen were activators. The PanK3 activators and inhibitors either stimulated or repressed CoA biosynthesis in HepG2/C3A cells. The flexible allosteric acetyl-CoA regulatory domain of PanK3 also binds the substrates, pantothenate and pantetheine, and small molecule inhibitors and activators to modulate PanK3 activity.

  6. Prevalence of EGFR Tyrosine Kinase Domain Mutations in Head and Neck Squamous Cell Carcinoma: Cohort Study and Systematic Review

    PubMed Central

    PERISANIDIS, CHRISTOS

    2017-01-01

    Background: Mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain (TKD) are associated with response and resistance to targeted therapy. The EGFR mutation status in patients with advanced oral and oropharyngeal squamous cell carcinoma (OOSCC) was evaluated. A systematic literature review was undertaken to summarize current evidence and estimate the overall prevalence of EGFR TKD mutations in patients with head and neck squamous cell carcinoma (HNSCC). Materials and Methods: Genomic DNA was extracted from formalin-fixed, paraffin-embedded tumor samples of 113 patients with OOSCC. Pyrosequencing was performed to investigate mutations in EGFR exons 18 to 21. Medline databases were searched for relevant studies. Studies reporting mutations in the EGFR TKD in HNSCC were eligible for inclusion in the systematic review. Results: No mutations in the EGFR TKD were observed in 113 samples of OOSCC. A total of 53 eligible studies were included in the systematic review. In total, from the review, 117 patients harboring a total of 159 EGFR TKD mutations were reported among 4122 patients with HNSCC. The overall prevalence of EGFR TKD mutations in HNSCC was 2.8%. Conclusion: Large-scale studies are warranted to provide further evidence regarding the mutation status of EGFR in patients with HNSCC. PMID:28064216

  7. MASK, a large ankyrin repeat and KH domain-containing protein involved in Drosophila receptor tyrosine kinase signaling.

    PubMed

    Smith, Rachel K; Carroll, Pamela M; Allard, John D; Simon, Michael A

    2002-01-01

    The receptor tyrosine kinases Sevenless (SEV) and the Epidermal growth factor receptor (EGFR) are required for the proper development of the Drosophila eye. The protein tyrosine phosphatase Corkscrew (CSW) is a common component of many RTK signaling pathways, and is required for signaling downstream of SEV and EGFR. In order to identify additional components of these signaling pathways, mutations that enhanced the phenotype of a dominant negative form of Corkscrew were isolated. This genetic screen identified the novel signaling molecule MASK, a large protein that contains two blocks of ankyrin repeats as well as a KH domain. MASK genetically interacts with known components of these RTK signaling pathways. In the developing eye imaginal disc, loss of MASK function generates phenotypes similar to those generated by loss of other components of the SEV and EGFR pathways. These phenotypes include compromised photoreceptor differentiation, cell survival and proliferation. Although MASK is localized predominantly in the cellular cytoplasm, it is not absolutely required for MAPK activation or nuclear translocation. Based on our results, we propose that MASK is a novel mediator of RTK signaling, and may act either downstream of MAPK or transduce signaling through a parallel branch of the RTK pathway.

  8. Mutations in TBCK, Encoding TBC1-Domain-Containing Kinase, Lead to a Recognizable Syndrome of Intellectual Disability and Hypotonia

    PubMed Central

    Bhoj, Elizabeth J.; Li, Dong; Harr, Margaret; Edvardson, Shimon; Elpeleg, Orly; Chisholm, Elizabeth; Juusola, Jane; Douglas, Ganka; Guillen Sacoto, Maria J.; Siquier-Pernet, Karine; Saadi, Abdelkrim; Bole-Feysot, Christine; Nitschke, Patrick; Narravula, Alekhya; Walke, Maria; Horner, Michele B.; Day-Salvatore, Debra-Lynn; Jayakar, Parul; Vergano, Samantha A. Schrier; Tarnopolsky, Mark A.; Hegde, Madhuri; Colleaux, Laurence; Crino, Peter; Hakonarson, Hakon

    2016-01-01

    Through an international multi-center collaboration, 13 individuals from nine unrelated families and affected by likely pathogenic biallelic variants in TBC1-domain-containing kinase (TBCK) were identified through whole-exome sequencing. All affected individuals were found to share a core phenotype of intellectual disability and hypotonia, and many had seizures and showed brain atrophy and white-matter changes on neuroimaging. Minor non-specific facial dysmorphism was also noted in some individuals, including multiple older children who developed coarse features similar to those of storage disorders. TBCK has been shown to regulate the mammalian target of rapamycin (mTOR) signaling pathway, which is also stimulated by exogenous leucine supplementation. TBCK was absent in cells from affected individuals, and decreased phosphorylation of phospho-ribosomal protein S6 was also observed, a finding suggestive of downregulation of mTOR signaling. Lastly, we demonstrated that activation of the mTOR pathway in response to L-leucine supplementation was retained, suggesting a possible avenue for directed therapies for this condition. PMID:27040691

  9. Moderate and strong static magnetic fields directly affect EGFR kinase domain orientation to inhibit cancer cell proliferation

    PubMed Central

    Wang, Wenchao; Li, Zhiyuan; Liu, Juanjuan; Yang, Xingxing; Ji, Xinmiao; Luo, Yan; Hu, Chen; Hou, Yubin; He, Qianqian; Fang, Jun; Wang, Junfeng; Liu, Qingsong; Li, Guohui; Lu, Qingyou; Zhang, Xin

    2016-01-01

    Static magnetic fields (SMFs) can affect cell proliferation in a cell-type and intensity-dependent way but the mechanism remains unclear. At the same time, although the diamagnetic anisotropy of proteins has been proposed decades ago, the behavior of isolated proteins in magnetic fields has not been directly observed. Here we show that SMFs can affect isolated proteins at the single molecular level in an intensity-dependent manner. We found that Epidermal Growth Factor Receptor (EGFR), a protein that is overexpressed and highly activated in multiple cancers, can be directly inhibited by SMFs. Using Liquid-phase Scanning Tunneling Microscopy (STM) to examine pure EGFR kinase domain proteins at the single molecule level in solution, we observed orientation changes of these proteins in response to SMFs. This may interrupt inter-molecular interactions between EGFR monomers, which are critical for their activation. In molecular dynamics (MD) simulations, 1-9T SMFs caused increased probability of EGFR in parallel with the magnetic field direction in an intensity-dependent manner. A superconducting ultrastrong 9T magnet reduced proliferation of CHO-EGFR cells (Chinese Hamster Ovary cells with EGFR overexpression) and EGFR-expressing cancer cell lines by ~35%, but minimally affected CHO cells. We predict that similar effects of magnetic fields can also be applied to some other proteins such as ion channels. Our paper will help clarify some dilemmas in this field and encourage further investigations in order to achieve a better understanding of the biological effects of SMFs. PMID:27223425

  10. Structural and functional analyses of minimal phosphopeptides targeting the polo-box domain of polo-like kinase 1

    SciTech Connect

    Yun, Sang-Moon; Moulaei, Tinoush; Lim, Dan; Bang, Jeong K.; Park, Jung-Eun; Shenoy, Shilpa R.; Liu, Fa; Kang, Young H.; Liao, Chenzhong; Soung, Nak-Kyun; Lee, Sunhee; Yoon, Do-Young; Lim, Yoongho; Lee, Dong-Hee; Otaka, Akira; Appella, Ettore; McMahon, James B.; Nicklaus, Marc C.; Burke, Jr., Terrence R.; Yaffe, Michael B.; Wlodawer, Alexander; Lee, Kyung S.

    2009-09-14

    Polo-like kinase-1 (Plk1) has a pivotal role in cell proliferation and is considered a potential target for anticancer therapy. The noncatalytic polo-box domain (PBD) of Plk1 forms a phosphoepitope binding module for protein-protein interaction. Here, we report the identification of minimal phosphopeptides that specifically interact with the PBD of human PLK1, but not those of the closely related PLK2 and PLK3. Comparative binding studies and analyses of crystal structures of the PLK1 PBD in complex with the minimal phosphopeptides revealed that the C-terminal SpT dipeptide functions as a high-affinity anchor, whereas the N-terminal residues are crucial for providing specificity and affinity to the interaction. Inhibition of the PLK1 PBD by phosphothreonine mimetic peptides was sufficient to induce mitotic arrest and apoptotic cell death. The mode of interaction between the minimal peptide and PBD may provide a template for designing therapeutic agents that target PLK1.

  11. C-terminal domain small phosphatase 1 and MAP kinase reciprocally control REST stability and neuronal differentiation

    PubMed Central

    Corson, Glen M.; McCleskey, Maxwell; Oyer, Jon A.; Mandel, Gail

    2014-01-01

    The repressor element 1 (RE1) silencing transcription factor (REST) in stem cells represses hundreds of genes essential to neuronal function. During neurogenesis, REST is degraded in neural progenitors to promote subsequent elaboration of a mature neuronal phenotype. Prior studies indicate that part of the degradation mechanism involves phosphorylation of two sites in the C terminus of REST that require activity of beta-transducin repeat containing E3 ubiquitin protein ligase, βTrCP. We identify a proline-directed phosphorylation motif, at serines 861/864 upstream of these sites, which is a substrate for the peptidylprolyl cis/trans isomerase, Pin1, as well as the ERK1/2 kinases. Mutation at S861/864 stabilizes REST, as does inhibition of Pin1 activity. Interestingly, we find that C-terminal domain small phosphatase 1 (CTDSP1), which is recruited by REST to neuronal genes, is present in REST immunocomplexes, dephosphorylates S861/864, and stabilizes REST. Expression of a REST peptide containing S861/864 in neural progenitors inhibits terminal neuronal differentiation. Together with previous work indicating that both REST and CTDSP1 are expressed to high levels in stem cells and down-regulated during neurogenesis, our results suggest that CTDSP1 activity stabilizes REST in stem cells and that ERK-dependent phosphorylation combined with Pin1 activity promotes REST degradation in neural progenitors. PMID:25197063

  12. Conformational heterogeneity within the LID domain mediates substrate binding to Escherichia coli adenylate kinase: function follows fluctuations.

    PubMed

    Schrank, Travis P; Wrabl, James O; Hilser, Vincent J

    2013-01-01

    Proteins exist as dynamic ensembles of molecules, implying that protein amino acid sequences evolved to code for both the ground state structure as well as the entire energy landscape of excited states. Accumulating theoretical and experimental evidence suggests that enzymes use such conformational fluctuations to facilitate allosteric processes important for substrate binding and possibly catalysis. This phenomenon can be clearly demonstrated in Escherichia coli adenylate kinase, where experimentally observed local unfolding of the LID subdomain, as opposed to a more commonly postulated rigid-body opening motion, is related to substrate binding. Because "entropy promoting" glycine mutations designed to increase specifically the local unfolding of the LID domain also affect substrate binding, changes in the excited energy landscape effectively tune the function of this enzyme without changing the ground state structure or the catalytic site. Thus, additional thermodynamic information, above and beyond the single folded structure of an enzyme-substrate complex, is likely required for a full and quantitative understanding of how enzymes work.

  13. BRAF(V600E) Kinase Domain Duplication Identified in Therapy-Refractory Melanoma Patient-Derived Xenografts.

    PubMed

    Kemper, Kristel; Krijgsman, Oscar; Kong, Xiangjun; Cornelissen-Steijger, Paulien; Shahrabi, Aida; Weeber, Fleur; van der Velden, Daphne L; Bleijerveld, Onno B; Kuilman, Thomas; Kluin, Roel J C; Sun, Chong; Voest, Emile E; Ju, Young Seok; Schumacher, Ton N M; Altelaar, A F Maarten; McDermott, Ultan; Adams, David J; Blank, Christian U; Haanen, John B; Peeper, Daniel S

    2016-06-28

    The therapeutic landscape of melanoma is improving rapidly. Targeted inhibitors show promising results, but drug resistance often limits durable clinical responses. There is a need for in vivo systems that allow for mechanistic drug resistance studies and (combinatorial) treatment optimization. Therefore, we established a large collection of patient-derived xenografts (PDXs), derived from BRAF(V600E), NRAS(Q61), or BRAF(WT)/NRAS(WT) melanoma metastases prior to treatment with BRAF inhibitor and after resistance had occurred. Taking advantage of PDXs as a limitless source, we screened tumor lysates for resistance mechanisms. We identified a BRAF(V600E) protein harboring a kinase domain duplication (BRAF(V600E/DK)) in ∼10% of the cases, both in PDXs and in an independent patient cohort. While BRAF(V600E/DK) depletion restored sensitivity to BRAF inhibition, a pan-RAF dimerization inhibitor effectively eliminated BRAF(V600E/DK)-expressing cells. These results illustrate the utility of this PDX platform and warrant clinical validation of BRAF dimerization inhibitors for this group of melanoma patients.

  14. Structure of a specific peptide complex of the carboxy-terminal SH2 domain from the p85 alpha subunit of phosphatidylinositol 3-kinase.

    PubMed Central

    Breeze, A L; Kara, B V; Barratt, D G; Anderson, M; Smith, J C; Luke, R W; Best, J R; Cartlidge, S A

    1996-01-01

    We have determined the solution structure of the C-terminal SH2 domain of the p85 alpha subunit of human phosphatidylinositol (PI) 3-kinase (EC 2.7.1.137) in complex with a phosphorylated tyrosine pentapeptide sequence from the platelet-derived growth factor receptor using heteronuclear nuclear magnetic resonance spectroscopy. Overall, the structure is similar to other SH2 domain complexes, but displays different detail interactions within the phosphotyrosine binding site and in the recognition site for the +3 methionine residue of the peptide, the side chain of which inserts into a particularly deep and narrow pocket which is displaced relative to that of other SH2 domains. The contacts made within this +3 pocket provide the structural basis for the strong selection for methionine at this position which characterizes the SH2 domains of PI3-kinase. Comparison with spectral and structural features of the uncomplexed domain shows that the long BG loop becomes less mobile in the presence of the bound peptide. In contrast, extreme resonance broadening encountered for most residues in the beta D', beta E and beta F strands and associated connecting loops of the domain in the absence of peptide persists in the complex, implying conformational averaging in this part of the molecule on a microsecond-to-millisecond time scale. Images PMID:8670861

  15. Virulence regulation with Venus flytrap domains: structure and function of the periplasmic moiety of the sensor-kinase BvgS.

    PubMed

    Dupré, Elian; Herrou, Julien; Lensink, Marc F; Wintjens, René; Vagin, Alexey; Lebedev, Andrey; Crosson, Sean; Villeret, Vincent; Locht, Camille; Antoine, Rudy; Jacob-Dubuisson, Françoise

    2015-03-01

    Two-component systems (TCS) represent major signal-transduction pathways for adaptation to environmental conditions, and regulate many aspects of bacterial physiology. In the whooping cough agent Bordetella pertussis, the TCS BvgAS controls the virulence regulon, and is therefore critical for pathogenicity. BvgS is a prototypical TCS sensor-kinase with tandem periplasmic Venus flytrap (VFT) domains. VFT are bi-lobed domains that typically close around specific ligands using clamshell motions. We report the X-ray structure of the periplasmic moiety of BvgS, an intricate homodimer with a novel architecture. By combining site-directed mutagenesis, functional analyses and molecular modeling, we show that the conformation of the periplasmic moiety determines the state of BvgS activity. The intertwined structure of the periplasmic portion and the different conformation and dynamics of its mobile, membrane-distal VFT1 domains, and closed, membrane-proximal VFT2 domains, exert a conformational strain onto the transmembrane helices, which sets the cytoplasmic moiety in a kinase-on state by default corresponding to the virulent phase of the bacterium. Signaling the presence of negative signals perceived by the periplasmic domains implies a shift of BvgS to a distinct state of conformation and activity, corresponding to the avirulent phase. The response to negative modulation depends on the integrity of the periplasmic dimer, indicating that the shift to the kinase-off state implies a concerted conformational transition. This work lays the bases to understand virulence regulation in Bordetella. As homologous sensor-kinases control virulence features of diverse bacterial pathogens, the BvgS structure and mechanism may pave the way for new modes of targeted therapeutic interventions.

  16. Virulence Regulation with Venus Flytrap Domains: Structure and Function of the Periplasmic Moiety of the Sensor-Kinase BvgS

    PubMed Central

    Lensink, Marc F.; Wintjens, René; Vagin, Alexey; Lebedev, Andrey; Crosson, Sean; Villeret, Vincent; Locht, Camille; Antoine, Rudy; Jacob-Dubuisson, Françoise

    2015-01-01

    Two-component systems (TCS) represent major signal-transduction pathways for adaptation to environmental conditions, and regulate many aspects of bacterial physiology. In the whooping cough agent Bordetella pertussis, the TCS BvgAS controls the virulence regulon, and is therefore critical for pathogenicity. BvgS is a prototypical TCS sensor-kinase with tandem periplasmic Venus flytrap (VFT) domains. VFT are bi-lobed domains that typically close around specific ligands using clamshell motions. We report the X-ray structure of the periplasmic moiety of BvgS, an intricate homodimer with a novel architecture. By combining site-directed mutagenesis, functional analyses and molecular modeling, we show that the conformation of the periplasmic moiety determines the state of BvgS activity. The intertwined structure of the periplasmic portion and the different conformation and dynamics of its mobile, membrane-distal VFT1 domains, and closed, membrane-proximal VFT2 domains, exert a conformational strain onto the transmembrane helices, which sets the cytoplasmic moiety in a kinase-on state by default corresponding to the virulent phase of the bacterium. Signaling the presence of negative signals perceived by the periplasmic domains implies a shift of BvgS to a distinct state of conformation and activity, corresponding to the avirulent phase. The response to negative modulation depends on the integrity of the periplasmic dimer, indicating that the shift to the kinase-off state implies a concerted conformational transition. This work lays the bases to understand virulence regulation in Bordetella. As homologous sensor-kinases control virulence features of diverse bacterial pathogens, the BvgS structure and mechanism may pave the way for new modes of targeted therapeutic interventions. PMID:25738876

  17. Protein Kinase A Is Central for Forward Transport of Two-pore Domain Potassium Channels K2P3.1 and K2P9.1*

    PubMed Central

    Mant, Alexandra; Elliott, David; Eyers, Patrick A.; O'Kelly, Ita M.

    2011-01-01

    Acid-sensitive two-pore domain potassium channels (K2P3.1 and K2P9.1) play key roles in both physiological and pathophysiological mechanisms, the most fundamental of which is control of resting membrane potential of cells in which they are expressed. These background “leak” channels are constitutively active once expressed at the plasma membrane, and hence tight control of their targeting and surface expression is fundamental to the regulation of K+ flux and cell excitability. The chaperone protein, 14-3-3, binds to a critical phosphorylated serine in the channel C termini of K2P3.1 and K2P9.1 (Ser393 and Ser373, respectively) and overcomes retention in the endoplasmic reticulum by βCOP. We sought to identify the kinase responsible for phosphorylation of the terminal serine in human and rat variants of K2P3.1 and K2P9.1. Adopting a bioinformatic approach, three candidate protein kinases were identified: cAMP-dependent protein kinase, ribosomal S6 kinase, and protein kinase C. In vitro phosphorylation assays were utilized to determine the ability of the candidate kinases to phosphorylate the channel C termini. Electrophysiological measurements of human K2P3.1 transiently expressed in HEK293 cells and cell surface assays of GFP-tagged K2P3.1 and K2P9.1 enabled the determination of the functional implications of phosphorylation by specific kinases. All of our findings support the conclusion that cAMP-dependent protein kinase is responsible for the phosphorylation of the terminal serine in both K2P3.1 and K2P9.1. PMID:21357689

  18. Protein kinase A is central for forward transport of two-pore domain potassium channels K2P3.1 and K2P9.1.

    PubMed

    Mant, Alexandra; Elliott, David; Eyers, Patrick A; O'Kelly, Ita M

    2011-04-22

    Acid-sensitive two-pore domain potassium channels (K2P3.1 and K2P9.1) play key roles in both physiological and pathophysiological mechanisms, the most fundamental of which is control of resting membrane potential of cells in which they are expressed. These background "leak" channels are constitutively active once expressed at the plasma membrane, and hence tight control of their targeting and surface expression is fundamental to the regulation of K(+) flux and cell excitability. The chaperone protein, 14-3-3, binds to a critical phosphorylated serine in the channel C termini of K2P3.1 and K2P9.1 (Ser(393) and Ser(373), respectively) and overcomes retention in the endoplasmic reticulum by βCOP. We sought to identify the kinase responsible for phosphorylation of the terminal serine in human and rat variants of K2P3.1 and K2P9.1. Adopting a bioinformatic approach, three candidate protein kinases were identified: cAMP-dependent protein kinase, ribosomal S6 kinase, and protein kinase C. In vitro phosphorylation assays were utilized to determine the ability of the candidate kinases to phosphorylate the channel C termini. Electrophysiological measurements of human K2P3.1 transiently expressed in HEK293 cells and cell surface assays of GFP-tagged K2P3.1 and K2P9.1 enabled the determination of the functional implications of phosphorylation by specific kinases. All of our findings support the conclusion that cAMP-dependent protein kinase is responsible for the phosphorylation of the terminal serine in both K2P3.1 and K2P9.1.

  19. WW Domains of the Yes-Kinase-Associated-Protein (YAP) Transcriptional Regulator Behave as Independent Units with Different Binding Preferences for PPxY Motif-Containing Ligands

    PubMed Central

    Iglesias-Bexiga, Manuel; Castillo, Francisco; Cobos, Eva S.; Oka, Tsutomu; Sudol, Marius; Luque, Irene

    2015-01-01

    YAP is a WW domain-containing effector of the Hippo tumor suppressor pathway, and the object of heightened interest as a potent oncogene and stemness factor. YAP has two major isoforms that differ in the number of WW domains they harbor. Elucidating the degree of co-operation between these WW domains is important for a full understanding of the molecular function of YAP. We present here a detailed biophysical study of the structural stability and binding properties of the two YAP WW domains aimed at investigating the relationship between both domains in terms of structural stability and partner recognition. We have carried out a calorimetric study of the structural stability of the two YAP WW domains, both isolated and in a tandem configuration, and their interaction with a set of functionally relevant ligands derived from PTCH1 and LATS kinases. We find that the two YAP WW domains behave as independent units with different binding preferences, suggesting that the presence of the second WW domain might contribute to modulate target recognition between the two YAP isoforms. Analysis of structural models and phage-display studies indicate that electrostatic interactions play a critical role in binding specificity. Together, these results are relevant to understand of YAP function and open the door to the design of highly specific ligands of interest to delineate the functional role of each WW domain in YAP signaling. PMID:25607641

  20. Rafoxanide and Closantel Inhibit SPAK and OSR1 Kinases by Binding to a Highly Conserved Allosteric Site on Their C-terminal Domains.

    PubMed

    AlAmri, Mubarak A; Kadri, Hachemi; Alderwick, Luke J; Simpkins, Nigel S; Mehellou, Youcef

    2017-03-31

    SPAK and OSR1 are two protein kinases that have emerged as attractive targets in the discovery of novel antihypertensive agents due to their role in regulating electrolyte balance in vivo. Herein we report the identification of an allosteric pocket on the highly conserved C-terminal domains of these two kinases, which influences their activity. We also show that some known WNK signaling inhibitors bind to this allosteric site. Using in silico screening, we identified the antiparasitic agent rafoxanide as a novel allosteric inhibitor of SPAK and OSR1. Collectively, this work will facilitate the rational design of novel SPAK and OSR1 kinase inhibitors that could be useful antihypertensive agents.

  1. Regioselective alkane hydroxylation with a mutant AlkB enzyme

    DOEpatents

    Koch, Daniel J.; Arnold, Frances H.

    2012-11-13

    AlkB from Pseudomonas putida was engineered using in-vivo directed evolution to hydroxylate small chain alkanes. Mutant AlkB-BMO1 hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. Mutant AlkB-BMO2 similarly hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. These biocatalysts are highly active for small chain alkane substrates and their regioselectivity is retained in whole-cell biotransformations.

  2. Imatinib binding to human c-Src is coupled to inter-domain allostery and suggests a novel kinase inhibition strategy

    PubMed Central

    Tsutsui, Yuko; Deredge, Daniel; Wintrode, Patrick L.; Hays, Franklin A.

    2016-01-01

    Imatinib (Gleevec), a non-receptor tyrosine kinase inhibitor (nRTKI), is one of the most successful anti-neoplastic drugs in clinical use. However, imatinib-resistant mutations are increasingly prevalent in patient tissues and driving development of novel imatinib analogs. We present a detailed study of the conformational dynamics, in the presence and absence of bound imatinib, for full-length human c-Src using hydrogen-deuterium exchange and mass spectrometry. Our results demonstrate that imatinib binding to the kinase domain effects dynamics of proline-rich or phosphorylated peptide ligand binding sites in distal c-Src SH3 and SH2 domains. These dynamic changes in functional regulatory sites, distal to the imatinib binding pocket, show similarities to structural transitions involved in kinase activation. These data also identify imatinib-sensitive, and imatinib-resistant, mutation sites. Thus, the current study identifies novel c-Src allosteric sites associated with imatinib binding and kinase activation and provide a framework for follow-on development of TKI binding modulators. PMID:27480221

  3. Structure of Ctk3, a subunit of the RNA polymerase II CTD kinase complex, reveals a noncanonical CTD-interacting domain fold.

    PubMed

    Mühlbacher, Wolfgang; Mayer, Andreas; Sun, Mai; Remmert, Michael; Cheung, Alan C M; Niesser, Jürgen; Soeding, Johannes; Cramer, Patrick

    2015-10-01

    CTDK-I is a yeast kinase complex that phosphorylates the C-terminal repeat domain (CTD) of RNA polymerase II (Pol II) to promote transcription elongation. CTDK-I contains the cyclin-dependent kinase Ctk1 (homologous to human CDK9/CDK12), the cyclin Ctk2 (human cyclin K), and the yeast-specific subunit Ctk3, which is required for CTDK-I stability and activity. Here we predict that Ctk3 consists of a N-terminal CTD-interacting domain (CID) and a C-terminal three-helix bundle domain. We determine the X-ray crystal structure of the N-terminal domain of the Ctk3 homologue Lsg1 from the fission yeast Schizosaccharomyces pombe at 2.0 Å resolution. The structure reveals eight helices arranged into a right-handed superhelical fold that resembles the CID domain present in transcription termination factors Pcf11, Nrd1, and Rtt103. Ctk3 however shows different surface properties and no binding to CTD peptides. Together with the known structure of Ctk1 and Ctk2 homologues, our results lead to a molecular framework for analyzing the structure and function of the CTDK-I complex.

  4. Amphiregulin triggered epidermal growth factor receptor activation confers in vivo crizotinib-resistance of EML4-ALK lung cancer and circumvention by epidermal growth factor receptor inhibitors.

    PubMed

    Taniguchi, Hirokazu; Takeuchi, Shinji; Fukuda, Koji; Nakagawa, Takayuki; Arai, Sachiko; Nanjo, Shigeki; Yamada, Tadaaki; Yamaguchi, Hiroyuki; Mukae, Hiroshi; Yano, Seiji

    2017-01-01

    Crizotinib, a first-generation anaplastic lymphoma kinase (ALK) tyrosine-kinase inhibitor, is known to be effective against echinoderm microtubule-associated protein-like 4 (EML4)-ALK-positive non-small cell lung cancers. Nonetheless, the tumors subsequently become resistant to crizotinib and recur in almost every case. The mechanism of the acquired resistance needs to be deciphered. In this study, we established crizotinib-resistant cells (A925LPE3-CR) via long-term administration of crizotinib to a mouse model of pleural carcinomatous effusions; this model involved implantation of the A925LPE3 cell line, which harbors the EML4-ALK gene rearrangement. The resistant cells did not have the secondary ALK mutations frequently occurring in crizotinib-resistant cells, and these cells were cross-resistant to alectinib and ceritinib as well. In cell clone #2, which is one of the clones of A925LPE3-CR, crizotinib sensitivity was restored via the inhibition of epidermal growth factor receptor (EGFR) by means of an EGFR tyrosine-kinase inhibitor (erlotinib) or an anti-EGFR antibody (cetuximab) in vitro and in the murine xenograft model. Cell clone #2 did not have an EGFR mutation, but the expression of amphiregulin (AREG), one of EGFR ligands, was significantly increased. A knockdown of AREG with small interfering RNAs restored the sensitivity to crizotinib. These data suggest that overexpression of EGFR ligands such as AREG can cause resistance to crizotinib, and that inhibition of EGFR signaling may be a promising strategy to overcome crizotinib resistance in EML4-ALK lung cancer.

  5. The Structure of the C-Terminal Domain of the Protein Kinase AtSOS2 Bound to the Calcium Sensor AtSOS3

    PubMed Central

    Sánchez-Barrena, María José; Fujii, Hiroaki; Angulo, Ivan; Martínez-Ripoll, Martín; Zhu, Jian-Kang; Albert, Armando

    2011-01-01

    SUMMARY The plant SOS2 family of protein kinases and their interacting activators, the SOS3 family of calcium-binding proteins, function together in decoding calcium signals elicited by different environmental stimuli. SOS2 is activated by Ca-SOS3 and subsequently phosphorylates the ion transporter SOS1 to bring about cellular ion homeostasis under salt stress. In addition to possessing the kinase activity, members of the SOS2 family of protein kinases can bind to protein phosphatase 2Cs. The crystal structure of the binary complex of Ca-SOS3 with the C-terminal regulatory moiety of SOS2 resolves central questions regarding the dual function of SOS2 as a kinase and a phosphatase-binding protein. A comparison with the structure of unbound SOS3 reveals the basis of the molecular function of this family of kinases and their interacting calcium sensors. Furthermore, our study suggests that the structure of the phosphatase-interaction domain of SOS2 defines a scaffold module conserved from yeast to human. PMID:17499048

  6. Direct Association of Sprouty-related Protein with an EVH1 Domain (SPRED) 1 or SPRED2 with DYRK1A Modifies Substrate/Kinase Interactions*

    PubMed Central

    Li, Dan; Jackson, Rebecca A.; Yusoff, Permeen; Guy, Graeme R.

    2010-01-01

    The mammalian SPRED (Sprouty-related protein with an EVH1 domain) proteins include a family of three members, SPRED1–3. Currently, little is known about their biochemistry. The best described, SPRED1, has been shown to inhibit the Ras/ERK pathway downstream of Ras. All three SPREDs have a cysteine-rich domain (CRD) that has high homology to the CRD of the Sprouty family of proteins, several of which are also Ras/ERK inhibitors. In the belief that binding partners would clarify SPRED function, we assayed for their associated proteins. Here, we describe the direct and endogenous interaction of SPRED1 and SPRED2 with the novel kinase, DYRK1A. DYRK1A has become the subject of recent research focus as it plays a central role in Caenorhabditis elegans oocyte maturation and egg activation, and there is strong evidence that it could be involved in Down syndrome in humans. Both SPRED1 and SPRED2 inhibit the ability of DYRK1A to phosphorylate its substrates, Tau and STAT3. This inhibition occurs via an interaction of the CRD of the SPREDs with the kinase domain of DYRK1A. DYRK1A substrates must bind to the kinase to enable phosphorylation, and SPRED proteins compete for the same binding site to modify this process. Our accumulated evidence indicates that the SPRED proteins are likely physiological modifiers of DYRK1A. PMID:20736167

  7. Kinase insert domain receptor/vascular endothelial growth factor receptor 2 (KDR) genetic variation is associated with ovarian hyperstimulation syndrome

    PubMed Central

    2014-01-01

    Background The objective of this investigation was to determine if kinase insert domain/vascular endothelial growth factor receptor 2 (KDR/VEGFR2) genetic variation was associated with the development of ovarian hyperstimulation syndrome (OHSS) in patients undergoing controlled ovarian hyperstimulation (COH). Methods This was a case–control study of 174 patients who underwent controlled ovarian stimulation. Patient blood samples were genotyped for single nucleotide polymorphisms (SNPs) spanning the KDR locus. OHSS development, clinical outcome variables, SNP and haplotype frequencies were compared between control (n = 155) and OHSS (n = 19) groups. Results Patients who developed OHSS had significantly higher response markers (estradiol levels of the day of hCG administration, number of follicles developed, number of eggs retrieved) than control patients. When adjusted for age and self-identified race, the rs2305945 G/T genotype was associated (P = 0.027) with a decreased risk (OR = 0.30; 95% CI = 0.10, 0.93) of developing OHSS using an overdominant model. The rs2305945 G/T variant was also associated with decreased COH response (number of follicles, number of eggs retrieved) in an overdominant model. The rs2305948, rs1870378, rs2305945 (C-T-G) haplotype was associated with both decreased COH response and OHSS risk (unadjusted OR = 0.10; 95% CI = 0.01, 0.80, P = 0.031). Conclusions The KDR receptor is believed to play a central role OHSS development and is a target for pharmacological prevention of OHSS. These results indicate that genetic variation in the KDR gene may impact individual risk of developing OHSS from COH. In addition, the rs2305948 SNP and C-T-G haplotype might serve as potential biomarkers for poor ovarian response to COH. PMID:24886133

  8. Tyrosine kinase discoidin domain receptors DDR1 and DDR2 are coordinately deregulated in triple-negative breast cancer.

    PubMed

    Toy, Kathy A; Valiathan, Rajeshwari R; Núñez, Fernando; Kidwell, Kelley M; Gonzalez, Maria E; Fridman, Rafael; Kleer, Celina G

    2015-02-01

    Receptor kinases Discoidin Domain Receptors (DDRs) 1 and 2 are emerging as new therapeutic targets in breast cancer (BC). However, the expression of DDR proteins during BC progression and their association with BC subtypes remain poorly defined. Herein we report the first comprehensive immunohistochemical analyses of DDR protein expression in a wide range of breast tissues. DDR1 and DDR2 expression was investigated by immunohistochemistry in 218 samples of normal breast (n = 10), ductal carcinoma in situ (DCIS, n = 10), and invasive carcinomas (n = 198), arrayed in tissue microarrays with comprehensive clinical and follow-up information. Staining was evaluated for cell type, subcellular localization, percentage and intensity (scores 1-4), and association with disease subtype and outcome. In normal epithelium and DCIS, DDR1 was highly expressed, while DDR2 was negative in normal epithelium, and in DCIS it localized to cells at the epithelial-stromal interface. Of the 198 invasive carcinomas, DDR1 was high in 87 (44 %) and low in 103 (52 %), and DDR2 was high in 110 (56 %) and low in 87 (44 %). High DDR2 was associated with high tumor grade (P = 0.002), triple-negative subtype (TNBC) (P < 0.0001), and worse survival (P = 0.037). We discovered a novel concordant deregulation of DDR expression, with a DDR1(Low)/DDR2(High) profile significantly associated with TNBC, compared to luminal tumors (P = 0.012), and with worse overall survival. In conclusion, DDR2 upregulation occurs in DCIS, before stromal invasion, and may reflect epithelial-stromal cross-talk. A DDR1(Low)/DDR2(High) protein profile is associated with TNBC and may identify invasive carcinomas with worse prognosis.

  9. Prognostic value of mixed lineage kinase domain-like protein expression in the survival of patients with gastric caner.

    PubMed

    Ertao, Zhai; Jianhui, Chen; Kang, Wang; Zhijun, Ye; Hui, Wu; Chuangqi, Chen; Changjiang, Qin; Sile, Chen; Yulong, He; Shirong, Cai

    2016-10-01

    The aim of this study was to detect mixed lineage kinase domain-like protein (MLKL) expression in gastric cancer (GC) and to analyze its association with the prognosis of GC patients. Immunohistochemical staining, Western blotting, and quantitative reverse-transcriptase polymerase chain reaction were performed to detect MLKL tissue expression in 117 GC patients. Clinicopathological characteristics and survival data were retrospectively analyzed to discover the clinical importance of MLKL expression. The chi-square test was used to analyze the relationship between MLKL expression and the clinicopathological characteristics. Survival curves were plotted by using the Kaplan-Meier method and compared using the log-rank test. Survival data were evaluated using univariate and multivariate Cox regression analyses. The expression of MLKL mRNA was significantly higher in adjacent normal samples than in the tumor tissues (P = 0.003). Clinicopathological analysis showed that MLKL expression was significantly correlated with age (P = 0.013), histologic type (P = 0.049), differentiation grade (P < 0.001), depth of invasion (P = 0.022), and lymph node metastasis (P = 0.003). Low MLKL expression was significantly associated with decreased overall survival (median 29 months vs. 56 months, P < 0.001). Multivariate analysis suggested that MLKL expression might be an independent prognostic indicator (HR = 0.645, 95 % CI, 0.446-1.165, P = 0.002) for GC patients. In conclusion, our findings provide evidence that MLKL might serve as a candidate tumor suppressor and a potential prognostic biomarker for GC.

  10. Anaplastic Lymphoma Kinase Rearrangement in Digestive Tract Cancer: Implication for Targeted Therapy in Chinese Population

    PubMed Central

    Wu, Jian; Guo, Lei; Qiu, Tian; Ling, Yun; Shan, Ling; Zhou, Haitao; Zhao, Dongbing; Wang, Jian; Liang, Jianwei; Zhao, Jianjun; Jiao, Yuchen; Lu, Ning; Zhao, Hong

    2015-01-01

    Background Anaplastic lymphoma kinase (ALK) rearrangements define a subgroup of lung cancer which is eligible to targeted kinase inhibition. The aim of this study is to observe the incidence rate of ALK fusion in a large cohort of Chinese digestive tract cancer patients. Patients and Methods Tissue microarray (TMA) was constructed from 808 digestive tract cancer cases, including 169 esophageal squamous cell carcinoma, 182 gastric cancer and 457 colorectal cancer (CRC) cases. We tested all cases for ALK expression via a fully automated immunohistochemistry (IHC) assay. The IHC-positive cases were subjected to fluorescence in situ hybridization (FISH), real-time polymerase chain reaction (qRT-PCR), target gene enrichment and sequencing for confirmation of ALK gene rearrangement and discovery of novel fusion partner. Results Among the tested cases, 2 (0.44%) CRC cases showed positive both by IHC and FISH. By qRT-PCR, EML4–ALK fusion was found in one IHC-positive CRC case. In another IHC-positive CRC case, target gene enrichment and sequencing revealed ALK was fused to a novel partner, spectrin beta non-erythrocytic 1 (SPTBN1). One gastric cancer case showed partially positive IHC result, but no fusion was found by FISH and gene sequencing. Conclusions The incidence rate of ALK gene fusion in Chinese CRC patients was 0.44%,but not detectable in gastric and esophageal cancers. The novel SPTBN1 -ALK fusion, together with other ALK fusion genes, may become a potential target for anti-ALK therapy. PMID:26678488

  11. Phosphopeptide binding to the N-terminal SH2 domain of the p85 alpha subunit of PI 3'-kinase: a heteronuclear NMR study.

    PubMed Central

    Hensmann, M.; Booker, G. W.; Panayotou, G.; Boyd, J.; Linacre, J.; Waterfield, M.; Campbell, I. D.

    1994-01-01

    The N-terminal src-homology 2 domain of the p85 alpha subunit of phosphatidylinositol 3' kinase (SH2-N) binds specifically to phosphotyrosine-containing sequences. Notably, it recognizes phosphorylated Tyr 751 within the kinase insert of the cytoplasmic domain of the activated beta PDGF receptor. A titration of a synthetic 12-residue phosphopeptide (ESVDY*VPMLDMK) into a solution of the SH2-N domain was monitored using heteronuclear 2D and 3D NMR spectroscopy. 2D-(15N-1H) heteronuclear single-quantum correlation (HSQC) experiments were performed at each point of the titration to follow changes in both 15N and 1H chemical shifts in NH groups. When mapped onto the solution structure of the SH2-N domain, these changes indicate a peptide-binding surface on the protein. Line shape analysis of 1D profiles of individual (15N-1H)-HSQC peaks at each point of the titration suggests a kinetic exchange model involving at least 2 steps. To characterize changes in the internal dynamics of the domain, the magnitude of the (15N-1H) heteronuclear NOE for the backbone amide of each residue was determined for the SH2-N domain with and without bound peptide. These data indicate that, on a nanosecond timescale, there is no significant change in the mobility of either loops or regions of secondary structure. A mode of peptide binding that involves little conformational change except in the residues directly involved in the 2 binding pockets of the p85 alpha SH2-N domain is suggested by this study. PMID:7522724

  12. BMP4 and BMP7 Suppress StAR and Progesterone Production via ALK3 and SMAD1/5/8-SMAD4 in Human Granulosa-Lutein Cells.

    PubMed

    Zhang, Han; Klausen, Christian; Zhu, Hua; Chang, Hsun-Ming; Leung, Peter C K

    2015-11-01

    Adequate production of progesterone by the corpus luteum is critical to the successful establishment of pregnancy. In animal models, bone morphogenetic protein (BMP) 4 and BMP7 have been shown to suppress either basal or gonadotropin-induced progesterone production, depending on the species examined. However, the effects of BMP4 and BMP7 on progesterone production in human granulosa cells are unknown. In the present study, we used immortalized (SVOG) and primary human granulosa-lutein cells to investigate the effects of BMP4 and BMP7 on steroidogenic acute regulatory protein (StAR) expression and progesterone production and to examine the underlying molecular mechanism. Treatment of primary and immortalized human granulosa cells with recombinant BMP4 or BMP7 decreased StAR expression and progesterone accumulation. In SVOG cells, the suppressive effects of BMP4 and BMP7 on StAR expression were blocked by pretreatment with inhibitors of activin receptor-like kinase (ALK)2/3/6 (dorsomorphin) or ALK2/3 (DMH1) but not ALK4/5/7 (SB-431542). Moreover, small interfering RNA-mediated depletion of ALK3, but not ALK2 or ALK6, reversed the effects of BMP4 and BMP7 on StAR expression. Likewise, BMP4- and BMP7-induced phosphorylation of SMAD 1/5/8 was reversed by treatment with DMH1 or small interfering RNA targeting ALK3. Knockdown of SMAD4, the essential common SMAD for BMP/TGF-β signaling, abolished the effects of BMP4 and BMP7 on StAR expression. Our results suggest that BMP4 and BMP7 down-regulate StAR and progesterone production via ALK3 and SMAD1/5/8-SMAD4 signaling in human granulosa-lutein cells.

  13. The interaction between the pleckstrin homology domain of ceramide kinase and phosphatidylinositol 4,5-bisphosphate regulates the plasma membrane targeting and ceramide 1-phosphate levels

    SciTech Connect

    Kim, Tack-Joong; Mitsutake, Susumu; Igarashi, Yasuyuki . E-mail: yigarash@pharm.hokudai.ac.jp

    2006-04-07

    Ceramide kinase (CERK) converts ceramide to ceramide-1-phosphate (C1P), which has recently emerged as a new bioactive molecule capable of regulating diverse cellular functions. The N-terminus of the CERK protein encompasses a sequence motif known as a pleckstrin homology (PH) domain. Although the PH domain was previously demonstrated to be an important domain for the subcellular localization of CERK, the precise properties of this domain remained unclear. In this study, we reveal that the PH domain of CERK exhibits high affinity for phosphatidylinositol 4,5-bisphosphate (PI(4,5)P{sub 2}), among other lipids. Furthermore, in COS7 cells, GFP-fused CERK translocated rapidly from the cytoplasm to the plasma membrane in response to hyper-osmotic stress, which is known to increase the intracellular PI(4,5)P{sub 2} levels, whereas a PH domain deletion mutant did not. Additionally, in [{sup 32}P]orthophosphate-labeled COS7 cells, the translocation of CERK to the plasma membrane induced a 2.8-fold increase in C1P levels. The study presented here provides insight into the crucial role of the CERK-PH domain in plasma membrane targeting, through its binding to PI(4,5)P{sub 2}, and subsequent induction of C1P production in the vicinity of the membrane.

  14. Modification in hydrophobic packing of HAMP domain induces a destabilization of the auto-phosphorylation site in the histidine kinase CpxA.

    PubMed

    Martinez, Marlet; Duclert-Savatier, Nathalie; Betton, Jean-Michel; Alzari, Pedro M; Nilges, Michael; Malliavin, Thérèse E

    2016-10-01

    The histidine kinases belong to the family of two-component systems, which serves in bacteria to couple environmental stimuli to adaptive responses. Most of the histidine kinases are homodimers, in which the HAMP and DHp domains assemble into an elongated helical region flanked by two CA domains. Recently, X-ray crystallographic structures of the cytoplasmic region of the Escherichia coli histidine kinase CpxA were determined and a phosphotransferase-defective mutant, M228V, located in HAMP, was identified. In the present study, we recorded 1 μs molecular dynamics trajectories to compare the behavior of the WT and M228V protein dimers. The M228V modification locally induces the appearance of larger voids within HAMP as well as a perturbation of the number of voids within DHp, thus destabilizing the HAMP and DHp hydrophobic packing. In addition, a disruption of the stacking interaction between F403 located in the lid of the CA domain involved in the auto-phosphorylation and R296 located in the interacting DHp region, is more often observed in the presence of the M228V modification. Experimental modifications R296A and R296D of CpxA have been observed to reduce also the CpxA activity. These observations agree with the destabilization of the R296/F403 stacking, and could be the sign of the transmission of a conformational event taking place in HAMP to the auto-phosphorylation site of histidine kinase. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 670-682, 2016.

  15. Human biliverdin reductase-based peptides activate and inhibit glucose uptake through direct interaction with the kinase domain of insulin receptor

    PubMed Central

    Gibbs, Peter E. M.; Lerner-Marmarosh, Nicole; Poulin, Amelia; Farah, Elie; Maines, Mahin D.

    2014-01-01

    Insulin binding changes conformation of the insulin receptor kinase (IRK) domain and initiates glucose uptake through the insulin, IGF-1, phosphatidyl inositol 3-kinase (PI3K), and MAPK pathways; human biliverdin reductase (hBVR) is an IRK substrate and pathway effector. This is the first report on hBVR peptide-mediated IRK activation and conformational change. 290KYCCSRK, which increased IRK Vmax without changing Km, stimulated glucose uptake and potentiated insulin and IGF-1 stimulation in 4 cell lines. KYCCSRK in native hBVR was necessary for the hBVR and IRK cross-activation. Peptide treatment also activated PI3K downstream effectors, Akt and ERK, phosphorylation, and Elk transcriptional activity. In cells transfected with CMV-regulated EGFP-VP-peptide plasmid, C292→A mutant did not stimulate glucose uptake; K296→A decreased uptake and kinase activity. KEDQYMKMTV, corresponding to hBVR's SH2-binding domain, was a potent inhibitor of glucose uptake and IRK. The mechanism of action of peptides was examined using cells expressing IRK (aa 988–1263) activated by coexpressed KYCCSRK. Three active cys-mutants of IRK, with fluorophore coupled to cysteines, C1056, C1138, or C1234, were examined for changes in fluorescence emission spectra in the presence of peptides. KYCCSRK and KEDQYMKMTV bound to different sites in IRK. The findings identify novel agents for activating or inhibiting insulin signaling and offer a new approach for treatment of type 2 diabetes and hypoglycemia.—Gibbs, P. E. M., Lerner-Marmarosh, N., Poulin, A., Farah, E., Maines, M. D. Human biliverdin reductase-based peptides activate and inhibit glucose uptake through direct interaction with the kinase domain of insulin receptor. PMID:24568842

  16. SRPK1 and Akt Protein Kinases Phosphorylate the RS Domain of Lamin B Receptor with Distinct Specificity: A Combined Biochemical and In Silico Approach

    PubMed Central

    Nikolakaki, Eleni; Vlassi, Metaxia; Giannakouros, Thomas

    2016-01-01

    Activated Akt has been previously implicated in acting on RS domain-containing proteins. However, it has been questioned whether its action is direct or it is mediated by co-existing SR kinase activity. To address this issue we studied in detail the phosphorylation of Lamin B Receptor (LBR) by Akt. Using synthetic peptides and a set of recombinant proteins expressing mutants of the LBR RS domain we now demonstrate that while all serines of the RS domain represent more or less equal phosphoacceptor sites for SRPK1, Ser80 and Ser82 are mainly targeted by Akt. 3D-modeling combined with molecular dynamics (MD) simulations show that amongst short, overlapping LBR RS-containing peptides complying with the minimum Akt recognition consensus sequence, only those bearing phosphosites either at Ser80 or Ser82 are able to fit into the active site of Akt, at least as effectively as its known substrate, GSK3-β. Combined our results provide evidence that Akt kinases directly phosphorylate an RS domain-containing protein and that both the residues N-terminal the phosphosite and at position +1 are essential for Akt specificity, with the latter substrate position being compatible with the arginine residue of RS-repeats. PMID:27105349

  17. The PAS domain-containing histidine kinase RpfS is a second sensor for the diffusible signal factor of Xanthomonas campestris.

    PubMed

    An, Shi-Qi; Allan, John H; McCarthy, Yvonne; Febrer, Melanie; Dow, J Maxwell; Ryan, Robert P

    2014-05-01

    A cell-cell signalling system mediated by the fatty acid signal DSF controls the virulence of Xanthomonas campestris pv. campestris (Xcc) to plants. The synthesis and recognition of the DSF signal depends upon different Rpf proteins. DSF signal generation requires RpfF whereas signal perception and transduction depends upon the sensor RpfC and regulator RpfG. Detailed analyses of the regulatory roles of different Rpf proteins have suggested the occurrence of further sensors for DSF. Here we have used a mutagenesis approach coupled with high-resolution transcriptional analysis to identify XC_2579 (RpfS) as a second sensor for DSF in Xcc. RpfS is a complex sensor kinase predicted to have multiple Per/Arnt/Sim (PAS) domains, a histidine kinase domain and a C-terminal receiver (REC) domain. Isothermal calorimetry showed that DSF bound to the isolated N-terminal PAS domain with a Kd of 1.4 μM. RpfS controlled expression of a sub-set of genes distinct from those controlled by RpfC to include genes involved in type IV secretion and chemotaxis. Mutation of XC_2579 was associated with a reduction in virulence of Xcc to Chinese Radish when assayed by leaf spraying but not by leaf inoculation, suggesting a role for RpfS-controlled factors in the epiphytic phase of the disease cycle.

  18. Durable brain response with pulse-dose crizotinib and ceritinib in ALK-positive non-small cell lung cancer compared with brain radiotherapy.

    PubMed

    Dudnik, Elizabeth; Siegal, Tali; Zach, Leor; Allen, Aaron M; Flex, Dov; Yust-Katz, Shlomit; Limon, Dror; Hirsch, Fred R; Peled, Nir

    2016-04-01

    Crizotinib achieves excellent systemic control in anaplastic lymphoma kinase-rearranged (ALK+) non-small cell lung cancer (NSCLC); however, central nervous system (CNS) metastases frequently occur as an early event. Whole brain irradiation, the standard treatment, results in neurocognitive impairment. We present a case series of three ALK+ NSCLC patients with progressing CNS metastases who were treated with pulse-dose crizotinib followed by ceritinib. Three ALK+ NSCLC patients treated between 2011 and 2014 (two males, two never smokers, age range 20-54years, all echinoderm microtubule-associated protein-like 4/ALK rearrangement), were diagnosed with progressing cerebral disease while receiving crizotinib. Clinico-pathological characteristics, treatments, and outcomes were analyzed. In two patients the progression was limited to the CNS, and radiological evidence of leptomeningeal spread was present in one patient. Sequential use of crizotinib 500mg administered once daily (pulse-dose) followed by ceritinib on progression achieved control of the disease in the CNS for over 18 months and over 7 months in Patient 1 and Patient 2, respectively. This strategy provided durable CNS control after whole-brain radiotherapy failure in Patient 1, and allowed the whole-brain radiotherapy to be deferred in Patient 2. Limited CNS progression was documented in Patient 3 while he was on standard-dose/pulse-dose crizotinib for 15months; durable (over 7 months) complete remission was achieved with stereotactic radiotherapy and ceritinib. Manipulating the crizotinib schedule in ALK+ NSCLC patients with CNS metastases and using a novel ALK-inhibitor at the time of further progression may provide durable CNS control and allow brain radiotherapy to be deferred.

  19. Anaplastic lymphoma kinase: signalling in development and disease

    PubMed Central

    Palmer, Ruth H.; Vernersson, Emma; Grabbe, Caroline; Hallberg, Bengt

    2009-01-01

    RTKs (receptor tyrosine kinases) play important roles in cellular proliferation and differentiation. In addition, RTKs reveal oncogenic potential when their kinase activities are constitutively enhanced by point mutation, amplification or rearrangement of the corresponding genes. The ALK (anaplastic lymphoma kinase) RTK was originally identified as a member of the insulin receptor subfamily of RTKs that acquires transforming capability when truncated and fused to NPM (nucleophosmin) in the t(2;5) chromosomal rearrangement associated with ALCL (anaplastic large cell lymphoma). To date, many chromosomal rearrangements leading to enhanced ALK activity have been described and are implicated in a number of cancer types. Recent reports of the EML4 (echinoderm microtubule-associated protein like 4)–ALK oncoprotein in NSCLC (non-small cell lung cancer), together with the identification of activating point mutations in neuroblastoma, have highlighted ALK as a significant player and target for drug development in cancer. In the present review we address the role of ALK in development and disease and discuss implications for the future. PMID:19459784

  20. [MAST2-like protein kinase from grape vine Vitis vinifera: cloning of catalytic domain cDNA].

    PubMed

    Briantseva, S A; Gavriushina, E S; Emets, A I; Karpov, P A; Blium, Ia B; Drygin, Iu F; Nadezhdina, E S

    2010-01-01

    The aim of our work is the identification of protein kinases phosphorylating microtubule proteins in plant cells. Using bioinformatic approach, we found genes of putative homologues of microtubule-associated mammalian protein kinase MAST2 in higher plant genomes. The gene of closest MAST2 homologue, putative protein, named GMLK (Grape MAST2-Like Kinase, A7NTE9_VITVI), was found in grape Vitis vinifera. We report here the cloning of cDNA of GMLK (A7NTE9) from Pinot Noir grape vine leaves.

  1. Crystallization and Preliminary X-ray Analysis of the Human Long Myosin Light-Chain Kinase 1-Specific Domain IgCAM3

    SciTech Connect

    W Vallen Graham; A Magis; K Bailey; J Turner; D Ostrov

    2011-12-31

    Myosin light-chain kinase-dependent tight junction regulation is a critical event in inflammatory cytokine-induced increases in epithelial paracellular permeability. MLCK is expressed in human intestinal epithelium as two isoforms, long MLCK1 and long MLCK2, and MLCK1 is specifically localized to the tight junction, where it regulates paracellular permeability. The sole difference between these long MLCK splice variants is the presence of an immunoglobulin-like cell-adhesion molecule domain, IgCAM3, in MLCK1. To gain insight into the structure of the IgCAM3 domain, the IgCAM3 domain of MLCK1 has been expressed, purified and crystallized. Preliminary X-ray diffraction data were collected to 2.0 {angstrom} resolution and were consistent with the primitive trigonal space group P2{sub 1}2{sub 1}2{sub 1}.

  2. A PAS domain with an oxygen labile [4Fe-4S](2+) cluster in the oxygen sensor kinase NreB of Staphylococcus carnosus.

    PubMed

    Müllner, Martin; Hammel, Oliver; Mienert, Bernd; Schlag, Steffen; Bill, Eckhard; Unden, Gottfried

    2008-12-30

    The cytoplasmic histidine sensor kinase NreB of Staphylococcus carnosus responds to O(2) and controls together with the response regulator NreC the expression of genes of nitrate/nitrite respiration. nreBC homologous genes were found in Staphylococcus strains and Bacillus clausii, and a modified form was found in some Lactobacillus strains. NreB contains a sensory domain with similarity to heme B binding PAS domains. Anaerobically prepared NreB of S. carnosus exhibited a (diamagnetic) [4Fe-4S](2+) cluster when assessed by Mossbauer spectroscopy. Upon reaction with air, the cluster was degraded with a half-life of approximately 2.5 min. No significant amounts of Mossbauer or EPR detectable intermediates were found during the decay, but magnetic Mossbauer spectra revealed formation of diamagnetic [2Fe-2S](2+) clusters. After extended exposure to air, NreB was devoid of a FeS cluster. Photoreduction with deazaflavin produced small amounts of [4Fe-4S](+), which were degraded subsequently. The magnetically perturbed Mossbauer spectrum of the [4Fe-4S](2+) cluster corroborated the S = 0 spin state and revealed uniform electric field gradient tensors of the iron sites, suggesting full delocalization of the valence electrons and binding of each of the Fe ions by four S ligands, including the ligand to the protein. Mutation of each of the four Cys residues inactivated NreB function in vivo in accordance with their role as ligands. [4Fe-4S](2+) cluster-containing NreB had high kinase activity. Exposure to air decreased the kinase activity and content of the [4Fe-4S](2+) cluster with similar half-lives. We conclude that the sensory domain of NreB represents a new type of PAS domain containing a [4Fe-4S](2+) cluster for sensing and function.

  3. Molecular cloning and characterization of two novel genes from hexaploid wheat that encode double PR-1 domains coupled with a receptor-like protein kinase.

    PubMed

    Lu, Shunwen; Faris, Justin D; Edwards, Michael C

    2017-04-01

    Hexaploid wheat (Triticum aestivum L.) contains at least 23 TaPr-1 genes encoding the group 1 pathogenesis-related (PR-1) proteins as identified in our previous work. Here, we report the cloning and characterization of TaPr-1-rk1 and TaPr-1-rk2, two novel genes closely related to the wheat PR-1 family. The two TaPr-1-rk genes are located on homoeologous chromosomes 3D and 3A, respectively, and each contains a large open reading frame (7385 or 6060 bp) that is interrupted by seven introns and subjected to alternative splicing (AS) with five or six isoforms of mRNA transcripts. The deduced full-length TaPR-1-RK1 and TaPR-1-RK2 proteins (95% identity) contain two repeat PR-1 domains, the second of which is fused via a transmembrane helix to a serine/threonine kinase catalytic (STKc) domain characteristic of receptor-like protein kinases. Phylogenetic analysis indicated that the two PR-1 domains of the TaPR-1-RK proteins form sister clades with their homologues identified in other monocot plants and are well separated from stand-alone PR-1 proteins, whereas the STKc domains may have originated from cysteine-rich receptor-like kinases (CRKs). Reverse-transcriptase-PCR analysis revealed that the TaPr-1-rk genes are predominantly expressed in wheat leaves and their expression levels are elevated in response to pathogen attack, such as infection by barley stripe mosaic virus (BSMV), and also to stress conditions, most obviously, to soil salinity. This is the first report of PR-1-CRK hybrid proteins in wheat. The data may shed new insights into the function/evolutionary origin of the PR-1 family and the STKc-mediated defense/stress response pathways in plants.

  4. The Structure of the Periplasmic Sensor Domain of the Histidine Kinase CusS Shows Unusual Metal Ion Coordination at the Dimeric Interface

    PubMed Central

    Affandi, Trisiani; Issaian, Aaron V.; McEvoy, Megan M.

    2016-01-01

    In bacteria, two-component systems act as signaling systems to respond to environmental stimuli. Two-component systems generally consist of a sensor histidine kinase and a response regulator, which work together through histidyl-aspartyl phospho-relay to result in gene regulation. One of the two-component systems in Escherichia coli, CusS-CusR, is known to induce expression of cusCFBA genes under increased periplasmic Cu(I) and Ag(I) concentrations to help maintain metal ion homeostasis. CusS is a membrane-associated histidine kinase with a periplasmic sensor domain connected to the cytoplasmic ATP-binding and catalytic domains through two transmembrane helices. The mechanism of how CusS senses increasing metal ion concentrations and activates CusR is not yet known. Here, we present the crystal structure of the Ag(I)-bound periplasmic sensor domain of CusS at a resolution of 2.15 Å. The structure reveals that CusS forms a homodimer with four Ag(I) binding sites per dimeric complex. Two symmetric metal binding sites are found at the dimeric interface, which are each formed by two histidines and one phenylalanine with an unusual cation-π interaction. The other metal ion binding sites are in a non-conserved region within each monomer. Functional analyses of CusS variants with mutations in the metal sites suggest that the metal ion binding site at the dimer interface is more important for function. The structural and functional data provide support for a model in which metal-induced dimerization results in increases in kinase activity in the cytoplasmic domains of CusS. PMID:27583660

  5. Distribution and evolution of multiple-step phosphorelay in prokaryotes: lateral domain recruitment involved in the formation of hybrid-type histidine kinases

    SciTech Connect

    Zhang, Weiwen; Shi, Liang

    2005-06-01

    Although most two-component signal transduction systems (TCSTS) use a simple phosphotransfer pathway from one histidine kinase (HK) to one response regulator (RR), a multiple-step phosphorelay involving a phosphotransfer scheme of His-Asp-His-Asp was discovered in recent years. Central to this multiple-step type signal transduction pathway are a hybrid-type HK, containing both an HK kinase domain and a RR receiver domain in a single protein, and a histidine-containing phosphotransfer (HPT) that can exist as either a domain in hybrid-type HKs or as a separate protein. While multiple-step phosphorelay systems predominant in eukaryotes, it has been previously suggested that they are less common in prokaryotes. In this study, we found that putative hybrid-type HKs were present in 56 out of 156 complete prokaryotic genomes, indicating that multiple-step phosphorelay systems are more common in prokaryotes than previously appreciated. Large expansions of hybrid-type HKs were observed in several types of bacterial species, including cyanobacteria, several bacteria involved in bacteria-eukaryote interaction, and metabolically versatile bacteria. Phylogenetic analysis indicated that there was no common ancestor for hybrid-type of HKs, and their origin and expansion was achieved by lateral recruitment of a receiver domain into an HK molecule and then duplication as one unit. Lateral recruitment of additional sensory domains such as PAS was also evident. HPT domains or proteins were identified in 32 of the genomes with hybrid-type HKs, however, no significant gene expansion was observed for HPTs even in genome with large number of hybrid-type HKs. In addition, the observation of fewer HPTs than hybrid-type HKs in almost all genomes studied suggests that there is no simple one-to-one relationship between them

  6. SENESCENCE-SUPPRESSED PROTEIN PHOSPHATASE Directly Interacts with the Cytoplasmic Domain of SENESCENCE-ASSOCIATED RECEPTOR-LIKE KINASE and Negatively Regulates Leaf Senescence in Arabidopsis1[OPEN

    PubMed Central

    Xiao, Dong; Cui, Yanjiao; Xu, Fan; Xu, Xinxin; Gao, Guanxiao; Wang, Yaxin; Guo, Zhaoxia; Wang, Dan; Wang, Ning Ning

    2015-01-01

    Reversible protein phosphorylation mediated by protein kinases and phosphatases plays an important role in the regulation of leaf senescence. We previously reported that the leucine-rich repeat receptor-like kinase SENESCENCE-ASSOCIATED RECEPTOR-LIKE KINASE (AtSARK) positively regulates leaf senescence in Arabidopsis (Arabidopsis thaliana). Here, we report the involvement of a protein serine/threonine phosphatase 2C-type protein phosphatase, SENESCENCE-SUPPRESSED PROTEIN PHOSPHATASE (SSPP), in the negative regulation of Arabidopsis leaf senescence. SSPP transcript levels decreased greatly during both natural senescence and SARK-induced precocious senescence. Overexpression of SSPP significantly delayed leaf senescence in Arabidopsis. Protein pull-down and bimolecular fluorescence complementation assays demonstrated that the cytosol-localized SSPP could interact with the cytoplasmic domain of the plasma membrane-localized AtSARK. In vitro assays showed that SSPP has protein phosphatase function and can dephosphorylate the cytosolic domain of AtSARK. Consistent with these observations, overexpression of SSPP effectively rescued AtSARK-induced precocious leaf senescence and changes in hormonal responses. All our results suggested that SSPP functions in sustaining proper leaf longevity and preventing early senescence by suppressing or perturbing SARK-mediated senescence signal transduction. PMID:26304848

  7. In vitro and in vivo activity of novel small-molecule inhibitors targeting the pleckstrin homology domain of protein kinase B/AKT.

    PubMed

    Moses, Sylvestor A; Ali, M Ahad; Zuohe, Song; Du-Cuny, Lei; Zhou, Li Li; Lemos, Robert; Ihle, Nathan; Skillman, A Geoffrey; Zhang, Shuxing; Mash, Eugene A; Powis, Garth; Meuillet, Emmanuelle J

    2009-06-15

    The phosphatidylinositol 3-kinase/AKT signaling pathway plays a critical role in activating survival and antiapoptotic pathways within cancer cells. Several studies have shown that this pathway is constitutively activated in many different cancer types. The goal of this study was to discover novel compounds that bind to the pleckstrin homology (PH) domain of AKT, thereby inhibiting AKT activation. Using proprietary docking software, 22 potential PH domain inhibitors were identified. Surface plasmon resonance spectroscopy was used to measure the binding of the compounds to the expressed PH domain of AKT followed by an in vitro activity screen in Panc-1 and MiaPaCa-2 pancreatic cancer cell lines. We identified a novel chemical scaffold in several of the compounds that binds selectively to the PH domain of AKT, inducing a decrease in AKT activation and causing apoptosis at low micromolar concentrations. Structural modifications of the scaffold led to compounds with enhanced inhibitory activity in cells. One compound, 4-dodecyl-N-(1,3,4-thiadiazol-2-yl)benzenesulfonamide, inhibited AKT and its downstream targets in cells as well as in pancreatic cancer cell xenografts in immunocompromised mice; it also exhibited good antitumor activity. In summary, a pharmacophore for PH domain inhibitors targeting AKT function was developed. Computer-aided modeling, synthesis, and testing produced novel AKT PH domain inhibitors that exhibit promising preclinical properties.

  8. Cooperativity in the two-domain arginine kinase from the sea anemone Anthopleura japonicus. II. Evidence from site-directed mutagenesis studies.

    PubMed

    Tada, Hiroshi; Suzuki, Tomohiko

    2010-08-01

    The arginine kinase (AK) from the sea anemone Anthopleura japonicus has an unusual two-domain structure (contiguous dimer; denoted by D1-D2). In a previous report, we suggested cooperativity in the contiguous dimer, which may be a result of domain-domain interactions, using MBP-fused enzymes. To further understand this observation, we inserted six-Lys residues into the linker region of the two-domain AK (D1-K6-D2 mutant) using His-tagged enzyme. The dissociation constants, K(a) and K(ia), of the mutant were similar to those of the wild-type enzyme but the catalytic constant, k(cat), was decreased to 28% that of the wild-type, indicating that some of the domain-domain interactions are lost due to the six-Lys insertion. Y68 plays a major role in arginine binding in the catalytic pocket in Limulus AK, and introduction of mutation at the Y68 position virtually abolishes catalytic activity. Thus, the constructed D1(Y68G)-D2 and D1-D2(Y68G) mutants mimic the D1(inactive)-D2(active) and D1(active)-D2(inactive) enzymes, respectively. The k(cat) values of both Y68 mutants were decreased to 13-18% that of the wild-type enzyme, which is much less than the 50% level of the two-domain enzyme. Thus, it is clear that substrate-binding to both domains is necessary for full expression of activity. In other words, substrate-binding appears to act as the trigger of the functional cooperativity in two-domain AK.

  9. Multiplexed transcriptome analysis to detect ALK, ROS1 and RET rearrangements in lung cancer

    PubMed Central

    Rogers, Toni-Maree; Arnau, Gisela Mir; Ryland, Georgina L.; Huang, Stephen; Lira, Maruja E.; Emmanuel, Yvette; Perez, Omar D.; Irwin, Darryl; Fellowes, Andrew P.; Wong, Stephen Q.; Fox, Stephen B.

    2017-01-01

    ALK, ROS1 and RET gene fusions are important predictive biomarkers for tyrosine kinase inhibitors in lung cancer. Currently, the gold standard method for gene fusion detection is Fluorescence In Situ Hybridization (FISH) and while highly sensitive and specific, it is also labour intensive, subjective in analysis, and unable to screen a large numbers of gene fusions. Recent developments in high-throughput transcriptome-based methods may provide a suitable alternative to FISH as they are compatible with multiplexing and diagnostic workflows. However, the concordance between these different methods compared with FISH has not been evaluated. In this study we compared the results from three transcriptome-based platforms (Nanostring Elements, Agena LungFusion panel and ThermoFisher NGS fusion panel) to those obtained from ALK, ROS1 and RET FISH on 51 clinical specimens. Overall agreement of results ranged from 86–96% depending on the platform used. While all platforms were highly sensitive, both the Agena panel and Thermo Fisher NGS fusion panel reported minor fusions that were not detectable by FISH. Our proof–of–principle study illustrates that transcriptome-based analyses are sensitive and robust methods for detecting actionable gene fusions in lung cancer and could provide a robust alternative to FISH testing in the diagnostic setting. PMID:28181564

  10. Galangin inhibits hypertrophic scar formation via ALK5/Smad2/3 signaling pathway.

    PubMed

    Zhang, Yifan; Shan, Shengzhou; Wang, Jing; Cheng, Xinyu; Yi, Bo; Zhou, Jia; Li, Qingfeng

    2016-02-01

    Hypertrophic scar (HS) is characterized by excessive fibrosis associated with aberrant function of fibroblasts. Currently, no satisfactory drug has been developed to treat the disease. Here we found that a flavonoid natural product, galangin, could significantly attenuate hypertrophic scar formation in a mechanical load-induced mouse model. Both in vivo and in vitro studies demonstrated that galangin remarkably inhibited collagen production, proliferation, and activation of fibroblasts. Besides, galangin suppressed the contractile ability of hypertrophic scar fibroblasts. Further Western blot analysis revealed that galangin dose-dependently down-regulated Smad2 and Smad3 phosphorylation. Such bioactivity of galangin resulted from its selective targeting to the activin receptor-like kinase 5 (ALK5) was demonstrated by ALK5 knockdown and over-expression experiments. Taken together, this compound could simultaneously inhibit both the accumulation of collagen and abnormal activation/proliferation of fibroblasts, which were the two pivotal factors for hypertrophic scar formation, thus suggesting that galangin serves as a potential agent for treatment of HS or other fibroproliferative disorders.

  11. Multiplexed transcriptome analysis to detect ALK, ROS1 and RET rearrangements in lung cancer.

    PubMed

    Rogers, Toni-Maree; Arnau, Gisela Mir; Ryland, Georgina L; Huang, Stephen; Lira, Maruja E; Emmanuel, Yvette; Perez, Omar D; Irwin, Darryl; Fellowes, Andrew P; Wong, Stephen Q; Fox, Stephen B

    2017-02-09

    ALK, ROS1 and RET gene fusions are important predictive biomarkers for tyrosine kinase inhibitors in lung cancer. Currently, the gold standard method for gene fusion detection is Fluorescence In Situ Hybridization (FISH) and while highly sensitive and specific, it is also labour intensive, subjective in analysis, and unable to screen a large numbers of gene fusions. Recent developments in high-throughput transcriptome-based methods may provide a suitable alternative to FISH as they are compatible with multiplexing and diagnostic workflows. However, the concordance between these different methods compared with FISH has not been evaluated. In this study we compared the results from three transcriptome-based platforms (Nanostring Elements, Agena LungFusion panel and ThermoFisher NGS fusion panel) to those obtained from ALK, ROS1 and RET FISH on 51 clinical specimens. Overall agreement of results ranged from 86-96% depending on the platform used. While all platforms were highly sensitive, both the Agena panel and Thermo Fisher NGS fusion panel reported minor fusions that were not detectable by FISH. Our proof-of-principle study illustrates that transcriptome-based analyses are sensitive and robust methods for detecting actionable gene fusions in lung cancer and could provide a robust alternative to FISH testing in the diagnostic setting.

  12. Kinase domain activation of FGFR2 yields high-grade lung adenocarcinoma sensitive to a Pan-FGFR inhibitor in a mouse model of NSCLC.

    PubMed

    Tchaicha, Jeremy H; Akbay, Esra A; Altabef, Abigail; Mikse, Oliver R; Kikuchi, Eiki; Rhee, Kevin; Liao, Rachel G; Bronson, Roderick T; Sholl, Lynette M; Meyerson, Matthew; Hammerman, Peter S; Wong, Kwok-Kin

    2014-09-01

    Somatic mutations in FGFR2 are present in 4% to 5% of patients diagnosed with non-small cell lung cancer (NSCLC). Amplification and mutations in FGFR genes have been identified in patients with NSCLCs, and clinical trials are testing the efficacy of anti-FGFR therapies. FGFR2 and other FGFR kinase family gene alterations have been found in both lung squamous cell carcinoma and lung adenocarcinoma, although mouse models of FGFR-driven lung cancers have not been reported. Here, we generated a genetically engineered mouse model (GEMM) of NSCLC driven by a kinase domain mutation in FGFR2. Combined with p53 ablation, primary grade 3/4 adenocarcinoma was induced in the lung epithelial compartment exhibiting locally invasive and pleiotropic tendencies largely made up of multinucleated cells. Tumors were acutely sensitive to pan-FGFR inhibition. This is the first FGFR2-driven lung cancer GEMM, which can be applied across different cancer indications in a preclinical setting.

  13. Crystal structures of C4-dicarboxylate ligand complexes with sensor domains of histidine kinases DcuS and DctB.

    PubMed

    Cheung, Jonah; Hendrickson, Wayne A

    2008-10-31

    Two-component signaling systems allow bacteria to adapt to changing environments. Typically, a chemical or other stimulus is detected by the periplasmic sensor domain of a transmembrane histidine kinase sensor, which in turn relays a signal through a phosphotransfer cascade to the cognate cytoplasmic response regulator. Such systems lead ultimately to changes in gene expression or cell motility. Mechanisms of ligand binding and signal transduction through the cell membrane in histidine kinases are not fully understood. In an effort to further understand such processes, we have solved the crystal structures of the periplasmic sensor domains of Escherichia coli DcuS and of Vibrio cholerae DctB in complex with the respective cognate ligands, malate and succinate. Both proteins are involved in the regulation of the transport and metabolism of C(4)-dicarboxylates, but they are not highly related by sequence similarity. Our work reveals that despite disparate sizes, both structures contain a similar characteristic alpha/beta PDC (PhoQ-DcuS-CitA) sensor-domain fold and display similar modes of ligand binding, suggesting similar mechanisms of function.

  14. Conformational transitions of the catalytic domain of heme-regulated eukaryotic initiation factor 2α kinase, a key translational regulatory molecule.

    PubMed

    Sreejith, R K; Suresh, C G; Bhosale, Siddharth H; Bhavnani, Varsha; Kumar, Avinash; Gaikwad, Sushama M; Pal, Jayanta K

    2012-01-01

    In mammalian cells, the heme-regulated inhibitor (HRI) plays a critical role in the regulation of protein synthesis at the initiation step through phosphorylation of α-subunit of the eukaryotic initiation factor 2 (eIF2). In this study we have cloned and performed biophysical characterization of the kinase catalytic domain (KD) of rabbit HRI. The KD described here comprises kinase 1, the kinase insertion domain (KI) and kinase 2. We report here the existence of an active and stable monomer of HRI (KD). The HRI (KD) containing three tryptophan residues was examined for its conformational transitions occurring under various denaturing conditions using steady-state and time-resolved tryptophan fluorescence, circular dichroism (CD) and hydrophobic dye binding. The parameter A and phase diagram analysis revealed multi-state unfolding and existence of three stable intermediates during guanidine hydrochloride (Gdn-HCl) induced unfolding of HRI (KD). The protein treated with 6 M Gdn-HCl showed collisional and static mechanism of acrylamide quenching and the constants (K(sv) = 3.08 M(-1) and K(s)= 5.62 M(-1)) were resolved using time resolved fluorescence titration. Based on pH, guanidine hydrochloride and temperature mediated transitions, HRI (KD) appears to exemplify a rigid molten globule-like intermediate with compact secondary structure, altered tertiary structure and exposed hydrophobic patches at pH 3.0. The results indicate the inherent structural stability of HRI (KD), a member of the class of stress response proteins.

  15. A case study from the chemistry core of the Pittsburgh Molecular Library Screening Center: the Polo-like kinase polo-box domain (Plk1-PBD).

    PubMed

    Wipf, Peter; Arnold, David; Carter, Karen; Dong, Shuzhi; Johnston, Paul A; Sharlow, Elizabeth; Lazo, John S; Huryn, Donna

    2009-01-01

    The Polo-like kinase (Plk) family comprises four cell cycle serine/threonine kinases, Plk1-4. Among these, Plk1 has been most thoroughly characterized; it contains a conserved kinase domain and a C-terminal docking site for S/T-phosphorylated proteins (polo-box domain, PBD). Polo-like kinases are deregulated in oncogenesis and therefore constitute a therapeutic target for cancer. A high throughput screening campaign was carried out by the Pittsburgh Molecular Library Screening Center (PMLSC), using a fluorescence polarization assay with recombinant Plk1-PBD to monitor the inhibition of binding of an optimal phosphopeptide substrate motif with recombinant Plk1-PBD. Screening of 97,090 small molecule library samples provided by the NIH Small Molecule Repository distributed by DPI Galapagos led to 11 confirmed hits. The Pittsburgh MLSCN Chemistry Core selected one of the structurally most tractable hits, SID 861574, for chemical hit-to-probe development. A broad chemistry program was initiated that developed new strategies for 6-amino- and 6-hydroxy uracil synthesis as well as acylanilides, and generated a total of 70 analogs. Out of 46 analogues tested, none, nor the resynthesized hit, showed affinity to Plk1-PBD in the follow up assays. In contrast, re-assays of the original screening materials displayed activities similar to the original HTS assay. We ultimately concluded that an impurity in the commercial material led to the positive screening artifact. This case study highlights our development of a synthesis of 6-position functionalized uracil analogs, but also illustrates the importance of careful quality and compound stability monitoring of screening collections.

  16. Treatment patterns and survival in patients with ALK-positive non-small-cell lung cancer: a Canadian retrospective study

    PubMed Central

    Kayaniyil, S.; Hurry, M.; Wilson, J.; Wheatley-Price, P.; Melosky, B.; Rothenstein, J.; Cohen, V.; Koch, C.; Zhang, J.; Osenenko, K.; Liu, G.

    2016-01-01

    Background Crizotinib was the first agent approved for the treatment of anaplastic lymphoma kinase (ALK)–positive (+) non-small-cell lung cancer (nsclc), followed by ceritinib. However, patients eventually progress or develop resistance to crizotinib. With limited real-world data available, the objective of the present work was to evaluate treatment patterns and survival after crizotinib in patients with locally advanced or metastatic ALK+ nsclc in Canada. Methods In this retrospective study at 6 oncology centres across Canada, medical records of patients with locally advanced or metastatic ALK+ nsclc were reviewed. Demographic and clinical characteristics, treatments, and outcomes data were abstracted. Analyses focused on patients who discontinued crizotinib treatment. Results Of the 97 patients included, 9 were crizotinib-naïve, and 39 were still receiving crizotinib at study end. The 49 patients who discontinued crizotinib treatment were included in the analysis. Of those 49 patients, 43% received ceritinib at any time, 20% subsequently received systemic chemotherapy only (but never ceritinib), and 37% received no further treatment or died before receiving additional treatment. Median overall survival from crizotinib discontinuation was shorter in patients who did not receive ceritinib than in those who received ceritinib (1.7 months vs. 20.4 months, p < 0.001). In a multivariable analysis, factors associated with poorer survival included lack of additional therapies (particularly ceritinib), male sex, and younger age, but not smoking status; patients of Asian ethnicity showed a nonsignificant trend toward improved survival. Conclusions A substantial proportion of patients with ALK+ nsclc received no further treatment or died before receiving additional treatment after crizotinib. Treatment with systemic agents was associated with improved survival, with ceritinib use being associated with the longest survival. PMID:28050149

  17. Molecular pharmacology and antitumor activity of PHT-427, a novel Akt/phosphatidylinositide-dependent protein kinase 1 pleckstrin homology domain inhibitor.

    PubMed

    Meuillet, Emmanuelle J; Zuohe, Song; Lemos, Robert; Ihle, Nathan; Kingston, John; Watkins, Ryan; Moses, Sylvestor A; Zhang, Shuxing; Du-Cuny, Lei; Herbst, Roy; Jacoby, Jörg J; Zhou, Li Li; Ahad, Ali M; Mash, Eugene A; Kirkpatrick, D Lynn; Powis, Garth

    2010-03-01

    Phosphatidylinositol 3-kinase/phosphatidylinositide-dependent protein kinase 1 (PDPK1)/Akt signaling plays a critical role in activating proliferation and survival pathways within cancer cells. We report the molecular pharmacology and antitumor activity of PHT-427, a compound designed to bind to the pleckstrin homology (PH) binding domain of signaling molecules important in cancer. Although originally designed to bind the PH domain of Akt, we now report that PHT-427 also binds to the PH domain of PDPK1. A series of PHT-427 analogues with variable C-4 to C-16 alkyl chain length were synthesized and tested. PHT-427 itself (C-12 chain) bound with the highest affinity to the PH domains of both PDPK1 and Akt. PHT-427 inhibited Akt and PDPK1 signaling and their downstream targets in sensitive but not resistant cells and tumor xenografts. When given orally, PHT-427 inhibited the growth of human tumor xenografts in immunodeficient mice, with up to 80% inhibition in the most sensitive tumors, and showed greater activity than analogues with C4, C6, or C8 alkyl chains. Inhibition of PDPK1 was more closely correlated to antitumor activity than Akt inhibition. Tumors with PIK3CA mutation were the most sensitive, and K-Ras mutant tumors were the least sensitive. Combination studies showed that PHT-427 has greater than additive antitumor activity with paclitaxel in breast cancer and with erlotinib in non-small cell lung cancer. When given >5 days, PHT-427 caused no weight loss or change in blood chemistry. Thus, we report a novel PH domain binding inhibitor of PDPK1/Akt signaling with significant in vivo antitumor activity and minimal toxicity.

  18. HIV-1 Tat-associated RNA polymerase C-terminal domain kinase, CDK2, phosphorylates CDK7 and stimulates Tat-mediated transcription.

    PubMed Central

    Nekhai, Sergei; Zhou, Meisheng; Fernandez, Anne; Lane, William S; Lamb, Ned J C; Brady, John; Kumar, Ajit

    2002-01-01

    HIV-1 gene expression is regulated by a viral transactivator protein (Tat) which induces transcriptional elongation of HIV-1 long tandem repeat (LTR). This induction requires hyperphosphorylation of the C-terminal domain (CTD) repeats of RNA polymerase II (Pol II). To achieve CTD hyperphosphorylation, Tat stimulates CTD kinases associated with general transcription factors of the promoter complex, specifically TFIIH-associated CDK7 and positive transcription factor b-associated CDK9 (cyclin-dependent kinase 9). Other studies indicate that Tat may bind an additional CTD kinase that regulates the target-specific phosphorylation of RNA Pol II CTD. We previously reported that Tat-associated T-cell-derived kinase (TTK), purified from human primary T-cells, stimulates Tat-dependent transcription of HIV-1 LTR in vivo [Nekhai, Shukla, Fernandez, Kumar and Lamb (2000) Virology 266, 246-256]. In the work presented here, we characterized the components of TTK by biochemical fractionation and the function of TTK in transcription assays in vitro. TTK uniquely co-purified with CDK2 and not with either CDK9 or CDK7. Tat induced the TTK-associated CDK2 kinase to phosphorylate CTD, specifically at Ser-2 residues. The TTK fraction restored Tat-mediated transcription activation of HIV-1 LTR in a HeLa nuclear extract immunodepleted of CDK9, but not in the HeLa nuclear extract double-depleted of CDK9 and CDK7. Direct microinjection of the TTK fraction augmented Tat transactivation of HIV-1 LTR in human primary HS68 fibroblasts. The results argue that TTK-associated CDK2 may function to maintain target-specific phosphorylation of RNA Pol II that is essential for Tat transactivation of HIV-1 promoter. They are also consistent with the observed cell-cycle-specific induction of viral gene transactivation. PMID:12049628

  19. Tyrosine 569 in the c-Fms juxtamembrane domain is essential for kinase activity and macrophage colony-stimulating factor-dependent internalization.

    PubMed Central

    Myles, G M; Brandt, C S; Carlberg, K; Rohrschneider, L R

    1994-01-01

    The receptor (Fms) for macrophage colony-stimulating factor (M-CSF) is a member of the tyrosine kinase class of growth factor receptors. It maintains survival, stimulates growth, and drives differentiation of the macrophage lineage of hematopoietic cells. Fms accumulates on the cell surface and becomes activated for signal transduction after M-CSF binding and is then internalized via endocytosis for eventual degradation in lysosomes. We have investigated the mechanism of endocytosis as part of the overall signaling process of this receptor and have identified an amino acid segment near the cytoplasmic juxtamembrane region surrounding tyrosine 569 that is important for internalization. Mutation of tyrosine 569 to alanine (Y569A) eliminates ligand-induced rapid endocytosis of receptor molecules. The mutant Fms Y569A also lacks tyrosine kinase activity; however, tyrosine kinase activity is not essential for endocytosis because the kinase inactive receptor Fms K614A does undergo ligand-induced endocytosis, albeit at a reduced rate. Mutation of tyrosine 569 to phenylalanine had no effect on the M-CSF-induced endocytosis of Fms, and a four-amino-acid sequence containing Y-569 could support endocytosis when transferred into the cytoplasmic juxtamembrane region of a glycophorin A construct. These results indicate that tyrosine 569 within the juxtamembrane region of Fms is part of a signal recognition sequence for endocytosis that does not require tyrosine phosphorylation at this site and that this domain also influences the kinase activity of the receptor. These results are consistent with a ligand-dependent step in recognition of the potential cryptic internalization signal. Images PMID:8007983

  20. Lumican Peptides: Rational Design Targeting ALK5/TGFBRI

    NASA Astrophysics Data System (ADS)

    Gesteira, Tarsis Ferreira; Coulson-Thomas, Vivien J.; Yuan, Yong; Zhang, Jianhua; Nader, Helena B.; Kao, Winston W.-Y.

    2017-02-01

    Lumican, a small leucine rich proteoglycan (SLRP), is a component of extracellular matrix which also functions as a matrikine regulating multiple cell activities. In the cornea, lumican maintains corneal transparency by regulating collagen fibrillogenesis, promoting corneal epithelial wound healing, regulating gene expression and maintaining corneal homeostasis. We have recently shown that a peptide designed from the 13 C-terminal amino acids of lumican (LumC13) binds to ALK5/TGFBR1 (type1 receptor of TGFβ) to promote wound healing. Herein we evaluate the mechanism by which this synthetic C-terminal amphiphilic peptide (LumC13), binds to ALK5. These studies clearly reveal that LumC13-ALK5 form a stable complex. In order to determine the minimal amino acids required for the formation of a stable lumican/ALK5 complex derivatives of LumC13 were designed and their binding to ALK5 investigated in silico. These LumC13 derivatives were tested both in vitro and in vivo to evaluate their ability to promote corneal epithelial cell migration and corneal wound healing, respectively. These validations add to the therapeutic value of LumC13 (Lumikine) and aid its clinical relevance of promoting the healing of corneal epithelium debridement. Moreover, our data validates the efficacy of our computational approach to design active peptides based on interactions of receptor and chemokine/ligand.

  1. Lumican Peptides: Rational Design Targeting ALK5/TGFBRI

    PubMed Central

    Gesteira, Tarsis Ferreira; Coulson-Thomas, Vivien J.; Yuan, Yong; Zhang, Jianhua; Nader, Helena B.; Kao, Winston W.-Y.

    2017-01-01

    Lumican, a small leucine rich proteoglycan (SLRP), is a component of extracellular matrix which also functions as a matrikine regulating multiple cell activities. In the cornea, lumican maintains corneal transparency by regulating collagen fibrillogenesis, promoting corneal epithelial wound healing, regulating gene expression and maintaining corneal homeostasis. We have recently shown that a peptide designed from the 13 C-terminal amino acids of lumican (LumC13) binds to ALK5/TGFBR1 (type1 receptor of TGFβ) to promote wound healing. Herein we evaluate the mechanism by which this synthetic C-terminal amphiphilic peptide (LumC13), binds to ALK5. These studies clearly reveal that LumC13-ALK5 form a stable complex. In order to determine the minimal amino acids required for the formation of a stable lumican/ALK5 complex derivatives of LumC13 were designed and their binding to ALK5 investigated in silico. These LumC13 derivatives were tested both in vitro and in vivo to evaluate their ability to promote corneal epithelial cell migration and corneal wound healing, respectively. These validations add to the therapeutic value of LumC13 (Lumikine) and aid its clinical relevance of promoting the healing of corneal epithelium debridement. Moreover, our data validates the efficacy of our computational approach to design active peptides based on interactions of receptor and chemokine/ligand. PMID:28181591

  2. Two novel alkane hydroxylase-rubredoxin fusion genes isolated from a Dietzia bacterium and the functions of fused rubredoxin domains in long-chain n-alkane degradation.

    PubMed

    Nie, Yong; Liang, Jieliang; Fang, Hui; Tang, Yue-Qin; Wu, Xiao-Lei

    2011-10-01

    Two alkane hydroxylase-rubredoxin fusion gene homologs (alkW1 and alkW2) were cloned from a Dietzia strain, designated DQ12-45-1b, which can grow on crude oil and n-alkanes ranging in length from 6 to 40 carbon atoms as sole carbon sources. Both AlkW1 and AlkW2 have an integral-membrane alkane monooxygenase (AlkB) conserved domain and a rubredoxin (Rd) conserved domain which are fused together. Phylogenetic analysis showed that these two AlkB-fused Rd domains formed a novel third cluster with all the Rds from the alkane hydroxylase-rubredoxin fusion gene clusters in Gram-positive bacteria and that this third cluster was distant from the known AlkG1- and AlkG2-type Rds. Expression of the alkW1 gene in DQ12-45-1b was induced when cells were grown on C(8) to C(32) n-alkanes as sole carbon sources, but expression of the alkW2 gene was not detected. Functional heterologous expression in an alkB deletion mutant of Pseudomonas fluorescens KOB2Δ1 suggested the alkW1 could restore the growth of KOB2Δ1 on C(14) and C(16) n-alkanes and induce faster growth on C(18) to C(32) n-alkanes than alkW1ΔRd, the Rd domain deletion mutant gene of alkW1, which also caused faster growth than KOB2Δ1 itself. In addition, the artificial fusion of AlkB from the Gram-negative P. fluorescens CHA0 and the Rds from both Gram-negative P. fluorescens CHA0 and Gram-positive Dietzia sp. DQ12-45-1b significantly increased the degradation of C(32) alkane compared to that seen with AlkB itself. In conclusion, the alkW1 gene cloned from Dietzia species encoded an alkane hydroxylase which increased growth on and degradation of n-alkanes up to C(32) in length, with its fused rubredoxin domain being necessary to maintain the functions. In addition, the fusion of alkane hydroxylase and rubredoxin genes from both Gram-positive and -negative bacteria can increase the degradation of long-chain n-alkanes (such as C(32)) in the Gram-negative bacterium.

  3. Structure of the iSH2 domain of Human phosphatidylinositol 3-kinase p85 beta Subunit Reveals Conformational Plasticity in the Interhelical Turn Region

    SciTech Connect

    C Schauder; L Ma; R Krug; G Montelione; R Guan

    2011-12-31

    Phosphatidylinositol 3-kinase (PI3K) proteins actively trigger signaling pathways leading to cell growth, proliferation and survival. These proteins have multiple isoforms and consist of a catalytic p110 subunit and a regulatory p85 subunit. The iSH2 domain of the p85 {beta} isoform has been implicated in the binding of nonstructural protein 1 (NS1) of influenza A viruses. Here, the crystal structure of human p85 {beta} iSH2 determined to 3.3 {angstrom} resolution is reported. The structure reveals that this domain mainly consists of a coiled-coil motif. Comparison with the published structure of the bovine p85 {beta} iSH2 domain bound to the influenza A virus nonstructural protein 1 indicates that little or no structural change occurs upon complex formation. By comparing this human p85 {beta} iSH2 structure with the bovine p85 {beta} iSH2 domain, which shares 99% sequence identity, and by comparing the multiple conformations observed within the asymmetric unit of the bovine iSH2 structure, it was found that this coiled-coil domain exhibits a certain degree of conformational variability or 'plasticity' in the interhelical turn region. It is speculated that this plasticity of p85 {beta} iSH2 may play a role in regulating its functional and molecular-recognition properties.

  4. Application of oxime-diversification to optimize ligand interactions within a cryptic pocket of the polo-like kinase 1 polo-box domain.

    PubMed

    Zhao, Xue Zhi; Hymel, David; Burke, Terrence R

    2016-10-15

    By a process involving initial screening of a set of 87 aldehydes using an oxime ligation-based strategy, we were able to achieve a several-fold affinity enhancement over one of the most potent previously known polo-like kinase 1 (Plk1) polo-box domain (PBD) binding inhibitors. This improved binding may result by accessing a newly identified auxiliary region proximal to a key hydrophobic cryptic pocket on the surface of the protein. Our findings could have general applicability to the design of PBD-binding antagonists.

  5. Mutations activating the yeast eIF-2 alpha kinase GCN2: isolation of alleles altering the domain related to histidyl-tRNA synthetases.

    PubMed Central

    Ramirez, M; Wek, R C; Vazquez de Aldana, C R; Jackson, B M; Freeman, B; Hinnebusch, A G

    1992-01-01

    The protein kinase GCN2 stimulates expression of the yeast transcriptional activator GCN4 at the translational level by phosphorylating the alpha subunit of translation initiation factor 2 (eIF-2 alpha) in amino acid-starved cells. Phosphorylation of eIF-2 alpha reduces its activity, allowing ribosomes to bypass short open reading frames present in the GCN4 mRNA leader and initiate translation at the GCN4 start codon. We describe here 17 dominant GCN2 mutations that lead to derepression of GCN4 expression in the absence of amino acid starvation. Seven of these GCN2c alleles map in the protein kinase moiety, and two in this group alter the presumed ATP-binding domain, suggesting that ATP binding is a regulated aspect of GCN2 function. Six GCN2c alleles map in a region related to histidyl-tRNA synthetases, and two in this group alter a sequence motif conserved among class II aminoacyl-tRNA synthetases that directly interacts with the acceptor stem of tRNA. These results support the idea that GCN2 kinase function is activated under starvation conditions by binding uncharged tRNA to the domain related to histidyl-tRNA synthetase. The remaining GCN2c alleles map at the extreme C terminus, a domain required for ribosome association of the protein. Representative mutations in each domain were shown to depend on the phosphorylation site in eIF-2 alpha for their effects on GCN4 expression and to increase the level of eIF-2 alpha phosphorylation in the absence of amino acid starvation. Synthetic GCN2c double mutations show greater derepression of GCN4 expression than the parental single mutations, and they have a slow-growth phenotype that we attribute to inhibition of general translation initiation. The phenotypes of the GCN2c alleles are dependent on GCN1 and GCN3, indicating that these two positive regulators of GCN4 expression mediate the inhibitory effects on translation initiation associated with activation of the yeast eIF-2 alpha kinase GCN2. Images PMID:1448107

  6. Photosensitivity of kinase activation by blue light involves the lifetime of a cysteinyl-flavin adduct intermediate, S390, in the photoreaction cycle of the LOV2 domain in phototropin, a plant blue light receptor.

    PubMed

    Okajima, Koji; Kashojiya, Sachiko; Tokutomi, Satoru

    2012-11-30

    Phototropin (phot) is a light-regulated protein kinase that mediates a variety of photoresponses in plants, such as phototropism, chloroplast positioning, and stomata opening. Arabidopsis has two homologues, phot1 and phot2, that share physiological functions depending on light intensity. A phot molecule has two photoreceptive light oxygen voltage-sensing domains, LOV1 and LOV2, and a Ser/Thr kinase domain. The LOV domains undergo a photocycle upon blue light (BL) stimulation, including transient adduct formation between the chromophore and a conserved cysteine (S390 intermediate) that leads to activation of the kinase. To uncover the mechanism underlying the photoactivation of the kinase, we have introduced a kinase assay system composed of a phot1 LOV2-linker-kinase polypeptide as a light-regulated kinase and its N-terminal polypeptide as an artificial substrate (Okajima, K., Matsuoka, D., and Tokutomi, S. (2011) LOV2-linker-kinase phosphorylates LOV1-containing N-terminal polypeptide substrate via photoreaction of LOV2 in Arabidopsis phototropin1. FEBS Lett. 585, 3391-3395). In the present study, we extended the assay system to phot2 and compared the photochemistry and kinase activation by BL between phot1 and phot2 to gain insight into the molecular basis for the different photosensitivities of phot1 and phot2. Photosensitivity of kinase activation by BL and the lifetime of S390 of phot1 were 10 times higher and longer, respectively, than those of phot2. This correlation was confirmed by an amino acid substitution experiment with phot1 to shorten the lifetime of S390. The present results demonstrated that the photosensitivity of kinase activation in phot involves the lifetime of S390 in LOV2, suggesting that the lifetime is one of the key factors for the different photosensitivities observed for phot1 and phot2.

  7. Oncoprotein kinase

    DOEpatents

    Karin, Michael; Hibi, Masahiko; Lin, Anning

    2001-02-27

    An isolated polypeptide (JNK) characterized by having a molecular weight of 46 kD or 55 kD as determined by reducing SDS-PAGE, having serine and theonine kinase activity, phosphorylating the c-Jun N-terminal activation domain and polynucleotide sequences and method of detection of JNK are provided herein. JNK phosphorylates c-Jun N-terminal activation domain which affects gene expression from AP-1 sites.

  8. Genetic inhibition of Anaplastic Lymphoma Kinase rescues cognitive impairments in Neurofibromatosis 1 mutant mice.

    PubMed

    Weiss, Joseph B; Weber, Sydney J; Torres, Eileen Ruth S; Marzulla, Tessa; Raber, Jacob

    2017-03-15

    Heterozygous Neurofibromatosis 1 (NF1) loss of function mutations occur in approximately 90% of patients with neurofibromatosis. A major, disabling phenotypic consequence of reduced NF1 function is cognitive impairment; a possibly related behavioral phenotype is impaired sleep. Recent results in Drosophila have demonstrated a genetic interaction between Anaplastic Lymphoma Kinase (Alk) and NF1 for both associative learning and sleep. Inhibition of Alk improves associative learning and sleep in heterozygous NF1 mutant flies. The results in Drosophila provide a strong motivation to investigate NF1/Alk genetic interactions in mice. In Drosophila, activation of Alk by its ligand, Jelly belly (Jeb), is the physiologically relevant target of negative regulation by NF1. Therefore, we tested whether genetic inhibition of Alk in heterozygous NF1 mutant mice attenuates or rescues cognitive impairments in mice. Our results are consistent with the hypothesis that NF1 functions in mice biochemically to inhibit signaling from Alk through Ras. The cognitive phenotypes observed in heterozygous NF1 mutant mice are rescued or ameliorated by genetic inhibition of Alk activity. In two tests of hippocampus-dependent learning, the Morris water maze and extinction of contextual fear, mutation of one or both alleles of Alk was sufficient to improve performance to wild type or near wild type levels in NF1-/+ mice. In addition, in NF1 mice genetic inhibition of Alk improves circadian activity levels. These data are intriguing in light of the circadian alterations seen in NF1 patients and indicate that inhibition of Alk activity may cognitively benefit patients with Neurofibromatosis 1.

  9. Cutting Edge: Molecular Structure of the IL-1R-Associated Kinase-4 Death Domain and Its Implications for TLR Signaling

    SciTech Connect

    Lasker, Michael V.; Gajjar, Mark M.; Nair, Satish K.

    2010-07-19

    IL-1R-associated kinase (IRAK) 4 is an essential component of innate immunity. IRAK-4 deficiency in mice and humans results in severe impairment of IL-1 and TLR signaling. We have solved the crystal structure for the death domain of Mus musculus IRAK-4 to 1.7 {angstrom} resolution. This is the first glimpse of the structural details of a mammalian IRAK family member. The crystal structure reveals a six-helical bundle with a prominent loop, which among IRAKs and Pelle, a Drosophila homologue, is unique to IRAK-4. This highly structured loop contained between helices two and three, comprises an 11-aa stretch. Although innate immune domain recognition is thought to be very similar between Drosophila and mammals, this structural component points to a drastic difference. This structure can be used as a framework for future mutation and deletion studies and potential drug design.

  10. Functional Isoforms of IκB Kinase α (IKKα) Lacking Leucine Zipper and Helix-Loop-Helix Domains Reveal that IKKα and IKKβ Have Different Activation Requirements

    PubMed Central

    McKenzie, Fergus R.; Connelly, Margery A.; Balzarano, Darlene; Müller, Jurgen R.; Geleziunas, Romas; Marcu, Kenneth B.

    2000-01-01

    The activity of the NF-κB family of transcription factors is regulated principally by phosphorylation and subsequent degradation of their inhibitory IκB subunits. Site-specific serine phosphorylation of IκBs by two IκB kinases (IKKα [also known as CHUK] and IKKβ) targets them for proteolysis. IKKα and -β have a unique structure, with an amino-terminal serine-threonine kinase catalytic domain and carboxy-proximal helix-loop-helix (HLH) and leucine zipper-like (LZip) amphipathic α-helical domains. Here, we describe the properties of two novel cellular isoforms of IKKα: IKKα-ΔH and IKKα-ΔLH. IKKα-ΔH and IKKα-ΔLH are differentially spliced isoforms of the IKKα mRNA lacking its HLH domain and both its LZip and HLH domains, respectively. IKKα is the major RNA species in most murine cells and tissues, except for activated T lymphocytes and the brain, where the alternatively spliced isoforms predominate. Remarkably, IKKα-ΔH and IKKα-ΔLH, like IKKα, respond to tumor necrosis factor alpha stimulation to potentiate NF-κB activation in HEK293 cells. A mutant, catalytically inactive form of IKKα blocked IKKα-, IKKα-ΔH-, and IKKα-ΔLH-mediated NF-κB activation. Akin to IKKα, its carboxy-terminally truncated isoforms associated with the upstream activator NIK (NF-κB-inducing kinase). In contrast to IKKα, IKKα-ΔLH failed to associate with either itself, IKKα, IKKβ, or NEMO-IKKγ-IKKAP1, while IKKα-ΔH complexed with IKKβ and IKKα but not with NEMO. Interestingly, each IKKα isoform rescued HEK293 cells from the inhibitory effects of a dominant-negative NEMO mutant, while IKKα could not. IKKα-ΔCm, a recombinant mutant of IKKα structurally akin to IKKα-ΔLH, was equally functional in these assays, but in sharp contrast, IKKβ-ΔCm, a structurally analogous mutant of IKKβ, was inactive. Our results demonstrate that the functional roles of seemingly analogous domains in IKKα and IKKβ need not be equivalent and can also exhibit

  11. Calcium-Dependent Protein Kinase in Ginger Binds with Importin-α through Its Junction Domain for Nuclear Localization, and Further Interacts with NAC Transcription Factor

    PubMed Central

    Vivek, Padmanabhan Jayanthi; Resmi, Mohankumar Saraladevi; Sreekumar, Sweda; Sivakumar, K. C.; Tuteja, Narendra; Soniya, Eppurathu Vasudevan

    2017-01-01

    Calcium-dependent protein kinases (CDPKs) are important sensors of Ca2+ elevations in plant cells regulating the gene expression linked with various cellular processes like stress response, growth and development, metabolism, and cytoskeleton dynamics. Ginger is an extensively used spice due to its unique flavor and immense medicinal value. The two major threats that interfere with the large scale production of ginger are the salinity and drought stress. ZoCDPK1 (Zingiber officinale Calcium-dependent protein kinase 1) is a salinity and drought-inducible CDPK gene isolated from ginger and undergoes dynamic subcellular localization during stress conditions. ZoCDPK1, with signature features of a typical Ca2+ regulated kinase, also possesses a bipartite nuclear localization sequence (NLS) in its junction domain (JD). A striking feature in ZoCDPK1 is the rare occurrence of a coupling between the NLS in JD and consensus sequences in regulatory domain. Here, we further identified its nature of nuclear localization and its interaction partners. In the homology model generated for ZoCDPK1, the regulatory domain mimics the crystal structure of the regulatory domain in Arabidopsis CDPK1. Molecular docking simulation of importin (ZoIMPα), an important protein involved in nuclear translocation, into the NLS of ZoCDPK1 was well-visualized. Furthermore, the direct interaction of ZoCDPK1 and ZoIMPα proteins was studied by the yeast 2-hybrid (Y2H) system, which confirmed that junction domain (JD) is an important interaction module required for ZoCDPK1 and ZoIMPα binding. The probable interacting partners of ZoCDPK1 were also identified using Y2H experiment. Of the 10 different stress-related interacting partners identified for ZoCDPK1, NAC transcription factor (TF) needs special mention, especially in the context of ZoCDPK1 function. The interaction between ZoCDPK1 and NAC TF, in fact, corroborate with the results of gene expression and over-expression studies of ZoCDPK1. Hence

  12. Crystallization of the glycogen-binding domain of the AMP-activated protein kinase β subunit and preliminary X-ray analysis

    SciTech Connect

    Polekhina, Galina Feil, Susanne C.; Gupta, Abhilasha; O’Donnell, Paul; Stapleton, David; Parker, Michael W.

    2005-01-01

    The glycogen-binding domain of the AMP-activated kinase β subunit has been crystallized in the presence of β-cyclodextrin. The structure has been determined by single isomorphous replacement and threefold averaging using in-house X-ray data collected from selenomethionine-substituted protein. AMP-activated protein kinase (AMPK) is an intracellular energy sensor that regulates metabolism in response to energy demand and supply by adjusting the ATP-generating and ATP-consuming pathways. AMPK potentially plays a critical role in diabetes and obesity as it is known to be activated by metforin and rosiglitazone, drugs used for the treatment of type II diabetes. AMPK is a heterotrimer composed of a catalytic α subunit and two regulatory subunits, β and γ. Mutations in the γ subunit are known to cause glycogen accumulation, leading to cardiac arrhythmias. Recently, a functional glycogen-binding domain (GBD) has been identified in the β subunit. Here, the crystallization of GBD in the presence of β-cyclodextrin is reported together with preliminary X-ray data analysis allowing the determination of the structure by single isomorphous replacement and threefold averaging using in-house X-ray data collected from a selenomethionine-substituted protein.

  13. Functional Domain Motions in Proteins on the 1 100 ns Timescale: Comparison of Neutron Spin-Echo Spectroscopy of Phosphoglycerate Kinase with Molecular-Dynamics Simulation

    SciTech Connect

    Smolin, Nikolai; Biehl, R; Kneller, Gerald; Richter, Dieter O; Smith, Jeremy C

    2011-01-01

    Protein function often requires large-scale domain motion. An exciting new development in the experimental characterization of domain motions in proteins is the application of neutron spin-echo spectroscopy (NSE). NSE directly probes coherent (i.e., pair correlated) scattering on the 1 100 ns timescale. Here, we report on all-atom molecular-dynamics (MD) simulation of a protein, phosphoglycerate kinase, from which we calculate small-angle neutron scattering (SANS) and NSE scattering properties. The simulation-derived and experimental-solution SANS results are in excellent agreement. The contributions of translational and rotational whole-molecule diffusion to the simulation-derived NSE and potential problems in their estimation are examined. Principal component analysis identifies types of domain motion that dominate the internal motion's contribution to the NSE signal, with the largest being classic hinge bending. The associated free-energy profiles are quasiharmonic and the frictional properties correspond to highly overdamped motion. The amplitudes of the motions derived by MD are smaller than those derived from the experimental analysis, and possible reasons for this difference are discussed. The MD results confirm that a significant component of the NSE arises from internal dynamics. They also demonstrate that the combination of NSE with MD is potentially useful for determining the forms, potentials of mean force, and time dependence of functional domain motions in proteins.

  14. Osmotic shock-dependent redistribution of diacylglycerol kinase η1 to non-ionic detergent-resistant membrane via pleckstrin homology and C1 domains.

    PubMed

    Matsutomo, Daisuke; Isozaki, Takeshi; Sakai, Hiromichi; Sakane, Fumio

    2013-02-01

    Diacylglycerol kinase (DGK) participates in regulating the intracellular concentrations of two bioactive lipids, diacylglycerol and phosphatidic acid. DGKη1 is a type II isozyme that contains a pleckstrin homology (PH) domain and a pair of C1 domains at the N-terminus and separated catalytic domains (catalytic subdomain-a and b). We previously reported that DGKη1 expressed in COS-7 cells is translocated from the cytoplasm to punctate granules that partially include endosomes in response to stress stimuli such as osmotic shock. However, the biochemical properties of the stress-dependent behaviour of DGKη1 remain unknown. Here, we have found that DGKη1 is redistributed from the cytosol to the non-ionic detergent (Nonidet P-40)-resistant membrane (DRM) in response to osmotic shock. Our results strongly suggested that the Nonidet P-40 insolubility of DGKη1 is due to neither cytoskeleton localization nor lipid raft association, implying that DGKη1 is distributed to detergent-resistant membrane microdomains that have a low lipid-to-protein ratio. We revealed, using a series of DGKη1 deletion mutants, that the PH and C1 domains play a pivotal role in osmotic shock-dependent DRM redistribution, whereas catalytic subdomain-a negatively regulates the event.

  15. GK4, a G-protein-coupled receptor with a phosphatidylinositol phosphate kinase domain in Phytophthora infestans, is involved in sporangia development and virulence.

    PubMed

    Hua, Chenlei; Meijer, Harold J G; de Keijzer, Jeroen; Zhao, Wei; Wang, Yuanchao; Govers, Francine

    2013-04-01

    For dispersal and host infection plant pathogens largely depend on asexual spores. Pathogenesis and sporulation are complex processes that are governed by cellular signalling networks including G-protein and phospholipid signalling. Oomycetes possess a family of novel proteins called GPCR-PIPKs (GKs) that are composed of a seven-transmembrane spanning (7-TM) domain fused to a phosphatidylinositol phosphate kinase (PIPK) domain. Based on this domain structure GKs are anticipated to link G-protein and phospholipid signal pathways; however, their functions are currently unknown. Expression analyses of the 12 GK genes in Phytophthora infestans and their orthologues in Phytophthora sojae, revealed differential expression during asexual development. PiGK1 and PiGK4 were fused to monomeric red fluorescent protein (mRFP) and ectopically expressed in P. infestans. In growing hyphae different subcellular distribution patterns were observed indicating that these two GKs act independently during development. We focused on the functional analyses of PiGK4. Its localization suggested involvement in cell differentiation and elongation and its 7-TM domain showed a canonical GPCR membrane topology. Silencing of GK4 and overexpression of full-length and truncated constructs in P. infestans revealed that PiGK4 is not only involved in spore germination and hyphal elongation but also in sporangia cleavage and infection.

  16. Investigating the Inhibitory Effect of Wortmannin in the Hotspot Mutation at Codon 1047 of PIK3CA Kinase Domain: A Molecular Docking and Molecular Dynamics Approach.

    PubMed

    Kumar, D Thirumal; Doss, C George Priya

    2016-01-01

    Oncogenic mutations in phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) are the most frequently reported in association with various forms of cancer. Several studies have reported the significance of hotspot mutations in a catalytic subunit of PIK3CA in association with breast cancer. Mutations are frequently observed in the highly conserved region of the kinase domain (797-1068 amino acids) of PIK3CA are activating or gain-of-function mutations. Mutation in codon 1047 occurs in the C-terminal region of the kinase domain with histidine (H) replaced by arginine (R), lysine (L), and tyrosine (Y). Pathogenicity and protein stability predictors PhD-SNP, Align GVGD, HANSA, iStable, and MUpro classified H1047R as highly deleterious when compared to H1047L and H1047Y. To explore the inhibitory activity of Wortmannin toward PIK3CA, the three-dimensional structure of the mutant protein was determined using homology modeling followed by molecular docking and molecular dynamics analysis. Docking studies were performed for the three mutants and native with Wortmannin to measure the differences in their binding pattern. Comparative docking study revealed that H1047R-Wortmannin complex has a higher number of hydrogen bonds as well as the best binding affinity next to the native protein. Furthermore, 100 ns molecular dynamics simulation was initiated with the docked complexes to understand the various changes induced by the mutation. Though Wortmannin was found to nullify the effect of H1047R over the protein, further studies are required for designing a better compound. As SNPs are major genetic variations observed in disease condition, personalized medicine would provide enhanced drug therapy.

  17. Effect of the tyrosine kinase inhibitor lapatinib on CUB-domain containing protein (CDCP1)-mediated breast cancer cell survival and migration

    SciTech Connect

    Seidel, Jeanette; Kunc, Klaudia; Possinger, Kurt; Jehn, Christian; Lueftner, Diana

    2011-10-14

    Highlights: {yields} CDCP1 downregulation reduces anchorage free survival of breast cancer cells. {yields} Anoikis of CDCP1-positive breast cancer cells is increased after CDCP1 downregulation. {yields} CDCP1 knockdown decreases migration and extensively reduces invasiveness in vitro. {yields} Proliferation rate does not correlate with CDCP1 expression. {yields} Lapatinib does not influence tyrosine kinases of CDCP1 signal transduction. -- Abstract: The surface receptor CUB domain-containing protein 1 (CDCP1) is highly expressed in several adenocarcinomas and speculated to participate in anchorage-independent cell survival and cell motility. Tyrosine kinase phosphorylation seems to be crucial for intracellular signaling of CDCP1. Lapatinib, a tyrosine kinase inhibitor (TKI), is approved for treatment of HER-2/neu overexpressing metastatic breast cancer and functions by preventing autophosphorylation following HER-2/neu receptor activation. This study aimed to investigate the effect of CDCP1 expression on anchorage-independent growth and cell motility of breast cancer cells. Moreover, studies were performed to examine if lapatinib provided any beneficial effect on HER-2/neu{sup (+)/-}/CDCP1{sup +} breast cancer cell lines. In our studies, we affirmed that CDCP1 prevents cells from undergoing apoptosis when cultured in the absence of cell-substratum anchorage and that migratory and invasive properties of these cells were decreased when CDCP1 was down-regulated. However, only HER-2/neu{sup +}, but not HER-2/neu{sup (+)/-} cells showed decreased proliferation and invasion and an enha