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Sample records for regulatory factors regulate

  1. The COP9 Signalosome Interacts with and Regulates Interferon Regulatory Factor 5 Protein Stability

    PubMed Central

    Korczeniewska, Justyna

    2013-01-01

    The transcription factor interferon regulatory factor 5 (IRF5) exerts crucial functions in the regulation of host immunity against extracellular pathogens, DNA damage-induced apoptosis, death receptor signaling, and macrophage polarization. Tight regulation of IRF5 is thus warranted for an efficient response toward extracellular stressors and for limiting autoimmune and inflammatory responses. Here we report that the COP9 signalosome (CSN), a general modulator of diverse cellular and developmental processes, associates constitutively with IRF5 and promotes its protein stability. The constitutive CSN/IRF5 interaction was identified using proteomics and confirmed by endogenous immunoprecipitations. The CSN/IRF5 interaction occurred on the carboxyl and amino termini of IRF5; a single internal deletion from amino acids 455 to 466 (Δ455-466) was found to significantly reduce IRF5 protein stability. CSN subunit 3 (CSN3) was identified as a direct interacting partner of IRF5, and knockdown of this subunit with small interfering RNAs resulted in enhanced degradation. Degradation was further augmented by knockdown of CSN1 and CSN3 together. The ubiquitin E1 inhibitor UBEI-41 or the proteasome inhibitor MG132 prevented IRF5 degradation, supporting the idea that its stability is regulated by the ubiquitin-proteasome system. Importantly, activation of IRF5 by the death receptor ligand tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resulted in enhanced degradation via loss of the CSN/IRF5 interaction. This study defines CSN to be a new interacting partner of IRF5 that controls its stability. PMID:23275442

  2. Regulation of Antisense Transcription by NuA4 Histone Acetyltransferase and Other Chromatin Regulatory Factors.

    PubMed

    Uprety, Bhawana; Kaja, Amala; Ferdoush, Jannatul; Sen, Rwik; Bhaumik, Sukesh R

    2016-01-01

    NuA4 histone lysine (K) acetyltransferase (KAT) promotes transcriptional initiation of TATA-binding protein (TBP)-associated factor (TAF)-dependent ribosomal protein genes. TAFs have also been recently found to enhance antisense transcription from the 3' end of the GAL10 coding sequence. However, it remains unknown whether, like sense transcription of the ribosomal protein genes, TAF-dependent antisense transcription of GAL10 also requires NuA4 KAT. Here, we show that NuA4 KAT associates with the GAL10 antisense transcription initiation site at the 3' end of the coding sequence. Such association of NuA4 KAT depends on the Reb1p-binding site that recruits Reb1p activator to the GAL10 antisense transcription initiation site. Targeted recruitment of NuA4 KAT to the GAL10 antisense transcription initiation site promotes GAL10 antisense transcription. Like NuA4 KAT, histone H3 K4/36 methyltransferases and histone H2B ubiquitin conjugase facilitate GAL10 antisense transcription, while the Swi/Snf and SAGA chromatin remodeling/modification factors are dispensable for antisense, but not sense, transcription of GAL10. Taken together, our results demonstrate for the first time the roles of NuA4 KAT and other chromatin regulatory factors in controlling antisense transcription, thus illuminating chromatin regulation of antisense transcription. PMID:26755557

  3. Interferon Regulatory Factor 4 (IRF-4) Targets IRF-5 to Regulate Epstein-Barr Virus Transformation*

    PubMed Central

    Xu, Dongsheng; Meyer, Florencia; Ehlers, Erica; Blasnitz, Laura; Zhang, Luwen

    2011-01-01

    The cellular interferon regulatory factor-4 (IRF-4), which is a member of IRF family, is involved in the development of multiple myeloma and Epstein-Barr virus (EBV)-mediated transformation of B lymphocytes. However, the molecular mechanism of IRF-4 in cellular transformation is unknown. We have found that knockdown of IRF-4 leads to high expression of IRF-5, a pro-apoptotic member in the IRF family. Overexpression of IRF-4 represses IRF-5 expression. Reduction of IRF-4 leads to growth inhibition, and the restoration of IRF-4 by exogenous plasmids correlates with the growth recovery and reduces IRF-5 expression. In addition, IRF-4 negatively regulates IRF-5 promoter reporter activities and binds to IRF-5 promoters in vivo and in vitro. Knockdown of IRF-5 rescues IRF-4 knockdown-mediated growth inhibition, and IRF-5 overexpression alone is sufficient to induce cellular growth inhibition of EBV-transformed cells. Therefore, IRF-5 is one of the targets of IRF-4, and IRF-4 regulates the growth of EBV-transformed cells partially through IRF-5. This work provides insight on how IRFs interact with one another to participate in viral pathogenesis and transformation. PMID:21454650

  4. Interferon Regulatory Factor (IRF)-4 regulates the expression of a subset of Th2 cytokines 1

    PubMed Central

    Ahyi, Ayele-Nati N.; Chang, Hua-Chen; Dent, Alexander L.; Nutt, Stephen L.; Kaplan, Mark H.

    2009-01-01

    Th2 cells can be subdivided into subpopulations depending on the level of a cytokine and the subsets of cytokines they produce. We have recently identified the ETS family transcription factor PU.1 as regulating heterogeneity in Th2 populations. To define additional factors that might contribute to Th2 heterogeneity, we examined the PU.1 interacting protein IFN-regulatory factor (IRF)-4. When Th2 cells are separated based on levels of IL-10 secretion, IRF4 expression segregates into the subset of Th2 cells expressing high levels of IL-10. Infection of total Th2 cells, and IL-10 non-secreting cells, with retrovirus expressing IRF4, resulted in increased IL-4 and IL-10 expression, no change in IL-5 or IL-13 production and decreased Il9 transcription. Transfection of an IRF4-specific siRNA into Th2 cells decreases IL-10 production. IRF4 directly binds the Il10 gene as evidenced by ChIP assay, and regulates Il10 control elements in a reporter assay. IRF4 interacts with PU.1, and in PU.1-deficient T cells there was an increase in IRF4 binding to the Il10 gene, and in the ability of IRF4 to induce IL-10 production compared to wild type cells and Il10 promoter activity in a reporter assay. Further heterogeneity of IRF4 expression was observed in Th2 cells analyzed for expression of multiple Th2 cytokines. Thus, IRF4 promotes the expression of a subset of Th2 cytokines and contributes to Th2 heterogeneity. PMID:19592658

  5. Muscle regulatory factors regulate T1R3 taste receptor expression.

    PubMed

    Kokabu, Shoichiro; Lowery, Jonathan W; Toyono, Takashi; Seta, Yuji; Hitomi, Suzuro; Sato, Tsuyoshi; Enoki, Yuichiro; Okubo, Masahiko; Fukushima, Yosuke; Yoda, Tetsuya

    2015-12-25

    T1R3 is a T1R class of G protein-coupled receptors, composing subunit of the umami taste receptor when complexed with T1R1. T1R3 was originally discovered in gustatory tissue but is now known to be expressed in a wide variety of tissues and cell types such the intestine, pancreatic β-cells, skeletal muscle, and heart. In addition to taste recognition, the T1R1/T1R3 complex functions as an amino acid sensor and has been proposed to be a control mechanism for the secretion of hormones, such as cholecystokinin, insulin, and duodenal HCO3(-) and activates the mammalian rapamycin complex 1 (MTORC1) to inhibit autophagy. T1R3 knockout mice have increased rate of autophagy in the heart, skeletal muscle and liver. Thus, T1R3 has multiple physiological functions and is widely expressed in vivo. However, the exact mechanisms regulating T1R3 expression are largely unknown. Here, we used comparative genomics and functional analyses to characterize the genomic region upstream of the annotated transcriptional start of human T1R3. This revealed that the T1R3 promoter in human and mouse resides in an evolutionary conserved region (ECR). We also identified a repressive element located upstream of the human T1R3 promoter that has relatively high degree of conservation with rhesus macaque. Additionally, the muscle regulatory factors MyoD and Myogenin regulate T1R3 expression and T1R3 expression increases with skeletal muscle differentiation of murine myoblast C2C12 cells. Taken together, our study raises the possibility that MyoD and Myogenin might control skeletal muscle metabolism and homeostasis through the regulation of T1R3 promoter activity. PMID:26545778

  6. Differential Regulation of Human Papillomavirus Type 8 by Interferon Regulatory Factors 3 and 7▿

    PubMed Central

    Oldak, Monika; Tolzmann, Liv; Wnorowski, Artur; Podgórska, Marta Justyna; Silling, Steffi; Lin, Rongtuan; Hiscott, John; Müller, Cornelia Sigrid Lissi; Vogt, Thomas; Smola, Hans; Smola, Sigrun

    2011-01-01

    The genus β human papillomavirus (HPV) type 8 is associated with nonmelanoma skin cancer in patients with epidermodysplasia verruciformis, and evidence for its protumorigenic potential in the general population increases. To date, strategies to suppress genus β HPV infections are limited. Interferon regulatory factors IRF-3 and IRF-7 play key roles in the activation of the innate immune response to viral infections. In this study, we show for the first time that both IRF-3 and IRF-7 regulate transcription of a papillomavirus, but with opposing effects. IRF-7, expressed in the suprabasal layers of human epidermis, increased HPV8 late promoter activity via direct binding to viral DNA. UV-B light-induced activation of the HPV8 promoter involved IRF-7 as a downstream effector. In contrast, IRF-3, expressed in all layers of human epidermis, induced strong HPV8 suppression in primary keratinocytes. IRF-3-mediated suppression prevailed over IRF-7-induced HPV8 transcription. Unlike the E6 oncoprotein of the mucosal high-risk HPV16, the HPV8 E6 protein did not bind to IRF-3 and only weakly antagonized its activity. Strong antiviral activity was also observed, when keratinocytes were treated with potent IRF-3 activators, poly(I:C) or RNA bearing 5′ phosphates. In conclusion, we show that IRF-3 activation induces a state of cell-autonomous immunity against HPV in primary human keratinocytes. Our study suggests that local application of IRF-3-activating compounds might constitute an attractive novel therapeutic strategy against HPV8-associated diseases, particularly in epidermodysplasia verruciformis patients. PMID:20980500

  7. PreImplantation factor (PIF*) regulates systemic immunity and targets protective regulatory and cytoskeleton proteins.

    PubMed

    Barnea, Eytan R; Hayrabedyan, Soren; Todorova, Krassimira; Almogi-Hazan, Osnat; Or, Reuven; Guingab, Joy; McElhinney, James; Fernandez, Nelson; Barder, Timothy

    2016-07-01

    Secreted by viable embryos, PIF is expressed by the placenta and found in maternal circulation. It promotes implantation and trophoblast invasion, achieving systemic immune homeostasis. Synthetic PIF successfully transposes endogenous PIF features to non-pregnant immune and transplant models. PIF affects innate and activated PBMC cytokines and genes expression. We report that PIF targets similar proteins in CD14+, CD4+ and CD8+ cells instigating integrated immune regulation. PIF-affinity chromatography followed by mass-spectrometry, pathway and heatmap analysis reveals that SET-apoptosis inhibitor, vimentin, myosin-9 and calmodulin are pivotal for immune regulation. PIF acts on macrophages down-stream of LPS (lipopolysaccharide-bacterial antigen) CD14/TLR4/MD2 complex, targeting myosin-9, thymosin-α1 and 14-3-3eta. PIF mainly targets platelet aggregation in CD4+, and skeletal proteins in CD8+ cells. Pathway analysis demonstrates that PIF targets and regulates SET, tubulin, actin-b, and S100 genes expression. PIF targets systemic immunity and has a short circulating half-life. Collectively, PIF targets identified; protective, immune regulatory and cytoskeleton proteins reveal mechanisms involved in the observed efficacy against immune disorders. PMID:26944449

  8. Gene Regulatory Network Inference of Immunoresponsive Gene 1 (IRG1) Identifies Interferon Regulatory Factor 1 (IRF1) as Its Transcriptional Regulator in Mammalian Macrophages

    PubMed Central

    Tallam, Aravind; Perumal, Thaneer M.; Antony, Paul M.; Jäger, Christian; Fritz, Joëlle V.; Vallar, Laurent; Balling, Rudi; del Sol, Antonio; Michelucci, Alessandro

    2016-01-01

    Immunoresponsive gene 1 (IRG1) is one of the highest induced genes in macrophages under pro-inflammatory conditions. Its function has been recently described: it codes for immune-responsive gene 1 protein/cis-aconitic acid decarboxylase (IRG1/CAD), an enzyme catalysing the production of itaconic acid from cis-aconitic acid, a tricarboxylic acid (TCA) cycle intermediate. Itaconic acid possesses specific antimicrobial properties inhibiting isocitrate lyase, the first enzyme of the glyoxylate shunt, an anaplerotic pathway that bypasses the TCA cycle and enables bacteria to survive on limited carbon conditions. To elucidate the mechanisms underlying itaconic acid production through IRG1 induction in macrophages, we examined the transcriptional regulation of IRG1. To this end, we studied IRG1 expression in human immune cells under different inflammatory stimuli, such as TNFα and IFNγ, in addition to lipopolysaccharides. Under these conditions, as previously shown in mouse macrophages, IRG1/CAD accumulates in mitochondria. Furthermore, using literature information and transcription factor prediction models, we re-constructed raw gene regulatory networks (GRNs) for IRG1 in mouse and human macrophages. We further implemented a contextualization algorithm that relies on genome-wide gene expression data to infer putative cell type-specific gene regulatory interactions in mouse and human macrophages, which allowed us to predict potential transcriptional regulators of IRG1. Among the computationally identified regulators, siRNA-mediated gene silencing of interferon regulatory factor 1 (IRF1) in macrophages significantly decreased the expression of IRG1/CAD at the gene and protein level, which correlated with a reduced production of itaconic acid. Using a synergistic approach of both computational and experimental methods, we here shed more light on the transcriptional machinery of IRG1 expression and could pave the way to therapeutic approaches targeting itaconic acid levels

  9. Gene Regulatory Network Inference of Immunoresponsive Gene 1 (IRG1) Identifies Interferon Regulatory Factor 1 (IRF1) as Its Transcriptional Regulator in Mammalian Macrophages.

    PubMed

    Tallam, Aravind; Perumal, Thaneer M; Antony, Paul M; Jäger, Christian; Fritz, Joëlle V; Vallar, Laurent; Balling, Rudi; Del Sol, Antonio; Michelucci, Alessandro

    2016-01-01

    Immunoresponsive gene 1 (IRG1) is one of the highest induced genes in macrophages under pro-inflammatory conditions. Its function has been recently described: it codes for immune-responsive gene 1 protein/cis-aconitic acid decarboxylase (IRG1/CAD), an enzyme catalysing the production of itaconic acid from cis-aconitic acid, a tricarboxylic acid (TCA) cycle intermediate. Itaconic acid possesses specific antimicrobial properties inhibiting isocitrate lyase, the first enzyme of the glyoxylate shunt, an anaplerotic pathway that bypasses the TCA cycle and enables bacteria to survive on limited carbon conditions. To elucidate the mechanisms underlying itaconic acid production through IRG1 induction in macrophages, we examined the transcriptional regulation of IRG1. To this end, we studied IRG1 expression in human immune cells under different inflammatory stimuli, such as TNFα and IFNγ, in addition to lipopolysaccharides. Under these conditions, as previously shown in mouse macrophages, IRG1/CAD accumulates in mitochondria. Furthermore, using literature information and transcription factor prediction models, we re-constructed raw gene regulatory networks (GRNs) for IRG1 in mouse and human macrophages. We further implemented a contextualization algorithm that relies on genome-wide gene expression data to infer putative cell type-specific gene regulatory interactions in mouse and human macrophages, which allowed us to predict potential transcriptional regulators of IRG1. Among the computationally identified regulators, siRNA-mediated gene silencing of interferon regulatory factor 1 (IRF1) in macrophages significantly decreased the expression of IRG1/CAD at the gene and protein level, which correlated with a reduced production of itaconic acid. Using a synergistic approach of both computational and experimental methods, we here shed more light on the transcriptional machinery of IRG1 expression and could pave the way to therapeutic approaches targeting itaconic acid levels

  10. Ikkepsilon regulates viral-induced interferon regulatory factor-3 activation via a redox-sensitive pathway

    SciTech Connect

    Indukuri, Hemalatha; Castro, Shawn M.; Liao, S.-M.; Feeney, Lee Ann; Dorsch, Marion; Coyle, Anthony J.; Garofalo, Roberto P.; Brasier, Allan R.; Casola, Antonella . E-mail: ancasola@utmb.edu

    2006-09-15

    Respiratory syncytial virus (RSV)-induced chemokine gene expression occurs through the activation of a subset of transcription factors, including Interferon Regulatory Factor (IRF)-3. In this study, we have investigated the signaling pathway leading to RSV-induced IRF-3 activation and whether it is mediated by intracellular reactive oxygen species (ROS) generation. Our results show that RSV infection induces expression and catalytic activity of IKK{epsilon}, a noncanonical IKK-like kinase. Expression of a kinase-inactive IKK{epsilon} blocks RSV-induced IRF-3 serine phosphorylation, nuclear translocation and DNA-binding, leading to inhibition of RANTES gene transcription, mRNA expression and protein synthesis. Treatment of alveolar epithelial cells with antioxidants or with NAD(P)H oxidase inhibitors abrogates RSV-induced chemokine secretion, IRF-3 phosphorylation and IKK{epsilon} induction, indicating that ROS generation plays a fundamental role in the signaling pathway leading to IRF-3 activation, therefore, identifying a novel molecular target for the development of strategies aimed to modify the inflammatory response associated with RSV infection of the lung.

  11. Zinc regulates a key transcriptional pathway for epileptogenesis via metal-regulatory transcription factor 1.

    PubMed

    van Loo, Karen M J; Schaub, Christina; Pitsch, Julika; Kulbida, Rebecca; Opitz, Thoralf; Ekstein, Dana; Dalal, Adam; Urbach, Horst; Beck, Heinz; Yaari, Yoel; Schoch, Susanne; Becker, Albert J

    2015-01-01

    Temporal lobe epilepsy (TLE) is the most common focal seizure disorder in adults. In many patients, transient brain insults, including status epilepticus (SE), are followed by a latent period of epileptogenesis, preceding the emergence of clinical seizures. In experimental animals, transcriptional upregulation of CaV3.2 T-type Ca(2+)-channels, resulting in an increased propensity for burst discharges of hippocampal neurons, is an important trigger for epileptogenesis. Here we provide evidence that the metal-regulatory transcription factor 1 (MTF1) mediates the increase of CaV3.2 mRNA and intrinsic excitability consequent to a rise in intracellular Zn(2+) that is associated with SE. Adeno-associated viral (rAAV) transfer of MTF1 into murine hippocampi leads to increased CaV3.2 mRNA. Conversely, rAAV-mediated expression of a dominant-negative MTF1 abolishes SE-induced CaV3.2 mRNA upregulation and attenuates epileptogenesis. Finally, data from resected human hippocampi surgically treated for pharmacoresistant TLE support the Zn(2+)-MTF1-CaV3.2 cascade, thus providing new vistas for preventing and treating TLE. PMID:26498180

  12. Zinc regulates a key transcriptional pathway for epileptogenesis via metal-regulatory transcription factor 1

    PubMed Central

    van Loo, Karen M. J.; Schaub, Christina; Pitsch, Julika; Kulbida, Rebecca; Opitz, Thoralf; Ekstein, Dana; Dalal, Adam; Urbach, Horst; Beck, Heinz; Yaari, Yoel; Schoch, Susanne; Becker, Albert J.

    2015-01-01

    Temporal lobe epilepsy (TLE) is the most common focal seizure disorder in adults. In many patients, transient brain insults, including status epilepticus (SE), are followed by a latent period of epileptogenesis, preceding the emergence of clinical seizures. In experimental animals, transcriptional upregulation of CaV3.2 T-type Ca2+-channels, resulting in an increased propensity for burst discharges of hippocampal neurons, is an important trigger for epileptogenesis. Here we provide evidence that the metal-regulatory transcription factor 1 (MTF1) mediates the increase of CaV3.2 mRNA and intrinsic excitability consequent to a rise in intracellular Zn2+ that is associated with SE. Adeno-associated viral (rAAV) transfer of MTF1 into murine hippocampi leads to increased CaV3.2 mRNA. Conversely, rAAV-mediated expression of a dominant-negative MTF1 abolishes SE-induced CaV3.2 mRNA upregulation and attenuates epileptogenesis. Finally, data from resected human hippocampi surgically treated for pharmacoresistant TLE support the Zn2+-MTF1-CaV3.2 cascade, thus providing new vistas for preventing and treating TLE. PMID:26498180

  13. A novel interferon regulatory factor family transcription factor, ICSAT/Pip/LSIRF, that negatively regulates the activity of interferon-regulated genes.

    PubMed Central

    Yamagata, T; Nishida, J; Tanaka, S; Sakai, R; Mitani, K; Yoshida, M; Taniguchi, T; Yazaki, Y; Hirai, H

    1996-01-01

    We have isolated a novel cDNA clone encoding interferon (IFN) consensus sequence-binding protein in adult T-cell leukemia cell line or activated T cells (ICSAT); this protein is the human homolog of the recently cloned Pip/LSIRF. ICSAT is structurally most closely related to the previously cloned ICSBP, a member of the IFN regulatory factor (IRF) family of proteins that binds to interferon consensus sequences (ICSs) found in many promoters of the IFN-regulated genes. Among T-cell lines investigated, ICSAT was abundantly expressed in human T-cell leukemia virus type 1 (HTLV-1)-infected T cells. When the HTLV-1 tax gene was expressed or phorbol myristake acetate-A23187 stimulation was used, ICSAT expression was induced in Jurkat cells which otherwise do not express ICSAT. When the binding of ICSAT to four different ICSs was tested, the relative differences in binding affinities for those ICSs were determined. To study the functional role of ICSAT, we performed cotransfection experiments with the human embryonal carcinoma cell line N-Tera2. ICSAT was demonstrated to possess repressive function over the gene activation induced by IFN stimulation or by IRF-1 cotransfection. Such repressive function is similar to that seen in IRF-2 or ICSBP. However, we have found that ICSAT has a different repressive effect from that of IRF-2 or ICSBP in some IFN-responsive reporter constructs. These results suggest that a novel mechanism of gene regulation by "differential repression" is used by multiple members of repressor proteins with different repressive effects on the IFN-responsive genes. PMID:8657101

  14. Na/H Exchange Regulatory Factor 1, a Novel AKT-associating Protein, Regulates Extracellular Signal-regulated Kinase Signaling through a B-Raf–Mediated Pathway

    PubMed Central

    Wang, Bin; Yang, Yanmei

    2008-01-01

    Na/H exchange regulatory factor 1 (NHERF1) is a scaffolding protein that regulates signaling and trafficking of several G protein-coupled receptors (GPCRs), including the parathyroid hormone receptor (PTH1R). GPCRs activate extracellular signal-regulated kinase (ERK)1/2 through different mechanisms. Here, we characterized NHERF1 regulation of PTH1R-stimulated ERK1/2. Parathyroid hormone (PTH) stimulated ERK1/2 phosphorylation by a protein kinase A (PKA)-dependent, but protein kinase C-, cyclic adenosine 5′-monophosphate-, and Rap1-independent pathway in Chinese hamster ovary cells stably transfected with the PTH1R and engineered to express NHERF1 under the control of tetracycline. NHERF1 blocked PTH-induced ERK1/2 phosphorylation downstream of PKA. This suggested that NHERF1 inhibitory effects on ERK1/2 occur at a postreceptor locus. Forskolin activated ERK1/2, and this effect was blocked by NHERF1. NHERF1 interacted with AKT and inhibited ERK1/2 activation by decreasing the stimulatory effect of 14-3-3 binding to B-Raf, while increasing the inhibitory influence of AKT negative regulation on ERK1/2 activation. This novel regulatory mechanism provides a new model by which cytoplasmic adapter proteins modulate ERK1/2 activation through a receptor-independent mechanism involving B-Raf. PMID:18272783

  15. Interferon regulatory factor 3 is a key regulation factor for inducing the expression of SAMHD1 in antiviral innate immunity

    PubMed Central

    Yang, Shen; Zhan, Yuan; Zhou, Yanjun; Jiang, Yifeng; Zheng, Xuchen; Yu, Lingxue; Tong, Wu; Gao, Fei; Li, Liwei; Huang, Qinfeng; Ma, Zhiyong; Tong, Guangzhi

    2016-01-01

    SAMHD1 is a type I interferon (IFN) inducible host innate immunity restriction factor that inhibits an early step of the viral life cycle. The underlying mechanisms of SAMHD1 transcriptional regulation remains elusive. Here, we report that inducing SAMHD1 upregulation is part of an early intrinsic immune response via TLR3 and RIG-I/MDA5 agonists that ultimately induce the nuclear translocation of the interferon regulation factor 3 (IRF3) protein. Further studies show that IRF3 plays a major role in upregulating endogenous SAMHD1 expression in a mechanism that is independent of the classical IFN-induced JAK-STAT pathway. Both overexpression and activation of IRF3 enhanced the SAMHD1 promoter luciferase activity, and activated IRF3 was necessary for upregulating SAMHD1 expression in a type I IFN cascade. We also show that the SAMHD1 promoter is a direct target of IRF3 and an IRF3 binding site is sufficient to render this promoter responsive to stimulation. Collectively, these findings indicate that upregulation of endogenous SAMHD1 expression is attributed to the phosphorylation and nuclear translocation of IRF3 and we suggest that type I IFN induction and induced SAMHD1 expression are coordinated. PMID:27411355

  16. MicroRNA-17 Modulates Regulatory T Cell Function by Targeting Co-regulators of the Foxp3 Transcription Factor.

    PubMed

    Yang, Huang-Yu; Barbi, Joseph; Wu, Chao-Yi; Zheng, Ying; Vignali, Paolo D A; Wu, Xingmei; Tao, Jin-Hui; Park, Benjamin V; Bandara, Shashika; Novack, Lewis; Ni, Xuhao; Yang, Xiaoping; Chang, Kwang-Yu; Wu, Ren-Chin; Zhang, Junran; Yang, Chih-Wei; Pardoll, Drew M; Li, Huabin; Pan, Fan

    2016-07-19

    Regulatory T (Treg) cells are important in maintaining self-tolerance and immune homeostasis. The Treg cell transcription factor Foxp3 works in concert with other co-regulatory molecules, including Eos, to determine the transcriptional signature and characteristic suppressive phenotype of Treg cells. Here, we report that the inflammatory cytokine interleukin-6 (IL-6) actively repressed Eos expression through microRNA-17 (miR-17). miR-17 expression increased in Treg cells in the presence of IL-6, and its expression negatively correlated with that of Eos. Treg cell suppressive activity was diminished upon overexpression of miR-17 in vitro and in vivo, which was mitigated upon co-expression of an Eos mutant lacking miR-17 target sites. Also, RNAi of miR-17 resulted in enhanced suppressive activity. Ectopic expression of miR-17 imparted effector-T-cell-like characteristics to Treg cells via the de-repression of genes encoding effector cytokines. Thus, miR-17 provides a potent layer of Treg cell control through targeting Eos and additional Foxp3 co-regulators. PMID:27438767

  17. Characterization of flounder ( Paralichthys olivaceus) FoxD5 and its function in regulating myogenic regulatory factor

    NASA Astrophysics Data System (ADS)

    Tan, Xungang; Zhang, Yuqing; Sun, Wei; Zhang, Peijun; Xu, Yongli

    2012-03-01

    As one member of winged helix domain transcription factors, FoxD5 was reported to be a trunk organizer. Recent study showed that zebrafish foxd5 is expressed in the somites. To further understand the function of FoxD5 in fish muscle development, the FoxD5 gene was isolated from flounder. Its expression pattern was analyzed by in situ hybridization, while its function in regulating myogenic regulatory factor, MyoD, was analyzed by ectopic expression. It showed that flounder FoxD5 was firstly expressed in the tailbud, adaxial cells, and neural plate of the head. In flounder embryo, FoxD5 is expressed not only in forebrain but also in somite cells that will form muscle in the future. When flounder FoxD5 was over-expressed in zebrafish by microinjection, the expression of zebrafish MyoD in the somites was reduced, suggesting that FoxD5 is involved in myogenesis by regulating the expression of MyoD.

  18. Store-operated Ca2+ Entry-associated Regulatory factor (SARAF) Plays an Important Role in the Regulation of Arachidonate-regulated Ca2+ (ARC) Channels.

    PubMed

    Albarran, Letizia; Lopez, Jose J; Woodard, Geoffrey E; Salido, Gines M; Rosado, Juan A

    2016-03-25

    The store-operated Ca(2+)entry-associated regulatory factor (SARAF) has recently been identified as a STIM1 regulatory protein that facilitates slow Ca(2+)-dependent inactivation of store-operated Ca(2+)entry (SOCE). Both the store-operated channels and the store-independent arachidonate-regulated Ca(2+)(ARC) channels are regulated by STIM1. In the present study, we show that, in addition to its location in the endoplasmic reticulum, SARAF is constitutively expressed in the plasma membrane, where it can interact with plasma membrane (PM)-resident ARC forming subunits in the neuroblastoma cell line SH-SY5Y. Using siRNA-based and overexpression approaches we report that SARAF negatively regulates store-independent Ca(2+)entry via the ARC channels. Arachidonic acid (AA) increases the association of PM-resident SARAF with Orai1. Finally, our results indicate that SARAF modulates the ability of AA to promote cell survival in neuroblastoma cells. In addition to revealing new insight into the biology of ARC channels in neuroblastoma cells, these findings provide evidence for an unprecedented location of SARAF in the plasma membrane. PMID:26817842

  19. The PDZ Protein Na+/H+ Exchanger Regulatory Factor-1 (NHERF1) Regulates Planar Cell Polarity and Motile Cilia Organization

    PubMed Central

    Stolz, Donna B.; Tsang, Michael; Friedman, Peter A.; Romero, Guillermo

    2016-01-01

    Directional flow of the cerebrospinal fluid requires coordinated movement of the motile cilia of the ependymal epithelium that lines the cerebral ventricles. Here we report that mice lacking the Na+/H+ Exchanger Regulatory Factor 1 (NHERF1/Slc9a3r1, also known as EBP50) develop profound communicating hydrocephalus associated with fewer and disorganized ependymal cilia. Knockdown of NHERF1/slc9a3r1 in zebrafish embryos also causes severe hydrocephalus of the hindbrain and impaired ciliogenesis in the otic vesicle. Ultrastructural analysis did not reveal defects in the shape or organization of individual cilia. Similar phenotypes have been described in animals with deficiencies in Wnt signaling and the Planar Cell Polarity (PCP) pathway. We show that NHERF1 binds the PCP core genes Frizzled (Fzd) and Vangl. We further show that NHERF1 assembles a ternary complex with Fzd4 and Vangl2 and promotes translocation of Vangl2 to the plasma membrane, in particular to the apical surface of ependymal cells. Taken together, these results strongly support an important role for NHERF1 in the regulation of PCP signaling and the development of functional motile cilia. PMID:27055101

  20. Interferon regulatory factors and TFIIB cooperatively regulate interferon-responsive promoter activity in vivo and in vitro.

    PubMed Central

    Wang, I M; Blanco, J C; Tsai, S Y; Tsai, M J; Ozato, K

    1996-01-01

    Interferon regulatory factors (IRFs) bind to the interferon-stimulated response element (ISRE) and regulate interferon- and virus-mediated gene expression. IRF-1 acts as a transcriptional activator, while IRF-2 acts as a repressor. Here we show that IRF-1 and IRF-2 bind to both cellular TFIIB, a component of the basal transcription machinery, and recombinant TFIIB (rTFIIB) and that this protein-protein interaction facilitates binding of IRFs to the ISRE. A functional interaction between TFIIB and IRF was assessed by a newly established in vitro transcription assay in which recombinant IRF-1 (rIRF-1) stimulated transcription specifically from an ISRE-containing template. With this assay we show that rIRF-1 and rTFIIB cooperatively enhance the ISRE promoter in vitro. We found that the activity of an ISRE-containing promoter was cooperatively enhanced upon cotransfection of TFIIB and IRF-1 cDNAs into P19 embryonal carcinoma cells, further demonstrating functional interactions in vivo. The cooperative enhancement by TFIIB and IRF-1 was independent of the TATA sequence in the ISRE promoter but dependent on the initiator sequence (Inr) and was abolished when P19 cells were induced to differentiate by retinoic acid treatment. In contrast, cotransfection of TFIIB and IRF-1 into NIH 3T3 cells resulted in a dose-dependent repression of promoter activation which occurred in a TATA-dependent manner. Our results indicate the presence of a cell type-specific factor that mediates the functional interaction between IRFs and TFIIB and that acts in conjunction with the requirement of TATA and Inr for promoter activation. PMID:8887661

  1. Regulation of alternative splicing of liver scavenger receptor class B gene by estrogen and the involved regulatory splicing factors.

    PubMed

    Zhang, Xiaohui; Moor, Andrea N; Merkler, Kathleen A; Liu, Qiyuan; McLean, Mark P

    2007-11-01

    The scavenger receptor class B isoforms (SR-B) type I and type II mediate the selective uptake of high-density lipoprotein cholesterol and promote reverse cholesterol transport, an important atherosclerosis protection mechanism, in the liver. Previously it was shown that the hepatic expression of SR-BI and SR-BII is regulated by estrogen. In the present study, we demonstrate that estrogen differentially regulates expression of the glycosylated and nonglycosylated forms of SR-BI and SR-BII in rat liver and hepatic cells. We report that estrogen mainly induces the down-regulation of glycosylated SR-BI and the up-regulation of nonglycosylated SR-BII. To study how estrogen regulates expression of the SR-B isoforms, we constructed a SR-B minigene containing minimal genomic sequences and were able to demonstrate that estrogen directly regulates the pre-mRNA alternative splicing of the exogenously expressed SR-B minigene in hepatic cells. Furthermore, we showed that the overexpression of splicing factors alternative splicing factor/splicing factor 2, Transformer (Tra)-2alpha, and Tra2beta changes the splicing pattern of SR-B dramatically, whereas other splicing factors, such as heterogeneous nuclear ribonucleoprotein-G, SC-35, and arginine/serine-rich p40, had no effect. We also demonstrate that estrogen regulates Tra2beta expression levels in liver cells. These studies suggest that estrogen may regulate SR-B isoform expression at both the RNA splicing and posttranslational modification levels and that, for alternative splicing regulation, estrogen may function by regulating the expression of the splicing factors alternative splicing factor/splicing factor 2, Tra2alpha, and especially Tra2beta. PMID:17673517

  2. Determination of a Comprehensive Alternative Splicing Regulatory Network and Combinatorial Regulation by Key Factors during the Epithelial-to-Mesenchymal Transition.

    PubMed

    Yang, Yueqin; Park, Juw Won; Bebee, Thomas W; Warzecha, Claude C; Guo, Yang; Shang, Xuequn; Xing, Yi; Carstens, Russ P

    2016-06-01

    The epithelial-to-mesenchymal transition (EMT) is an essential biological process during embryonic development that is also implicated in cancer metastasis. While the transcriptional regulation of EMT has been well studied, the role of alternative splicing (AS) regulation in EMT remains relatively uncharacterized. We previously showed that the epithelial cell-type-specific proteins epithelial splicing regulatory proteins 1 (ESRP1) and ESRP2 are important for the regulation of many AS events that are altered during EMT. However, the contributions of the ESRPs and other splicing regulators to the AS regulatory network in EMT require further investigation. Here, we used a robust in vitro EMT model to comprehensively characterize splicing switches during EMT in a temporal manner. These investigations revealed that the ESRPs are the major regulators of some but not all AS events during EMT. We determined that the splicing factor RBM47 is downregulated during EMT and also regulates numerous transcripts that switch splicing during EMT. We also determined that Quaking (QKI) broadly promotes mesenchymal splicing patterns. Our study highlights the broad role of posttranscriptional regulation during the EMT and the important role of combinatorial regulation by different splicing factors to fine tune gene expression programs during these physiological and developmental transitions. PMID:27044866

  3. Acetylation-dependent regulation of essential iPS-inducing factors: a regulatory crossroad for pluripotency and tumorigenesis

    PubMed Central

    Dai, Xiangpeng; Liu, Pengda; Lau, Alan W; Liu, Yueyong; Inuzuka, Hiroyuki

    2014-01-01

    Induced pluripotent stem (iPS) cells can be generated from somatic cells by coexpression of four transcription factors: Sox2, Oct4, Klf4, and c-Myc. However, the low efficiency in generating iPS cells and the tendency of tumorigenesis hinder the therapeutic applications for iPS cells in treatment of human diseases. To this end, it remains largely unknown how the iPS process is subjected to regulation by upstream signaling pathway(s). Here, we report that Akt regulates the iPS process by modulating posttranslational modifications of these iPS factors in both direct and indirect manners. Specifically, Akt directly phosphorylates Oct4 to modulate the Oct4/Sox2 heterodimer formation. Furthermore, Akt either facilitates the p300-mediated acetylation of Oct4, Sox2, and Klf4, or stabilizes Klf4 by inactivating GSK3, thus indirectly modulating stemness. As tumorigenesis shares possible common features and mechanisms with iPS, our study suggests that Akt inhibition might serve as a cancer therapeutic approach to target cancer stem cells. PMID:25116380

  4. The Regulatory T Cell Lineage Factor Foxp3 Regulates Gene Expression through Several Distinct Mechanisms Mostly Independent of Direct DNA Binding

    PubMed Central

    Andersen, Kristian G.; Hebenstreit, Daniel; Teichmann, Sarah A.; Betz, Alexander G.

    2015-01-01

    The lineage factor Foxp3 is essential for the development and maintenance of regulatory T cells, but little is known about the mechanisms involved. Here, we demonstrate that an N-terminal proline-rich interaction region is crucial for Foxp3’s function. Subdomains within this key region link Foxp3 to several independent mechanisms of transcriptional regulation. Our study suggests that Foxp3, even in the absence of its DNA-binding forkhead domain, acts as a bridge between DNA-binding interaction partners and proteins with effector function permitting it to regulate a large number of genes. We show that, in one such mechanism, Foxp3 recruits class I histone deacetylases to the promoters of target genes, counteracting activation-induced histone acetylation and thereby suppressing their expression. PMID:26107960

  5. Ubiquitin-associated Domain-containing Ubiquitin Regulatory X (UBX) Protein UBXN1 Is a Negative Regulator of Nuclear Factor κB (NF-κB) Signaling*

    PubMed Central

    Wang, Yu-Bo; Tan, Bo; Mu, Rui; Chang, Yan; Wu, Min; Tu, Hai-Qing; Zhang, Yu-Cheng; Guo, Sai-Sai; Qin, Xuan-He; Li, Tao; Li, Wei-Hua; Li, Ai-Ling; Zhang, Xue-Min; Li, Hui-Yan

    2015-01-01

    Excessive nuclear factor κB (NF-κB) activation should be precisely controlled as it contributes to multiple immune and inflammatory diseases. However, the negative regulatory mechanisms of NF-κB activation still need to be elucidated. Various types of polyubiquitin chains have proved to be involved in the process of NF-κB activation. Many negative regulators linked to ubiquitination, such as A20 and CYLD, inhibit IκB kinase activation in the NF-κB signaling pathway. To find new NF-κB signaling regulators linked to ubiquitination, we used a small scale siRNA library against 51 ubiquitin-associated domain-containing proteins and screened out UBXN1, which contained both ubiquitin-associated and ubiquitin regulatory X (UBX) domains as a negative regulator of TNFα-triggered NF-κB activation. Overexpression of UBXN1 inhibited TNFα-triggered NF-κB activation, although knockdown of UBXN1 had the opposite effect. UBX domain-containing proteins usually act as valosin-containing protein (VCP)/p97 cofactors. However, knockdown of VCP/p97 barely affected UBXN1-mediated NF-κB inhibition. At the same time, we found that UBXN1 interacted with cellular inhibitors of apoptosis proteins (cIAPs), E3 ubiquitin ligases of RIP1 in the TNFα receptor complex. UBXN1 competitively bound to cIAP1, blocked cIAP1 recruitment to TNFR1, and sequentially inhibited RIP1 polyubiquitination in response to TNFα. Therefore, our findings demonstrate that UBXN1 is an important negative regulator of the TNFα-triggered NF-κB signaling pathway by mediating cIAP recruitment independent of VCP/p97. PMID:25681446

  6. Fas-Associated Factor 1 Negatively Regulates the Antiviral Immune Response by Inhibiting Translocation of Interferon Regulatory Factor 3 to the Nucleus

    PubMed Central

    Song, Soonhwa; Lee, Jae-Jin; Kim, Hee-Jung; Lee, Jeong Yoon; Chang, Jun

    2016-01-01

    This study is designed to examine the cellular functions of human Fas-associated factor 1 (FAF1) containing multiple ubiquitin-related domains. Microarray analyses revealed that interferon-stimulated genes related to the antiviral response are significantly increased in FAF1-knockdown HeLa cells. Silencing FAF1 enhanced the poly(I·C)- and respiratory syncytial virus (RSV)-induced production of type I interferons (IFNs), the target genes of interferon regulator factor 3 (IRF3). IRF3 is a key transcription factor in IFN-β signaling responsible for the host innate immune response. This study also found that FAF1 and IRF3 physically associate with IPO5/importin-β3 and that overexpression of FAF1 reduces the interaction between IRF3 and IPO5/importin-β3. These findings suggest that FAF1 negatively regulates IRF3-mediated IFN-β production and the antiviral innate immune response by regulating nuclear translocation of IRF3. We conclude that FAF1 plays a novel role in negatively regulating virus-induced IFN-β production and the antiviral response by inhibiting the translocation of active, phosphorylated IRF3 from the cytosol to the nucleus. PMID:26811330

  7. Valproic acid regulates erythro-megakaryocytic differentiation through the modulation of transcription factors and microRNA regulatory micro-networks.

    PubMed

    Trécul, Anne; Morceau, Franck; Gaigneaux, Anthoula; Schnekenburger, Michael; Dicato, Mario; Diederich, Marc

    2014-11-15

    Valproic acid (VPA) exhibits important pharmacological properties but has been reported to trigger side effects, notably on the hematological system. We previously reported that VPA affects hematopoietic homeostasis by inhibiting erythroid differentiation and promoting myeloid and megakaryocyte differentiation. Here, we analyzed the effect of VPA on regulatory factors involved in erythro-megakaryocytic differentiation pathways, including transcription factors and microRNAs (miRs). We demonstrate that VPA inhibited erythroid differentiation in erythropoietin (Epo)-stimulated TF1 leukemia cells and CD34(+)/hematopoietic stem cells (HSCs) and in aclacinomycin-(Acla)-treated K562 cells. Mir-144/451 gene expression was decreased in all erythroid and megakaryocyte models in correlation with GATA-1 inhibition. In Epo-stimulated CD34(+)/HSCs, VPA induced the expression of the ETS family transcription factors PU.1, ETS-1, GABP-α, Fli-1 and GATA-2, which are all known to be negative regulators of erythropoiesis, while it promoted the megakaryocytic pathway. PU.1 and ETS-1 expression were induced in correlation with miR-155 inhibition; however, the GATA-1/PU.1 interaction was promoted. Using megakaryoblastic Meg-01 cells, we demonstrated that VPA induced megakaryocyte morphological features and CD61 expression. GATA-2 and miR-27a expression were increased in correlation with a decrease in RUNX1 mRNA expression, suggesting megakaryocyte differentiation. Finally, by using valpromide and the Class I HDACi MS-275, we validated that the well-described HDACi activity of VPA is not required in the inhibitory effect on erythropoiesis. Overall, this report shows that VPA modulates the erythro-megakaryocytic differentiation program through regulatory micro-networks involving GATA and ETS transcription factors and miRNAs, notably the GATA-1/miR-144/451 axis. PMID:25241289

  8. Light-dependent and circadian clock-regulated activation of sterol regulatory element-binding protein, X-box-binding protein 1, and heat shock factor pathways.

    PubMed

    Hatori, Megumi; Hirota, Tsuyoshi; Iitsuka, Michiko; Kurabayashi, Nobuhiro; Haraguchi, Shogo; Kokame, Koichi; Sato, Ryuichiro; Nakai, Akira; Miyata, Toshiyuki; Tsutsui, Kazuyoshi; Fukada, Yoshitaka

    2011-03-22

    The circadian clock is phase-delayed or -advanced by light when given at early or late subjective night, respectively. Despite the importance of the time-of-day-dependent phase responses to light, the underlying molecular mechanism is poorly understood. Here, we performed a comprehensive analysis of light-inducible genes in the chicken pineal gland, which consists of light-sensitive clock cells representing a prototype of the clock system. Light stimulated expression of 62 genes and 40 ESTs by >2.5-fold, among which genes responsive to the heat shock and endoplasmic reticulum stress as well as their regulatory transcription factors heat shock factor (HSF)1, HSF2, and X-box-binding protein 1 (XBP1) were strongly activated when a light pulse was given at late subjective night. In contrast, the light pulse at early subjective night caused prominent induction of E4bp4, a key regulator in the phase-delaying mechanism of the pineal clock, along with activation of a large group of cholesterol biosynthetic genes that are targets of sterol regulatory element-binding protein (SREBP) transcription factor. We found that the light pulse stimulated proteolytic formation of active SREBP-1 that, in turn, transactivated E4bp4 expression, linking SREBP with the light-input pathway of the pineal clock. As an output of light activation of cholesterol biosynthetic genes, we found light-stimulated pineal production of a neurosteroid, 7α-hydroxypregnenolone, demonstrating a unique endocrine function of the pineal gland. Intracerebroventricular injection of 7α-hydroxypregnenolone activated locomotor activities of chicks. Our study on the genome-wide gene expression analysis revealed time-of-day-dependent light activation of signaling pathways and provided molecular connection between gene expression and behavior through neurosteroid release from the pineal gland. PMID:21383147

  9. Down-regulation of interferon regulatory factor 4 gene expression in leukemic cells due to hypermethylation of CpG motifs in the promoter region

    PubMed Central

    Ortmann, Christina A.; Burchert, Andreas; Hölzle, Katharina; Nitsche, Andreas; Wittig, Burghardt; Neubauer, Andreas; Schmidt, Manuel

    2005-01-01

    Although the bcr-abl translocation has been shown to be the causative genetic aberration in chronic myeloid leukemia (CML), there is mounting evidence that the deregulation of other genes, such as the transcription factor interferon regulatory factor 4 (IRF-4), is also implicated in the pathogenesis of CML. Promoter methylation of CpG target sites or direct deletions/insertions of genes are mechanisms of a reversible or permanent silencing of gene expression, respectively. Therefore, we investigated whether IRF-4 promoter methylation or mutation may be involved in the regulation of IRF-4 expression in leukemia cells. Whereas promoter mutations or structural rearrangements could be excluded as a cause of altered IRF-4 expression in hematopoietic cells, the IRF-4 promoter methylation status was found to significantly influence IRF-4 transcription. First, treatment of IRF-4-negative lymphoid, myeloid and monocytic cell lines with the methylation-inhibitor 5-aza-2-deoxycytidine resulted in a time- and concentration-dependent increase of IRF-4 mRNA and protein levels. Second, using a restriction-PCR-assay and bisulfite-sequencing we identified specifically methylated CpG sites in IRF-4-negative but not in IRF-4-positive cells. Third, we clearly determined promoter methylation as a mechanism for IRF-4 down-regulation via reporter gene assays, but did not detect an association of methylational status and mRNA expression of DNA methyltransferases or methyl-CpG-binding proteins. Together, these data suggest CpG site-specific IRF-4 promoter methylation as a putative mechanism of down-regulated IRF-4 expression in leukemia. PMID:16396836

  10. Regulation of IFN regulatory factor-7 and IFN-alpha production by enveloped virus and lipopolysaccharide in human plasmacytoid dendritic cells.

    PubMed

    Dai, Jihong; Megjugorac, Nicholas J; Amrute, Sheela B; Fitzgerald-Bocarsly, Patricia

    2004-08-01

    Human plasmacytoid dendritic cells (PDC) are a major source of IFN-alpha upon exposure to enveloped viruses and TLR-7 and TLR-9 ligands. Although IFN regulatory factor-7 (IRF-7) is known to play an essential role in virus-activated transcription of IFN-alpha genes, the molecular mechanisms of IFN-alpha production in human PDC remain poorly understood. We and others have recently reported high constitutive levels of IRF-7 expression in PDC as compared with other PBMC. In this study, we demonstrate that both LPS and HSV up-regulate the expression of IRF-7 in PDC, and that this enhancement of IRF-7 is dependent on NF-kappa B activation. The NF-kappa B inhibitors MG132 and pyrrolidinedithiocarbamate efficiently inhibited the induction of IRF-7 by HSV or LPS, and also down-regulated the constitutive expression of IRF-7 in PDC and blocked the HSV-induced production of IFN-alpha. In addition, we found that nuclear translocation of IRF-7 occurred rapidly in response to HSV stimulation, but not in response to LPS, which is consistent with the stimulation of IFN-alpha production by virus and not by LPS. Although LPS by itself was not able to induce IFN-alpha production, it led to rapid up-regulation of TLR-4 on PDC and increased the magnitude and accelerated the kinetics of HSV-induced IFN-alpha production in PDC, providing a mechanism that might be operative in a scenario of mixed infection. In contrast to the current concept of IFN-alpha regulation established in cell lines, this study strongly supports the immediate availability of high constitutive levels of IRF-7 expression in PDC, and suggests an activation required for IRF-7 that contributes to IFN-alpha production in virus-stimulated PDC. PMID:15265881

  11. A novel function of interferon regulatory factor-1: inhibition of Th2 cells by down-regulating the Il4 gene during Listeria infection.

    PubMed

    Maruyama, Saho; Kanoh, Makoto; Matsumoto, Akira; Kuwahara, Makoto; Yamashita, Masakatsu; Asano, Yoshihiro

    2015-03-01

    Infection with certain pathogens induces a shift of the Th subset balance to a Th1 dominant state. This, in turn, results in the suppression of Th2 responses. We focused on the involvement of interferon regulatory factor-1 (IRF-1) in the suppression of Th2 cells during Listeria infection. We found that the inhibition of IL-4 production by Th2 cells is mediated by a soluble factor (LmSN) produced by Listeria-infected antigen-presenting cells. The inhibition is not observed with T cells from Irf1 gene-targeted mice. IRF-1 suppresses transcription of the Il4 gene in Th2 cells. Under the influence of the LmSN, IRF-1 binds to the 3' untranslated region (UTR) region of the Il4 gene and down-regulates Il4 gene transcription. Finally, we identified IL-1α and IL-1β as the mediator of the LmSN activity. Signaling through IL-1R induces the stabilization and/or nuclear translocation of IRF-1. We propose that IRF-1 functions to induce the T-cell subset shift via a novel mechanism. Under the influence of IL-1, IRF-1 translocates into the nucleus and acts on the 3'UTR region of the Il4 gene, thus inhibiting its transcription in Th2 cells. As a result, the immune system shifts predominantly to a Th1 response during Listeria infection, resulting in effective protection of the host. PMID:25280793

  12. Interferon-regulatory factor 1 is an immediate-early gene under transcriptional regulation by prolactin in Nb2 T cells.

    PubMed Central

    Yu-Lee, L Y; Hrachovy, J A; Stevens, A M; Schwarz, L A

    1990-01-01

    The pituitary peptide hormone prolactin (Prl) is a potent inducer of Nb2 T lymphoma cell proliferation. To analyze the early genetic response to the mitogenic signals of Prl, a cDNA library was constructed from Nb2 T cells stimulated for 4 h with Prl and the protein synthesis inhibitor cycloheximide. Of 26 distinct clones isolated by differential screening, one clone, designated c25, exhibited extremely rapid but transient kinetics of induction by Prl and superinduction by Prl plus cycloheximide. Run-on transcription analysis indicated that c25 gene transcription was induced greater than 20-fold within 30 to 60 min of Prl stimulation. Surprisingly, DNA sequence analysis of c25 cDNA revealed that this Prl-inducible early-response gene is the rat homolog of the mouse transcription factor interferon-regulatory factor 1 (IRF-1), sharing 91% coding sequence similarity with mouse IRF-1. At the protein level, rat IRF-1 shares 97% and 92% homology with mouse IRF-1 and human IRF-1, respectively, suggesting that this molecule has been functionally conserved throughout evolution. Our studies show that the gene for IRF-1 is an immediate-early gene in Prl-stimulated T cells, which suggests that IRF-1 is a multifunctional molecule. In addition to its role in regulating growth-inhibitory interferon genes, IRF-1 may, therefore, also play a stimulatory role in cell proliferation. The gene for IRF-1 is one of the earliest genes known to be transcriptionally regulated by Prl. Images PMID:2342469

  13. Differential Regulation of Interferon Regulatory Factor (IRF)-7 and IRF-9 Gene Expression in the Central Nervous System during Viral Infection

    PubMed Central

    Ousman, Shalina S.; Wang, Jianping; Campbell, Iain L.

    2005-01-01

    Interferon regulatory factors (IRFs) are a family of transcription factors involved in the regulation of the interferons (IFNs) and other genes that may have an essential role in antiviral defense in the central nervous system, although this is currently not well defined. Therefore, we examined the regulation of IRF gene expression in the brain during viral infection. Several IRF genes (IRF-2, -3, -5, -7, and -9) were expressed at low levels in the brain of uninfected mice. Following intracranial infection with lymphocytic choriomeningitis virus (LCMV), expression of the IRF-7 and IRF-9 genes increased significantly by day 2. IRF-7 and IRF-9 gene expression in the brain was widespread at sites of LCMV infection, with the highest levels in infiltrating mononuclear cells, microglia/macrophages, and neurons. IRF-7 and IRF-9 gene expression was increased in LCMV-infected brain from IFN-γ knockout (KO) but not IFN-α/βR KO animals. In the brain, spleen, and liver or cultured glial and spleen cells, IRF-7 but not IRF-9 gene expression increased with delayed kinetics in the absence of STAT1 but not STAT2 following LCMV infection or IFN-α treatment, respectively. The stimulation of IRF-7 gene expression by IFN-α in glial cell culture was prevented by cycloheximide. Thus, (i) many of the IRF genes were expressed constitutively in the mouse brain; (ii) the IRF-7 and IRF-9 genes were upregulated during viral infection, a process dependent on IFN-α/β but not IFN-γ; and (iii) IRF-7 but not IRF-9 gene expression can be stimulated in a STAT1-independent but STAT2-dependent fashion via unidentified indirect pathways coupled to the activation of the IFN-α/β receptor. PMID:15919906

  14. MicroRNAs regulate T-cell production of interleukin-9 and identify hypoxia-inducible factor-2α as an important regulator of T helper 9 and regulatory T-cell differentiation.

    PubMed

    Singh, Yogesh; Garden, Oliver A; Lang, Florian; Cobb, Bradley S

    2016-09-01

    MicroRNAs (miRNAs) regulate many aspects of helper T cell (Th) development and function. Here we found that they are required for the suppression of interleukin-9 (IL-9) expression in Th9 cells and other Th subsets. Two highly related miRNAs (miR-15b and miR-16) that we previously found to play an important role in regulatory T (Treg) cell differentiation were capable of suppressing IL-9 expression when they were over-expressed in Th9 cells. We used these miRNAs as tools to identify novel regulators of IL-9 expression and found that they could regulate the expression of Epas1, which encodes hypoxia-inducible factor (HIF)-2α. HIF proteins regulate metabolic pathway usage that is important in determining appropriate Th differentiation. The related protein, HIF-1α enhances Th17 differentiation and inhibits Treg cell differentiation. Here we found that HIF-2α was required for IL-9 expression in Th9 cells, but its expression was not sufficient in other Th subsets. Furthermore, HIF-2α suppressed Treg cell differentiation like HIF-1α, demonstrating both similar and distinct roles of the HIF proteins in Th differentiation and adding a further dimension to their function. Ironically, even though miR-15b and miR-16 suppressed HIF-2α expression in Treg cells, inhibiting their function in Treg cells did not lead to an increase in IL-9 expression. Therefore, the physiologically relevant miRNAs that regulate IL-9 expression in Treg cells and other subsets remain unknown. Nevertheless, the analysis of miR-15b and miR-16 function led to the discovery of the importance of HIF-2α so this work demonstrated the utility of studying miRNA function to identify novel regulatory pathways in helper T-cell development. PMID:27278750

  15. Interferon (IFN) Consensus Sequence-binding Protein, a Transcription Factor of the IFN Regulatory Factor Family, Regulates Immune Responses In Vivo through Control of Interleukin 12 Expression

    PubMed Central

    Giese, Nathalia A.; Gabriele, Lucia; Doherty, T. Mark; Klinman, Dennis M.; Tadesse-Heath, Lekidelu; Contursi, Christina; Epstein, Suzanne L.; Morse, Herbert C.

    1997-01-01

    Mice with a null mutation of the gene encoding interferon consensus sequence-binding protein (ICSBP) develop a chronic myelogenous leukemia-like syndrome and mount impaired responses to certain viral and bacterial infections. To gain a mechanistic understanding of the contributions of ICSBP to humoral and cellular immunity, we characterized the responses of control and ICSBP−/− mice to infection with influenza A (flu) and Leishmania major (L. major). Mice of both genotypes survived infections with flu, but differed markedly in the isotype distribution of antiflu antibodies. In sera of normal mice, immunoglobulin (Ig)G2a antibodies were dominant over IgG1 antibodies, a pattern indicative of a T helper cell type 1 (Th1)-driven response. In sera of ICSBP−/− mice, however, IgG1 antibodies dominated over IgG2a antibodies, a pattern indicative of a Th2-driven response. The dominance of IgG1 and IgE over IgG2a was detected in the sera of uninfected mice as well. A seeming Th2 bias of ICSBP-deficient mice was also uncovered in their inability to control infection with L. major, where resistance is known to be dependent on IL-12 and IFN-γ as components of a Th1 response. Infected ICSBP-deficient mice developed fulminant, disseminated leishmaniasis as a result of failure to mount a Th1-mediated curative response, although T cells remained capable of secreting IFN-γ and macrophages of producing nitric oxide. Compromised Th1 differentiation in ICSBP−/− mice could not be attributed to hyporesponsiveness of CD4+ T cells to interleukin (IL)-12; however, the ability of uninfected and infected ICSBP-deficient mice to produce IL-12 was markedly impaired. This indicates that ICSBP is a deciding factor in Th responses governing humoral and cellular immunity through its role in regulating IL-12 expression. PMID:9348311

  16. Factors associated with regulatory action involving investigation of illnesses associated with Shiga toxin-producing Escherichia coli in products regulated by the Food Safety and Inspection Service.

    PubMed

    Green, Alice L; Seys, Scott; Douris, Aphrodite; Levine, Jeoff; Robertson, Kis

    2014-07-01

    We described characteristics of the Escherichia coli O157 and Escherichia coli non-O157 illness investigations conducted by the United States Department of Agriculture's Food Safety and Inspection Service (FSIS) during the 5-year period from 2006 through 2010. We created a multivariable logistic regression model to determine characteristics of these investigations that were associated with FSIS regulatory action, which was defined as having occurred if a product recall occurred or if FSIS personnel performed an environmental health assessment (Food Safety Assessment) at the implicated establishment. During this period, FSIS took regulatory action in 38 of 88 (43%) investigations. Illness investigations in which FoodNet states were involved were more likely to result in regulatory action. Illness investigations in which state and local traceback, or FSIS traceback occurred were more likely to result in regulatory action. Reasons for lack of action included evidence of cross-contamination after the product left a regulated establishment, delayed notification, lack of epidemiological information, and insufficient product information. PMID:24826872

  17. The R2R3-MYB–Like Regulatory Factor EOBI, Acting Downstream of EOBII, Regulates Scent Production by Activating ODO1 and Structural Scent-Related Genes in Petunia[C][W

    PubMed Central

    Spitzer-Rimon, Ben; Farhi, Moran; Albo, Boaz; Cna’ani, Alon; Ben Zvi, Michal Moyal; Masci, Tania; Edelbaum, Orit; Yu, Yixun; Shklarman, Elena; Ovadis, Marianna; Vainstein, Alexander

    2012-01-01

    Flower scent is a highly dynamic trait, under developmental, spatial, and diurnal regulation. The mechanism governing scent production is only beginning to be unraveled. In petunia (Petunia hybrida), EMISSION OF BENZENOIDS II (EOBII) controls transcription of both the shikimate pathway-regulating MYB factor ODORANT1 (ODO1) and phenylpropanoid scent-related structural genes. A promoter-activation screen identified an R2R3-MYB–like regulatory factor of phenylpropanoid volatile biosynthesis acting downstream of EOBII, designated EOBI. EOBI silencing led to downregulation of ODO1 and numerous structural scent-related genes from both the shikimate and phenylpropanoid pathways. The ability of EOBI to directly activate ODO1, as revealed by electrophoretic mobility shift assay and yeast one-hybrid analysis, place EOBI upstream of ODO1 in regulating substrate availability for volatile biosynthesis. Interestingly, ODO1-silenced transgenic petunia flowers accumulated higher EOBI transcript levels than controls, suggesting a complex feedback loop between these regulatory factors. The accumulation pattern of EOBI transcript relative to EOBII and ODO1, and the effect of up/downregulation of EOBII on transcript levels of EOBI and ODO1, further support these factors' hierarchical relationships. The dependence of scent production on EOBI expression and its direct interaction with both regulatory and structural genes provide evidence for EOBI’s wide-ranging involvement in the production of floral volatiles. PMID:23275577

  18. Circuitry and dynamics of human transcription factor regulatory networks

    PubMed Central

    Neph, Shane; Stergachis, Andrew B.; Reynolds, Alex; Sandstrom, Richard; Borenstein, Elhanan; Stamatoyannopoulos, John A.

    2012-01-01

    SUMMARY The combinatorial cross-regulation of hundreds of sequence-specific transcription factors defines a regulatory network that underlies cellular identity and function. Here we use genome-wide maps of in vivo DNaseI footprints to assemble an extensive core human regulatory network comprising connections among 475 sequence-specific transcription factors, and to analyze the dynamics of these connections across 41 diverse cell and tissue types. We find that human transcription factor networks are highly cell-selective and are driven by cohorts of factors that include regulators with previously unrecognized roles in control of cellular identity. Moreover, we identify many widely expressed factors that impact transcriptional regulatory networks in a cell-selective manner. Strikingly, in spite of their inherent diversity, all cell type regulatory networks independently converge on a common architecture that closely resembles the topology of living neuronal networks. Together, our results provide the first description of the circuitry, dynamics, and organizing principles of the human transcription factor regulatory network. PMID:22959076

  19. Transcription factor trapping by RNA in gene regulatory elements

    PubMed Central

    Sigova, Alla A.; Abraham, Brian J.; Ji, Xiong; Molinie, Benoit; Hannett, Nancy M.; Eric Guo, Yang; Jangi, Mohini; Giallourakis, Cosmas C.; Sharp, Phillip A.; Young, Richard A.

    2016-01-01

    Transcription factors (TFs) bind specific sequences in promoter-proximal and distal DNA elements in order to regulate gene transcription. RNA is transcribed from both of these DNA elements, and some DNA-binding TFs bind RNA. Hence, RNA transcribed from regulatory elements may contribute to stable TF occupancy at these sites. We show that the ubiquitously expressed TF YY1 binds to both gene regulatory elements and also to their associated RNA species genome-wide. Reduced transcription of regulatory elements diminishes YY1 occupancy whereas artificial tethering of RNA enhances YY1 occupancy at these elements. We propose that RNA makes a modest but important contribution to the maintenance of certain TFs at gene regulatory elements and suggest that transcription of regulatory elements produces a positive feedback loop that contributes to the stability of gene expression programs. PMID:26516199

  20. Transcription factor trapping by RNA in gene regulatory elements.

    PubMed

    Sigova, Alla A; Abraham, Brian J; Ji, Xiong; Molinie, Benoit; Hannett, Nancy M; Guo, Yang Eric; Jangi, Mohini; Giallourakis, Cosmas C; Sharp, Phillip A; Young, Richard A

    2015-11-20

    Transcription factors (TFs) bind specific sequences in promoter-proximal and -distal DNA elements to regulate gene transcription. RNA is transcribed from both of these DNA elements, and some DNA binding TFs bind RNA. Hence, RNA transcribed from regulatory elements may contribute to stable TF occupancy at these sites. We show that the ubiquitously expressed TF Yin-Yang 1 (YY1) binds to both gene regulatory elements and their associated RNA species across the entire genome. Reduced transcription of regulatory elements diminishes YY1 occupancy, whereas artificial tethering of RNA enhances YY1 occupancy at these elements. We propose that RNA makes a modest but important contribution to the maintenance of certain TFs at gene regulatory elements and suggest that transcription of regulatory elements produces a positive-feedback loop that contributes to the stability of gene expression programs. PMID:26516199

  1. Regulatory T cells: regulators of life.

    PubMed

    Schumacher, Anne; Zenclussen, Ana Claudia

    2014-08-01

    Pregnancy still represents one of the most fascinating paradoxical phenomena in science. Immediately after conception, the maternal immune system is challenged by the presence of foreign paternal antigens in the semen. This triggers mechanisms of recognition and tolerance that all together allow the embryo to implant and later the fetus to develop. Tolerance mechanisms to maintain pregnancy are of special interest as they defy the classical immunology rules. Several cell types, soluble factors, and immune regulatory molecules have been proposed to contribute to fetal tolerance. Within these, regulatory T cells (Treg) are one of the most studied immune cell populations lately. They are reportedly involved in fetal acceptance. Here, we summarize several aspects of Treg biology in normal and pathologic pregnancies focusing on Treg frequencies, subtypes, antigen specificity, and activity as well as on factors influencing Treg generation, recruitment, and function. This review also highlights the contribution of fetal Treg in tolerance induction and addresses the role of Treg in autoimmune diseases and infections during gestation. Finally, the potential of Treg as a predictive marker for the success of assisted reproductive techniques and for therapeutic interventions is discussed. PMID:24661545

  2. Factors regulating microglia activation

    PubMed Central

    Kierdorf, Katrin; Prinz, Marco

    2013-01-01

    Microglia are resident macrophages of the central nervous system (CNS) that display high functional similarities to other tissue macrophages. However, it is especially important to create and maintain an intact tissue homeostasis to support the neuronal cells, which are very sensitive even to minor changes in their environment. The transition from the “resting” but surveying microglial phenotype to an activated stage is tightly regulated by several intrinsic (e.g., Runx-1, Irf8, and Pu.1) and extrinsic factors (e.g., CD200, CX3CR1, and TREM2). Under physiological conditions, minor changes of those factors are sufficient to cause fatal dysregulation of microglial cell homeostasis and result in severe CNS pathologies. In this review, we discuss recent achievements that gave new insights into mechanisms that ensure microglia quiescence. PMID:23630462

  3. Uncovering Transcriptional Regulatory Networks by Sparse Bayesian Factor Model

    NASA Astrophysics Data System (ADS)

    Meng, Jia; Zhang, Jianqiu(Michelle); Qi, Yuan(Alan); Chen, Yidong; Huang, Yufei

    2010-12-01

    The problem of uncovering transcriptional regulation by transcription factors (TFs) based on microarray data is considered. A novel Bayesian sparse correlated rectified factor model (BSCRFM) is proposed that models the unknown TF protein level activity, the correlated regulations between TFs, and the sparse nature of TF-regulated genes. The model admits prior knowledge from existing database regarding TF-regulated target genes based on a sparse prior and through a developed Gibbs sampling algorithm, a context-specific transcriptional regulatory network specific to the experimental condition of the microarray data can be obtained. The proposed model and the Gibbs sampling algorithm were evaluated on the simulated systems, and results demonstrated the validity and effectiveness of the proposed approach. The proposed model was then applied to the breast cancer microarray data of patients with Estrogen Receptor positive ([InlineEquation not available: see fulltext.]) status and Estrogen Receptor negative ([InlineEquation not available: see fulltext.]) status, respectively.

  4. 76 FR 3821 - Improving Regulation and Regulatory Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-21

    ..., employees, or agents, or any other person. (Presidential Sig.) THE WHITE HOUSE, January 18, 2011. [FR Doc... Regulation and Regulatory Review By the authority vested in me as President by the Constitution and the laws of the United States of America, and in order to improve regulation and regulatory review, it...

  5. Expression profile of carp IFN correlate with the up-regulation of interferon regulatory factor-1 (IRF-1) in vivo and in vitro: the pivotal molecules in antiviral defense.

    PubMed

    Shan, Shijuan; Qi, Chenchen; Zhu, Yaoyao; Li, Hua; An, Liguo; Yang, Guiwen

    2016-05-01

    Interferon regulatory factors (IRFs) are a family of transcription factors that mediate the transcriptional regulation of interferon (IFN) genes and IFN-inducible genes. In this study, IRF-1 gene is cloned from the common carp, Cyprinus carpio L., named CcIRF-1. The full-length cDNA of CcIRF-1 is 1427 bp, including an open reading frame of 861 bp encoding a protein of 286 amino acids. The putative CcIRF-1 is characterized by a conserved DNA-binding domain and includes a signature of six conserved tryptophan residues. The genomic sequence of CcIRF-1 is described, which consists of 9 exons and 8 introns. The sequence analysis shows that CcIRF-1 is clustered into IRF-1 subfamily, and has the closest relationship with the zebrafish IRF-1. CcIRF-1 is found constitutively expressed in different organs of healthy common carp. The main findings are that CcIRF-1 is up-regulated following stimulation with poly(I:C) in all tested tissues. Moreover, the downstream gene of IRF-1 - IFN is found to be correlated with the up-regulation of IRF-1 after injection with poly(I:C). Furthermore, we also isolate the peripheral blood leukocytes (PBLs) and find that there is a relevance between the expression profile of CcIRF-1 and IFN in poly(I:C) stimulated PBLs. PMID:26993613

  6. Factors that regulate embryonic gustatory development.

    PubMed

    Krimm, Robin F

    2007-01-01

    Numerous molecular factors orchestrate the development of the peripheral taste system. The unique anatomy/function of the taste system makes this system ideal for understanding the mechanisms by which these factors function; yet the taste system is underutilized for this role. This review focuses on some of the many factors that are known to regulate gustatory development, and discusses a few topics where more work is needed. Some attention is given to factors that regulate epibranchial placode formation, since gustatory neurons are thought to be primarily derived from this region. Epibranchial placodes appear to arise from a pan-placodal region and a number of regulatory factors control the differentiation of individual placodes. Gustatory neuron differentiation is regulated by a series of transcription factors and perhaps bone morphongenic proteins (BMP). As neurons differentiate, they also proliferate such that their numbers exceed those in the adult, and this is followed by developmental death. Some of these cell-cycling events are regulated by neurotrophins. After gustatory neurons become post-mitotic, axon outgrowth occurs. Axons are guided by multiple chemoattractive and chemorepulsive factors, including semaphorins, to the tongue epithelium. Brain derived neurotrophic factor (BDNF), functions as a targeting factor in the final stages of axon guidance and is required for gustatory axons to find and innervate taste epithelium. Numerous factors are involved in the development of gustatory papillae including Sox-2, Sonic hedge hog and Wnt-beta-catenin signaling. It is likely that just as many factors regulate taste bud differentiation; however, these factors have not yet been identified. Studies examining the molecular factors that regulate terminal field formation in the nucleus of the solitary tract are also lacking. However, it is possible that some of the factors that regulate geniculate ganglion development, outgrowth, guidance and targeting of peripheral

  7. Regulating the regulators: modulators of transcription factor activity.

    PubMed

    Everett, Logan; Hansen, Matthew; Hannenhalli, Sridhar

    2010-01-01

    Gene transcription is largely regulated by DNA-binding transcription factors (TFs). However, the TF activity itself is modulated via, among other things, post-translational modifications (PTMs) by specific modification enzymes in response to cellular stimuli. TF-PTMs thus serve as "molecular switchboards" that map upstream signaling events to the downstream transcriptional events. An important long-term goal is to obtain a genome-wide map of "regulatory triplets" consisting of a TF, target gene, and a modulator gene that specifically modulates the regulation of the target gene by the TF. A variety of genome-wide data sets can be exploited by computational methods to obtain a rough map of regulatory triplets, which can guide directed experiments. However, a prerequisite to developing such computational tools is a systematic catalog of known instances of regulatory triplets. We first describe PTM-Switchboard, a recent database that stores triplets of genes such that the ability of one gene (the TF) to regulate a target gene is dependent on one or more PTMs catalyzed by a third gene, the modifying enzyme. We also review current computational approaches to infer regulatory triplets from genome-wide data sets and conclude with a discussion of potential future research. PTM-Switchboard is accessible at http://cagr.pcbi.upenn.edu/PTMswitchboard / PMID:20827600

  8. Dietary cholecalciferol regulates the recruitment and growth of skeletal muscle fibers and the expressions of myogenic regulatory factors and the myosin heavy chain in European sea bass larvae.

    PubMed

    Alami-Durante, Hélène; Cluzeaud, Marianne; Bazin, Didier; Mazurais, David; Zambonino-Infante, José L

    2011-12-01

    The aim of this study was to determine whether dietary cholecalciferol affects the recruitment and growth of axial skeletal muscle fibers in first-feeding European sea bass. Larvae were fed diets containing 0.28 (VD-L, low dose), 0.69 (VD-C, control dose), or 3.00 (VD-H, high dose) mg cholecalciferol/kg from 9 to 44 d posthatching (dph). Larvae were sampled at 44 dph for quantification of somatic growth, muscle growth, and muscle growth dynamics and at 22 and 44 dph for the relative quantification of transcripts encoded by genes involved in myogenesis, cell proliferation, and muscle structure. The weight increase of the VD-L-fed larvae was less than that of the VD-H-fed group, whereas that of VD-C-fed larvae was intermediate. The level of expression of genes involved in cell proliferation (PCNA) and early myogenesis (Myf5) decreased between 22 and 44 dph, whereas that of the myogenic determination factor MyoD1 and that of genes involved in muscle structure and function (myosin heavy chain, myosin light chains 2 and 3) increased. Dietary cholecalciferol regulated Myf5, MyoD1, myogenin, and myosin heavy chain gene expression, with a gene-specific shape of response. The maximum hypertrophy of white muscle fibers was higher in larvae fed the VD-C and VD-H diets than in larvae fed the VD-L diet. White muscle hyperplasia was highly stimulated in VD-H-fed larvae compared to VD-L- and VD-C-fed ones. These findings demonstrate a dietary cholecalciferol effect on skeletal muscle growth mechanisms of a Teleost species. PMID:22013200

  9. Bayesian non-negative factor analysis for reconstructing transcription factor mediated regulatory networks

    PubMed Central

    2011-01-01

    Background Transcriptional regulation by transcription factor (TF) controls the time and abundance of mRNA transcription. Due to the limitation of current proteomics technologies, large scale measurements of protein level activities of TFs is usually infeasible, making computational reconstruction of transcriptional regulatory network a difficult task. Results We proposed here a novel Bayesian non-negative factor model for TF mediated regulatory networks. Particularly, the non-negative TF activities and sample clustering effect are modeled as the factors from a Dirichlet process mixture of rectified Gaussian distributions, and the sparse regulatory coefficients are modeled as the loadings from a sparse distribution that constrains its sparsity using knowledge from database; meantime, a Gibbs sampling solution was developed to infer the underlying network structure and the unknown TF activities simultaneously. The developed approach has been applied to simulated system and breast cancer gene expression data. Result shows that, the proposed method was able to systematically uncover TF mediated transcriptional regulatory network structure, the regulatory coefficients, the TF protein level activities and the sample clustering effect. The regulation target prediction result is highly coordinated with the prior knowledge, and sample clustering result shows superior performance over previous molecular based clustering method. Conclusions The results demonstrated the validity and effectiveness of the proposed approach in reconstructing transcriptional networks mediated by TFs through simulated systems and real data. PMID:22166063

  10. Regulatory factors of induced pluripotency: current status

    PubMed Central

    Ning, Bo; Qian, Chen

    2014-01-01

    Somatic cells can be reprogrammed to induced pluripotent stem cells (iPSCs) through enforced expression of four transcription factors [Oct4, Sox2, Klf4, and c-Myc (OSKM)]; however, the reprogramming efficiency is extremely low. This finding raises fundamental questions about the regulators that influence the change in epigenetic stability and endowment of dedifferentiation potential during reprogramming. Identification of such regulators is critical to removing the roadblocks impeding the efficient generation of safe iPSCs and their successful translation into clinical therapies. In this review, we summarize the current progress that has been made in understanding cellular reprogramming, with an emphasis on the molecular mechanisms of epigenetic regulators in induced pluripotency.

  11. Regulations.gov Federal Regulatory Portal

    ERIC Educational Resources Information Center

    Ashlin, John; Davis, Richard; Dalecky, Selene; Grasso, Richard; LaPlant, Lisa; Morales, Oscar; Nelson, Jennifer; White, Michael; Whitt, Sharon A.

    2004-01-01

    The Regulations.gov Online Rulemaking Project is 1 of the 24 e-Government Initiatives on the President's Management Agenda (PMA), which was announced by the White House in 2001. The Regulations.gov Web site is the central electronic rulemaking portal for the federal government. Through a single Web site, citizens can search, view, and comment on…

  12. Ectopic expression of interferon regulatory factor-1 potentiates granulocytic differentiation.

    PubMed Central

    Coccia, E M; Stellacci, E; Valtieri, M; Masella, B; Feccia, T; Marziali, G; Hiscott, J; Testa, U; Peschle, C; Battistini, A

    2001-01-01

    Numerous transcription factors allow haematopoietic cells to respond to lineage- and stage-specific cytokines and to act as their effectors. It is increasingly evident that the interferon regulatory factor-1 (IRF-1) transcription factor can selectively regulate different sets of genes depending on the cell type and/or the nature of cellular stimuli, evoking distinct responses in each. In the present study, we investigated mechanisms underlying the differentiation-inducing properties of granulocytic colony-stimulating factor (G-CSF) and whether IRF transcription factors are functionally relevant in myeloid differentiation. Both normal human progenitors and murine 32Dcl3 myeloblasts induced to differentiate along the granulocytic pathway showed an up-regulation of IRF-1 expression. Ectopic expression of IRF-1 did not abrogate the growth factor requirement of 32Dcl3 cells, although a small percentage of cells that survived cytokine deprivation differentiated fully to neutrophils. Moreover, in the presence of G-CSF, granulocytic differentiation of IRF-1-expressing cells was accelerated, as assessed by morphology and expression of specific differentiation markers. Down-modulation of c-Myb protein and direct stimulation of lysozyme promoter activity by IRF-1 were also observed. Conversely, constitutive expression of IRF-2, a repressor of IRF-1 transcriptional activity, completely abrogated the G-CSF-induced neutrophilic maturation. We conclude that IRF-1 exerts a pivotal role in granulocytic differentiation and that its induction by G-CSF represents a limiting step in the early events of differentiation. PMID:11716756

  13. Performance-Based (Risk-Informed) Regulation: A Regulatory Perspective

    SciTech Connect

    Kadambi, N. Prasad

    2005-01-15

    Performance-based regulation (PBR) has been mandated at the national level in the United States and at the agency level, where appropriate, at the U.S. Nuclear Regulatory Commission (USNRC). Guidance has been developed that implements the USNRC's definitions of PBR and other such conceptual regulatory improvements. This paper describes why PBR is important, what constitutes PBR in the context of direction provided at the USNRC, and how PBR can be implemented using a five-step process. The process steps articulate questions to be posed by the analyst regarding various aspects of a regulatory issue so that a suitably performance-based resolution can be developed. A regulatory alternative thus developed can be included among other options to be considered as part of the regulatory decision-making process.

  14. Regulation of transcription factors via natural decoys in genomic DNA.

    PubMed

    Kemme, Catherine A; Nguyen, Dan; Chattopadhyay, Abhijnan; Iwahara, Junji

    2016-08-01

    Eukaryotic genomic DNA contains numerous high-affinity sites for transcription factors. Only a small fraction of these sites directly regulates target genes. Other high-affinity sites can serve as naturally present decoys that sequester transcription factors. Such natural decoys in genomic DNA may provide novel regulatory mechanisms for transcription factors. PMID:27384377

  15. Effects of 12 metal ions on iron regulatory protein 1 (IRP-1) and hypoxia-inducible factor-1 alpha (HIF-1{alpha}) and HIF-regulated genes

    SciTech Connect

    Li Qin; Chen Haobin; Huang Xi; Costa, Max . E-mail: costam@env.med.nyu.edu

    2006-06-15

    Several metal ions that are carcinogenic affect cellular iron homeostasis by competing with iron transporters or iron-regulated enzymes. Some metal ions can mimic a hypoxia response in cells under normal oxygen tension, and induce expression of HIF-1{alpha}-regulated genes. This study investigated whether 12 metal ions altered iron homeostasis in human lung carcinoma A549 cells as measured by an activation of IRP-1 and ferritin level. We also studied hypoxia signaling by measuring HIF-1{alpha} protein levels, hypoxia response element (HRE)-driven luciferase reporter activity, and Cap43 protein level (an HIF-1{alpha} responsive gene). Our results show the following: (i) Ni(II), Co(II), V(V), Mn(II), and to a lesser extent As(III) and Cu(II) activated the binding of IRP-1 to IRE after 24 h, while the other metal ions had no effect; (ii) 10 of 12 metal ions induced HIF-1{alpha} protein but to strikingly different degrees. Two of these metal ions, Al(III) and Cd(II), did not induce HIF-1{alpha} protein; however, as indicated below, only Ni(II), Co (II), and to lesser extent Mn(II) and V(V) activated HIF-1{alpha}-dependent transcription. The combined effects of both [Ni(II) + As(III)] and [Ni(II) + Cr(VI)] on HIF-1{alpha} protein were synergistic; (iii) Addition of Fe(II) with Ni(II), Co(II), and Cr(VI) attenuated the induction of HIF-1{alpha} after 4 h treatment; (iv) Ni(II), Co(II), and Mn(II) significantly decrease ferritin level after 24 h exposure; (v) Ni(II), Co(II), V(V), and Mn(II) activated HRE reporter gene after 20 h treatment; (vi) Ni(II), Co(II), V(V), and Mn(II) increased the HIF-1-dependent Cap43 protein level after 24 h treatment. In conclusion, only Ni (II), Co (II), and to a lesser extent Mn(II) and V(V) significantly stabilized HIF-1{alpha} protein, activated IRP, decreased the levels of ferritin, induced the transcription of HIF-dependent reporter, and increased the expression of Cap43 protein levels (HIF-dependent gene). The mechanism for the

  16. Transcriptional regulation of the operon encoding stress-responsive ECF sigma factor SigH and its anti-sigma factor RshA, and control of its regulatory network in Corynebacterium glutamicum

    PubMed Central

    2012-01-01

    Background The expression of genes in Corynebacterium glutamicum, a Gram-positive non-pathogenic bacterium used mainly for the industrial production of amino acids, is regulated by seven different sigma factors of RNA polymerase, including the stress-responsive ECF-sigma factor SigH. The sigH gene is located in a gene cluster together with the rshA gene, putatively encoding an anti-sigma factor. The aim of this study was to analyze the transcriptional regulation of the sigH and rshA gene cluster and the effects of RshA on the SigH regulon, in order to refine the model describing the role of SigH and RshA during stress response. Results Transcription analyses revealed that the sigH gene and rshA gene are cotranscribed from four sigH housekeeping promoters in C. glutamicum. In addition, a SigH-controlled rshA promoter was found to only drive the transcription of the rshA gene. To test the role of the putative anti-sigma factor gene rshA under normal growth conditions, a C. glutamicum rshA deletion strain was constructed and used for genome-wide transcription profiling with DNA microarrays. In total, 83 genes organized in 61 putative transcriptional units, including those previously detected using sigH mutant strains, exhibited increased transcript levels in the rshA deletion mutant compared to its parental strain. The genes encoding proteins related to disulphide stress response, heat stress proteins, components of the SOS-response to DNA damage and proteasome components were the most markedly upregulated gene groups. Altogether six SigH-dependent promoters upstream of the identified genes were determined by primer extension and a refined consensus promoter consisting of 45 original promoter sequences was constructed. Conclusions The rshA gene codes for an anti-sigma factor controlling the function of the stress-responsive sigma factor SigH in C. glutamicum. Transcription of rshA from a SigH-dependent promoter may serve to quickly shutdown the SigH-dependent stress

  17. Regulation of the Interferon regulatory factor-8 (IRF-8) Tumor Suppressor Gene by the Signal Transducer and Activator of Transcription 5 (STAT5) Transcription Factor in Chronic Myeloid Leukemia*

    PubMed Central

    Waight, Jeremy D.; Banik, Debarati; Griffiths, Elizabeth A.; Nemeth, Michael J.; Abrams, Scott I.

    2014-01-01

    Tyrosine kinase inhibitors such as imatinib can effectively target the BCR-ABL oncoprotein in a majority of patients with chronic myeloid leukemia (CML). Unfortunately, some patients are resistant primarily to imatinib and others develop drug resistance, prompting interest in the discovery of new drug targets. Although much of this resistance can be explained by the presence of mutations within the tyrosine kinase domain of BCR-ABL, such mutations are not universally identified. Interferon regulatory factor-8 (IRF-8) is a transcription factor that is essential for myelopoiesis. Depressed IRF-8 levels are observed in a majority of CML patients and Irf-8−/− mice exhibit a CML-like disease. The underlying mechanisms of IRF-8 loss in CML are unknown. We hypothesized that BCR-ABL suppresses transcription of IRF-8 through STAT5, a proximal BCR-ABL target. Treatment of primary cells from newly diagnosed CML patients in chronic phase as well as BCR-ABL+ cell lines with imatinib increased IRF-8 transcription. Furthermore, IRF-8 expression in cell line models was necessary for imatinib-induced antitumor responses. We have demonstrated that IRF-8 is a direct target of STAT5 and that silencing of STAT5 induced IRF-8 expression. Conversely, activating STAT5 suppressed IRF-8 transcription. Finally, we showed that STAT5 blockade using a recently discovered antagonist increased IRF-8 expression in patient samples. These data reveal a previously unrecognized BCR-ABL-STAT5-IRF-8 network, which widens the repertoire of potentially new anti-CML targets. PMID:24753251

  18. Master Regulators, Regulatory Networks, and Pathways of Glioblastoma Subtypes

    PubMed Central

    Bozdag, Serdar; Li, Aiguo; Baysan, Mehmet; Fine, Howard A

    2014-01-01

    Glioblastoma multiforme (GBM) is the most common malignant brain tumor. GBM samples are classified into subtypes based on their transcriptomic and epigenetic profiles. Despite numerous studies to better characterize GBM biology, a comprehensive study to identify GBM subtype- specific master regulators, gene regulatory networks, and pathways is missing. Here, we used FastMEDUSA to compute master regulators and gene regulatory networks for each GBM subtype. We also ran Gene Set Enrichment Analysis and Ingenuity Pathway Analysis on GBM expression dataset from The Cancer Genome Atlas Project to compute GBM- and GBM subtype-specific pathways. Our analysis was able to recover some of the known master regulators and pathways in GBM as well as some putative novel regulators and pathways, which will aide in our understanding of the unique biology of GBM subtypes. PMID:25368508

  19. A C-terminal motif found in the β2-adrenergic receptor, P2Y1 receptor and cystic fibrosis transmembrane conductance regulator determines binding to the Na+/H+ exchanger regulatory factor family of PDZ proteins

    PubMed Central

    Hall, Randy A.; Ostedgaard, Lynda S.; Premont, Richard T.; Blitzer, Jeremy T.; Rahman, Nadeem; Welsh, Michael J.; Lefkowitz, Robert J.

    1998-01-01

    The Na+/H+ exchanger regulatory factor (NHERF) binds to the tail of the β2-adrenergic receptor and plays a role in adrenergic regulation of Na+/H+ exchange. NHERF contains two PDZ domains, the first of which is required for its interaction with the β2 receptor. Mutagenesis studies of the β2 receptor tail revealed that the optimal C-terminal motif for binding to the first PDZ domain of NHERF is D-S/T-x-L, a motif distinct from those recognized by other PDZ domains. The first PDZ domain of NHERF-2, a protein that is 52% identical to NHERF and also known as E3KARP, SIP-1, and TKA-1, exhibits binding preferences very similar to those of the first PDZ domain of NHERF. The delineation of the preferred binding motif for the first PDZ domain of the NHERF family of proteins allows for predictions for other proteins that may interact with NHERF or NHERF-2. For example, as would be predicted from the β2 receptor tail mutagenesis studies, NHERF binds to the tail of the purinergic P2Y1 receptor, a seven-transmembrane receptor with an intracellular C-terminal tail ending in D-T-S-L. NHERF also binds to the tail of the cystic fibrosis transmembrane conductance regulator, which ends in D-T-R-L. Because the preferred binding motif of the first PDZ domain of the NHERF family of proteins is found at the C termini of a variety of intracellular proteins, NHERF and NHERF-2 may be multifunctional adaptor proteins involved in many previously unsuspected aspects of intracellular signaling. PMID:9671706

  20. 76 FR 8940 - Regulatory Review of Existing DOT Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-16

    ... regulation and regulatory review (76 FR 3821, 1/21/11). Executive Order 13563 reaffirms and builds upon... Planning and Review,'' (58 FR 51735, 10/4/1993), by requiring Federal agencies to design cost- effective... Secretary (OST) and the following operating administrations (OAs): Federal Aviation Administration...

  1. 76 FR 31279 - Regulatory Guidance: Applicability of the Federal Motor Carrier Safety Regulations to Operators...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-31

    ...FMCSA requests public comment on: (1) Previously published regulatory guidance on the distinction between interstate and intrastate commerce in deciding whether operations of commercial motor vehicles within the boundaries of a single State are subject to the Federal Motor Carrier Safety Regulations (FMCSRs); (2) the factors the States are using in deciding whether farm vehicle drivers......

  2. Regulation of the Arabidopsis CBF regulon by a complex low-temperature regulatory network.

    PubMed

    Park, Sunchung; Lee, Chin-Mei; Doherty, Colleen J; Gilmour, Sarah J; Kim, YongSig; Thomashow, Michael F

    2015-04-01

    Exposure of Arabidopsis thaliana plants to low non-freezing temperatures results in an increase in freezing tolerance that involves action of the C-repeat binding factor (CBF) regulatory pathway. CBF1, CBF2 and CBF3, which are rapidly induced in response to low temperature, encode closely related AP2/ERF DNA-binding proteins that recognize the C-repeat (CRT)/dehydration-responsive element (DRE) DNA regulatory element present in the promoters of CBF-regulated genes. The CBF transcription factors alter the expression of more than 100 genes, known as the CBF regulon, which contribute to an increase in freezing tolerance. In this study, we investigated the extent to which cold induction of the CBF regulon is regulated by transcription factors other than CBF1, CBF2 and CBF3, and whether freezing tolerance is dependent on a functional CBF-CRT/DRE regulatory module. To address these issues we generated transgenic lines that constitutively overexpressed a truncated version of CBF2 that had dominant negative effects on the function of the CBF-CRT/DRE regulatory module, and 11 transcription factors encoded by genes that were rapidly cold-induced in parallel with the 'first-wave' CBF genes, and determined the effects that overexpressing these proteins had on global gene expression and freezing tolerance. Our results indicate that cold regulation of the CBF regulon involves extensive co-regulation by other first-wave transcription factors; that the low-temperature regulatory network beyond the CBF pathway is complex and highly interconnected; and that the increase in freezing tolerance that occurs with cold acclimation is only partially dependent on the CBF-CRT/DRE regulatory module. PMID:25736223

  3. Innovative farmers and regulatory gatekeepers: Genetically modified crops regulation and adoption in developing countries.

    PubMed

    Sinebo, Woldeyesus; Maredia, Karim

    2016-01-01

    The regulation of genetically modified (GM) crops is a topical issue in agriculture and environment over the past 2 decades. The objective of this paper is to recount regulatory and adoption practices in some developing countries that have successfully adopted GM crops so that aspiring countries may draw useful lessons and best practices for their biosafatey regulatory regimes. The first 11 mega-GM crops growing countries each with an area of more than one million hectares in 2014 were examined. Only five out of the 11 countries had smooth and orderly adoption of these crops as per the regulatory requirement of each country. In the remaining 6 countries (all developing countries), GM crops were either introduced across borders without official authorization, released prior to regulatory approval or unapproved seeds were sold along with the approved ones in violation to the existing regulations. Rapid expansion of transgenic crops over the past 2 decades in the developing world was a result of an intense desire by farmers to adopt these crops irrespective of regulatory roadblocks. Lack of workable biosafety regulatory system and political will to support GM crops encouraged unauthorized access to GM crop varieties. In certain cases, unregulated access in turn appeared to result in the adoption of substandard or spurious technology which undermined performance and productivity. An optimal interaction among the national agricultural innovation systems, biosafety regulatory bodies, biotech companies and high level policy makers is vital in making a workable regulated progress in the adoption of GM crops. Factoring forgone opportunities to farmers to benefit from GM crops arising from overregulation into biosafety risk analysis and decision making is suggested. Building functional biosafety regulatory systems that balances the needs of farmers to access and utilize the GM technology with the regulatory imperatives to ensure adequate safety to the environment and human

  4. Search for regulatory factors of the pituitary-specific transcription factor PROP1 gene

    PubMed Central

    NISHIMURA, Naoto; UEHARU, Hiroki; NISHIHARA, Hiroto; SHIBUYA, Shiori; YOSHIDA, Saishu; HIGUCHI, Masashi; KANNO, Naoko; HORIGUCHI, Kotaro; KATO, Takako; KATO, Yukio

    2015-01-01

    Pituitary-specific transcription factor PROP1, a factor important for pituitary organogenesis, appears on rat embryonic day 11.5 (E11.5) in SOX2-expressing stem/progenitor cells and always coexists with SOX2 throughout life. PROP1-positive cells at one point occupy all cells in Rathke’s pouch, followed by a rapid decrease in their number. Their regulatory factors, except for RBP-J, have not yet been clarified. This study aimed to use the 3 kb upstream region and 1st intron of mouse prop1 to pinpoint a group of factors selected on the basis of expression in the early pituitary gland for expression of Prop1. Reporter assays for SOX2 and RBP-J showed that the stem/progenitor marker SOX2 has cell type-dependent inhibitory and activating functions through the proximal and distal upstream regions of Prop1, respectively, while RBP-J had small regulatory activity in some cell lines. Reporter assays for another 39 factors using the 3 kb upstream regions in CHO cells ultimately revealed that 8 factors, MSX2, PAX6, PIT1, PITX1, PITX2, RPF1, SOX8 and SOX11, but not RBP-J, regulate Prop1 expression. Furthermore, a synergy effect with SOX2 was observed for an additional 10 factors, FOXJ1, HES1, HEY1, HEY2, KLF6, MSX1, RUNX1, TEAD2, YBX2 and ZFP36Ll, which did not show substantial independent action. Thus, we demonstrated 19 candidates, including SOX2, to be regulatory factors of Prop1 expression. PMID:26640231

  5. Search for regulatory factors of the pituitary-specific transcription factor PROP1 gene.

    PubMed

    Nishimura, Naoto; Ueharu, Hiroki; Nishihara, Hiroto; Shibuya, Shiori; Yoshida, Saishu; Higuchi, Masashi; Kanno, Naoko; Horiguchi, Kotaro; Kato, Takako; Kato, Yukio

    2016-02-20

    Pituitary-specific transcription factor PROP1, a factor important for pituitary organogenesis, appears on rat embryonic day 11.5 (E11.5) in SOX2-expressing stem/progenitor cells and always coexists with SOX2 throughout life. PROP1-positive cells at one point occupy all cells in Rathke's pouch, followed by a rapid decrease in their number. Their regulatory factors, except for RBP-J, have not yet been clarified. This study aimed to use the 3 kb upstream region and 1st intron of mouse prop1 to pinpoint a group of factors selected on the basis of expression in the early pituitary gland for expression of Prop1. Reporter assays for SOX2 and RBP-J showed that the stem/progenitor marker SOX2 has cell type-dependent inhibitory and activating functions through the proximal and distal upstream regions of Prop1, respectively, while RBP-J had small regulatory activity in some cell lines. Reporter assays for another 39 factors using the 3 kb upstream regions in CHO cells ultimately revealed that 8 factors, MSX2, PAX6, PIT1, PITX1, PITX2, RPF1, SOX8 and SOX11, but not RBP-J, regulate Prop1 expression. Furthermore, a synergy effect with SOX2 was observed for an additional 10 factors, FOXJ1, HES1, HEY1, HEY2, KLF6, MSX1, RUNX1, TEAD2, YBX2 and ZFP36Ll, which did not show substantial independent action. Thus, we demonstrated 19 candidates, including SOX2, to be regulatory factors of Prop1 expression. PMID:26640231

  6. Na+/H+ Exchanger Regulatory Factor 1 Overexpression-dependent Increase of Cytoskeleton Organization Is Fundamental in the Rescue of F508del Cystic Fibrosis Transmembrane Conductance Regulator in Human Airway CFBE41o- Cells

    PubMed Central

    Favia, Maria; Guerra, Lorenzo; Fanelli, Teresa; Cardone, Rosa Angela; Monterisi, Stefania; Di Sole, Francesca; Castellani, Stefano; Chen, Mingmin; Seidler, Ursula; Reshkin, Stephan Joel; Conese, Massimo

    2010-01-01

    We have demonstrated that Na+/H+ exchanger regulatory factor 1 (NHERF1) overexpression in CFBE41o- cells induces a significant redistribution of F508del cystic fibrosis transmembrane conductance regulator (CFTR) from the cytoplasm to the apical membrane and rescues CFTR-dependent chloride secretion. Here, we observe that CFBE41o- monolayers displayed substantial disassembly of actin filaments and that overexpression of wild-type (wt) NHERF1 but not NHERF1-Δ Ezrin-Radixin-Moesin (ERM) increased F-actin assembly and organization. Furthermore, the dominant-negative band Four-point one, Ezrin, Radixin, Moesin homology (FERM) domain of ezrin reversed the wt NHERF1 overexpression-induced increase in both F-actin and CFTR-dependent chloride secretion. wt NHERF1 overexpression enhanced the interaction between NHERF1 and both CFTR and ezrin and between ezrin and actin and the overexpression of wt NHERF1, but not NHERF1-ΔERM, also increased the phosphorylation of ezrin in the apical region of the cell monolayers. Furthermore, wt NHERF1 increased RhoA activity and transfection of constitutively active RhoA in CFBE41o- cells was sufficient to redistribute phospho-ezrin to the membrane fraction and rescue both the F-actin content and the CFTR-dependent chloride efflux. Rho kinase (ROCK) inhibition, in contrast, reversed the wt NHERF1 overexpression-induced increase of membrane phospho-ezrin, F-actin content, and CFTR-dependent secretion. We conclude that NHERF1 overexpression in CFBE41o- rescues CFTR-dependent chloride secretion by forming the multiprotein complex RhoA-ROCK-ezrin-actin that, via actin cytoskeleton reorganization, tethers F508del CFTR to the cytoskeleton stabilizing it on the apical membrane. PMID:19889841

  7. Foxo transcription factors control regulatory T cell development and function

    PubMed Central

    Kerdiles, Yann M.; Stone, Erica L.; Beisner, Daniel L.; McGargill, Maureen A.; Ch'en, Irene L.; Stockmann, Christian; Katayama, Carol D.; Hedrick, Stephen M.

    2010-01-01

    SUMMARY Foxo transcription factors integrate extrinsic signals to regulate cell division, differentiation and survival, and specific functions of lymphoid and myeloid cells. Here we showed the absence of Foxo1 severely curtailed the development of Foxp3+ regulatory T (Treg) cells, and those that developed were nonfunctional in vivo. The loss of function included diminished CTLA-4 receptor expression as the Ctla4 gene was a direct target of Foxo1. T cell specific loss of Foxo1 resulted in exocrine pancreatitis, hind limb paralysis, multi-organ lymphocyte infiltration, anti-nuclear antibodies and expanded germinal centers. Foxo-mediated control over Treg cell specification was further revealed by the inability of TGF-β cytokine to suppress T-bet transcription factor in the absence of Foxo1, resulting in IFN-γ-secretion. In addition the absence of Foxo3 exacerbated the effects of the loss of Foxo1. Thus, Foxo transcription factors guide the contingencies of T cell differentiation and specific functions of effector cell populations. PMID:21167754

  8. A compendium of Caenhorabditis elegans regulatory transcription factors: a resource for mapping transcription regulatory networks

    PubMed Central

    Reece-Hoyes, John S; Deplancke, Bart; Shingles, Jane; Grove, Christian A; Hope, Ian A; Walhout, Albertha JM

    2005-01-01

    Background Transcription regulatory networks are composed of interactions between transcription factors and their target genes. Whereas unicellular networks have been studied extensively, metazoan transcription regulatory networks remain largely unexplored. Caenorhabditis elegans provides a powerful model to study such metazoan networks because its genome is completely sequenced and many functional genomic tools are available. While C. elegans gene predictions have undergone continuous refinement, this is not true for the annotation of functional transcription factors. The comprehensive identification of transcription factors is essential for the systematic mapping of transcription regulatory networks because it enables the creation of physical transcription factor resources that can be used in assays to map interactions between transcription factors and their target genes. Results By computational searches and extensive manual curation, we have identified a compendium of 934 transcription factor genes (referred to as wTF2.0). We find that manual curation drastically reduces the number of both false positive and false negative transcription factor predictions. We discuss how transcription factor splice variants and dimer formation may affect the total number of functional transcription factors. In contrast to mouse transcription factor genes, we find that C. elegans transcription factor genes do not undergo significantly more splicing than other genes. This difference may contribute to differences in organism complexity. We identify candidate redundant worm transcription factor genes and orthologous worm and human transcription factor pairs. Finally, we discuss how wTF2.0 can be used together with physical transcription factor clone resources to facilitate the systematic mapping of C. elegans transcription regulatory networks. Conclusion wTF2.0 provides a starting point to decipher the transcription regulatory networks that control metazoan development and function

  9. Loregic: A Method to Characterize the Cooperative Logic of Regulatory Factors

    PubMed Central

    Wang, Daifeng; Yan, Koon-Kiu; Sisu, Cristina; Cheng, Chao; Rozowsky, Joel; Meyerson, William; Gerstein, Mark B.

    2015-01-01

    The topology of the gene-regulatory network has been extensively analyzed. Now, given the large amount of available functional genomic data, it is possible to go beyond this and systematically study regulatory circuits in terms of logic elements. To this end, we present Loregic, a computational method integrating gene expression and regulatory network data, to characterize the cooperativity of regulatory factors. Loregic uses all 16 possible two-input-one-output logic gates (e.g. AND or XOR) to describe triplets of two factors regulating a common target. We attempt to find the gate that best matches each triplet’s observed gene expression pattern across many conditions. We make Loregic available as a general-purpose tool (github.com/gersteinlab/loregic). We validate it with known yeast transcription-factor knockout experiments. Next, using human ENCODE ChIP-Seq and TCGA RNA-Seq data, we are able to demonstrate how Loregic characterizes complex circuits involving both proximally and distally regulating transcription factors (TFs) and also miRNAs. Furthermore, we show that MYC, a well-known oncogenic driving TF, can be modeled as acting independently from other TFs (e.g., using OR gates) but antagonistically with repressing miRNAs. Finally, we inter-relate Loregic’s gate logic with other aspects of regulation, such as indirect binding via protein-protein interactions, feed-forward loop motifs and global regulatory hierarchy. PMID:25884877

  10. Asymmetric Regulation of Peripheral Genes by Two Transcriptional Regulatory Networks

    PubMed Central

    Li, Jing-Ru; Suzuki, Takahiro; Nishimura, Hajime; Kishima, Mami; Maeda, Shiori; Suzuki, Harukazu

    2016-01-01

    Transcriptional regulatory network (TRN) reconstitution and deconstruction occur simultaneously during reprogramming; however, it remains unclear how the starting and targeting TRNs regulate the induction and suppression of peripheral genes. Here we analyzed the regulation using direct cell reprogramming from human dermal fibroblasts to monocytes as the platform. We simultaneously deconstructed fibroblastic TRN and reconstituted monocytic TRN; monocytic and fibroblastic gene expression were analyzed in comparison with that of fibroblastic TRN deconstruction only or monocytic TRN reconstitution only. Global gene expression analysis showed cross-regulation of TRNs. Detailed analysis revealed that knocking down fibroblastic TRN positively affected half of the upregulated monocytic genes, indicating that intrinsic fibroblastic TRN interfered with the expression of induced genes. In contrast, reconstitution of monocytic TRN showed neutral effects on the majority of fibroblastic gene downregulation. This study provides an explicit example that demonstrates how two networks together regulate gene expression during cell reprogramming processes and contributes to the elaborate exploration of TRNs. PMID:27483142

  11. Biosynthesis of nitric oxide activates iron regulatory factor in macrophages.

    PubMed Central

    Drapier, J C; Hirling, H; Wietzerbin, J; Kaldy, P; Kühn, L C

    1993-01-01

    Biosynthesis of nitric oxide (NO) from L-arginine modulates activity of iron-dependent enzymes, including mitochondrial acontiase, an [Fe-S] protein. We examined the effect of NO on the activity of iron regulatory factor (IRF), a cytoplasmic protein which modulates both ferritin mRNA translation and transferrin receptor mRNA stability by binding to specific mRNA sequences called iron responsive elements (IREs). Murine macrophages were activated with interferon-gamma and lipopolysaccharide to induce NO synthase activity and cultured in the presence or absence of NG-substituted analogues of L-arginine which served as selective inhibitors of NO synthesis. Measurement of the nitrite concentration in the culture medium was taken as an index of NO production. Mitochondria-free cytosols were then prepared and aconitase activity as well as IRE binding activity and induction of IRE binding activity were correlated and depended on NO synthesis after IFN-gamma and/or LPS stimulation. Authentic NO gas as well as the NO-generating compound 3-morpholinosydnonimine (SIN-1) also conversely modulated aconitase and IRE binding activities of purified recombinant IRF. These results provide evidence that endogenously produced NO may modulate the post-transcriptional regulation of genes involved in iron homeostasis and support the hypothesis that the [Fe-S] cluster of IRF mediates iron-dependent regulation. Images PMID:7504626

  12. Transcription factor-microRNA synergistic regulatory network revealing the mechanism of polycystic ovary syndrome

    PubMed Central

    LIU, HAI-YING; HUANG, YU-LING; LIU, JIAN-QIAO; HUANG, QING

    2016-01-01

    Polycystic ovary syndrome (PCOS) is the most common type of endocrine disorder, affecting 5–11% of women of reproductive age worldwide. Transcription factors (TFs) and microRNAs are considered to have crucial roles in the developmental process of several diseases and have synergistic regulatory actions. However, the effects of TFs and microRNAs, and the patterns of their cooperation in the synergistic regulatory network of PCOS, remain to be elucidated. The present study aimed to determine the possible mechanism of PCOS, based on a TF-microRNA synergistic regulatory network. Initially, the differentially expressed genes (DEGs) in PCOS were identified using microarray data of the GSE34526 dataset. Subsequently, the TFs and microRNAs which regulated the DEGs of PCOS were identified, and a PCOS-associated TF-microRNA synergistic regulatory network was constructed. This network included 195 DEGs, 136 TFs and 283 microRNAs, and the DEGs were regulated by TFs and microRNAs. Based on topological and functional enrichment analyses, SP1, mir-355-5p and JUN were identified as potentially crucial regulators in the development of PCOS and in characterizing the regulatory mechanism. In conclusion, the TF-microRNA synergistic regulatory network constructed in the present study provides novel insight on the molecular mechanism of PCOS in the form of synergistic regulated model. PMID:27035648

  13. Deciphering Cis-Regulatory Element Mediated Combinatorial Regulation in Rice under Blast Infected Condition.

    PubMed

    Deb, Arindam; Kundu, Sudip

    2015-01-01

    Combinations of cis-regulatory elements (CREs) present at the promoters facilitate the binding of several transcription factors (TFs), thereby altering the consequent gene expressions. Due to the eminent complexity of the regulatory mechanism, the combinatorics of CRE-mediated transcriptional regulation has been elusive. In this work, we have developed a new methodology that quantifies the co-occurrence tendencies of CREs present in a set of promoter sequences; these co-occurrence scores are filtered in three consecutive steps to test their statistical significance; and the significantly co-occurring CRE pairs are presented as networks. These networks of co-occurring CREs are further transformed to derive higher order of regulatory combinatorics. We have further applied this methodology on the differentially up-regulated gene-sets of rice tissues under fungal (Magnaporthe) infected conditions to demonstrate how it helps to understand the CRE-mediated combinatorial gene regulation. Our analysis includes a wide spectrum of biologically important results. The CRE pairs having a strong tendency to co-occur often exhibit very similar joint distribution patterns at the promoters of rice. We couple the network approach with experimental results of plant gene regulation and defense mechanisms and find evidences of auto and cross regulation among TF families, cross-talk among multiple hormone signaling pathways, similarities and dissimilarities in regulatory combinatorics between different tissues, etc. Our analyses have pointed a highly distributed nature of the combinatorial gene regulation facilitating an efficient alteration in response to fungal attack. All together, our proposed methodology could be an important approach in understanding the combinatorial gene regulation. It can be further applied to unravel the tissue and/or condition specific combinatorial gene regulation in other eukaryotic systems with the availability of annotated genomic sequences and suitable

  14. Deciphering Cis-Regulatory Element Mediated Combinatorial Regulation in Rice under Blast Infected Condition

    PubMed Central

    Deb, Arindam; Kundu, Sudip

    2015-01-01

    Combinations of cis-regulatory elements (CREs) present at the promoters facilitate the binding of several transcription factors (TFs), thereby altering the consequent gene expressions. Due to the eminent complexity of the regulatory mechanism, the combinatorics of CRE-mediated transcriptional regulation has been elusive. In this work, we have developed a new methodology that quantifies the co-occurrence tendencies of CREs present in a set of promoter sequences; these co-occurrence scores are filtered in three consecutive steps to test their statistical significance; and the significantly co-occurring CRE pairs are presented as networks. These networks of co-occurring CREs are further transformed to derive higher order of regulatory combinatorics. We have further applied this methodology on the differentially up-regulated gene-sets of rice tissues under fungal (Magnaporthe) infected conditions to demonstrate how it helps to understand the CRE-mediated combinatorial gene regulation. Our analysis includes a wide spectrum of biologically important results. The CRE pairs having a strong tendency to co-occur often exhibit very similar joint distribution patterns at the promoters of rice. We couple the network approach with experimental results of plant gene regulation and defense mechanisms and find evidences of auto and cross regulation among TF families, cross-talk among multiple hormone signaling pathways, similarities and dissimilarities in regulatory combinatorics between different tissues, etc. Our analyses have pointed a highly distributed nature of the combinatorial gene regulation facilitating an efficient alteration in response to fungal attack. All together, our proposed methodology could be an important approach in understanding the combinatorial gene regulation. It can be further applied to unravel the tissue and/or condition specific combinatorial gene regulation in other eukaryotic systems with the availability of annotated genomic sequences and suitable

  15. Reconstruction and topological characterization of the sigma factor regulatory network of Mycobacterium tuberculosis.

    PubMed

    Chauhan, Rinki; Ravi, Janani; Datta, Pratik; Chen, Tianlong; Schnappinger, Dirk; Bassler, Kevin E; Balázsi, Gábor; Gennaro, Maria Laura

    2016-01-01

    Accessory sigma factors, which reprogram RNA polymerase to transcribe specific gene sets, activate bacterial adaptive responses to noxious environments. Here we reconstruct the complete sigma factor regulatory network of the human pathogen Mycobacterium tuberculosis by an integrated approach. The approach combines identification of direct regulatory interactions between M. tuberculosis sigma factors in an E. coli model system, validation of selected links in M. tuberculosis, and extensive literature review. The resulting network comprises 41 direct interactions among all 13 sigma factors. Analysis of network topology reveals (i) a three-tiered hierarchy initiating at master regulators, (ii) high connectivity and (iii) distinct communities containing multiple sigma factors. These topological features are likely associated with multi-layer signal processing and specialized stress responses involving multiple sigma factors. Moreover, the identification of overrepresented network motifs, such as autoregulation and coregulation of sigma and anti-sigma factor pairs, provides structural information that is relevant for studies of network dynamics. PMID:27029515

  16. Reconstruction and topological characterization of the sigma factor regulatory network of Mycobacterium tuberculosis

    PubMed Central

    Chauhan, Rinki; Ravi, Janani; Datta, Pratik; Chen, Tianlong; Schnappinger, Dirk; Bassler, Kevin E.; Balázsi, Gábor; Gennaro, Maria Laura

    2016-01-01

    Accessory sigma factors, which reprogram RNA polymerase to transcribe specific gene sets, activate bacterial adaptive responses to noxious environments. Here we reconstruct the complete sigma factor regulatory network of the human pathogen Mycobacterium tuberculosis by an integrated approach. The approach combines identification of direct regulatory interactions between M. tuberculosis sigma factors in an E. coli model system, validation of selected links in M. tuberculosis, and extensive literature review. The resulting network comprises 41 direct interactions among all 13 sigma factors. Analysis of network topology reveals (i) a three-tiered hierarchy initiating at master regulators, (ii) high connectivity and (iii) distinct communities containing multiple sigma factors. These topological features are likely associated with multi-layer signal processing and specialized stress responses involving multiple sigma factors. Moreover, the identification of overrepresented network motifs, such as autoregulation and coregulation of sigma and anti-sigma factor pairs, provides structural information that is relevant for studies of network dynamics. PMID:27029515

  17. HANFORD REGULATORY EXPERIENCE REGULATION AT HANFORD A CASE STUDY

    SciTech Connect

    HAWKINS AR

    2007-09-24

    Hanford has played a pivotal role in the United States' defense for more than 60 years, beginning with the Manhattan Project in the 1940s. During its history, the Hanford Site has had nine reactors producing plutonium for the United States' nuclear weapons program. All the reactors were located next to the Columbia River and all had associated low-level radioactive and hazardous waste releases. Site cleanup, which formally began in 1989 with the signing of the Hanford Federal Facility Agreement and Consent Order, also known as the Tri-Party Agreement, involves more than 1,600 waste sites and burial grounds, and the demolition of more than 1,500buildings and structures, Cleanup is scheduled to be complete by 2035. Regulatory oversight of the cleanup is being performed by the U.S. Environmental Protection Agency (EPA) and the Washington State Department of Ecology(Ecology) under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and the Revised Code of Washington, 'Hazardous Waste Management.' Cleanup of the waste sites and demolition of the many buildings and structures generates large volumes of contaminated soil, equipment, demolition debris, and other wastes that must be disposed of in a secure manner to prevent further environmental degradation. From a risk perspective, it is essential the cleanup waste be moved to a disposal facility located well away from the Columbia River. The solution was to construct very large engineered landfill that meets all technical regulatory requirements, on the Hanford Site Central Plateau approximately 10kilometers from the river and 100metersabovegroundwater. This landfill, called the Environmental Restoration Disposal Facility or ERDF is a series of cells, each 150x 300 meters wide at the bottom and 20 meters deep. This paper looks at the substantive environmental regulations applied to ERDF, and how the facility is designed to protect the environment and meet regulatory requirements. The paper

  18. Decreased Transcription Factor Binding Levels Nearby Primate Pseudogenes Suggest Regulatory Degeneration.

    PubMed

    Douglas, Gavin M; Wilson, Michael D; Moses, Alan M

    2016-06-01

    Characteristics of pseudogene degeneration at the coding level are well-known, such as a shift toward neutral rates of nonsynonymous substitutions and gain of frameshift mutations. In contrast, degeneration of pseudogene transcriptional regulation is not well understood. Here, we test two predictions of regulatory degeneration along a pseudogenized lineage: 1) Decreased transcription factor (TF) binding and 2) accelerated evolution in putative cis-regulatory regions.We find evidence for decreased TF binding levels nearby two primate pseudogenes compared with functional liver genes. However, the majority of TF-bound sequences nearby pseudogenes do not show evidence for lineage-specific accelerated rates of evolution. We conclude that decreases in TF binding level could be a marker for regulatory degeneration, while sequence degeneration in primate cis-regulatory modules may be obscured by background rates of TF binding site turnover. PMID:26882985

  19. Decreased Transcription Factor Binding Levels Nearby Primate Pseudogenes Suggest Regulatory Degeneration

    PubMed Central

    Douglas, Gavin M.; Wilson, Michael D.; Moses, Alan M.

    2016-01-01

    Characteristics of pseudogene degeneration at the coding level are well-known, such as a shift toward neutral rates of nonsynonymous substitutions and gain of frameshift mutations. In contrast, degeneration of pseudogene transcriptional regulation is not well understood. Here, we test two predictions of regulatory degeneration along a pseudogenized lineage: 1) Decreased transcription factor (TF) binding and 2) accelerated evolution in putative cis-regulatory regions. We find evidence for decreased TF binding levels nearby two primate pseudogenes compared with functional liver genes. However, the majority of TF-bound sequences nearby pseudogenes do not show evidence for lineage-specific accelerated rates of evolution. We conclude that decreases in TF binding level could be a marker for regulatory degeneration, while sequence degeneration in primate cis-regulatory modules may be obscured by background rates of TF binding site turnover. PMID:26882985

  20. Identification of tissue-specific cis-regulatory modules based on interactions between transcription factors

    PubMed Central

    Yu, Xueping; Lin, Jimmy; Zack, Donald J; Qian, Jiang

    2007-01-01

    Background Evolutionary conservation has been used successfully to help identify cis-acting DNA regions that are important in regulating tissue-specific gene expression. Motivated by increasing evidence that some DNA regulatory regions are not evolutionary conserved, we have developed an approach for cis-regulatory region identification that does not rely upon evolutionary sequence conservation. Results The conservation-independent approach is based on an empirical potential energy between interacting transcription factors (TFs). In this analysis, the potential energy is defined as a function of the number of TF interactions in a genomic region and the strength of the interactions. By identifying sets of interacting TFs, the analysis locates regions enriched with the binding sites of these interacting TFs. We applied this approach to 30 human tissues and identified 6232 putative cis-regulatory modules (CRMs) regulating 2130 tissue-specific genes. Interestingly, some genes appear to be regulated by different CRMs in different tissues. Known regulatory regions are highly enriched in our predicted CRMs. In addition, DNase I hypersensitive sites, which tend to be associated with active regulatory regions, significantly overlap with the predicted CRMs, but not with more conserved regions. We also find that conserved and non-conserved CRMs regulate distinct gene groups. Conserved CRMs control more essential genes and genes involved in fundamental cellular activities such as transcription. In contrast, non-conserved CRMs, in general, regulate more non-essential genes, such as genes related to neural activity. Conclusion These results demonstrate that identifying relevant sets of binding motifs can help in the mapping of DNA regulatory regions, and suggest that non-conserved CRMs play an important role in gene regulation. PMID:17996093

  1. From System-Wide Differential Gene Expression to Perturbed Regulatory Factors: A Combinatorial Approach

    PubMed Central

    Mahajan, Gaurang; Mande, Shekhar C.

    2015-01-01

    High-throughput experiments such as microarrays and deep sequencing provide large scale information on the pattern of gene expression, which undergoes extensive remodeling as the cell dynamically responds to varying environmental cues or has its function disrupted under pathological conditions. An important initial step in the systematic analysis and interpretation of genome-scale expression alteration involves identification of a set of perturbed transcriptional regulators whose differential activity can provide a proximate hypothesis to account for these transcriptomic changes. In the present work, we propose an unbiased and logically natural approach to transcription factor enrichment. It involves overlaying a list of experimentally determined differentially expressed genes on a background regulatory network coming from e.g. literature curation or computational motif scanning, and identifying that subset of regulators whose aggregated target set best discriminates between the altered and the unaffected genes. In other words, our methodology entails testing of all possible regulatory subnetworks, rather than just the target sets of individual regulators as is followed in most standard approaches. We have proposed an iterative search method to efficiently find such a combination, and benchmarked it on E. coli microarray and regulatory network data available in the public domain. Comparative analysis carried out on artificially generated differential expression profiles, as well as empirical factor overexpression data for M. tuberculosis, shows that our methodology provides marked improvement in accuracy of regulatory inference relative to the standard method that involves evaluating factor enrichment in an individual manner. PMID:26562430

  2. Identification of Neurodegenerative Factors Using Translatome-Regulatory Network Analysis

    PubMed Central

    Brichta, Lars; Shin, William; Jackson-Lewis, Vernice; Blesa, Javier; Yap, Ee-Lynn; Walker, Zachary; Zhang, Jack; Roussarie, Jean-Pierre; Alvarez, Mariano J.; Califano, Andrea; Przedborski, Serge; Greengard, Paul

    2016-01-01

    For degenerative disorders of the central nervous system, the major obstacle to therapeutic advancement has been the challenge of identifying the key molecular mechanisms underlying neuronal loss. We developed a combinatorial approach including translational profiling and brain regulatory network analysis to search for key determinants of neuronal survival or death. Following the generation of transgenic mice for cell type-specific profiling of midbrain dopaminergic neurons, we established and compared translatome libraries reflecting the molecular signature of these cells at baseline or under degenerative stress. Analysis of these libraries by interrogating a context-specific brain regulatory network led to the identification of a repertoire of intrinsic upstream regulators that drive the dopaminergic stress response. The altered activity of these regulators was not associated with changes in their expression levels. This strategy can be generalized for the elucidation of novel molecular determinants involved in the degeneration of other classes of neurons. PMID:26214373

  3. Characterizing the interplay betwen mulitple levels of organization within bacterial sigma factor regulatory networks

    SciTech Connect

    Yu, Qiu; Nagarajan, Harish; Embree, Mallory; Shieu, Wendy; Abate, Elisa; Juarez, Katy; Cho, Byung-Kwan; Elkins, James G; Nevin, Kelly P.; Barrett, Christian; Lovley, Derek; Palsson, Bernhard O.; Zengler, Karsten

    2013-01-01

    Bacteria contain multiple sigma factors, each targeting diverse, but often overlapping sets of promoters, thereby forming a complex network. The layout and deployment of such a sigma factor network directly impacts global transcriptional regulation and ultimately dictates the phenotype. Here we integrate multi-omic data sets to determine the topology, the operational, and functional states of the sigma factor network in Geobacter sulfurreducens, revealing a unique network topology of interacting sigma factors. Analysis of the operational state of the sigma factor network shows a highly modular structure with sN being the major regulator of energy metabolism. Surprisingly, the functional state of the network during the two most divergent growth conditions is nearly static, with sigma factor binding profiles almost invariant to environmental stimuli. This first comprehensive elucidation of the interplay between different levels of the sigma factor network organization is fundamental to characterize transcriptional regulatory mechanisms in bacteria.

  4. Metabolic Regulation of Regulatory T Cell Development and Function

    PubMed Central

    Coe, David John; Kishore, Madhav; Marelli-Berg, Federica

    2014-01-01

    It is now well established that the effector T cell (Teff) response is regulated by a series of metabolic switches. Quiescent T cells predominantly require adenosine triphosphate-generating processes, whereas proliferating Teff require high metabolic flux through growth-promoting pathways, such as glycolysis. Pathways that control metabolism and immune cell function are intimately linked, and changes in cell metabolism at both the cell and system levels have been shown to enhance or suppress specific T cell effector functions. Furthermore, functionally distinct T cell subsets require distinct energetic and biosynthetic pathways to support their specific functional needs. In particular, naturally occurring regulatory T cells (Treg) are characterized by a unique metabolic signature distinct to that of conventional Teff cells. We here briefly review the signaling pathways that control Treg metabolism and how this metabolic phenotype integrates their differentiation and function. Ultimately, these metabolic features may provide new opportunities for the therapeutic modulation of unwanted immune responses. PMID:25477880

  5. Unity power factor switching regulator

    NASA Technical Reports Server (NTRS)

    Rippel, Wally E. (Inventor)

    1983-01-01

    A single or multiphase boost chopper regulator operating with unity power factor, for use such as to charge a battery is comprised of a power section for converting single or multiphase line energy into recharge energy including a rectifier (10), one inductor (L.sub.1) and one chopper (Q.sub.1) for each chopper phase for presenting a load (battery) with a current output, and duty cycle control means (16) for each chopper to control the average inductor current over each period of the chopper, and a sensing and control section including means (20) for sensing at least one load parameter, means (22) for producing a current command signal as a function of said parameter, means (26) for producing a feedback signal as a function of said current command signal and the average rectifier voltage output over each period of the chopper, means (28) for sensing current through said inductor, means (18) for comparing said feedback signal with said sensed current to produce, in response to a difference, a control signal applied to the duty cycle control means, whereby the average inductor current is proportionate to the average rectifier voltage output over each period of the chopper, and instantaneous line current is thereby maintained proportionate to the instantaneous line voltage, thus achieving a unity power factor. The boost chopper is comprised of a plurality of converters connected in parallel and operated in staggered phase. For optimal harmonic suppression, the duty cycles of the switching converters are evenly spaced, and by negative coupling between pairs 180.degree. out-of-phase, peak currents through the switches can be reduced while reducing the inductor size and mass.

  6. The effect of hyperammonemia on myostatin and myogenic regulatory factor gene expression in broiler embryos

    PubMed Central

    Stern, R.A.; Ashwell, C.M.; Dasarathy, S.; Mozdziak, P.E.

    2015-01-01

    Myogenesis is facilitated by four myogenic regulatory factors and is significantly inhibited by myostatin. The objective of the current study was to examine embryonic gene regulation of myostatin/myogenic regulatory factors, and subsequent manipulations of protein synthesis, in broiler embryos under induced hyperammonemia. Broiler eggs were injected with ammonium acetate solution four times over 48 hours beginning on either embryonic day (ED) 15 or 17. Serum ammonia concentration was significantly higher (P < 0.05) in ammonium acetate injected embryos for both ED17 and ED19 collected samples when compared to sham-injected controls. Expression of mRNA, extracted from pectoralis major of experimental and control embryos, was measured using real-time quantitative PCR for myostatin, myogenic regulatory factors myogenic factor 5, myogenic determination factor 1, myogenin, myogenic regulatory factor 4, and paired box 7. A significantly lower (P < 0.01) myostatin expression was accompanied by a higher serum ammonia concentration in both ED17 and ED19 collected samples. Myogenic factor 5 expression was higher (P < 0.05) in ED17 collected samples administered ammonium acetate. In both ED17 and ED19 collected samples, myogenic regulatory factor 4 was lower (P ≤ 0.05) in ammonium acetate injected embryos. No significant difference was seen in myogenic determination factor 1, myogenin, or paired box 7 expression between treatment groups for either age of sample collection. Additionally, there was no significant difference in BrdU staining of histological samples taken from treated and control embryos. Myostatin protein levels were evaluated by Western blot analysis, and also showed lower myostatin expression (P < 0.05). Overall, it appears possible to inhibit myostatin expression through hyperammonemia, which is expected to have a positive effect on embryonic myogenesis and postnatal muscle growth. PMID:25689990

  7. Nitrogen-source regulation of yeast gamma-glutamyl transpeptidase synthesis involves the regulatory network including the GATA zinc-finger factors Gln3, Nil1/Gat1 and Gzf3.

    PubMed Central

    Springael, Jean-Yves; Penninckx, Michel J

    2003-01-01

    In Saccharomyces cerevisiae, the CIS2 gene encodes gamma-glutamyl transpeptidase (gamma-GT; EC 2.3.2.2), the main GSH-degrading enzyme. The promoter region of CIS2 contains one stress-response element (CCCCT) and eight GAT(T/A)A core sequences, probably involved in nitrogen-regulated transcription. We show in the present study that expression of CIS2 is indeed regulated according to the nature of the nitrogen source. Expression is highest in cells growing on a poor nitrogen source such as urea. Under these conditions, the GATA zinc-finger transcription factors Nil1 and Gln3 are both required for CIS2 expression, Nil1 appearing as the more important factor. We further show that Gzf3, another GATA zinc-finger protein, acts as a negative regulator in nitrogen-source control of CIS2 expression. During growth on a preferred nitrogen source like NH(4)(+), CIS2 expression is repressed through a mechanism involving (at least) the Gln3-binding protein Ure2/GdhCR. Induction of CIS2 expression during nitrogen starvation is dependent on Gln3 and Nil1. Furthermore, rapamycin causes similar CIS2 activation, indicating that the target of rapamycin signalling pathway controls CIS2 expression via Gln3 and Nil1 in nitrogen-starved cells. Finally, our results show that CIS2 expression is induced mainly by nitrogen starvation but apparently not by other types of stress. PMID:12529169

  8. Putative regulatory factors associated with intramuscular fat content.

    PubMed

    Cesar, Aline S M; Regitano, Luciana C A; Koltes, James E; Fritz-Waters, Eric R; Lanna, Dante P D; Gasparin, Gustavo; Mourão, Gerson B; Oliveira, Priscila S N; Reecy, James M; Coutinho, Luiz L

    2015-01-01

    Intramuscular fat (IMF) content is related to insulin resistance, which is an important prediction factor for disorders, such as cardiovascular disease, obesity and type 2 diabetes in human. At the same time, it is an economically important trait, which influences the sensorial and nutritional value of meat. The deposition of IMF is influenced by many factors such as sex, age, nutrition, and genetics. In this study Nellore steers (Bos taurus indicus subspecies) were used to better understand the molecular mechanisms involved in IMF content. This was accomplished by identifying differentially expressed genes (DEG), biological pathways and putative regulatory factors. Animals included in this study had extreme genomic estimated breeding value (GEBV) for IMF. RNA-seq analysis, gene set enrichment analysis (GSEA) and co-expression network methods, such as partial correlation coefficient with information theory (PCIT), regulatory impact factor (RIF) and phenotypic impact factor (PIF) were utilized to better understand intramuscular adipogenesis. A total of 16,101 genes were analyzed in both groups (high (H) and low (L) GEBV) and 77 DEG (FDR 10%) were identified between the two groups. Pathway Studio software identified 13 significantly over-represented pathways, functional classes and small molecule signaling pathways within the DEG list. PCIT analyses identified genes with a difference in the number of gene-gene correlations between H and L group and detected putative regulatory factors involved in IMF content. Candidate genes identified by PCIT include: ANKRD26, HOXC5 and PPAPDC2. RIF and PIF analyses identified several candidate genes: GLI2 and IGF2 (RIF1), MPC1 and UBL5 (RIF2) and a host of small RNAs, including miR-1281 (PIF). These findings contribute to a better understanding of the molecular mechanisms that underlie fat content and energy balance in muscle and provide important information for the production of healthier beef for human consumption. PMID:26042666

  9. Putative Regulatory Factors Associated with Intramuscular Fat Content

    PubMed Central

    Cesar, Aline S. M.; Regitano, Luciana C. A.; Koltes, James E.; Fritz-Waters, Eric R.; Lanna, Dante P. D.; Gasparin, Gustavo; Mourão, Gerson B.; Oliveira, Priscila S. N.; Reecy, James M.; Coutinho, Luiz L.

    2015-01-01

    Intramuscular fat (IMF) content is related to insulin resistance, which is an important prediction factor for disorders, such as cardiovascular disease, obesity and type 2 diabetes in human. At the same time, it is an economically important trait, which influences the sensorial and nutritional value of meat. The deposition of IMF is influenced by many factors such as sex, age, nutrition, and genetics. In this study Nellore steers (Bos taurus indicus subspecies) were used to better understand the molecular mechanisms involved in IMF content. This was accomplished by identifying differentially expressed genes (DEG), biological pathways and putative regulatory factors. Animals included in this study had extreme genomic estimated breeding value (GEBV) for IMF. RNA-seq analysis, gene set enrichment analysis (GSEA) and co-expression network methods, such as partial correlation coefficient with information theory (PCIT), regulatory impact factor (RIF) and phenotypic impact factor (PIF) were utilized to better understand intramuscular adipogenesis. A total of 16,101 genes were analyzed in both groups (high (H) and low (L) GEBV) and 77 DEG (FDR 10%) were identified between the two groups. Pathway Studio software identified 13 significantly over-represented pathways, functional classes and small molecule signaling pathways within the DEG list. PCIT analyses identified genes with a difference in the number of gene-gene correlations between H and L group and detected putative regulatory factors involved in IMF content. Candidate genes identified by PCIT include: ANKRD26, HOXC5 and PPAPDC2. RIF and PIF analyses identified several candidate genes: GLI2 and IGF2 (RIF1), MPC1 and UBL5 (RIF2) and a host of small RNAs, including miR-1281 (PIF). These findings contribute to a better understanding of the molecular mechanisms that underlie fat content and energy balance in muscle and provide important information for the production of healthier beef for human consumption. PMID:26042666

  10. REGULATORY OR REGULATING PUBLICS? THE EUROPEAN UNION'S REGULATION OF EMERGING HEALTH TECHNOLOGIES AND CITIZEN PARTICIPATION

    PubMed Central

    Flear, Mark L.; Pickersgill, Martyn D.

    2013-01-01

    ‘Citizen participation’ includes various participatory techniques and is frequently viewed as an unproblematic and important social good when used as part of the regulation of the innovation and implementation of science and technology. This is perhaps especially evident in debates around ‘anticipatory governance’ or ‘upstream engagement’. Here, we interrogate this thesis using the example of the European Union's regulation of emerging health technologies (such as nanotechnology). In this case, citizen participation in regulatory debate is concerned with innovative objects for medical application that are considered to be emergent or not yet concrete. Through synthesising insights from law, regulatory studies, critical theory, and science and technology studies, we seek to cast new light on the promises, paradoxes, and pitfalls of citizen participation as a tool or technology of regulation in itself. As such we aim to generate a new vantage point from which to view the values and sociotechnical imaginaries that are both ‘designed-in’ and ‘designed-out’ of citizen participation. In so doing, we show not only how publics (do not) regulate technologies, but also how citizens themselves are regulated through the techniques of participation. PMID:23222171

  11. Regulatory or regulating publics? The European Union's regulation of emerging health technologies and citizen participation.

    PubMed

    Flear, Mark L; Pickersgill, Martyn D

    2013-01-01

    'Citizen participation' includes various participatory techniques and is frequently viewed as an unproblematic and important social good when used as part of the regulation of the innovation and implementation of science and technology. This is perhaps especially evident in debates around 'anticipatory governance' or 'upstream engagement'. Here, we interrogate this thesis using the example of the European Union's regulation of emerging health technologies (such as nanotechnology). In this case, citizen participation in regulatory debate is concerned with innovative objects for medical application that are considered to be emergent or not yet concrete. Through synthesising insights from law, regulatory studies, critical theory, and science and technology studies, we seek to cast new light on the promises, paradoxes, and pitfalls of citizen participation as a tool or technology of regulation in itself. As such we aim to generate a new vantage point from which to view the values and sociotechnical imaginaries that are both 'designed-in' and 'designed-out' of citizen participation. In so doing, we show not only how publics (do not) regulate technologies, but also how citizens themselves are regulated through the techniques of participation. PMID:23222171

  12. 7 CFR 4284.906 - State laws, local laws, regulatory commission regulations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false State laws, local laws, regulatory commission...-Added Producer Grant Program General § 4284.906 State laws, local laws, regulatory commission regulations. If there are conflicts between this subpart and State or local laws or regulatory...

  13. 7 CFR 4284.906 - State laws, local laws, regulatory commission regulations.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false State laws, local laws, regulatory commission...-Added Producer Grant Program General § 4284.906 State laws, local laws, regulatory commission regulations. If there are conflicts between this subpart and State or local laws or regulatory...

  14. 7 CFR 4284.906 - State laws, local laws, regulatory commission regulations.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false State laws, local laws, regulatory commission...-Added Producer Grant Program General § 4284.906 State laws, local laws, regulatory commission regulations. If there are conflicts between this subpart and State or local laws or regulatory...

  15. Regulatory Impact Analysis: a new tool for better regulation at ANVISA.

    PubMed

    Alves, Flávia Neves Rocha; Peci, Alketa

    2011-08-01

    Regulatory Impact Analysis, which is recommended to regulatory departments, aims to improve regulatory quality by providing information about the costs and benefits of regulation as well as solutions to current issues to enhance the decision-making process. This article discusses the importance of Regulatory Impact Analysis in the context of the National Agency for Sanitary Surveillance performance as well as the agency's current phase of regulation improvement and strengthening. Also, the main definitions related to the regulatory field as well as some international case experiences are presented. PMID:21779641

  16. Tumor suppressor properties of the splicing regulatory factor RBM10.

    PubMed

    Hernández, Jordi; Bechara, Elias; Schlesinger, Doerte; Delgado, Javier; Serrano, Luis; Valcárcel, Juan

    2016-04-01

    RBM10 is an RNA binding protein and alternative splicing regulator frequently mutated in lung adenocarcinomas. Recent results indicate that RBM10 inhibits proliferation of lung cancer cells by promoting skipping of exon 9 of the gene NUMB, a frequent alternative splicing change in lung cancer generating a negative regulator of Notch signaling. Complementing these observations, we show that knock down of RBM10 in human cancer cells enhances growth of mouse tumor xenografts, confirming that RBM10 acts as a tumor suppressor, while knock down of an oncogenic mutant version of RBM10 reduces xenograft tumor growth. A RBM10 mutation found in lung cancer cells, V354E, disrupts RBM10-mediated regulation of NUMB alternative splicing, inducing the cell proliferation-promoting isoform. We now show that 2 natural RBM10 isoforms that differ by the presence or absence of V354 in the second RNA Recognition Motif (RRM2), display similar regulatory effects on NUMB alternative splicing, suggesting that V354E actively disrupts RBM10 activity. Structural modeling localizes V354 in the outside surface of one α-helix opposite to the RNA binding surface of RBM10, and we show that the mutation does not compromise binding of the RRM2 domain to NUMB RNA regulatory sequences. We further show that other RBM10 mutations found in lung adenocarcinomas also compromise regulation of NUMB exon 9. Collectively, our previous and current results reveal that RBM10 is a tumor suppressor that represses Notch signaling and cell proliferation through the regulation of NUMB alternative splicing. PMID:26853560

  17. Tumor suppressor properties of the splicing regulatory factor RBM10

    PubMed Central

    Hernández, Jordi; Bechara, Elias; Schlesinger, Doerte; Delgado, Javier; Serrano, Luis; Valcárcel, Juan

    2016-01-01

    ABSTRACT RBM10 is an RNA binding protein and alternative splicing regulator frequently mutated in lung adenocarcinomas. Recent results indicate that RBM10 inhibits proliferation of lung cancer cells by promoting skipping of exon 9 of the gene NUMB, a frequent alternative splicing change in lung cancer generating a negative regulator of Notch signaling. Complementing these observations, we show that knock down of RBM10 in human cancer cells enhances growth of mouse tumor xenografts, confirming that RBM10 acts as a tumor suppressor, while knock down of an oncogenic mutant version of RBM10 reduces xenograft tumor growth. A RBM10 mutation found in lung cancer cells, V354E, disrupts RBM10-mediated regulation of NUMB alternative splicing, inducing the cell proliferation-promoting isoform. We now show that 2 natural RBM10 isoforms that differ by the presence or absence of V354 in the second RNA Recognition Motif (RRM2), display similar regulatory effects on NUMB alternative splicing, suggesting that V354E actively disrupts RBM10 activity. Structural modeling localizes V354 in the outside surface of one α-helix opposite to the RNA binding surface of RBM10, and we show that the mutation does not compromise binding of the RRM2 domain to NUMB RNA regulatory sequences. We further show that other RBM10 mutations found in lung adenocarcinomas also compromise regulation of NUMB exon 9. Collectively, our previous and current results reveal that RBM10 is a tumor suppressor that represses Notch signaling and cell proliferation through the regulation of NUMB alternative splicing. PMID:26853560

  18. Regulatory module network of basic/helix-loop-helix transcription factors in mouse brain

    PubMed Central

    Li, Jing; Liu, Zijing J; Pan, Yuchun C; Liu, Qi; Fu, Xing; Cooper, Nigel GF; Li, Yixue; Qiu, Mengsheng; Shi, Tieliu

    2007-01-01

    Background The basic/helix-loop-helix (bHLH) proteins are important components of the transcriptional regulatory network, controlling a variety of biological processes, especially the development of the central nervous system. Until now, reports describing the regulatory network of the bHLH transcription factor (TF) family have been scarce. In order to understand the regulatory mechanisms of bHLH TFs in mouse brain, we inferred their regulatory network from genome-wide gene expression profiles with the module networks method. Results A regulatory network comprising 15 important bHLH TFs and 153 target genes was constructed. The network was divided into 28 modules based on expression profiles. A regulatory-motif search shows the complexity and diversity of the network. In addition, 26 cooperative bHLH TF pairs were also detected in the network. This cooperation suggests possible physical interactions or genetic regulation between TFs. Interestingly, some TFs in the network regulate more than one module. A novel cross-repression between Neurod6 and Hey2 was identified, which may control various functions in different brain regions. The presence of TF binding sites (TFBSs) in the promoter regions of their target genes validates more than 70% of TF-target gene pairs of the network. Literature mining provides additional support for five modules. More importantly, the regulatory relationships among selected key components are all validated in mutant mice. Conclusion Our network is reliable and very informative for understanding the role of bHLH TFs in mouse brain development and function. It provides a framework for future experimental analyses. PMID:18021424

  19. Decoding the regulatory landscape of melanoma reveals TEADS as regulators of the invasive cell state

    PubMed Central

    Verfaillie, Annelien; Imrichova, Hana; Atak, Zeynep Kalender; Dewaele, Michael; Rambow, Florian; Hulselmans, Gert; Christiaens, Valerie; Svetlichnyy, Dmitry; Luciani, Flavie; Van den Mooter, Laura; Claerhout, Sofie; Fiers, Mark; Journe, Fabrice; Ghanem, Ghanem-Elias; Herrmann, Carl; Halder, Georg; Marine, Jean-Christophe; Aerts, Stein

    2015-01-01

    Transcriptional reprogramming of proliferative melanoma cells into a phenotypically distinct invasive cell subpopulation is a critical event at the origin of metastatic spreading. Here we generate transcriptome, open chromatin and histone modification maps of melanoma cultures; and integrate this data with existing transcriptome and DNA methylation profiles from tumour biopsies to gain insight into the mechanisms underlying this key reprogramming event. This shows thousands of genomic regulatory regions underlying the proliferative and invasive states, identifying SOX10/MITF and AP-1/TEAD as regulators, respectively. Knockdown of TEADs shows a previously unrecognized role in the invasive gene network and establishes a causative link between these transcription factors, cell invasion and sensitivity to MAPK inhibitors. Using regulatory landscapes and in silico analysis, we show that transcriptional reprogramming underlies the distinct cellular states present in melanoma. Furthermore, it reveals an essential role for the TEADs, linking it to clinically relevant mechanisms such as invasion and resistance. PMID:25865119

  20. Arabidopsis Ensemble Reverse-Engineered Gene Regulatory Network Discloses Interconnected Transcription Factors in Oxidative Stress[W

    PubMed Central

    Vermeirssen, Vanessa; De Clercq, Inge; Van Parys, Thomas; Van Breusegem, Frank; Van de Peer, Yves

    2014-01-01

    The abiotic stress response in plants is complex and tightly controlled by gene regulation. We present an abiotic stress gene regulatory network of 200,014 interactions for 11,938 target genes by integrating four complementary reverse-engineering solutions through average rank aggregation on an Arabidopsis thaliana microarray expression compendium. This ensemble performed the most robustly in benchmarking and greatly expands upon the availability of interactions currently reported. Besides recovering 1182 known regulatory interactions, cis-regulatory motifs and coherent functionalities of target genes corresponded with the predicted transcription factors. We provide a valuable resource of 572 abiotic stress modules of coregulated genes with functional and regulatory information, from which we deduced functional relationships for 1966 uncharacterized genes and many regulators. Using gain- and loss-of-function mutants of seven transcription factors grown under control and salt stress conditions, we experimentally validated 141 out of 271 predictions (52% precision) for 102 selected genes and mapped 148 additional transcription factor-gene regulatory interactions (49% recall). We identified an intricate core oxidative stress regulatory network where NAC13, NAC053, ERF6, WRKY6, and NAC032 transcription factors interconnect and function in detoxification. Our work shows that ensemble reverse-engineering can generate robust biological hypotheses of gene regulation in a multicellular eukaryote that can be tested by medium-throughput experimental validation. PMID:25549671

  1. 3 CFR 13563 - Executive Order 13563 of January 18, 2011. Improving Regulation and Regulatory Review

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 3 The President 1 2012-01-01 2012-01-01 false Executive Order 13563 of January 18, 2011. Improving Regulation and Regulatory Review 13563 Order 13563 Presidential Documents Executive Orders Executive Order 13563 of January 18, 2011 EO 13563 Improving Regulation and Regulatory Review By the authority vested in me as President by the...

  2. 3 CFR 13579 - Executive Order 13579 of July 11, 2011. Regulation and Independent Regulatory Agencies

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 3 The President 1 2012-01-01 2012-01-01 false Executive Order 13579 of July 11, 2011. Regulation and Independent Regulatory Agencies 13579 Order 13579 Presidential Documents Executive Orders Executive Order 13579 of July 11, 2011 EO 13579 Regulation and Independent Regulatory Agencies By the authority vested in me as President by the...

  3. Thymic Versus Induced Regulatory T Cells – Who Regulates the Regulators?

    PubMed Central

    Povoleri, Giovanni Antonio Maria; Scottà, Cristiano; Nova-Lamperti, Estefania Andrea; John, Susan; Lombardi, Giovanna; Afzali, Behdad

    2013-01-01

    Physiological health must balance immunological responsiveness against foreign pathogens with tolerance toward self-components and commensals. Disruption of this balance causes autoimmune diseases/chronic inflammation, in case of excessive immune responses, and persistent infection/immunodeficiency if regulatory components are overactive. This homeostasis occurs at two different levels: at a resting state to prevent autoimmune disease, as autoreactive effector T-cells (Teffs) are only partially deleted in the thymus, and during inflammation to prevent excessive tissue injury, contract the immune response, and enable tissue repair. Adaptive immune cells with regulatory function (“regulatory T-cells”) are essential to control Teffs. Two sets of regulatory T cell are required to achieve the desired control: those emerging de novo from embryonic/neonatal thymus (“thymic” or tTregs), whose function is to control autoreactive Teffs to prevent autoimmune diseases, and those induced in the periphery (“peripheral” or pTregs) to acquire regulatory phenotype in response to pathogens/inflammation. The differentiation mechanisms of these cells determine their commitment to lineage and plasticity toward other phenotypes. tTregs, expressing high levels of IL-2 receptor alpha chain (CD25), and the transcription factor Foxp3, are the most important, since mutations or deletions in these genes cause fatal autoimmune diseases in both mice and men. In the periphery, instead, Foxp3+ pTregs can be induced from naïve precursors in response to environmental signals. Here, we discuss molecular signatures and induction processes, mechanisms and sites of action, lineage stability, and differentiating characteristics of both Foxp3+ and Foxp3− populations of regulatory T cells, derived from the thymus or induced peripherally. We relate these predicates to programs of cell-based therapy for the treatment of autoimmune diseases and induction of tolerance to transplants. PMID

  4. Rel Induces Interferon Regulatory Factor 4 (IRF-4) Expression in Lymphocytes

    PubMed Central

    Grumont, Raelene J.; Gerondakis, Steve

    2000-01-01

    In lymphocytes, the Rel transcription factor is essential in establishing a pattern of gene expression that promotes cell proliferation, survival, and differentiation. Here we show that mitogen-induced expression of interferon (IFN) regulatory factor 4 (IRF-4), a lymphoid-specific member of the IFN family of transcription factors, is Rel dependent. Consistent with IRF-4 functioning as a repressor of IFN-induced gene expression, the absence of IRF-4 expression in c-rel−/− B cells coincided with a greater sensitivity of these cells to the antiproliferative activity of IFNs. In turn, enforced expression of an IRF-4 transgene restored IFN modulated c-rel−/− B cell proliferation to that of wild-type cells. This cross-regulation between two different signaling pathways represents a novel mechanism that Rel/nuclear factor κB can repress the transcription of IFN-regulated genes in a cell type–specific manner. PMID:10770796

  5. Interaction of Trypanosoma cruzi adenylate cyclase with liver regulatory factors.

    PubMed Central

    Eisenschlos, C; Flawiá, M M; Torruella, M; Torres, H N

    1986-01-01

    Trypanosoma cruzi adenylate cyclase catalytic subunits may interact with regulatory factors from rat liver membranes, reconstituting heterologous systems which are catalytically active in assay mixtures containing MgATP. The systems show stimulatory responses to glucagon and guanosine 5'-[beta gamma-imido]triphosphate (p[NH]ppG) or fluoride. Reconstitution was obtained by three different methods: fusion of rat liver membranes (pretreated with N-ethylmaleimide) to T. cruzi membranes; interaction of detergent extracts of rat liver membranes with T. cruzi membranes; or interaction of purified preparations of T. cruzi adenylate cyclase and of liver membrane factors in phospholipid vesicles. The liver factors responsible for the guanine nucleotide effect were characterized as the NS protein. Data also indicate that reconstitution requires the presence of a membrane substrate. PMID:2947568

  6. The regulation and regulatory role of collagenase in bone

    NASA Technical Reports Server (NTRS)

    Partridge, N. C.; Walling, H. W.; Bloch, S. R.; Omura, T. H.; Chan, P. T.; Pearman, A. T.; Chou, W. Y.

    1996-01-01

    Interstitial collagenase plays an important role in both the normal and pathological remodeling of collagenous extracellular matrices, including skeletal tissues. The enzyme is a member of the family of matrix metalloproteinases. Only one rodent interstitial collagenase has been found but there are two human enzymes, human collagenase-1 and -3, the latter being the homologue of the rat enzyme. In developing rat and mouse bone, collagenase is expressed by hypertrophic chondrocytes, osteoblasts, and osteocytes, a situation that is replicated in a fracture callus. Cultured osteoblasts derived from neonatal rat calvariae show greater amounts of collagenase transcripts late in differentiation. These levels can be regulated by parathyroid hormone (PTH), retinoic acid, and insulin-like growth factors, as well as the degree of matrix mineralization. Much of the work on collagenase in bone has been derived from studies on the rat osteosarcoma cell line, UMR 106-01. All bone-resorbing agents stimulate these cells to produce collagenase mRNA and protein, with PTH being the most potent stimulator. Determination of secreted levels of collagenase has been difficult because UMR cells, normal rat osteoblasts, and rat fibroblasts possess a scavenger receptor that removes the enzyme from the extracellular space, internalizes and degrades it, thus imposing another level of control. PTH can also regulate the abundance of the receptor as well as the expression and synthesis of the enzyme. Regulation of the collagenase gene by PTH appears to involve the cAMP pathway as well as a primary response gene, possibly Fos, which then contributes to induction of the collagenase gene. The rat collagenase gene contains an activator protein-1 sequence that is necessary for basal expression, but other promoter regions may also participate in PTH regulation. Thus, there are many levels of regulation of collagenase in bone perhaps constraining what would otherwise be a rampant enzyme.

  7. Regulation by transcription factors in bacteria: beyond description.

    PubMed

    Balleza, Enrique; López-Bojorquez, Lucia N; Martínez-Antonio, Agustino; Resendis-Antonio, Osbaldo; Lozada-Chávez, Irma; Balderas-Martínez, Yalbi I; Encarnación, Sergio; Collado-Vides, Julio

    2009-01-01

    Transcription is an essential step in gene expression and its understanding has been one of the major interests in molecular and cellular biology. By precisely tuning gene expression, transcriptional regulation determines the molecular machinery for developmental plasticity, homeostasis and adaptation. In this review, we transmit the main ideas or concepts behind regulation by transcription factors and give just enough examples to sustain these main ideas, thus avoiding a classical ennumeration of facts. We review recent concepts and developments: cis elements and trans regulatory factors, chromosome organization and structure, transcriptional regulatory networks (TRNs) and transcriptomics. We also summarize new important discoveries that will probably affect the direction of research in gene regulation: epigenetics and stochasticity in transcriptional regulation, synthetic circuits and plasticity and evolution of TRNs. Many of the new discoveries in gene regulation are not extensively tested with wetlab approaches. Consequently, we review this broad area in Inference of TRNs and Dynamical Models of TRNs. Finally, we have stepped backwards to trace the origins of these modern concepts, synthesizing their history in a timeline schema. PMID:19076632

  8. Regulation by transcription factors in bacteria: beyond description

    PubMed Central

    Balleza, Enrique; López-Bojorquez, Lucia N; Martínez-Antonio, Agustino; Resendis-Antonio, Osbaldo; Lozada-Chávez, Irma; Balderas-Martínez, Yalbi I; Encarnación, Sergio; Collado-Vides, Julio

    2009-01-01

    Transcription is an essential step in gene expression and its understanding has been one of the major interests in molecular and cellular biology. By precisely tuning gene expression, transcriptional regulation determines the molecular machinery for developmental plasticity, homeostasis and adaptation. In this review, we transmit the main ideas or concepts behind regulation by transcription factors and give just enough examples to sustain these main ideas, thus avoiding a classical ennumeration of facts. We review recent concepts and developments: cis elements and trans regulatory factors, chromosome organization and structure, transcriptional regulatory networks (TRNs) and transcriptomics. We also summarize new important discoveries that will probably affect the direction of research in gene regulation: epigenetics and stochasticity in transcriptional regulation, synthetic circuits and plasticity and evolution of TRNs. Many of the new discoveries in gene regulation are not extensively tested with wetlab approaches. Consequently, we review this broad area in Inference of TRNs and Dynamical Models of TRNs. Finally, we have stepped backwards to trace the origins of these modern concepts, synthesizing their history in a timeline schema. PMID:19076632

  9. [ASSESSMENT OF EXTREME FACTORS OF SHIFT WORK IN ARCTIC CONDITIONS BY WORKERS WITH DIFFERENT REGULATORY PROCESSES].

    PubMed

    Korneeva, Ya A; Simonova, N N

    2016-01-01

    A man working on a shift basis in the Arctic, every day is under the influence of various extreme factors which are inevitable for oil and gas indudtry. To adapt to shift work employees use various resources of the individual. The purpose of research is the determination of personal resources of shift workers to overcome the adverse factors of the environment in the Arctic. The study involved 191 builder of main gas pipelines, working in shifts in the Tyumen region (the length of the shift 52 days of arrival) at the age of 23 to 59 (mean age 34.9 ± 8.1) years. Methods: psychological testing, questioning, observation, descriptive statistics, discriminant step by step analysis. There was revealed the correlation between the subjective assessment of the majority of adverse climatic factors in the regulatory process "assessment of results"; production factors--regulatory processes such as flexibility, autonomy, simulation, and the general level of self-regulation; social factors are more associated with the severity of such regulatory processes, flexibility and evaluation of results. PMID:27430072

  10. Rgg influences the expression of multiple regulatory loci to coregulate virulence factor expression in Streptococcus pyogenes.

    PubMed

    Chaussee, Michael S; Sylva, Gail L; Sturdevant, Daniel E; Smoot, Laura M; Graham, Morag R; Watson, Robert O; Musser, James M

    2002-02-01

    The human pathogen Streptococcus pyogenes secretes many proteins to the cell wall and extracellular environment that contribute to virulence. Rgg regulates the expression of several exoproteins including a cysteine protease (SPE B), a nuclease (MF-1), a putative nuclease (MF-3), and autolysin. The functional heterogeneity of Rgg-regulated exoproteins and the lack of a conserved regulatory motif in the promoter regions of the genes suggested that Rgg interacts with additional regulatory networks to influence gene expression. DNA microarrays were used to test this hypothesis by comparing genomewide transcript profiles of S. pyogenes NZ131 and isogenic derivative NZ131 rgg during the exponential phase of growth. Transcripts of known and putative virulence-associated genes were more abundant in the rgg mutant, including emm, scpA, orfX, scl1, hasAB, slo, sagA, ska, speH, grab, mac, mf-1, and mf-3. Increased transcription of emm, scpA, and orfX in the rgg mutant was associated with increased production of the corresponding proteins. Differences in the expression of virulence-associated genes were associated with changes in the expression of several regulatory genes, including mga, sagA, csrRS, and fasBCA. The results show that Rgg influences the expression of multiple regulatory networks to coregulate virulence factor expression in S. pyogenes. PMID:11796609

  11. Ethylene Response Factors: A Key Regulatory Hub in Hormone and Stress Signaling.

    PubMed

    Müller, Maren; Munné-Bosch, Sergi

    2015-09-01

    Ethylene is essential for many developmental processes and a key mediator of biotic and abiotic stress responses in plants. The ethylene signaling and response pathway includes Ethylene Response Factors (ERFs), which belong to the transcription factor family APETALA2/ERF. It is well known that ERFs regulate molecular response to pathogen attack by binding to sequences containing AGCCGCC motifs (the GCC box), a cis-acting element. However, recent studies suggest that several ERFs also bind to dehydration-responsive elements and act as a key regulatory hub in plant responses to abiotic stresses. Here, we review some of the recent advances in our understanding of the ethylene signaling and response pathway, with emphasis on ERFs and their role in hormone cross talk and redox signaling under abiotic stresses. We conclude that ERFs act as a key regulatory hub, integrating ethylene, abscisic acid, jasmonate, and redox signaling in the plant response to a number of abiotic stresses. PMID:26103991

  12. Amphiregulin enhances regulatory T cell-suppressive function via the epidermal growth factor receptor.

    PubMed

    Zaiss, Dietmar M W; van Loosdregt, Jorg; Gorlani, Andrea; Bekker, Cornelis P J; Gröne, Andrea; Sibilia, Maria; van Bergen en Henegouwen, Paul M P; Roovers, Rob C; Coffer, Paul J; Sijts, Alice J A M

    2013-02-21

    Epidermal growth factor receptor (EGFR) is known to be critically involved in tissue development and homeostasis as well as in the pathogenesis of cancer. Here we showed that Foxp3(+) regulatory T (Treg) cells express EGFR under inflammatory conditions. Stimulation with the EGF-like growth factor Amphiregulin (AREG) markedly enhanced Treg cell function in vitro, and in a colitis and tumor vaccination model we showed that AREG was critical for efficient Treg cell function in vivo. In addition, mast cell-derived AREG fully restored optimal Treg cell function. These findings reveal EGFR as a component in the regulation of local immune responses and establish a link between mast cells and Treg cells. Targeting of this immune regulatory mechanism may contribute to the therapeutic successes of EGFR-targeting treatments in cancer patients. PMID:23333074

  13. Total Binding Affinity Profiles of Regulatory Regions Predict Transcription Factor Binding and Gene Expression in Human Cells

    PubMed Central

    Molineris, Ivan; Provero, Paolo

    2015-01-01

    Transcription factors regulate gene expression by binding regulatory DNA. Understanding the rules governing such binding is an essential step in describing the network of regulatory interactions, and its pathological alterations. We show that describing regulatory regions in terms of their profile of total binding affinities for transcription factors leads to increased predictive power compared to methods based on the identification of discrete binding sites. This applies both to the prediction of transcription factor binding as revealed by ChIP-seq experiments and to the prediction of gene expression through RNA-seq. Further significant improvements in predictive power are obtained when regulatory regions are defined based on chromatin states inferred from histone modification data. PMID:26599758

  14. Interaction between Major Nitrogen Regulatory Protein NIT2 and Pathway-Specific Regulatory Factor NIT4 Is Required for Their Synergistic Activation of Gene Expression in Neurospora crassa

    PubMed Central

    Feng, Bo; Marzluf, George A.

    1998-01-01

    In Neurospora crassa, the major nitrogen regulatory protein, NIT2, a member of the GATA family of transcription factors, controls positively the expression of numerous genes which specify nitrogen catabolic enzymes. Expression of the highly regulated structural gene nit-3, which encodes nitrate reductase, is dependent upon a synergistic interaction of NIT2 with a pathway-specific control protein, NIT4, a member of the GAL4 family of fungal regulatory factors. The NIT2 and NIT4 proteins both bind at specific recognition elements in the nit-3 promoter, but, in addition, we show that a direct protein-protein interaction between NIT2 and NIT4 is essential for optimal expression of the nit-3 structural gene. Neurospora possesses at least five different GATA factors which control different areas of cellular function, but which have a similar DNA binding specificity. Significantly, only NIT2, of the several Neurospora GATA factors examined, interacts with NIT4. We propose that protein-protein interactions of the individual GATA factors with additional pathway-specific regulatory factors determine each of their specific regulatory functions. PMID:9632783

  15. What explains regulatory failure? Analysing the architecture of health care regulation in two Indian states.

    PubMed

    Sheikh, Kabir; Saligram, Prasanna S; Hort, Krishna

    2015-02-01

    Regulating health care is a pre-eminent policy challenge in many low- and middle-income countries (LMIC), particularly those with a strong private health sector. Yet, the regulatory approaches instituted in these countries have often been reported to be ineffective-India being exemplary. There is limited empirical research on the architecture and processes of health care regulation in LMIC that would explain these regulatory failures. We undertook a research study in two Indian states, with the aims of (1) mapping the organizations engaged with, and the written policies focused on health care regulation, (2) identifying gaps in the design and implementation of policies for health care regulation and (3) investigating underlying reasons for the identified gaps. We adopted a stepped research approach and applied a framework of basic regulatory functions for health care, to assess prevailing gaps in policy design and implementation. Qualitative research methods were employed including in-depth interviews with 32 representatives of regulatory organizations and document review. Several gaps in policy design were observed across both states, with a number of basic regulatory functions not underwritten in law, nor assigned to a regulatory organization to enact. In some instances the contents of regulatory policies had been weakened or diluted, rendering them less effective. Implementation gaps were also extensively reported in both states. Regulatory gaps were underpinned by human resource constraints, ambivalence in the roles of regulatory organizations, ineffective co-ordination between regulatory groups and extensive contestation of regulatory policies by private stakeholders. The findings are instructive that prevailing arrangements for health care regulation are ill equipped to enact several basic functions, and further that the performance of regulatory organizations is subject to pressures and distortions similar to those characterizing the wider health system

  16. INTERFERON REGULATORY FACTOR 4 AND 8 IN B CELL DEVELOPMENT

    PubMed Central

    Lu, Runqing

    2010-01-01

    IRF4 and 8 are members of the interferon regulatory factor family of transcription factors and have been shown to be essential for the development and function of T cells, macrophages and dendritic cells. A series of recent studies have further demonstrated critical functions for IRF4 and 8 at several stages of B cell development including pre-B cell development, receptor editing, germinal center reaction and plasma cell generation. Collectively, these new studies provide molecular insights into the function of IRF4 and 8 and underscore a requirement for IRF4 and 8 throughout B cell development. This review focuses on the recent advances on roles of IRF4 and 8 in B cell development. PMID:18775669

  17. Transcription factor MITF and remodeller BRG1 define chromatin organisation at regulatory elements in melanoma cells

    PubMed Central

    Laurette, Patrick; Strub, Thomas; Koludrovic, Dana; Keime, Céline; Le Gras, Stéphanie; Seberg, Hannah; Van Otterloo, Eric; Imrichova, Hana; Siddaway, Robert; Aerts, Stein; Cornell, Robert A; Mengus, Gabrielle; Davidson, Irwin

    2015-01-01

    Microphthalmia-associated transcription factor (MITF) is the master regulator of the melanocyte lineage. To understand how MITF regulates transcription, we used tandem affinity purification and mass spectrometry to define a comprehensive MITF interactome identifying novel cofactors involved in transcription, DNA replication and repair, and chromatin organisation. We show that MITF interacts with a PBAF chromatin remodelling complex comprising BRG1 and CHD7. BRG1 is essential for melanoma cell proliferation in vitro and for normal melanocyte development in vivo. MITF and SOX10 actively recruit BRG1 to a set of MITF-associated regulatory elements (MAREs) at active enhancers. Combinations of MITF, SOX10, TFAP2A, and YY1 bind between two BRG1-occupied nucleosomes thus defining both a signature of transcription factors essential for the melanocyte lineage and a specific chromatin organisation of the regulatory elements they occupy. BRG1 also regulates the dynamics of MITF genomic occupancy. MITF-BRG1 interplay thus plays an essential role in transcription regulation in melanoma. DOI: http://dx.doi.org/10.7554/eLife.06857.001 PMID:25803486

  18. Reconstructing genome-wide regulatory network of E. coli using transcriptome data and predicted transcription factor activities

    PubMed Central

    2011-01-01

    Background Gene regulatory networks play essential roles in living organisms to control growth, keep internal metabolism running and respond to external environmental changes. Understanding the connections and the activity levels of regulators is important for the research of gene regulatory networks. While relevance score based algorithms that reconstruct gene regulatory networks from transcriptome data can infer genome-wide gene regulatory networks, they are unfortunately prone to false positive results. Transcription factor activities (TFAs) quantitatively reflect the ability of the transcription factor to regulate target genes. However, classic relevance score based gene regulatory network reconstruction algorithms use models do not include the TFA layer, thus missing a key regulatory element. Results This work integrates TFA prediction algorithms with relevance score based network reconstruction algorithms to reconstruct gene regulatory networks with improved accuracy over classic relevance score based algorithms. This method is called Gene expression and Transcription factor activity based Relevance Network (GTRNetwork). Different combinations of TFA prediction algorithms and relevance score functions have been applied to find the most efficient combination. When the integrated GTRNetwork method was applied to E. coli data, the reconstructed genome-wide gene regulatory network predicted 381 new regulatory links. This reconstructed gene regulatory network including the predicted new regulatory links show promising biological significances. Many of the new links are verified by known TF binding site information, and many other links can be verified from the literature and databases such as EcoCyc. The reconstructed gene regulatory network is applied to a recent transcriptome analysis of E. coli during isobutanol stress. In addition to the 16 significantly changed TFAs detected in the original paper, another 7 significantly changed TFAs have been detected by

  19. Functional antagonism between inhibitor of DNA binding (Id) and adipocyte determination and differentiation factor 1/sterol regulatory element-binding protein-1c (ADD1/SREBP-1c) trans-factors for the regulation of fatty acid synthase promoter in adipocytes.

    PubMed Central

    Moldes, M; Boizard, M; Liepvre, X L; Fève, B; Dugail, I; Pairault, J

    1999-01-01

    We show that Id (inhibitor of DNA binding) 2 and Id3, dominant negative members of the helix-loop-helix (HLH) family, interact with the adipocyte determination and differentiation factor 1 (ADD1)/sterol regulatory element-binding protein (SREBP) 1c, a transcription factor of the basic HLH-leucine zipper family that controls the expression of several key genes of adipose metabolism. Gel mobility-shift assays performed with in vitro-translated ADD1, Id2 or Id3 proteins and a fatty acid synthase (FAS) promoter oligonucleotide showed evidence for a marked inhibition of the formation of DNA-ADD1 complexes by Id2 or Id3 proteins. Co-immunoprecipitation studies using in vitro-translated proteins demonstrated further the physical interaction of Id and ADD1/SREBP-1c proteins in the absence of DNA. Using the FAS gene as a model of an ADD1-regulated promoter in transiently transfected isolated rat adipocytes or mature 3T3-L1 adipocytes, a potent inhibition of the activity of the FAS-chloramphenicol acetyltransferase reporter gene was observed by overexpression of Id2 or Id3. Reciprocally, co-transfection of Id3 antisense and ADD1 expression vectors in preadipocytes potentiated the ADD1/SREBP-1c effect on the FAS promoter activity. Finally, in the non adipogenic NIH-3T3 cell line, most of the ADD1-mediated trans-activation of the FAS promoter was counteracted by co-transfection of Id2 or Id3 expression vectors. Previous studies have indicated Id gene expression to be down-regulated during adipogenesis [Moldes, Lasnier, Fève, Pairault and Djian (1997) Mol. Cell. Biol. 17, 1796-1804]. We here demonstrated that there was a dramatic rise of Id2 and Id3 mRNA levels when 3T3-L1 adipocytes or isolated rat fat cells were exposed to lipolytic and anti-lipogenic agents, forskolin and isoproterenol. Taken together, our data show that Id products are functionally involved in modulating ADD1/SREBP-1c transcriptional activity, and thus lipogenesis in adipocytes. PMID:10585876

  20. Transcription profile of Escherichia coli: genomic SELEX search for regulatory targets of transcription factors

    PubMed Central

    Ishihama, Akira; Shimada, Tomohiro; Yamazaki, Yukiko

    2016-01-01

    Bacterial genomes are transcribed by DNA-dependent RNA polymerase (RNAP), which achieves gene selectivity through interaction with sigma factors that recognize promoters, and transcription factors (TFs) that control the activity and specificity of RNAP holoenzyme. To understand the molecular mechanisms of transcriptional regulation, the identification of regulatory targets is needed for all these factors. We then performed genomic SELEX screenings of targets under the control of each sigma factor and each TF. Here we describe the assembly of 156 SELEX patterns of a total of 116 TFs performed in the presence and absence of effector ligands. The results reveal several novel concepts: (i) each TF regulates more targets than hitherto recognized; (ii) each promoter is regulated by more TFs than hitherto recognized; and (iii) the binding sites of some TFs are located within operons and even inside open reading frames. The binding sites of a set of global regulators, including cAMP receptor protein, LeuO and Lrp, overlap with those of the silencer H-NS, suggesting that certain global regulators play an anti-silencing role. To facilitate sharing of these accumulated SELEX datasets with the research community, we compiled a database, ‘Transcription Profile of Escherichia coli’ (www.shigen.nig.ac.jp/ecoli/tec/). PMID:26843427

  1. Transcription profile of Escherichia coli: genomic SELEX search for regulatory targets of transcription factors.

    PubMed

    Ishihama, Akira; Shimada, Tomohiro; Yamazaki, Yukiko

    2016-03-18

    Bacterial genomes are transcribed by DNA-dependent RNA polymerase (RNAP), which achieves gene selectivity through interaction with sigma factors that recognize promoters, and transcription factors (TFs) that control the activity and specificity of RNAP holoenzyme. To understand the molecular mechanisms of transcriptional regulation, the identification of regulatory targets is needed for all these factors. We then performed genomic SELEX screenings of targets under the control of each sigma factor and each TF. Here we describe the assembly of 156 SELEX patterns of a total of 116 TFs performed in the presence and absence of effector ligands. The results reveal several novel concepts: (i) each TF regulates more targets than hitherto recognized; (ii) each promoter is regulated by more TFs than hitherto recognized; and (iii) the binding sites of some TFs are located within operons and even inside open reading frames. The binding sites of a set of global regulators, including cAMP receptor protein, LeuO and Lrp, overlap with those of the silencer H-NS, suggesting that certain global regulators play an anti-silencing role. To facilitate sharing of these accumulated SELEX datasets with the research community, we compiled a database, 'Transcription Profile of Escherichia coli' (www.shigen.nig.ac.jp/ecoli/tec/). PMID:26843427

  2. T regulatory cells and their counterparts: masters of immune regulation.

    PubMed

    Ozdemir, C; Akdis, M; Akdis, C A

    2009-05-01

    The interaction of environmental and genetic factors with the immune system can lead to the development of allergic diseases. The essential step in this progress is the generation of allergen-specific CD4(+) T-helper (Th) type 2 cells that mediate several effector functions. The influence of Th2 cytokines leads to the production of allergen-specific IgE antibodies by B cells, development and recruitment of eosinophils, mucus production and bronchial hyperreactivity, as well as tissue homing of other Th2 cells and eosinophils. Meanwhile, Th1 cells may contribute to chronicity and the effector phases. T cells termed T regulatory (Treg) cells, which have immunosuppressive functions and cytokine profiles distinct from that of either Th1 or Th2 cells, have been intensely investigated during the last 13 years. Treg cell response is characterized by an abolished allergen-specific T cell proliferation and the suppressed secretion of Th1 and Th2-type cytokines. Treg cells are able to inhibit the development of allergen-specific Th2 and Th1 cell responses and therefore play an important role in a healthy immune response to allergens. In addition, Treg cells potently suppress IgE production and directly or indirectly suppress the activity of effector cells of allergic inflammation, such as eosinophils, basophils and mast cells. Currently, Treg cells represent an exciting area of research, where understanding the mechanisms of peripheral tolerance to allergens may soon lead to more rational and safer approaches for the prevention and cure of allergic diseases. PMID:19422105

  3. Clinical trials in "emerging markets": regulatory considerations and other factors.

    PubMed

    Singh, Romi; Wang, Ouhong

    2013-11-01

    Clinical studies are being placed in emerging markets as part of global drug development programs to access large pool of eligible patients and to benefit from a cost effective structure. However, over the last few years, the definition of "emerging markets" is being revisited, especially from a regulatory perspective. For purposes of this article, countries outside US, EU and the traditional "western countries" are discussed. Multiple factors are considered for placement of clinical studies such as adherence to Good Clinical Practice (GCP), medical infrastructure & standard of care, number of eligible patients, etc. This article also discusses other quantitative factors such as country's GDP, patent applications, healthcare expenditure, healthcare infrastructure, corruption, innovation, etc. These different factors and indexes are correlated to the number of clinical studies ongoing in the "emerging markets". R&D, healthcare expenditure, technology infrastructure, transparency, and level of innovation, show a significant correlation with the number of clinical trials being conducted in these countries. This is the first analysis of its kind to evaluate and correlate the various other factors to the number of clinical studies in a country. PMID:24070788

  4. A validated gene regulatory network and GWAS identifies early regulators of T cell-associated diseases.

    PubMed

    Gustafsson, Mika; Gawel, Danuta R; Alfredsson, Lars; Baranzini, Sergio; Björkander, Janne; Blomgran, Robert; Hellberg, Sandra; Eklund, Daniel; Ernerudh, Jan; Kockum, Ingrid; Konstantinell, Aelita; Lahesmaa, Riita; Lentini, Antonio; Liljenström, H Robert I; Mattson, Lina; Matussek, Andreas; Mellergård, Johan; Mendez, Melissa; Olsson, Tomas; Pujana, Miguel A; Rasool, Omid; Serra-Musach, Jordi; Stenmarker, Margaretha; Tripathi, Subhash; Viitala, Miro; Wang, Hui; Zhang, Huan; Nestor, Colm E; Benson, Mikael

    2015-11-11

    Early regulators of disease may increase understanding of disease mechanisms and serve as markers for presymptomatic diagnosis and treatment. However, early regulators are difficult to identify because patients generally present after they are symptomatic. We hypothesized that early regulators of T cell-associated diseases could be found by identifying upstream transcription factors (TFs) in T cell differentiation and by prioritizing hub TFs that were enriched for disease-associated polymorphisms. A gene regulatory network (GRN) was constructed by time series profiling of the transcriptomes and methylomes of human CD4(+) T cells during in vitro differentiation into four helper T cell lineages, in combination with sequence-based TF binding predictions. The TFs GATA3, MAF, and MYB were identified as early regulators and validated by ChIP-seq (chromatin immunoprecipitation sequencing) and small interfering RNA knockdowns. Differential mRNA expression of the TFs and their targets in T cell-associated diseases supports their clinical relevance. To directly test if the TFs were altered early in disease, T cells from patients with two T cell-mediated diseases, multiple sclerosis and seasonal allergic rhinitis, were analyzed. Strikingly, the TFs were differentially expressed during asymptomatic stages of both diseases, whereas their targets showed altered expression during symptomatic stages. This analytical strategy to identify early regulators of disease by combining GRNs with genome-wide association studies may be generally applicable for functional and clinical studies of early disease development. PMID:26560356

  5. Transcriptional Regulatory Network Analysis of MYB Transcription Factor Family Genes in Rice

    PubMed Central

    Smita, Shuchi; Katiyar, Amit; Chinnusamy, Viswanathan; Pandey, Dev M.; Bansal, Kailash C.

    2015-01-01

    MYB transcription factor (TF) is one of the largest TF families and regulates defense responses to various stresses, hormone signaling as well as many metabolic and developmental processes in plants. Understanding these regulatory hierarchies of gene expression networks in response to developmental and environmental cues is a major challenge due to the complex interactions between the genetic elements. Correlation analyses are useful to unravel co-regulated gene pairs governing biological process as well as identification of new candidate hub genes in response to these complex processes. High throughput expression profiling data are highly useful for construction of co-expression networks. In the present study, we utilized transcriptome data for comprehensive regulatory network studies of MYB TFs by “top-down” and “guide-gene” approaches. More than 50% of OsMYBs were strongly correlated under 50 experimental conditions with 51 hub genes via “top-down” approach. Further, clusters were identified using Markov Clustering (MCL). To maximize the clustering performance, parameter evaluation of the MCL inflation score (I) was performed in terms of enriched GO categories by measuring F-score. Comparison of co-expressed cluster and clads analyzed from phylogenetic analysis signifies their evolutionarily conserved co-regulatory role. We utilized compendium of known interaction and biological role with Gene Ontology enrichment analysis to hypothesize function of coexpressed OsMYBs. In the other part, the transcriptional regulatory network analysis by “guide-gene” approach revealed 40 putative targets of 26 OsMYB TF hubs with high correlation value utilizing 815 microarray data. The putative targets with MYB-binding cis-elements enrichment in their promoter region, functional co-occurrence as well as nuclear localization supports our finding. Specially, enrichment of MYB binding regions involved in drought-inducibility implying their regulatory role in drought

  6. Inferring the role of transcription factors in regulatory networks

    PubMed Central

    Veber, Philippe; Guziolowski, Carito; Le Borgne, Michel; Radulescu, Ovidiu; Siegel, Anne

    2008-01-01

    Background Expression profiles obtained from multiple perturbation experiments are increasingly used to reconstruct transcriptional regulatory networks, from well studied, simple organisms up to higher eukaryotes. Admittedly, a key ingredient in developing a reconstruction method is its ability to integrate heterogeneous sources of information, as well as to comply with practical observability issues: measurements can be scarce or noisy. In this work, we show how to combine a network of genetic regulations with a set of expression profiles, in order to infer the functional effect of the regulations, as inducer or repressor. Our approach is based on a consistency rule between a network and the signs of variation given by expression arrays. Results We evaluate our approach in several settings of increasing complexity. First, we generate artificial expression data on a transcriptional network of E. coli extracted from the literature (1529 nodes and 3802 edges), and we estimate that 30% of the regulations can be annotated with about 30 profiles. We additionally prove that at most 40.8% of the network can be inferred using our approach. Second, we use this network in order to validate the predictions obtained with a compendium of real expression profiles. We describe a filtering algorithm that generates particularly reliable predictions. Finally, we apply our inference approach to S. cerevisiae transcriptional network (2419 nodes and 4344 interactions), by combining ChIP-chip data and 15 expression profiles. We are able to detect and isolate inconsistencies between the expression profiles and a significant portion of the model (15% of all the interactions). In addition, we report predictions for 14.5% of all interactions. Conclusion Our approach does not require accurate expression levels nor times series. Nevertheless, we show on both data, real and artificial, that a relatively small number of perturbation experiments are enough to determine a significant portion of

  7. The Regulatory Role of Activating Transcription Factor 2 in Inflammation

    PubMed Central

    Yu, Tao; Li, Yong Jun; Bian, Ai Hong; Zuo, Hui Bin; Zhu, Ti Wen; Ji, Sheng Xiang; Kong, Fanming; Yin, De Qing; Wang, Chuan Bao; Wang, Zi Fu; Wang, Hong Qun; Yang, Yanyan; Yoo, Byong Chul

    2014-01-01

    Activating transcription factor 2 (ATF2) is a member of the leucine zipper family of DNA-binding proteins and is widely distributed in tissues including the liver, lung, spleen, and kidney. Like c-Jun and c-Fos, ATF2 responds to stress-related stimuli and may thereby influence cell proliferation, inflammation, apoptosis, oncogenesis, neurological development and function, and skeletal remodeling. Recent studies clarify the regulatory role of ATF2 in inflammation and describe potential inhibitors of this protein. In this paper, we summarize the properties and functions of ATF2 and explore potential applications of ATF2 inhibitors as tools for research and for the development of immunosuppressive and anti-inflammatory drugs. PMID:25049453

  8. 21 CFR 16.24 - Regulatory hearing required by the act or a regulation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Regulatory hearing required by the act or a regulation. 16.24 Section 16.24 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL REGULATORY HEARING BEFORE THE FOOD AND DRUG ADMINISTRATION Initiation of Proceedings §...

  9. The archaeal feast/famine regulatory protein: Potential roles of its assembly forms for regulating transcription

    PubMed Central

    Koike, Hideaki; Ishijima, Sanae A.; Clowney, Lester; Suzuki, Masashi

    2004-01-01

    The classification feast/famine regulatory proteins (FFRPs) encompasses archaeal DNA-binding proteins with Escherichia coli transcription factors, the leucine-responsive regulatory protein and the asparagine synthase C gene product. In this paper, we describe two forms of the archaeal FFRP FL11 (pot0434017), both assembled from dimers. When crystallized, a helical cylinder is formed with six dimers per turn. In contrast, in solution, disks are formed, most likely consisting of four dimers each; an observation by cryoelectron microscopy. Whereas each dimer binds a 13-bp sequence, different forms will discriminate between promoters, based on the numbers of repeating 13-bp sequences, and types of linkers inserted between them, which are either of 7-8 or ≈18 bp. The amino acid sequences of these FFRPs are designed to form the same type of 3D structures, and the transition between their assembly forms is regulated by interaction with small molecules. These considerations lead us to propose a possible mechanism for regulating a number of genes by varying assembly forms and by combining different FFRPs into these assemblies, responding to environmental changes. PMID:14976242

  10. Regulatory network analysis reveals novel regulators of seed desiccation tolerance in Arabidopsis thaliana.

    PubMed

    González-Morales, Sandra Isabel; Chávez-Montes, Ricardo A; Hayano-Kanashiro, Corina; Alejo-Jacuinde, Gerardo; Rico-Cambron, Thelma Y; de Folter, Stefan; Herrera-Estrella, Luis

    2016-08-30

    Desiccation tolerance (DT) is a remarkable process that allows seeds in the dry state to remain viable for long periods of time that in some instances exceed 1,000 y. It has been postulated that seed DT evolved by rewiring the regulatory and signaling networks that controlled vegetative DT, which itself emerged as a crucial adaptive trait of early land plants. Understanding the networks that regulate seed desiccation tolerance in model plant systems would provide the tools to understand an evolutionary process that played a crucial role in the diversification of flowering plants. In this work, we used an integrated approach that included genomics, bioinformatics, metabolomics, and molecular genetics to identify and validate molecular networks that control the acquisition of DT in Arabidopsis seeds. Two DT-specific transcriptional subnetworks were identified related to storage of reserve compounds and cellular protection mechanisms that act downstream of the embryo development master regulators LEAFY COTYLEDON 1 and 2, FUSCA 3, and ABSCICIC ACID INSENSITIVE 3. Among the transcription factors identified as major nodes in the DT regulatory subnetworks, PLATZ1, PLATZ2, and AGL67 were confirmed by knockout mutants and overexpression in a desiccation-intolerant mutant background to play an important role in seed DT. Additionally, we found that constitutive expression of PLATZ1 in WT plants confers partial DT in vegetative tissues. PMID:27551092

  11. The archaeal feast/famine regulatory protein: Potential roles of its assembly forms for regulating transcription

    NASA Astrophysics Data System (ADS)

    Koike, Hideaki; Ishijima, Sanae A.; Clowney, Lester; Suzuki, Masashi

    2004-03-01

    The classification feast/famine regulatory proteins (FFRPs) encompasses archaeal DNA-binding proteins with Escherichia coli transcription factors, the leucine-responsive regulatory protein and the asparagine synthase C gene product. In this paper, we describe two forms of the archaeal FFRP FL11 (pot0434017), both assembled from dimers. When crystallized, a helical cylinder is formed with six dimers per turn. In contrast, in solution, disks are formed, most likely consisting of four dimers each; an observation by cryoelectron microscopy. Whereas each dimer binds a 13-bp sequence, different forms will discriminate between promoters, based on the numbers of repeating 13-bp sequences, and types of linkers inserted between them, which are either of 7-8 or 18 bp. The amino acid sequences of these FFRPs are designed to form the same type of 3D structures, and the transition between their assembly forms is regulated by interaction with small molecules. These considerations lead us to propose a possible mechanism for regulating a number of genes by varying assembly forms and by combining different FFRPs into these assemblies, responding to environmental changes.

  12. Gene duplication of type-B ARR transcription factors systematically extends transcriptional regulatory structures in Arabidopsis

    PubMed Central

    Choi, Seung Hee; Hyeon, Do Young; Lee, ll Hwan; Park, Su Jin; Han, Seungmin; Lee, In Chul; Hwang, Daehee; Nam, Hong Gil

    2014-01-01

    Many of duplicated genes are enriched in signaling pathways. Recently, gene duplication of kinases has been shown to provide genetic buffering and functional diversification in cellular signaling. Transcription factors (TFs) are also often duplicated. However, how duplication of TFs affects their regulatory structures and functions of target genes has not been explored at the systems level. Here, we examined regulatory and functional roles of duplication of three major ARR TFs (ARR1, 10, and 12) in Arabidopsis cytokinin signaling using wild-type and single, double, and triple deletion mutants of the TFs. Comparative analysis of gene expression profiles obtained from Arabidopsis roots in wild-type and these mutants showed that duplication of ARR TFs systematically extended their transcriptional regulatory structures, leading to enhanced robustness and diversification in functions of target genes, as well as in regulation of cellular networks of target genes. Therefore, our results suggest that duplication of TFs contributes to robustness and diversification in functions of target genes by extending transcriptional regulatory structures. PMID:25425016

  13. Cleavage factor Im (CFIm) as a regulator of alternative polyadenylation.

    PubMed

    Hardy, Jessica G; Norbury, Chris J

    2016-08-15

    Most mammalian protein coding genes are subject to alternative cleavage and polyadenylation (APA), which can generate distinct mRNA 3'UTRs with differing regulatory potential. Although this process has been intensely studied in recent years, it remains unclear how and to what extent cleavage site selection is regulated under different physiological conditions. The cleavage factor Im (CFIm) complex is a core component of the mammalian cleavage machinery, and the observation that its depletion causes transcriptome-wide changes in cleavage site use makes it a key candidate regulator of APA. This review aims to summarize current knowledge of the CFIm complex, and explores the evidence surrounding its potential contribution to regulation of APA. PMID:27528751

  14. Role of basic leucine zipper proteins in transcriptional regulation of the steroidogenic acute regulatory protein gene

    PubMed Central

    Manna, Pulak R.; Dyson, Matthew T.; Stocco, Douglas M.

    2016-01-01

    The regulation of steroidogenic acute regulatory protein (StAR) gene transcription by cAMP-dependent mechanisms occurs in the absence of a consensus cAMP response element (CRE, TGACGTGA). This regulation is coordinated by multiple transcription factors that bind to sequence-specific elements located approximately 150 bp upstream of the transcription start site. Among the proteins that bind within this region, the basic leucine zipper (bZIP) family of transcription factors, i.e. CRE binding protein (CREB)/CRE modulator (CREM)/activating transcription factor (ATF), activator protein 1 (AP-1; Fos/Jun), and CCAAT enhancer binding protein β (C/EBPβ), interact with an overlapping region (−81/−72 bp) in the StAR promoter, mediate stimulus-transcription coupling of cAMP signaling and play integral roles in regulating StAR gene expression. These bZIP proteins are structurally similar and bind to DNA sequences as dimers; however, they exhibit discrete transcriptional activities, interact with several transcription factors and other properties that contribute in their regulatory functions. The 5′-flanking −81/−72 bp region of the StAR gene appears to function as a key element within a complex cAMP response unit by binding to different bZIP members, and the StAR promoter displays variable states of cAMP responsivity contingent upon the occupancy of these cis-elements with these transcription factors. The expression and activities of CREB/CREM/ATF, Fos/Jun and C/EBPβ have been demonstrated to be mediated by a plethora of extracellular signals, and the phosphorylation of these proteins at several Ser and Thr residues allows recruitment of the transcriptional coactivator CREB binding protein (CBP) or its functional homolog p300 to the StAR promoter. This review will focus on the current level of understanding of the roles of selective bZIP family proteins within the complex series of processes involved in regulating StAR gene transcription. PMID:19150388

  15. The Hematopoietic Stem and Progenitor Cell Cistrome: GATA Factor-Dependent cis-Regulatory Mechanisms.

    PubMed

    Hewitt, K J; Johnson, K D; Gao, X; Keles, S; Bresnick, E H

    2016-01-01

    Transcriptional regulators mediate the genesis and function of the hematopoietic system by binding complex ensembles of cis-regulatory elements to establish genetic networks. While thousands to millions of any given cis-element resides in a genome, how transcriptional regulators select these sites and how site attributes dictate functional output is not well understood. An instructive system to address this problem involves the GATA family of transcription factors that control vital developmental and physiological processes and are linked to multiple human pathologies. Although GATA factors bind DNA motifs harboring the sequence GATA, only a very small subset of these abundant motifs are occupied in genomes. Mechanistic studies revealed a unique configuration of a GATA factor-regulated cis-element consisting of an E-box and a downstream GATA motif separated by a short DNA spacer. GATA-1- or GATA-2-containing multiprotein complexes at these composite elements control transcription of genes critical for hematopoietic stem cell emergence in the mammalian embryo, hematopoietic progenitor cell regulation, and erythroid cell maturation. Other constituents of the complex include the basic helix-loop-loop transcription factor Scl/TAL1, its heterodimeric partner E2A, and the Lim domain proteins LMO2 and LDB1. This chapter reviews the structure/function of E-box-GATA composite cis-elements, which collectively constitute an important sector of the hematopoietic stem and progenitor cell cistrome. PMID:27137654

  16. Translational repression by the human iron-regulatory factor (IRF) in Saccharomyces cerevisiae.

    PubMed Central

    Oliveira, C C; Goossen, B; Zanchin, N I; McCarthy, J E; Hentze, M W; Stripecke, R

    1993-01-01

    The regulation of the synthesis of ferritin and erythroid 5-aminolevulinate synthase in mammalian cells is mediated by the interaction of the iron regulatory factor (IRF) with a specific recognition site, the iron responsive element (IRE), in the 5' untranslated regions (UTRs) of the respective mRNAs. A new modular expression system was designed to allow reconstruction of this regulatory system in Saccharomyces cerevisiae. This comprised two components: a constitutively expressed reporter gene (luc; encoding luciferase) preceded by a 5' UTR including an IRE sequence, and an inducibly expressed cDNA encoding human IRF. Induction of the latter led to the in vivo synthesis of IRF, which in turn showed IRE-binding activity and also repressed translation of the luc mRNA bearing an IRE-containing 5' UTR. The upper stem-loop region of an IRE, with no further IRE-specific flanking sequences, sufficed for recognition and repression by IRF. Translational regulation of IRE-bearing mRNAs could also be demonstrated in cell-free yeast extracts. This work defines a minimal system for IRF/IRE translational regulation in yeast that requires no additional mammalian-specific components, thus providing direct proof that IRF functions as a translational repressor in vivo. It should be a useful tool as the basis for more detailed studies of eukaryotic translational regulation. Images PMID:8265343

  17. Regulatory impact analysis of the proposed acid-rain implementation regulations

    SciTech Connect

    Not Available

    1991-09-16

    This regulatory impact analysis (RIA) was developed in response to Executive Order (EO) 12291, which requires Federal Agencies to assess the costs, benefits, and impacts of all 'major' regulations. In compliance with EO 12291, this RIA assesses costs, benefits and impacts for the important provisions of Title IV. EPA divided its analysis of the Acid Rain Program into two parts. First, EPA analyzed the effects of the statute in the absence of any implementation regulations. In the second part of the analysis, EPA examined a 'regulatory' case that included both the SO2 reductions and the implementation regulations. By comparing costs under the regulatory case to those under the absent regulations case, EPA was able to isolate the incremental savings provided by the regulations. At the same time, by combining the two parts of the analysis, EPA was able to show the total costs imposed by the Acid Rain Program (the statute and the regulations) as a whole.

  18. Evolution of context dependent regulation by expansion of feast/famine regulatory proteins

    SciTech Connect

    Plaisier, Christopher L.; Lo, Fang -Yin; Ashworth, Justin; Brooks, Aaron N.; Beer, Karlyn D.; Kaur, Amardeep; Pan, Min; Reiss, David J.; Facciotti, Marc T.; Baliga, Nitin S.

    2014-11-14

    Expansion of transcription factors is believed to have played a crucial role in evolution of all organisms by enabling them to deal with dynamic environments and colonize new environments. We investigated how the expansion of the Feast/Famine Regulatory Protein (FFRP) or Lrp-like proteins into an eight-member family in Halobacterium salinarum NRC-1 has aided in niche-adaptation of this archaeon to a complex and dynamically changing hypersaline environment. We mapped genome-wide binding locations for all eight FFRPs, investigated their preference for binding different effector molecules, and identified the contexts in which they act by analyzing transcriptional responses across 35 growth conditions that mimic different environmental and nutritional conditions this organism is likely to encounter in the wild. Integrative analysis of these data constructed an FFRP regulatory network with conditionally active states that reveal how interrelated variations in DNA-binding domains, effector-molecule preferences, and binding sites in target gene promoters have tuned the functions of each FFRP to the environments in which they act. We demonstrate how conditional regulation of similar genes by two FFRPs, AsnC (an activator) and VNG1237C (a repressor), have striking environment-specific fitness consequences for oxidative stress management and growth, respectively. This study provides a systems perspective into the evolutionary process by which gene duplication within a transcription factor family contributes to environment-specific adaptation of an organism.

  19. Evolution of context dependent regulation by expansion of feast/famine regulatory proteins

    DOE PAGESBeta

    Plaisier, Christopher L.; Lo, Fang -Yin; Ashworth, Justin; Brooks, Aaron N.; Beer, Karlyn D.; Kaur, Amardeep; Pan, Min; Reiss, David J.; Facciotti, Marc T.; Baliga, Nitin S.

    2014-11-14

    Expansion of transcription factors is believed to have played a crucial role in evolution of all organisms by enabling them to deal with dynamic environments and colonize new environments. We investigated how the expansion of the Feast/Famine Regulatory Protein (FFRP) or Lrp-like proteins into an eight-member family in Halobacterium salinarum NRC-1 has aided in niche-adaptation of this archaeon to a complex and dynamically changing hypersaline environment. We mapped genome-wide binding locations for all eight FFRPs, investigated their preference for binding different effector molecules, and identified the contexts in which they act by analyzing transcriptional responses across 35 growth conditions thatmore » mimic different environmental and nutritional conditions this organism is likely to encounter in the wild. Integrative analysis of these data constructed an FFRP regulatory network with conditionally active states that reveal how interrelated variations in DNA-binding domains, effector-molecule preferences, and binding sites in target gene promoters have tuned the functions of each FFRP to the environments in which they act. We demonstrate how conditional regulation of similar genes by two FFRPs, AsnC (an activator) and VNG1237C (a repressor), have striking environment-specific fitness consequences for oxidative stress management and growth, respectively. This study provides a systems perspective into the evolutionary process by which gene duplication within a transcription factor family contributes to environment-specific adaptation of an organism.« less

  20. Regulation of endochondral ossification by transcription factors.

    PubMed

    Nishimura, Riko; Hata, Kenji; Ono, Koichiro; Amano, Katsuhiko; Takigawa, Yoko; Wakabayashi, Makoto; Takashima, Rikako; Yoneda, Toshiyuki

    2012-01-01

    Endochondral ossification is very unique and complex biological event which is associated with skeletal development and tissue partnering. Genetic studies and gene-targeting approaches identified several transcription factors that play important roles in endochondral ossification. These transcription factors sequentially and harmoniously regulate each step of endochondral ossification, and consequently maintain the spatio-temporal control of the program. Importantly, these transcription factors form large protein complex to control chromatin remodeling, histone modification, transcription and splicing steps during endochondral ossification. It is also important to understand how these transcription factors regulate expression of their target genes. Biochemical and molecular cloning techniques largely contributed to identification of the components of the transcriptional complex and the target genes. Most recently, importance of endoplasmic reticulum (ER) stress in endochondral ossification has been reported. A transcription factor, BBF2H7, functions as an ER stress sensor in chondrocytes through regulation of appropriate secretion of chondrogenic matrices. We would like to discuss how the transcription factors regulate endochondral ossification. PMID:22652803

  1. Intracellular Concentrations of 65 Species of Transcription Factors with Known Regulatory Functions in Escherichia coli

    PubMed Central

    Kori, Ayako; Koshio, Etsuko; Yamada, Kayoko; Maeda, Hiroto; Shimada, Tomohiro; Makinoshima, Hideki; Iwata, Akira; Fujita, Nobuyuki

    2014-01-01

    The expression pattern of the Escherichia coli genome is controlled in part by regulating the utilization of a limited number of RNA polymerases among a total of its approximately 4,600 genes. The distribution pattern of RNA polymerase changes from modulation of two types of protein-protein interactions: the interaction of core RNA polymerase with seven species of the sigma subunit for differential promoter recognition and the interaction of RNA polymerase holoenzyme with about 300 different species of transcription factors (TFs) with regulatory functions. We have been involved in the systematic search for the target promoters recognized by each sigma factor and each TF using the newly developed Genomic SELEX system. In parallel, we developed the promoter-specific (PS)-TF screening system for identification of the whole set of TFs involved in regulation of each promoter. Understanding the regulation of genome transcription also requires knowing the intracellular concentrations of the sigma subunits and TFs under various growth conditions. This report describes the intracellular levels of 65 species of TF with known function in E. coli K-12 W3110 at various phases of cell growth and at various temperatures. The list of intracellular concentrations of the sigma factors and TFs provides a community resource for understanding the transcription regulation of E. coli under various stressful conditions in nature. PMID:24837290

  2. Pesticide regulations for agriculture: Chemically flawed regulatory practice.

    PubMed

    Gamble, Donald S; Bruccoleri, Aldo G

    2016-08-01

    Two categories of pesticide soil models now exist. Government regulatory agencies use pesticide fate and transport hydrology models, including versions of PRZM.gw. They have good descriptions of pesticide transport by water flow. Their descriptions of chemical mechanisms are unrealistic, having been postulated using the universally accepted but incorrect pesticide soil science. The objective of this work is to report experimental tests of a pesticide soil model in use by regulatory agencies and to suggest possible improvements. Tests with experimentally based data explain why PRZM.gw predictions can be wrong by orders of magnitude. Predictive spreadsheet models are the other category. They are experimentally based, with chemical stoichiometry applied to integral kinetic rate laws for sorption, desorption, intra-particle diffusion, and chemical reactions. They do not account for pesticide transport through soils. Each category of models therefore lacks what the other could provide. They need to be either harmonized or replaced. Some preliminary tests indicate that an experimental mismatch between the categories of models will have to be resolved. Reports of pesticides in the environment and the medical problems that overlap geographically indicate that government regulatory practice needs to account for chemical kinetics and mechanisms. Questions about possible cause and effect links could then be investigated. PMID:27166991

  3. Vav family exchange factors: an integrated regulatory and functional view.

    PubMed

    Bustelo, Xosé R

    2014-01-01

    The Vav family is a group of tyrosine phosphorylation-regulated signal transduction molecules hierarchically located downstream of protein tyrosine kinases. The main function of these proteins is to work as guanosine nucleotide exchange factors (GEFs) for members of the Rho GTPase family. In addition, they can exhibit a variety of catalysis-independent roles in specific signaling contexts. Vav proteins play essential signaling roles for both the development and/or effector functions of a large variety of cell lineages, including those belonging to the immune, nervous, and cardiovascular systems. They also contribute to pathological states such as cancer, immune-related dysfunctions, and atherosclerosis. Here, I will provide an integrated view about the evolution, regulation, and effector properties of these signaling molecules. In addition, I will discuss the pros and cons for their potential consideration as therapeutic targets. PMID:25483299

  4. Vav family exchange factors: an integrated regulatory and functional view

    PubMed Central

    Bustelo, Xosé R

    2014-01-01

    The Vav family is a group of tyrosine phosphorylation-regulated signal transduction molecules hierarchically located downstream of protein tyrosine kinases. The main function of these proteins is to work as guanosine nucleotide exchange factors (GEFs) for members of the Rho GTPase family. In addition, they can exhibit a variety of catalysis-independent roles in specific signaling contexts. Vav proteins play essential signaling roles for both the development and/or effector functions of a large variety of cell lineages, including those belonging to the immune, nervous, and cardiovascular systems. They also contribute to pathological states such as cancer, immune-related dysfunctions, and atherosclerosis. Here, I will provide an integrated view about the evolution, regulation, and effector properties of these signaling molecules. In addition, I will discuss the pros and cons for their potential consideration as therapeutic targets. PMID:25483299

  5. Engineering Synthetic cis-Regulatory Elements for Simultaneous Recognition of Three Transcriptional Factors in Bacteria.

    PubMed

    Amores, Gerardo Ruiz; Guazzaroni, María-Eugenia; Silva-Rocha, Rafael

    2015-12-18

    Recognition of cis-regulatory elements by transcription factors (TF) at target promoters is crucial to gene regulation in bacteria. In this process, binding of TFs to their cognate sequences depends on a set of physical interactions between these proteins and specific nucleotides in the operator region. Previously, we showed that in silico optimization algorithms are able to generate short sequences that are recognized by two different TFs of Escherichia coli, namely, CRP and IHF, thus generating an AND logic gate. Here, we expanded this approach in order to engineer DNA sequences that can be simultaneously recognized by three unrelated TFs (CRP, IHF, and Fis). Using in silico optimization and experimental validation strategies, we were able to obtain a candidate promoter (Plac-CFI1) regulated by only two TFs with an AND logic, thus demonstrating a limitation in the design. Subsequently, we modified the algorithm to allow the optimization of extended sequences, and were able to design two synthetic promoters (PCFI20-1 and PCFI22-5) that were functional in vivo. Expression assays in E. coli mutant strains for each TF revealed that while CRP positively regulates the promoter activities, IHF and Fis are strong repressors of both the promoter variants. Taken together, our results demonstrate the potential of in silico strategies in bacterial synthetic promoter engineering. Furthermore, the study also shows how small modifications in cis-regulatory elements can drastically affect the final logic of the resulting promoter. PMID:26305598

  6. An alternative QSAR-based approach for predicting the bioconcentration factor for regulatory purposes.

    PubMed

    Gissi, Andrea; Gadaleta, Domenico; Floris, Matteo; Olla, Stefania; Carotti, Angelo; Novellino, Ettore; Benfenati, Emilio; Nicolotti, Orazio

    2014-01-01

    The REACH (Registration, Evaluation, Authorization and restriction of Chemicals) and BPR (Biocide Product Regulation) regulations strongly promote the use of non-animal testing techniques to evaluate chemical risk. This has renewed the interest towards alternative methods such as QSAR in the regulatory context. The assessment of Bioconcentration Factor (BCF) required by these regulations is expensive, in terms of costs, time, and laboratory animal sacrifices. Herein, we present QSAR models based on the ANTARES dataset, which is a large collection of known and verified experimental BCF data. Among the models developed, the best results were obtained from a nine-descriptor highly predictive model. This model was derived from a training set of 608 chemicals and challenged against a validation and blind set containing 152 and 76 chemicals. The model's robustness was further controlled through several validation strategies and the implementation of a multi-step approach for the applicability domain. Suitable safety margins were used to increase sensitivity. The easy interpretability of the model is ensured by the use of meaningful biokinetics descriptors. The satisfactory predictive power for external compounds suggests that the new models could represent a reliable alternative to the in vivo assay, helping the registrants to fulfill regulatory requirements in compliance with the ethical and economic necessity to reduce animal testing. PMID:24247988

  7. External and internal factors regulating photosynthesis

    SciTech Connect

    Teskey, R.O.; Sheriff, D.W.; Hollinger, D.Y.; Thomas, R.B.

    1995-07-01

    Photosynthesis is simultaneously regulated by many factors. Environmental factors, consisting primarily of light, water, heat, carbon dioxide, and other gases, can have direct effects on photosynthesis when they alter rates of chemical processes in the photosynthetic pathway. Environmental factors, along with nutrients and sink demands for carbohydrates, may also have indirect effects on photosynthesis. Indirect effects are the result of changes in nonphotosynthetic processes that, in turn, alter the rate of photosynthesis. A final category of regulators, photosynthetic framework, consists of substances that compose the physiologically active compounds and structures that form the basis of the light and dark reactions responsible for photosynthesis. The framework determines the photosynthetic capacity of a plant or organ, i.e., the rate of photosynthesis achievable when direct and indirect effects are nonlimiting. In this chapter we have divided the discussion of factors that regulate photosynthesis in conifers into these three categories, framework, direct effects, and indirect effects, because of an expanding appreciation in the field of environmental physiology that external and internal factors can simultaneously regulate photosynthesis by both direct and indirect means. We offer this outline as a logical way of presenting and discussing these issues.

  8. Current Regulation of Private Police: Regulatory Agency Experience and Views.

    ERIC Educational Resources Information Center

    Kakalik, James S.; Wildhorn, Sorrel

    This report is the third in a series of five describing a 16-month study of the nature and extent of the private police industry in the United States, its problems, present regulation, and the laws impinging on it. Licensing and regulation of the industry in every state and several cities are described in this volume. Extensive tables present the…

  9. Scientists versus regulators: precaution, novelty & regulatory oversight as predictors of perceived risks of engineered nanomaterials.

    PubMed

    Beaudrie, Christian E H; Satterfield, Terre; Kandlikar, Milind; Harthorn, Barbara H

    2014-01-01

    Engineered nanoscale materials (ENMs) present a difficult challenge for risk assessors and regulators. Continuing uncertainty about the potential risks of ENMs means that expert opinion will play an important role in the design of policies to minimize harmful implications while supporting innovation. This research aims to shed light on the views of 'nano experts' to understand which nanomaterials or applications are regarded as more risky than others, to characterize the differences in risk perceptions between expert groups, and to evaluate the factors that drive these perceptions. Our analysis draws from a web-survey (N = 404) of three groups of US and Canadian experts: nano-scientists and engineers, nano-environmental health and safety scientists, and regulatory scientists and decision-makers. Significant differences in risk perceptions were found across expert groups; differences found to be driven by underlying attitudes and perceptions characteristic of each group. Nano-scientists and engineers at the upstream end of the nanomaterial life cycle perceived the lowest levels of risk, while those who are responsible for assessing and regulating risks at the downstream end perceived the greatest risk. Perceived novelty of nanomaterial risks, differing preferences for regulation (i.e. the use of precaution versus voluntary or market-based approaches), and perceptions of the risk of technologies in general predicted variation in experts' judgments of nanotechnology risks. Our findings underscore the importance of involving a diverse selection of experts, particularly those with expertise at different stages along the nanomaterial lifecycle, during policy development. PMID:25222742

  10. Splicing regulation: From a parts list of regulatory elements to an integrated splicing code

    PubMed Central

    Wang, Zefeng; Burge, Christopher B.

    2008-01-01

    Alternative splicing of pre-mRNAs is a major contributor to both proteomic diversity and control of gene expression levels. Splicing is tightly regulated in different tissues and developmental stages, and its disruption can lead to a wide range of human diseases. An important long-term goal in the splicing field is to determine a set of rules or “code” for splicing that will enable prediction of the splicing pattern of any primary transcript from its sequence. Outside of the core splice site motifs, the bulk of the information required for splicing is thought to be contained in exonic and intronic cis-regulatory elements that function by recruitment of sequence-specific RNA-binding protein factors that either activate or repress the use of adjacent splice sites. Here, we summarize the current state of knowledge of splicing cis-regulatory elements and their context-dependent effects on splicing, emphasizing recent global/genome-wide studies and open questions. PMID:18369186

  11. Caveolin-1 regulates TCR signal strength and regulatory T-cell differentiation into alloreactive T cells.

    PubMed

    Schönle, Anne; Hartl, Frederike A; Mentzel, Jan; Nöltner, Theresa; Rauch, Katharina S; Prestipino, Alessandro; Wohlfeil, Sebastian A; Apostolova, Petya; Hechinger, Anne-Kathrin; Melchinger, Wolfgang; Fehrenbach, Kerstin; Guadamillas, Marta C; Follo, Marie; Prinz, Gabriele; Ruess, Ann-Katrin; Pfeifer, Dietmar; Angel Del Pozo, Miguel; Schmitt-Graeff, Annette; Duyster, Justus; Hippen, Keli I; Blazar, Bruce R; Schachtrup, Kristina; Minguet, Susana; Zeiser, Robert

    2016-04-14

    Caveolin-1 (Cav-1) is a key organizer of membrane specializations and a scaffold protein that regulates signaling in multiple cell types. We found increased Cav-1 expression in human and murine T cells after allogeneic hematopoietic cell transplantation. Indeed, Cav-1(-/-)donor T cells caused less severe acute graft-versus-host disease (GVHD) and yielded higher numbers of regulatory T cells (Tregs) compared with controls. Depletion of Tregs from the graft abrogated this protective effect. Correspondingly, Treg frequencies increased when Cav-1(-/-)T cells were exposed to transforming growth factor-β/T-cell receptor (TCR)/CD28 activation or alloantigen stimulation in vitro compared with wild-type T cells. Mechanistically, we found that the phosphorylation of Cav-1 is dispensable for the control of T-cell fate by using a nonphosphorylatable Cav-1 (Y14F/Y14F) point-mutation variant. Moreover, the close proximity of lymphocyte-specific protein tyrosine kinase (Lck) to the TCR induced by TCR-activation was reduced in Cav-1(-/-)T cells. Therefore, less TCR/Lck clustering results in suboptimal activation of the downstream signaling events, which correlates with the preferential development into a Treg phenotype. Overall, we report a novel role for Cav-1 in TCR/Lck spatial distribution upon TCR triggering, which controls T-cell fate toward a regulatory phenotype. This alteration translated into a significant increase in the frequency of Tregs and reduced GVHD in vivo. PMID:26837700

  12. Global analysis of p53-regulated transcription identifies its direct targets and unexpected regulatory mechanisms

    PubMed Central

    Allen, Mary Ann; Andrysik, Zdenek; Dengler, Veronica L; Mellert, Hestia S; Guarnieri, Anna; Freeman, Justin A; Sullivan, Kelly D; Galbraith, Matthew D; Luo, Xin; Kraus, W Lee; Dowell, Robin D; Espinosa, Joaquin M

    2014-01-01

    The p53 transcription factor is a potent suppressor of tumor growth. We report here an analysis of its direct transcriptional program using Global Run-On sequencing (GRO-seq). Shortly after MDM2 inhibition by Nutlin-3, low levels of p53 rapidly activate ∼200 genes, most of them not previously established as direct targets. This immediate response involves all canonical p53 effector pathways, including apoptosis. Comparative global analysis of RNA synthesis vs steady state levels revealed that microarray profiling fails to identify low abundance transcripts directly activated by p53. Interestingly, p53 represses a subset of its activation targets before MDM2 inhibition. GRO-seq uncovered a plethora of gene-specific regulatory features affecting key survival and apoptotic genes within the p53 network. p53 regulates hundreds of enhancer-derived RNAs. Strikingly, direct p53 targets harbor pre-activated enhancers highly transcribed in p53 null cells. Altogether, these results enable the study of many uncharacterized p53 target genes and unexpected regulatory mechanisms. DOI: http://dx.doi.org/10.7554/eLife.02200.001 PMID:24867637

  13. Childcare Regulations: Regulatory Enforcement in Ireland. What Happens When the Inspector Calls?

    ERIC Educational Resources Information Center

    Moloney, Mary

    2016-01-01

    Childcare regulations ensure children's rights to Early Childhood Care and Education settings that protect them from harm and promote their healthy development. To ensure that settings comply, power is vested with regulatory bodies that are tasked with enforcing regulations. Using a qualitative methodology, 43 interviews were undertaken with Early…

  14. Nuclear transport factors: global regulation of mitosis.

    PubMed

    Forbes, Douglass J; Travesa, Anna; Nord, Matthew S; Bernis, Cyril

    2015-08-01

    The unexpected repurposing of nuclear transport proteins from their function in interphase to an equally vital and very different set of functions in mitosis was very surprising. The multi-talented cast when first revealed included the import receptors, importin alpha and beta, the small regulatory GTPase RanGTP, and a subset of nuclear pore proteins. In this review, we report that recent years have revealed new discoveries in each area of this expanding story in vertebrates: (a) The cast of nuclear import receptors playing a role in mitotic spindle regulation has expanded: both transportin, a nuclear import receptor, and Crm1/Xpo1, an export receptor, are involved in different aspects of spindle assembly. Importin beta and transportin also regulate nuclear envelope and pore assembly. (b) The role of nucleoporins has grown to include recruiting the key microtubule nucleator - the γ-TuRC complex - and the exportin Crm1 to the mitotic kinetochores of humans. Together they nucleate microtubule formation from the kinetochores toward the centrosomes. (c) New research finds that the original importin beta/RanGTP team have been further co-opted by evolution to help regulate other cellular and organismal activities, ranging from the actual positioning of the spindle within the cell perimeter, to regulation of a newly discovered spindle microtubule branching activity, to regulation of the interaction of microtubule structures with specific actin structures. (d) Lastly, because of the multitudinous roles of karyopherins throughout the cell cycle, a recent large push toward testing their potential as chemotherapeutic targets has begun to yield burgeoning progress in the clinic. PMID:25982429

  15. Identifying combinatorial regulation of transcription factors and binding motifs

    PubMed Central

    Kato, Mamoru; Hata, Naoya; Banerjee, Nilanjana; Futcher, Bruce; Zhang, Michael Q

    2004-01-01

    Background Combinatorial interaction of transcription factors (TFs) is important for gene regulation. Although various genomic datasets are relevant to this issue, each dataset provides relatively weak evidence on its own. Developing methods that can integrate different sequence, expression and localization data have become important. Results Here we use a novel method that integrates chromatin immunoprecipitation (ChIP) data with microarray expression data and with combinatorial TF-motif analysis. We systematically identify combinations of transcription factors and of motifs. The various combinations of TFs involved multiple binding mechanisms. We reconstruct a new combinatorial regulatory map of the yeast cell cycle in which cell-cycle regulation can be drawn as a chain of extended TF modules. We find that the pairwise combination of a TF for an early cell-cycle phase and a TF for a later phase is often used to control gene expression at intermediate times. Thus the number of distinct times of gene expression is greater than the number of transcription factors. We also see that some TF modules control branch points (cell-cycle entry and exit), and in the presence of appropriate signals they can allow progress along alternative pathways. Conclusions Combining different data sources can increase statistical power as demonstrated by detecting TF interactions and composite TF-binding motifs. The original picture of a chain of simple cell-cycle regulators can be extended to a chain of composite regulatory modules: different modules may share a common TF component in the same pathway or a TF component cross-talking to other pathways. PMID:15287978

  16. The Ets-1 transcription factor controls the development and function of natural regulatory T cells.

    PubMed

    Mouly, Enguerran; Chemin, Karine; Nguyen, Hai Vu; Chopin, Martine; Mesnard, Laurent; Leite-de-Moraes, Maria; Burlen-defranoux, Odile; Bandeira, Antonio; Bories, Jean-Christophe

    2010-09-27

    Regulatory T cells (T reg cells) constitute a population of CD4(+) T cells that limits immune responses. The transcription factor Foxp3 is important for determining the development and function of T reg cells; however, the molecular mechanisms that trigger and maintain its expression remain incompletely understood. In this study, we show that mice deficient for the Ets-1 transcription factor (Ets-1(-/-)) developed T cell-mediated splenomegaly and systemic autoimmunity that can be blocked by functional wild-type T reg cells. Spleens of Ets-1(-/-) mice contained mostly activated T cells, including Th2-polarized CD4(+) cells and had reduced percentages of T reg cells. Splenic and thymic Ets-1(-/-) T reg cells expressed low levels of Foxp3 and displayed the CD103 marker that characterizes antigen-experienced T reg cells. Thymic development of Ets-1(-/-) T reg cells appeared intrinsically altered as Foxp3-expressing cells differentiate poorly in mixed fetal liver reconstituted chimera and fetal thymic organ culture. Ets-1(-/-) T reg cells showed decreased in vitro suppression activity and did not protect Rag2(-/-) hosts from naive T cell-induced inflammatory bowel disease. Furthermore, in T reg cells, Ets-1 interacted with the Foxp3 intronic enhancer and was required for demethylation of this regulatory sequence. These data demonstrate that Ets-1 is required for the development of natural T reg cells and suggest a role for this transcription factor in the regulation of Foxp3 expression. PMID:20855499

  17. Regulatory network of microRNAs, target genes, transcription factors and host genes in endometrial cancer.

    PubMed

    Xue, Lu-Chen; Xu, Zhi-Wen; Wang, Kun-Hao; Wang, Ning; Zhang, Xiao-Xu; Wang, Shang

    2015-01-01

    Genes and microRNAs (miRNAs) have important roles in human oncology. However, most of the biological factors are reported in disperse form which makes it hard to discover the pathology. In this study, genes and miRNAs involved in human endometrial cancer(EC) were collected and formed into regulatory networks following their interactive relations, including miRNAs targeting genes, transcription factors (TFs) regulating miRNAs and miRNAs included in their host genes. Networks are constructed hierarchically at three levels: differentially expressed, related and global. Among the three, the differentially expressed network is the most important and fundamental network that contains the key genes and miRNAs in EC. The target genes, TFs and miRNAs are differentially expressed in EC so that any mutation in them may impact on EC development. Some key pathways in networks were highlighted to analyze how they interactively influence other factors and carcinogenesis. Upstream and downstream pathways of the differentially expressed genes and miRNAs were compared and analyzed. The purpose of this study was to partially reveal the deep regulatory mechanisms in EC using a new method that combines comprehensive genes and miRNAs together with their relationships. It may contribute to cancer prevention and gene therapy of EC. PMID:25684474

  18. Tissue-specific targeting of cell fate regulatory genes by E2f factors.

    PubMed

    Julian, L M; Liu, Y; Pakenham, C A; Dugal-Tessier, D; Ruzhynsky, V; Bae, S; Tsai, S-Y; Leone, G; Slack, R S; Blais, A

    2016-04-01

    Cell cycle proteins are important regulators of diverse cell fate decisions, and in this capacity have pivotal roles in neurogenesis and brain development. The mechanisms by which cell cycle regulation is integrated with cell fate control in the brain and other tissues are poorly understood, and an outstanding question is whether the cell cycle machinery regulates fate decisions directly or instead as a secondary consequence of proliferative control. Identification of the genes targeted by E2 promoter binding factor (E2f) transcription factors, effectors of the pRb/E2f cell cycle pathway, will provide essential insights into these mechanisms. We identified the promoter regions bound by three neurogenic E2f factors in neural precursor cells in a genome-wide manner. Through bioinformatic analyses and integration of published genomic data sets we uncovered hundreds of transcriptionally active E2f-bound promoters corresponding to genes that control cell fate processes, including key transcriptional regulators and members of the Notch, fibroblast growth factor, Wnt and Tgf-β signaling pathways. We also demonstrate a striking enrichment of the CCCTC binding factor transcription factor (Ctcf) at E2f3-bound nervous system-related genes, suggesting a potential regulatory co-factor for E2f3 in controlling differentiation. Finally, we provide the first demonstration of extensive tissue specificity among E2f target genes in mammalian cells, whereby E2f3 promoter binding is well conserved between neural and muscle precursors at genes associated with cell cycle processes, but is tissue-specific at differentiation-associated genes. Our findings implicate the cell cycle pathway as a widespread regulator of cell fate genes, and suggest that E2f3 proteins control cell type-specific differentiation programs by regulating unique sets of target genes. This work significantly enhances our understanding of how the cell cycle machinery impacts cell fate and differentiation, and will

  19. Lineage-Specific Modulation of Interleukin 4 Signaling by Interferon Regulatory Factor 4

    PubMed Central

    Gupta, Sanjay; Jiang, Man; Anthony, Alissa; Pernis, Alessandra B.

    1999-01-01

    Interleukin (IL)-4 is an immunoregulatory cytokine that exerts distinct biological activities on different cell types. Our studies indicate that interferon regulatory factor (IRF)-4 is both a target and a modulator of the IL-4 signaling cascade. IRF-4 expression is strongly upregulated upon costimulation of B cells with CD40 and IL-4. Furthermore, we find that IRF-4 can interact with signal transducer and activator of transcription (Stat)6 and drive the expression of IL-4–inducible genes. The transactivating ability of IRF-4 is blocked by the repressor factor BCL-6. Since expression of IRF-4 is mostly confined to lymphoid cells, these data provide a potential mechanism by which IL-4–inducible genes can be regulated in a lineage-specific manner. PMID:10601358

  20. Interferon regulatory factor 5 in human autoimmunity and murine models of autoimmune disease.

    PubMed

    Eames, Hayley L; Corbin, Alastair L; Udalova, Irina A

    2016-01-01

    Interferon regulatory factor 5 (IRF5) has been demonstrated as a key transcription factor of the immune system, playing important roles in modulating inflammatory immune responses in numerous cell types including dendritic cells, macrophages, and B cells. As well as driving the expression of type I interferon in antiviral responses, IRF5 is also crucial for driving macrophages toward a proinflammatory phenotype by regulating cytokine and chemokine expression and modulating B-cell maturity and antibody production. This review highlights the functional importance of IRF5 in a disease setting, by discussing polymorphic mutations at the human Irf5 locus that lead to susceptibility to systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel disease. In concordance with this, we also discuss lessons in IRF5 functionality learned from murine in vivo models of autoimmune disease and inflammation and hypothesize that modulation of IRF5 activity and expression could provide potential therapeutic benefits in the clinic. PMID:26207886

  1. Tropomyosin flexural rigidity and single ca(2+) regulatory unit dynamics: implications for cooperative regulation of cardiac muscle contraction and cardiomyocyte hypertrophy.

    PubMed

    Loong, Campion K P; Badr, Myriam A; Chase, P Bryant

    2012-01-01

    Striated muscle contraction is regulated by dynamic and cooperative interactions among Ca(2+), troponin, and tropomyosin on the thin filament. While Ca(2+) regulation has been extensively studied, little is known about the dynamics of individual regulatory units and structural changes of individual tropomyosin molecules in relation to their mechanical properties, and how these factors are altered by cardiomyopathy mutations in the Ca(2+) regulatory proteins. In this hypothesis paper, we explore how various experimental and analytical approaches could broaden our understanding of the cooperative regulation of cardiac contraction in health and disease. PMID:22493584

  2. Regulatory T Cells: Molecular Actions on Effector Cells in Immune Regulation

    PubMed Central

    Arce-Sillas, Asiel; Álvarez-Luquín, Diana Denisse; Tamaya-Domínguez, Beatriz; Gomez-Fuentes, Sandra; Trejo-García, Abel; Melo-Salas, Marlene; Cárdenas, Graciela; Rodríguez-Ramírez, Juan; Adalid-Peralta, Laura

    2016-01-01

    T regulatory cells play a key role in the control of the immune response, both in health and during illness. While the mechanisms through which T regulatory cells exert their function have been extensively described, their molecular effects on effector cells have received little attention. Thus, this revision is aimed at summarizing our current knowledge on those regulation mechanisms on the target cells from a molecular perspective. PMID:27298831

  3. Microphthalmia transcription factor regulates pancreatic β-cell function.

    PubMed

    Mazur, Magdalena A; Winkler, Marcus; Ganic, Elvira; Colberg, Jesper K; Johansson, Jenny K; Bennet, Hedvig; Fex, Malin; Nuber, Ulrike A; Artner, Isabella

    2013-08-01

    Precise regulation of β-cell function is crucial for maintaining blood glucose homeostasis. Pax6 is an essential regulator of β-cell-specific factors like insulin and Glut2. Studies in the developing eye suggest that Pax6 interacts with Mitf to regulate pigment cell differentiation. Here, we show that Mitf, like Pax6, is expressed in all pancreatic endocrine cells during mouse postnatal development and in the adult islet. A Mitf loss-of-function mutation results in improved glucose tolerance and enhanced insulin secretion but no increase in β-cell mass in adult mice. Mutant β-cells secrete more insulin in response to glucose than wild-type cells, suggesting that Mitf is involved in regulating β-cell function. In fact, the transcription of genes critical for maintaining glucose homeostasis (insulin and Glut2) and β-cell formation and function (Pax4 and Pax6) is significantly upregulated in Mitf mutant islets. The increased Pax6 expression may cause the improved β-cell function observed in Mitf mutant animals, as it activates insulin and Glut2 transcription. Chromatin immunoprecipitation analysis shows that Mitf binds to Pax4 and Pax6 regulatory regions, suggesting that Mitf represses their transcription in wild-type β-cells. We demonstrate that Mitf directly regulates Pax6 transcription and controls β-cell function. PMID:23610061

  4. Microphthalmia Transcription Factor Regulates Pancreatic β-Cell Function

    PubMed Central

    Mazur, Magdalena A.; Winkler, Marcus; Ganić, Elvira; Colberg, Jesper K.; Johansson, Jenny K.; Bennet, Hedvig; Fex, Malin; Nuber, Ulrike A.; Artner, Isabella

    2013-01-01

    Precise regulation of β-cell function is crucial for maintaining blood glucose homeostasis. Pax6 is an essential regulator of β-cell–specific factors like insulin and Glut2. Studies in the developing eye suggest that Pax6 interacts with Mitf to regulate pigment cell differentiation. Here, we show that Mitf, like Pax6, is expressed in all pancreatic endocrine cells during mouse postnatal development and in the adult islet. A Mitf loss-of-function mutation results in improved glucose tolerance and enhanced insulin secretion but no increase in β-cell mass in adult mice. Mutant β-cells secrete more insulin in response to glucose than wild-type cells, suggesting that Mitf is involved in regulating β-cell function. In fact, the transcription of genes critical for maintaining glucose homeostasis (insulin and Glut2) and β-cell formation and function (Pax4 and Pax6) is significantly upregulated in Mitf mutant islets. The increased Pax6 expression may cause the improved β-cell function observed in Mitf mutant animals, as it activates insulin and Glut2 transcription. Chromatin immunoprecipitation analysis shows that Mitf binds to Pax4 and Pax6 regulatory regions, suggesting that Mitf represses their transcription in wild-type β-cells. We demonstrate that Mitf directly regulates Pax6 transcription and controls β-cell function. PMID:23610061

  5. Regulatory role of the respiratory supercomplex factors in Saccharomyces cerevisiae

    PubMed Central

    Rydström Lundin, Camilla; Ott, Martin; Ädelroth, Pia; Brzezinski, Peter

    2016-01-01

    The respiratory supercomplex factors (Rcf) 1 and 2 mediate supramolecular interactions between mitochondrial complexes III (ubiquinol-cytochrome c reductase; cyt. bc1) and IV (cytochrome c oxidase; CytcO). In addition, removal of these polypeptides results in decreased activity of CytcO, but not of cyt. bc1. In the present study, we have investigated the kinetics of ligand binding, the single-turnover reaction of CytcO with O2, and the linked cyt. bc1-CytcO quinol oxidation-oxygen-reduction activities in mitochondria in which Rcf1 or Rcf2 were removed genetically (strains rcf1Δ and rcf2Δ, respectively). The data show that in the rcf1Δ and rcf2Δ strains, in a significant fraction of the population, ligand binding occurs over a time scale that is ∼100-fold faster (τ ≅ 100 μs) than observed with the wild-type mitochondria (τ ≅ 10 ms), indicating structural changes. This effect is specific to removal of Rcf and not dissociation of the cyt. bc1–CytcO supercomplex. Furthermore, in the rcf1Δ and rcf2Δ strains, the single-turnover reaction of CytcO with O2 was incomplete. This observation indicates that the lower activity of CytcO is caused by a fraction of inactive CytcO rather than decreased CytcO activity of the entire population. Furthermore, the data suggest that the Rcf1 polypeptide mediates formation of an electron-transfer bridge from cyt. bc1 to CytcO via a tightly bound cyt. c. We discuss the significance of the proposed regulatory mechanism of Rcf1 and Rcf2 in the context of supramolecular interactions between cyt. bc1 and CytcO. PMID:27432958

  6. Regulatory role of the respiratory supercomplex factors in Saccharomyces cerevisiae.

    PubMed

    Rydström Lundin, Camilla; von Ballmoos, Christoph; Ott, Martin; Ädelroth, Pia; Brzezinski, Peter

    2016-08-01

    The respiratory supercomplex factors (Rcf) 1 and 2 mediate supramolecular interactions between mitochondrial complexes III (ubiquinol-cytochrome c reductase; cyt. bc1) and IV (cytochrome c oxidase; CytcO). In addition, removal of these polypeptides results in decreased activity of CytcO, but not of cyt. bc1 In the present study, we have investigated the kinetics of ligand binding, the single-turnover reaction of CytcO with O2, and the linked cyt. bc1-CytcO quinol oxidation-oxygen-reduction activities in mitochondria in which Rcf1 or Rcf2 were removed genetically (strains rcf1Δ and rcf2Δ, respectively). The data show that in the rcf1Δ and rcf2Δ strains, in a significant fraction of the population, ligand binding occurs over a time scale that is ∼100-fold faster (τ ≅ 100 μs) than observed with the wild-type mitochondria (τ ≅ 10 ms), indicating structural changes. This effect is specific to removal of Rcf and not dissociation of the cyt. bc1-CytcO supercomplex. Furthermore, in the rcf1Δ and rcf2Δ strains, the single-turnover reaction of CytcO with O2 was incomplete. This observation indicates that the lower activity of CytcO is caused by a fraction of inactive CytcO rather than decreased CytcO activity of the entire population. Furthermore, the data suggest that the Rcf1 polypeptide mediates formation of an electron-transfer bridge from cyt. bc1 to CytcO via a tightly bound cyt. c We discuss the significance of the proposed regulatory mechanism of Rcf1 and Rcf2 in the context of supramolecular interactions between cyt. bc1 and CytcO. PMID:27432958

  7. 76 FR 15891 - Improving Regulation and Regulatory Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-22

    ... Web site at http://www.regulations.gov . Additional instructions on providing comments through the... will be available on the USPTO Web site at http://www.uspto.gov . All comments submitted through the Federal eRulemaking Portal will be made publicly available on that Web site. Because comments will be...

  8. Protein Synthesis Initiation Factors: Phosphorylation and Regulation

    SciTech Connect

    Karen S. Browning

    2009-06-15

    The initiation of the synthesis of proteins is a fundamental process shared by all living organisms. Each organism has both shared and unique mechanisms for regulation of this vital process. Higher plants provide for a major amount of fixation of carbon from the environment and turn this carbon into food and fuel sources for our use. However, we have very little understanding of how plants regulate the synthesis of the proteins necessary for these metabolic processes. The research carried out during the grant period sought to address some of these unknowns in the regulation of protein synthesis initiation. Our first goal was to determine if phosphorylation plays a significant role in plant initiation of protein synthesis. The role of phosphorylation, although well documented in mammalian protein synthesis regulation, is not well studied in plants. We showed that several of the factors necessary for the initiation of protein synthesis were targets of plant casein kinase and showed differential phosphorylation by the plant specific isoforms of this kinase. In addition, we identified and confirmed the phosphorylation sites in five of the plant initiation factors. Further, we showed that phosphorylation of one of these factors, eIF5, affected the ability of the factor to participate in the initiation process. Our second goal was to develop a method to make initiation factor 3 (eIF3) using recombinant methods. To date, we successfully cloned and expressed 13/13 subunits of wheat eIF3 in E. coli using de novo gene construction methods. The final step in this process is to place the subunits into three different plasmid operons for co-expression. Successful completion of expression of eIF3 will be an invaluable tool to the plant translation community.

  9. Transcription Factor Hepatocyte Nuclear Factor-1β Regulates Renal Cholesterol Metabolism.

    PubMed

    Aboudehen, Karam; Kim, Min Soo; Mitsche, Matthew; Garland, Kristina; Anderson, Norma; Noureddine, Lama; Pontoglio, Marco; Patel, Vishal; Xie, Yang; DeBose-Boyd, Russell; Igarashi, Peter

    2016-08-01

    HNF-1β is a tissue-specific transcription factor that is expressed in the kidney and other epithelial organs. Humans with mutations in HNF-1β develop kidney cysts, and HNF-1β regulates the transcription of several cystic disease genes. However, the complete spectrum of HNF-1β-regulated genes and pathways is not known. Here, using chromatin immunoprecipitation/next generation sequencing and gene expression profiling, we identified 1545 protein-coding genes that are directly regulated by HNF-1β in murine kidney epithelial cells. Pathway analysis predicted that HNF-1β regulates cholesterol metabolism. Expression of dominant negative mutant HNF-1β or kidney-specific inactivation of HNF-1β decreased the expression of genes that are essential for cholesterol synthesis, including sterol regulatory element binding factor 2 (Srebf2) and 3-hydroxy-3-methylglutaryl-CoA reductase (Hmgcr). HNF-1β mutant cells also expressed lower levels of cholesterol biosynthetic intermediates and had a lower rate of cholesterol synthesis than control cells. Additionally, depletion of cholesterol in the culture medium mitigated the inhibitory effects of mutant HNF-1β on the proteins encoded by Srebf2 and Hmgcr, and HNF-1β directly controlled the renal epithelial expression of proprotein convertase subtilisin-like kexin type 9, a key regulator of cholesterol uptake. These findings reveal a novel role of HNF-1β in a transcriptional network that regulates intrarenal cholesterol metabolism. PMID:26712526

  10. Regulatory focus and generalized trust: the impact of prevention-focused self-regulation on trusting others.

    PubMed

    Keller, Johannes; Mayo, Ruth; Greifeneder, Rainer; Pfattheicher, Stefan

    2015-01-01

    The current research suggests that taking self-regulatory mechanisms into account provides insights regarding individuals' responses to threats in social interactions. In general, based on the notion that a prevention-focused orientation of self-regulation is associated with a need for security and a vigilant tendency to avoid losses and other types of negative events we advocate that a prevention-focused orientation, both as a disposition as well as a situationally induced state, lowers generalized trust, thus hindering cooperation within social interactions that entail threats. Specifically, we found that the more individuals' habitual self-regulatory orientation is dominated by a prevention focus, the less likely they are to score high on a self-report measure of generalized trust (Study 1), and to express trust in a trust game paradigm as manifested in lower sums of transferred money (Studies 2 and 3). Similar findings were found when prevention focus was situationally manipulated (Study 4). Finally, one possible factor underlying the impact of prevention-focused self-regulation on generalized trust was demonstrated as individuals with a special sensitivity to negative information were significantly affected by a subtle prevention focus manipulation (versus control condition) in that they reacted with reduced trust in the trust game (Study 5). In sum, the current findings document the crucial relevance of self-regulatory orientations as conceptualized in regulatory focus theory regarding generalized trust and responses to threats within a social interaction. The theoretical and applied implications of the findings are discussed. PMID:25852585

  11. Regulatory focus and generalized trust: the impact of prevention-focused self-regulation on trusting others

    PubMed Central

    Keller, Johannes; Mayo, Ruth; Greifeneder, Rainer; Pfattheicher, Stefan

    2015-01-01

    The current research suggests that taking self-regulatory mechanisms into account provides insights regarding individuals’ responses to threats in social interactions. In general, based on the notion that a prevention-focused orientation of self-regulation is associated with a need for security and a vigilant tendency to avoid losses and other types of negative events we advocate that a prevention-focused orientation, both as a disposition as well as a situationally induced state, lowers generalized trust, thus hindering cooperation within social interactions that entail threats. Specifically, we found that the more individuals’ habitual self-regulatory orientation is dominated by a prevention focus, the less likely they are to score high on a self-report measure of generalized trust (Study 1), and to express trust in a trust game paradigm as manifested in lower sums of transferred money (Studies 2 and 3). Similar findings were found when prevention focus was situationally manipulated (Study 4). Finally, one possible factor underlying the impact of prevention-focused self-regulation on generalized trust was demonstrated as individuals with a special sensitivity to negative information were significantly affected by a subtle prevention focus manipulation (versus control condition) in that they reacted with reduced trust in the trust game (Study 5). In sum, the current findings document the crucial relevance of self-regulatory orientations as conceptualized in regulatory focus theory regarding generalized trust and responses to threats within a social interaction. The theoretical and applied implications of the findings are discussed. PMID:25852585

  12. Identification and functional analysis of interferon regulatory factor 3 in Lateolabrax maculatus.

    PubMed

    Chen, Xiao-Wu; Wei, Qun; Wang, Zhi-Peng; Wang, Chun-Lei; Bi, Yan-Hui; Gu, Yi-Feng

    2016-10-01

    The interferon (IFN) regulatory factor 3 (IRF3) is a member of the IFN regulatory transcription factor family, which binds to the IFN-stimulated response element (ISRE) within the promoter of IFN genes and IFN-stimulated genes. In this study, the IRF3 cDNA of sea perch Lateolabrax maculatus (SpIRF3) was identified, which contained 1781 bp with an open reading frame of 1398 bp that coded a 465 amino acid protein. The SpIRF3 protein shared conserved characterizations with its homologues and displayed the conserved DNA-binding domain, IRF association domain, serine-rich C-terminal domain, and tryptophan residue cluster. Phylogenetic analysis illustrated that SpIRF3 belonged to the IRF3 subfamily. Subcellular localization analysis showed that SpIRF3 mainly resided in the cytoplasm without stimuli but translocated into nuclei in the presence of poly I:C. Real-time PCR data indicated that SpIRF3 was transcriptionally up-regulated by poly I:C stimulation in various organs. Moreover, reporter assay revealed that SpIRF3 functioned as a modulator in triggering the IFN response by inducing the activity of IFN and ISRE-containing promoter. These data revealed that SpIRF3 was a potential molecule in the IFN immune defense system against viral infection. PMID:27181713

  13. Human CHAC1 Protein Degrades Glutathione, and mRNA Induction Is Regulated by the Transcription Factors ATF4 and ATF3 and a Bipartite ATF/CRE Regulatory Element.

    PubMed

    Crawford, Rebecca R; Prescott, Eugenia T; Sylvester, Charity F; Higdon, Ashlee N; Shan, Jixiu; Kilberg, Michael S; Mungrue, Imran N

    2015-06-19

    Using an unbiased systems genetics approach, we previously predicted a role for CHAC1 in the endoplasmic reticulum stress pathway, linked functionally to activating transcription factor 4 (ATF4) following treatment with oxidized phospholipids, a model for atherosclerosis. Mouse and yeast CHAC1 homologs have been shown to degrade glutathione in yeast and a cell-free system. In this report, we further defined the ATF4-CHAC1 interaction by cloning the human CHAC1 promoter upstream of a luciferase reporter system for in vitro assays in HEK293 and U2OS cells. Mutation and deletion analyses defined two major cis DNA elements necessary and sufficient for CHAC1 promoter-driven luciferase transcription under conditions of ER stress or ATF4 coexpression: the -267 ATF/cAMP response element (CRE) site and a novel -248 ATF/CRE modifier (ACM) element. We also examined the ability of the CHAC1 ATF/CRE and ACM sequences to bind ATF4 and ATF3 using immunoblot-EMSA and confirmed ATF4, ATF3, and CCAAT/enhancer-binding protein β binding at the human CHAC1 promoter in the proximity of the ATF/CRE and ACM using ChIP. To further validate the function of CHAC1 in a human cell model, we measured glutathione levels in HEK293 cells with enhanced CHAC1 expression. Overexpression of CHAC1 led to a robust depletion of glutathione, which was alleviated in a CHAC1 catalytic mutant. These results suggest an important role for CHAC1 in oxidative stress and apoptosis with implications for human health and disease. PMID:25931127

  14. Human CHAC1 Protein Degrades Glutathione, and mRNA Induction Is Regulated by the Transcription Factors ATF4 and ATF3 and a Bipartite ATF/CRE Regulatory Element*

    PubMed Central

    Crawford, Rebecca R.; Prescott, Eugenia T.; Sylvester, Charity F.; Higdon, Ashlee N.; Shan, Jixiu; Kilberg, Michael S.; Mungrue, Imran N.

    2015-01-01

    Using an unbiased systems genetics approach, we previously predicted a role for CHAC1 in the endoplasmic reticulum stress pathway, linked functionally to activating transcription factor 4 (ATF4) following treatment with oxidized phospholipids, a model for atherosclerosis. Mouse and yeast CHAC1 homologs have been shown to degrade glutathione in yeast and a cell-free system. In this report, we further defined the ATF4-CHAC1 interaction by cloning the human CHAC1 promoter upstream of a luciferase reporter system for in vitro assays in HEK293 and U2OS cells. Mutation and deletion analyses defined two major cis DNA elements necessary and sufficient for CHAC1 promoter-driven luciferase transcription under conditions of ER stress or ATF4 coexpression: the −267 ATF/cAMP response element (CRE) site and a novel −248 ATF/CRE modifier (ACM) element. We also examined the ability of the CHAC1 ATF/CRE and ACM sequences to bind ATF4 and ATF3 using immunoblot-EMSA and confirmed ATF4, ATF3, and CCAAT/enhancer-binding protein β binding at the human CHAC1 promoter in the proximity of the ATF/CRE and ACM using ChIP. To further validate the function of CHAC1 in a human cell model, we measured glutathione levels in HEK293 cells with enhanced CHAC1 expression. Overexpression of CHAC1 led to a robust depletion of glutathione, which was alleviated in a CHAC1 catalytic mutant. These results suggest an important role for CHAC1 in oxidative stress and apoptosis with implications for human health and disease. PMID:25931127

  15. Regulation of cardiac metabolism and function by lipogenic factors.

    PubMed

    Bednarski, Tomasz; Pyrkowska, Aleksandra; Opasińska, Agnieszka; Dobrzyń, Paweł

    2016-01-01

    The heart has a limited capacity for lipogenesis and de novo lipid synthesis. However, expression of lipogenic genes in cardiomyocytes is unexpectedly high. Recent studies showed that lipogenic genes are important factors regulating cardiac metabolism and function. Long chain fatty acids are a major source of ATP required for proper heart function, and under aerobic conditions, the heart derives 60-90% of the energy necessary for contractile function from fatty acid oxidation. On the other hand, cardiac lipid over-accumulation (e.g. ceramides, diacylglycerols) leads to heart dysfunction. Downregulation of the lipogenic genes' expression (e.g. sterol regulatory element binding protein 1, stearoyl-CoA desaturase, acetyl-CoA kwacarboxylase) decreased heart steatosis and cardiomyocyte apoptosis, improving systolic and diastolic function of the left ventricle. Lipogenic factors also regulate fatty acids and glucose utilization in the heart, underlining their important role in maintaining energetic homeostasis in pathological states. Fatty acid synthase, the enzyme catalyzing fatty acids de novo synthesis, affects cardiac calcium signaling through regulation of L-type calcium channel activity. Thus, a growing body of evidence suggests that the role of lipogenic genes in cardiomyocytes may be distinct from other tissues. Here, we review recent advances made in understanding the role of lipogenic genes in the control of heart metabolism and its involvement in the pathogenesis of lipotoxic cardiomyopathy. PMID:27333934

  16. Hydrogen peroxide sensing, signaling and regulation of transcription factors

    PubMed Central

    Marinho, H. Susana; Real, Carla; Cyrne, Luísa; Soares, Helena; Antunes, Fernando

    2014-01-01

    The regulatory mechanisms by which hydrogen peroxide (H2O2) modulates the activity of transcription factors in bacteria (OxyR and PerR), lower eukaryotes (Yap1, Maf1, Hsf1 and Msn2/4) and mammalian cells (AP-1, NRF2, CREB, HSF1, HIF-1, TP53, NF-κB, NOTCH, SP1 and SCREB-1) are reviewed. The complexity of regulatory networks increases throughout the phylogenetic tree, reaching a high level of complexity in mammalians. Multiple H2O2 sensors and pathways are triggered converging in the regulation of transcription factors at several levels: (1) synthesis of the transcription factor by upregulating transcription or increasing both mRNA stability and translation; (ii) stability of the transcription factor by decreasing its association with the ubiquitin E3 ligase complex or by inhibiting this complex; (iii) cytoplasm–nuclear traffic by exposing/masking nuclear localization signals, or by releasing the transcription factor from partners or from membrane anchors; and (iv) DNA binding and nuclear transactivation by modulating transcription factor affinity towards DNA, co-activators or repressors, and by targeting specific regions of chromatin to activate individual genes. We also discuss how H2O2 biological specificity results from diverse thiol protein sensors, with different reactivity of their sulfhydryl groups towards H2O2, being activated by different concentrations and times of exposure to H2O2. The specific regulation of local H2O2 concentrations is also crucial and results from H2O2 localized production and removal controlled by signals. Finally, we formulate equations to extract from typical experiments quantitative data concerning H2O2 reactivity with sensor molecules. Rate constants of 140 M−1 s−1 and ≥1.3 × 103 M−1 s−1 were estimated, respectively, for the reaction of H2O2 with KEAP1 and with an unknown target that mediates NRF2 protein synthesis. In conclusion, the multitude of H2O2 targets and mechanisms provides an opportunity for highly

  17. Regulatory network analysis of transcription factors, microRNAs, target genes and host genes in human multiple myeloma.

    PubMed

    Huang, Zhuoyan; Xu, Zhiwen; Kunhao Wang, Kunhao Wang; Wang, Ning; Wang, Shang

    2015-11-01

    In recent years, molecular biologists have achieved great advance in micro RNA (miRNA) and gene investigation about the pathogenesis of multiple myeloma (MM). Existing research data of the transcription factors (TFs) and miRNAs is disperse and unorganized, which prevents researchers from investigating the mechanism and analyze regulatory pathways of MM systematically. In our research, regulatory interactions among miRNAs, TFs, host genes and target genes were imported to construct regulatory networks at three levels, including the abnormally expressed network and the related network as well as the global network. The abnormally expressed network was primary investigated cause it was an experimentally validated topological network, and it systematically explained the regulatory mechanism of MM. Its outstanding significance lies in that if we correct each abnormally expressed gene and miRNA to normal expression level by transcriptional control adjustment, thus the whole genetic expression network will return to normal state, and MM may not relapse. Additionally, analyses and comparisons to upstream as well as downstream of abnormally expressed miRNAs and genes in three networks highlighted some important regulators and key signaling pathways. For example, STAT3 and hsa-miR-125b, PIAS3 and hsa-miR-21 respectively formed self adaptation feedback regulations. The current research proposed a novel perspective to systematically explained the regulatory mechanism of MM and may contribute to further research and therapy of carcinomas. PMID:26687742

  18. Inferring regulatory element landscapes and transcription factor networks from cancer methylomes.

    PubMed

    Yao, Lijing; Shen, Hui; Laird, Peter W; Farnham, Peggy J; Berman, Benjamin P

    2015-01-01

    Recent studies indicate that DNA methylation can be used to identify transcriptional enhancers, but no systematic approach has been developed for genome-wide identification and analysis of enhancers based on DNA methylation. We describe ELMER (Enhancer Linking by Methylation/Expression Relationships), an R-based tool that uses DNA methylation to identify enhancers and correlates enhancer state with expression of nearby genes to identify transcriptional targets. Transcription factor motif analysis of enhancers is coupled with expression analysis of transcription factors to infer upstream regulators. Using ELMER, we investigated more than 2,000 tumor samples from The Cancer Genome Atlas. We identified networks regulated by known cancer drivers such as GATA3 and FOXA1 (breast cancer), SOX17 and FOXA2 (endometrial cancer), and NFE2L2, SOX2, and TP63 (squamous cell lung cancer). We also identified novel networks with prognostic associations, including RUNX1 in kidney cancer. We propose ELMER as a powerful new paradigm for understanding the cis-regulatory interface between cancer-associated transcription factors and their functional target genes. PMID:25994056

  19. Forkhead transcription factors regulate mosquito reproduction

    PubMed Central

    Hansen, Immo A.; Sieglaff, Douglas H.; Munro, James B.; Shiao, Shin-Hong; Cruz, Josefa; Lee, Iris W.; Heraty, John M.; Raikhel, Alexander S.

    2007-01-01

    Forkhead box (Fox) genes encode a family of transcription factors defined by a ‘winged helix’ DNA-binding domain. In this study we aimed to identify Fox factors that are expressed within the fat body of the yellow fever mosquito Aedes aegypti, and determine whether any of these are involved in the regulation of mosquito yolk protein gene expression. The Ae. aegypti genome contains eighteen loci that encode putative Fox factors. Our stringent cladistic analysis has profound implications for the use of Fox genes as phylogenetic markers. Twelve Ae. aegypti Fox genes are expressed within various tissues of adult females, six of which are expressed within the fat body. All six Fox genes expressed in the fat body displayed dynamic expression profiles following a blood meal. We knocked down the ’fat body Foxes’ through RNAi to determine whether these “knockdowns” hindered amino acid-induced vitellogenin gene expression. We also determined the effect of these knockdowns on the number of eggs deposited following a blood meal. Knockdown of FoxN1, FoxN2, FoxL, and FoxO, had a negative effect on amino acid- induced vitellogenin gene expression and resulted in significantly fewer eggs laid. Our analysis stresses the importance of Fox transcription factors in regulating mosquito reproduction. PMID:17681238

  20. Mutant Huntingtin Downregulates Myelin Regulatory Factor-Mediated Myelin Gene Expression and Affects Mature Oligodendrocytes

    PubMed Central

    Huang, Brenda; Wei, Wenjie; Wang, Guohao; Gaertig, Marta A.; Feng, Yue; Wang, Wei; Li, Xiao-Jiang; Li, Shihua

    2015-01-01

    SUMMARY Growing evidence indicates that non-neuronal mutant huntingtin toxicity plays an important role in Huntington’s disease (HD); however, whether and how mutant huntingtin affects oligodendrocytes, which are vitally important for neural function and axonal integrity, remain unclear. We first verified the presence of mutant huntingtin in oligodendrocytes in HD140Q knock-in mice. We then established transgenic mice (PLP-150Q) that selectively express mutant huntingtin in oligodendrocytes. PLP-150Q mice show progressive neurological symptoms and early death, as well as age-dependent demyelination and reduced expression of myelin genes that are downstream of myelin regulatory factor (MYRF or MRF), a transcriptional regulator that specifically activates and maintains the expression of myelin genes in mature oligodendrocytes. Consistently, mutant huntingtin binds abnormally to MYRF and affects its transcription activity. Our findings suggest that dysfunction of mature oligodendrocytes is involved in HD pathogenesis and may also make a good therapeutic target. PMID:25789755

  1. Interferon regulatory factor 9 is critical for neointima formation following vascular injury.

    PubMed

    Zhang, Shu-Min; Zhu, Li-Hua; Chen, Hou-Zao; Zhang, Ran; Zhang, Peng; Jiang, Ding-Sheng; Gao, Lu; Tian, Song; Wang, Lang; Zhang, Yan; Wang, Pi-Xiao; Zhang, Xiao-Fei; Zhang, Xiao-Dong; Liu, De-Pei; Li, Hongliang

    2014-01-01

    Interferon regulatory factor 9 (IRF9) has various biological functions and regulates cell survival; however, its role in vascular biology has not been explored. Here we demonstrate a critical role for IRF9 in mediating neointima formation following vascular injury. Notably, in mice, IRF9 ablation inhibits the proliferation and migration of vascular smooth muscle cells (VSMCs) and attenuates intimal thickening in response to injury, whereas IRF9 gain-of-function promotes VSMC proliferation and migration, which aggravates arterial narrowing. Mechanistically, we show that the transcription of the neointima formation modulator SIRT1 is directly inhibited by IRF9. Importantly, genetic manipulation of SIRT1 in smooth muscle cells or pharmacological modulation of SIRT1 activity largely reverses the neointima-forming effect of IRF9. Together, our findings suggest that IRF9 is a vascular injury-response molecule that promotes VSMC proliferation and implicate a hitherto unrecognized 'IRF9-SIRT1 axis' in vasculoproliferative pathology modulation. PMID:25319116

  2. Mutant huntingtin downregulates myelin regulatory factor-mediated myelin gene expression and affects mature oligodendrocytes.

    PubMed

    Huang, Brenda; Wei, WenJie; Wang, Guohao; Gaertig, Marta A; Feng, Yue; Wang, Wei; Li, Xiao-Jiang; Li, Shihua

    2015-03-18

    Growing evidence indicates that non-neuronal mutant huntingtin toxicity plays an important role in Huntington's disease (HD); however, whether and how mutant huntingtin affects oligodendrocytes, which are vitally important for neural function and axonal integrity, remains unclear. We first verified the presence of mutant huntingtin in oligodendrocytes in HD140Q knockin mice. We then established transgenic mice (PLP-150Q) that selectively express mutant huntingtin in oligodendrocytes. PLP-150Q mice show progressive neurological symptoms and early death, as well as age-dependent demyelination and reduced expression of myelin genes that are downstream of myelin regulatory factor (MYRF or MRF), a transcriptional regulator that specifically activates and maintains the expression of myelin genes in mature oligodendrocytes. Consistently, mutant huntingtin binds abnormally to MYRF and affects its transcription activity. Our findings suggest that dysfunction of mature oligodendrocytes is involved in HD pathogenesis and may also make a good therapeutic target. PMID:25789755

  3. Epigenetic Regulation of Individual Modules of the immunoglobulin heavy chain locus 3' Regulatory Region.

    PubMed

    Birshtein, Barbara K

    2014-01-01

    The Igh locus undergoes an amazing array of DNA rearrangements and modifications during B cell development. During early stages, the variable region gene is constructed from constituent variable (V), diversity (D), and joining (J) segments (VDJ joining). B cells that successfully express an antibody can be activated, leading to somatic hypermutation (SHM) focused on the variable region, and class switch recombination (CSR), which substitutes downstream constant region genes for the originally used Cμ constant region gene. Many investigators, ourselves included, have sought to understand how these processes specifically target the Igh locus and avoid other loci and potential deleterious consequences of malignant transformation. Our laboratory has concentrated on a complex regulatory region (RR) that is located downstream of Cα, the most 3' of the Igh constant region genes. The ~40 kb 3' RR, which is predicted to serve as a downstream major regulator of the Igh locus, contains two distinct segments: an ~28 kb region comprising four enhancers, and an adjacent ~12 kb region containing multiple CTCF and Pax5 binding sites. Analysis of targeted mutations in mice by a number of investigators has concluded that the entire 3' RR enhancer region is essential for SHM and CSR (but not for VDJ joining) and for high levels of expression of multiple isotypes. The CTCF/Pax5 binding region is a candidate for influencing VDJ joining early in B cell development and serving as a potential insulator of the Igh locus. Components of the 3' RR are subject to a variety of epigenetic changes during B cell development, i.e., DNAse I hypersensitivity, histone modifications, and DNA methylation, in association with transcription factor binding. I propose that these changes provide a foundation by which regulatory elements in modules of the 3' RR function by interacting with each other and with target sequences of the Igh locus. PMID:24795714

  4. 76 FR 50433 - Regulatory Guidance: Applicability of the Federal Motor Carrier Safety Regulations to Operators...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-15

    ... vehicles (76 FR 31279). Recognizing that changes in regulatory guidance (if implemented by a State) could... the Federal Motor Carrier Safety Regulations to Operators of Certain Farm Vehicles and Off-Road...) to operators of farm vehicles: first, the interpretation of interstate commerce as it applies...

  5. 75 FR 4305 - Regulatory Guidance Concerning the Applicability of the Federal Motor Carrier Safety Regulations...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-27

    ... Applicability of the Federal Motor Carrier Safety Regulations to Texting by Commercial Motor Vehicle Drivers.... SUMMARY: The FMCSA announces regulatory guidance concerning texting while driving a commercial motor... operators engaged in ``texting'' on an electronic device while driving a CMV in interstate...

  6. Dopamine receptor regulating factor, DRRF: a zinc finger transcription factor.

    PubMed

    Hwang, C K; D'Souza, U M; Eisch, A J; Yajima, S; Lammers, C H; Yang, Y; Lee, S H; Kim, Y M; Nestler, E J; Mouradian, M M

    2001-06-19

    Dopamine receptor genes are under complex transcription control, determining their unique regional distribution in the brain. We describe here a zinc finger type transcription factor, designated dopamine receptor regulating factor (DRRF), which binds to GC and GT boxes in the D1A and D2 dopamine receptor promoters and effectively displaces Sp1 and Sp3 from these sequences. Consequently, DRRF can modulate the activity of these dopamine receptor promoters. Highest DRRF mRNA levels are found in brain with a specific regional distribution including olfactory bulb and tubercle, nucleus accumbens, striatum, hippocampus, amygdala, and frontal cortex. Many of these brain regions also express abundant levels of various dopamine receptors. In vivo, DRRF itself can be regulated by manipulations of dopaminergic transmission. Mice treated with drugs that increase extracellular striatal dopamine levels (cocaine), block dopamine receptors (haloperidol), or destroy dopamine terminals (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) show significant alterations in DRRF mRNA. The latter observations provide a basis for dopamine receptor regulation after these manipulations. We conclude that DRRF is important for modulating dopaminergic transmission in the brain. PMID:11390978

  7. Design-based regulation and patient safety: a regulatory studies perspective.

    PubMed

    Yeung, Karen; Dixon-Woods, Mary

    2010-08-01

    The optimal choice of regulatory approach for securing patient safety is an important problem. In this review article, we show how insights from the field of regulatory studies can provide a conceptual apparatus for analysis of important problems in the regulation of medicine and healthcare. Design-based regulation operates through technical constraints that are self-executing. Technology, by concretising rules about proper behaviour and conduct, not only functions as a regulatory instrument, but may also encode particular values and versions of rationality. As debates in the broader area of "code" or "design"-based regulation, including the crime prevention context have highlighted, design-based approaches may have significant social, political and ethical implications. Though design-based regulation can be an attractive solution where there is widespread agreement about what constitutes good medical practice, it is considerably more problematic where there is contestation about what constitutes an error and who owns the definition of an error. Design-based regulation involves challenges to professional agency and authority, and engages with wider debates about the regulation of the medical profession. It is vital that the introduction of patient safety technology is sensitive to the values and motives that get encoded in design. PMID:20538395

  8. Modulation of neoplastic gene regulatory pathways by the RNA-binding factor AUF1

    PubMed Central

    Zucconi, Beth E.; Wilson, Gerald M.

    2013-01-01

    The mRNA-binding protein AUF1 regulates the expression of many key players in cancer including proto-oncogenes, regulators of apoptosis and the cell cycle, and pro-inflammatory cytokines, principally by directing the decay kinetics of their encoded mRNAs. Most studies support an mRNA-destabilizing role for AUF1, although other findings suggest additional functions for this factor. In this review, we explore how changes in AUF1 isoform distribution, subcellular localization, and post-translational protein modifications can influence the metabolism of targeted mRNAs. However, several lines of evidence also support a role for AUF1 in the initiation and/or development of cancer. Many AUF1-targeted transcripts encode products that control pro- and anti-oncogenic processes. Also, overexpression of AUF1 enhances tumorigenesis in murine models, and AUF1 levels are enhanced in some tumors. Finally, signaling cascades that modulate AUF1 function are deregulated in some cancerous tissues. Together, these features suggest that AUF1 may play a prominent role in regulating the expression of many genes that can contribute to tumorigenic phenotypes, and that this post-transcriptional regulatory control point may be subverted by diverse mechanisms in neoplasia. PMID:21622178

  9. Specific detection of interferon regulatory factor 5 (IRF5): A case of antibody inequality

    PubMed Central

    Li, Dan; De, Saurav; Li, Dan; Song, Su; Matta, Bharati; Barnes, Betsy J.

    2016-01-01

    Interferon regulatory factor 5 (IRF5) is a member of the IRF family of transcription factors. IRF5 was first identified and characterized as a transcriptional regulator of type I interferon expression after virus infection. In addition to its critical role(s) in the regulation and development of host immunity, subsequent studies revealed important roles for IRF5 in autoimmunity, cancer, obesity, pain, cardiovascular disease, and metabolism. Based on these important disease-related findings, a large number of commercial antibodies have become available to study the expression and function of IRF5. Here we validate a number of these antibodies for the detection of IRF5 by immunoblot, flow cytometry, and immunofluorescence or immunohistochemistry using well-established positive and negative controls. Somewhat surprising, the majority of commercial antibodies tested were unable to specifically recognize human or mouse IRF5. We present data on antibodies that do specifically recognize human or mouse IRF5 in a particular application. These findings reiterate the importance of proper controls and molecular weight standards for the analysis of protein expression. Given that dysregulated IRF5 expression has been implicated in the pathogenesis of numerous diseases, including autoimmune and cancer, results indicate that caution should be used in the evaluation and interpretation of IRF5 expression analysis. PMID:27481535

  10. MYC TRANSCRIPTION FACTORS: KEY REGULATORS BEHIND ESTABLISHMENT AND MAINTENANCE OF PLURIPOTENCY

    PubMed Central

    Smith, Keriayn; Dalton, Stephen

    2011-01-01

    Summary The interplay between transcription factors, epigenetic modifiers, chromatin remodelers and miRNAs form the foundation of a complex regulatory network required for establishment and maintenance of the pluripotent state. Recent work indicates that Myc transcription factors are essential elements of this regulatory system. Despite numerous reports however, aspects of how Myc controls self-renewal and pluripotency remain obscure. Here, we review evidence supporting the placement of Myc as a central regulator of the pluripotent state and discuss possible mechanisms of action. PMID:21082893

  11. Gravity, an Regulation Factor in BMSCs Differentiation to osteoblasts

    NASA Astrophysics Data System (ADS)

    Yan, Huang; Yinghui, Li; Fen, Yang; Zhongquan, Dai

    PURPOSE Most studies of regulatory mechanisms of adult stem cell differentiation are concentrated in chemical factors but few efforts are put into physical factors Recent space life science studies indicate mechanical factors participate in the differentiation of cells The aim of this study is to investigate the effects of simulated microgravity or hypergravity on the osteogenic differentiation of rat bone marrow mesenchymal stem cells BMSCs METHODOLOGY The BMSCs at day 7 were added osteogenic inducer 10nM dexamethasone 10mM beta -glycerophosphate and 50 mu M asorbic acid-2-phosphate for 7 days and cultured under simulated microgravity or hypergravity 2g for 1 day 3 days 5 days or 7 days RESULTS After treating BMSCs with osteogenic inducer and hypergravity the cells expressed more ColIA1 Cbfa1 and ALP than in single steogenic inducer treatment Reversely the cells treated with osteogenic inducer and simulated microgravity expressed less ColIA1 Cbfa1 and ALP CONCLUSIONS Our study suggests that hypergravity promotes the osteogenic differentiation of BMSCs and simulated microgravity inhibits this process Gravity is an important regulation factor in BMSCs differentiation to osteoblasts

  12. Identification of the transcription factor ZEB1 as a central component of the adipogenic gene regulatory network.

    PubMed

    Gubelmann, Carine; Schwalie, Petra C; Raghav, Sunil K; Röder, Eva; Delessa, Tenagne; Kiehlmann, Elke; Waszak, Sebastian M; Corsinotti, Andrea; Udin, Gilles; Holcombe, Wiebke; Rudofsky, Gottfried; Trono, Didier; Wolfrum, Christian; Deplancke, Bart

    2014-01-01

    Adipose tissue is a key determinant of whole body metabolism and energy homeostasis. Unraveling the regulatory mechanisms underlying adipogenesis is therefore highly relevant from a biomedical perspective. Our current understanding of fat cell differentiation is centered on the transcriptional cascades driven by the C/EBP protein family and the master regulator PPARγ. To elucidate further components of the adipogenic gene regulatory network, we performed a large-scale transcription factor (TF) screen overexpressing 734 TFs in mouse pre-adipocytes and probed their effect on differentiation. We identified 22 novel pro-adipogenic TFs and characterized the top ranking TF, ZEB1, as being essential for adipogenesis both in vitro and in vivo. Moreover, its expression levels correlate with fat cell differentiation potential in humans. Genomic profiling further revealed that this TF directly targets and controls the expression of most early and late adipogenic regulators, identifying ZEB1 as a central transcriptional component of fat cell differentiation. PMID:25163748

  13. A WRKY Transcription Factor Regulates Fe Translocation under Fe Deficiency.

    PubMed

    Yan, Jing Ying; Li, Chun Xiao; Sun, Li; Ren, Jiang Yuan; Li, Gui Xin; Ding, Zhong Jie; Zheng, Shao Jian

    2016-07-01

    Iron (Fe) deficiency affects plant growth and development, leading to reduction of crop yields and quality. Although the regulation of Fe uptake under Fe deficiency has been well studied in the past decade, the regulatory mechanism of Fe translocation inside the plants remains unknown. Here, we show that a WRKY transcription factor WRKY46 is involved in response to Fe deficiency. Lack of WRKY46 (wrky46-1 and wrky46-2 loss-of-function mutants) significantly affects Fe translocation from root to shoot and thus causes obvious chlorosis on the new leaves under Fe deficiency. Gene expression analysis reveals that expression of a nodulin-like gene (VACUOLAR IRON TRANSPORTER1-LIKE1 [VITL1]) is dramatically increased in wrky46-1 mutant. VITL1 expression is inhibited by Fe deficiency, while the expression of WRKY46 is induced in the root stele. Moreover, down-regulation of VITL1 expression can restore the chlorosis phenotype on wrky46-1 under Fe deficiency. Further yeast one-hybrid and chromatin immunoprecipitation experiments indicate that WRKY46 is capable of binding to the specific W-boxes present in the VITL1 promoter. In summary, our results demonstrate that WRKY46 plays an important role in the control of root-to-shoot Fe translocation under Fe deficiency condition via direct regulation of VITL1 transcript levels. PMID:27208259

  14. Product feedback regulation implicated in translational control of the Trypanosoma brucei S-adenosylmethionine decarboxylase regulatory subunit prozyme

    PubMed Central

    Xiao, Yanjing; Nguyen, Suong; Kim, Sok Ho; Volkov, Oleg A.; Tu, Benjamin P.; Phillips, Margaret A.

    2013-01-01

    Summary Human African sleeping sickness (HAT) is caused by the parasitic protozoan Trypanosoma brucei. Polyamine biosynthesis is an important drug target in the treatment of HAT. Previously we showed that trypanosomatid S-adenosylmethionine decarboxylase (AdoMetDC), a key enzyme for biosynthesis of the polyamine spermidine, is activated by heterodimer formation with an inactive paralog termed prozyme. Furthermore, prozyme protein levels were regulated in response reduced AdoMetDC activity. Herein we show that T. brucei encodes three prozyme transcripts. The 3’UTRs of these transcripts were mapped and chloramphenicol acetyltransferase (CAT) reporter constructs were used to identify a 1.2 kb region that contained a 3’UTR prozyme regulatory element sufficient to up regulate CAT protein levels (but not RNA) upon AdoMetDC inhibition, supporting the hypothesis that prozyme expression is regulated translationally. To gain insight into trans-acting factors, genetic rescue of AdoMetDC RNAi knockdown lines with human AdoMetDC was performed leading to rescue of the cell growth block, and restoration of prozyme protein to wild-type levels. Polyamine and AdoMet metabolite analysis showed that prozyme protein levels were inversely proportional to intracellular levels of decarboxylated AdoMet (dcAdoMet). These data suggest that prozyme translation may be regulated by dcAdoMet, a metabolite not previously identified to play a regulatory role. PMID:23634831

  15. Stress-induced Start Codon Fidelity Regulates Arsenite-inducible Regulatory Particle-associated Protein (AIRAP) Translation*

    PubMed Central

    Zach, Lolita; Braunstein, Ilana; Stanhill, Ariel

    2014-01-01

    Initial steps in protein synthesis are highly regulated processes as they define the reading frame of the translation machinery. Eukaryotic translation initiation is a process facilitated by numerous factors (eIFs), aimed to form a “scanning” mechanism toward the initiation codon. Translation initiation of the main open reading frame (ORF) in an mRNA transcript has been reported to be regulated by upstream open reading frames (uORFs) in a manner of re-initiation. This mode of regulation is governed by the phosphorylation status of eIF2α and controlled by cellular stresses. Another mode of translational initiation regulation is leaky scanning, and this regulatory process has not been extensively studied. We have identified arsenite-inducible regulatory particle-associated protein (AIRAP) transcript to be translationally induced during arsenite stress conditions. AIRAP transcript contains a single uORF in a poor-kozak context. AIRAP translation induction is governed by means of leaky scanning and not re-initiation. This induction of AIRAP is solely dependent on eIF1 and the uORF kozak context. We show that eIF1 is phosphorylated under specific conditions that induce protein misfolding and have biochemically characterized this site of phosphorylation. Our data indicate that leaky scanning like re-initiation is responsive to stress conditions and that leaky scanning can induce ORF translation by bypassing poor kozak context of a single uORF transcript. PMID:24898249

  16. Deciphering RNA Regulatory Elements Involved in the Developmental and Environmental Gene Regulation of Trypanosoma brucei

    PubMed Central

    Gazestani, Vahid H.; Salavati, Reza

    2015-01-01

    Trypanosoma brucei is a vector-borne parasite with intricate life cycle that can cause serious diseases in humans and animals. This pathogen relies on fine regulation of gene expression to respond and adapt to variable environments, with implications in transmission and infectivity. However, the involved regulatory elements and their mechanisms of actions are largely unknown. Here, benefiting from a new graph-based approach for finding functional regulatory elements in RNA (GRAFFER), we have predicted 88 new RNA regulatory elements that are potentially involved in the gene regulatory network of T. brucei. We show that many of these newly predicted elements are responsive to both transcriptomic and proteomic changes during the life cycle of the parasite. Moreover, we found that 11 of predicted elements strikingly resemble previously identified regulatory elements for the parasite. Additionally, comparison with previously predicted motifs on T. brucei suggested the superior performance of our approach based on the current limited knowledge of regulatory elements in T. brucei. PMID:26529602

  17. Inferring Gene Regulatory Networks Using Conditional Regulation Pattern to Guide Candidate Genes

    PubMed Central

    Xiao, Fei; Gao, Lin; Ye, Yusen; Hu, Yuxuan; He, Ruijie

    2016-01-01

    Combining path consistency (PC) algorithms with conditional mutual information (CMI) are widely used in reconstruction of gene regulatory networks. CMI has many advantages over Pearson correlation coefficient in measuring non-linear dependence to infer gene regulatory networks. It can also discriminate the direct regulations from indirect ones. However, it is still a challenge to select the conditional genes in an optimal way, which affects the performance and computation complexity of the PC algorithm. In this study, we develop a novel conditional mutual information-based algorithm, namely RPNI (Regulation Pattern based Network Inference), to infer gene regulatory networks. For conditional gene selection, we define the co-regulation pattern, indirect-regulation pattern and mixture-regulation pattern as three candidate patterns to guide the selection of candidate genes. To demonstrate the potential of our algorithm, we apply it to gene expression data from DREAM challenge. Experimental results show that RPNI outperforms existing conditional mutual information-based methods in both accuracy and time complexity for different sizes of gene samples. Furthermore, the robustness of our algorithm is demonstrated by noisy interference analysis using different types of noise. PMID:27171286

  18. Mutagenesis of GATA motifs controlling the endoderm regulator elt-2 reveals distinct dominant and secondary cis-regulatory elements.

    PubMed

    Du, Lawrence; Tracy, Sharon; Rifkin, Scott A

    2016-04-01

    Cis-regulatory elements (CREs) are crucial links in developmental gene regulatory networks, but in many cases, it can be difficult to discern whether similar CREs are functionally equivalent. We found that despite similar conservation and binding capability to upstream activators, different GATA cis-regulatory motifs within the promoter of the C. elegans endoderm regulator elt-2 play distinctive roles in activating and modulating gene expression throughout development. We fused wild-type and mutant versions of the elt-2 promoter to a gfp reporter and inserted these constructs as single copies into the C. elegans genome. We then counted early embryonic gfp transcripts using single-molecule RNA FISH (smFISH) and quantified gut GFP fluorescence. We determined that a single primary dominant GATA motif located 527bp upstream of the elt-2 start codon was necessary for both embryonic activation and later maintenance of transcription, while nearby secondary GATA motifs played largely subtle roles in modulating postembryonic levels of elt-2. Mutation of the primary activating site increased low-level spatiotemporally ectopic stochastic transcription, indicating that this site acts repressively in non-endoderm cells. Our results reveal that CREs with similar GATA factor binding affinities in close proximity can play very divergent context-dependent roles in regulating the expression of a developmentally critical gene in vivo. PMID:26896592

  19. Negative feedback confers mutational robustness in yeast transcription factor regulation

    PubMed Central

    Denby, Charles M.; Im, Joo Hyun; Yu, Richard C.; Pesce, C. Gustavo; Brem, Rachel B.

    2012-01-01

    Organismal fitness depends on the ability of gene networks to function robustly in the face of environmental and genetic perturbations. Understanding the mechanisms of this stability is one of the key aims of modern systems biology. Dissecting the basis of robustness to mutation has proven a particular challenge, with most experimental models relying on artificial DNA sequence variants engineered in the laboratory. In this work, we hypothesized that negative regulatory feedback could stabilize gene expression against the disruptions that arise from natural genetic variation. We screened yeast transcription factors for feedback and used the results to establish ROX1 (Repressor of hypOXia) as a model system for the study of feedback in circuit behaviors and its impact across genetically heterogeneous populations. Mutagenesis experiments revealed the mechanism of Rox1 as a direct transcriptional repressor at its own gene, enabling a regulatory program of rapid induction during environmental change that reached a plateau of moderate steady-state expression. Additionally, in a given environmental condition, Rox1 levels varied widely across genetically distinct strains; the ROX1 feedback loop regulated this variation, in that the range of expression levels across genetic backgrounds showed greater spread in ROX1 feedback mutants than among strains with the ROX1 feedback loop intact. Our findings indicate that the ROX1 feedback circuit is tuned to respond to perturbations arising from natural genetic variation in addition to its role in induction behavior. We suggest that regulatory feedback may be an important element of the network architectures that confer mutational robustness across biology. PMID:22355134

  20. Antiviral factors and type I/III interferon expression associated with regulatory factors in the oral epithelial cells from HIV-1-serodiscordant couples.

    PubMed

    Cervantes, Cesar A C; Oliveira, Luanda M S; Manfrere, Kelly C G; Lima, Josenilson F; Pereira, Natalli Z; Duarte, Alberto J S; Sato, Maria N

    2016-01-01

    Individuals who remain HIV-seronegative despite repeated unprotected exposure to the virus are defined as exposed seronegative (ESN) individuals. Innate and adaptive immunity, as well as genetic factors, provide ESNs with important advantages that allow for low infection susceptibility. The majority of HIV-1-infected individuals undergo antiretroviral therapy, which can decrease the level of HIV-1 exposure in ESNs. We analyzed type I interferon (IFN)-related antiviral and regulatory factors in peripheral blood mononuclear cells (PBMCs) and oral epithelial cells from serodiscordant couples. Our findings revealed that ESNs did not induce the expression of antiviral factors (APOBEC-3G, TRIM5-α, SAMDH1, STING, TBk1) or regulatory factors (Trex, Foxo3, Socs3, IL-10) in PBMCs, unlike their HIV-1-infected partners. In contrast, ESNs upregulated APOBEC-3G and type I/III IFNs (IFNs-α,-β/-λ) in oral mucosal epithelial cells similar to their HIV-infected partners. The serodiscordant groups exhibited an increased expression of type I IFN-induced regulators, such as Trex and Foxo3, in oral epithelial cells. TLR7, TLR8 and TLR9 were expressed in oral epithelial cells of both ESNs and HIV-1-infected subjects. These findings revealed evidence of antiviral factors, type I/III interferon and regulatory factor expression only in the oral mucosal compartment of ESNs, while HIV-1-infected partners systemically and oral mucosal expressed the antiviral profile. PMID:27168019

  1. Antiviral factors and type I/III interferon expression associated with regulatory factors in the oral epithelial cells from HIV-1-serodiscordant couples

    PubMed Central

    Cervantes, Cesar A. C.; Oliveira, Luanda M. S.; Manfrere, Kelly C. G.; Lima, Josenilson F.; Pereira, Natalli Z.; Duarte, Alberto J. S.; Sato, Maria N.

    2016-01-01

    Individuals who remain HIV-seronegative despite repeated unprotected exposure to the virus are defined as exposed seronegative (ESN) individuals. Innate and adaptive immunity, as well as genetic factors, provide ESNs with important advantages that allow for low infection susceptibility. The majority of HIV-1-infected individuals undergo antiretroviral therapy, which can decrease the level of HIV-1 exposure in ESNs. We analyzed type I interferon (IFN)-related antiviral and regulatory factors in peripheral blood mononuclear cells (PBMCs) and oral epithelial cells from serodiscordant couples. Our findings revealed that ESNs did not induce the expression of antiviral factors (APOBEC-3G, TRIM5-α, SAMDH1, STING, TBk1) or regulatory factors (Trex, Foxo3, Socs3, IL-10) in PBMCs, unlike their HIV-1-infected partners. In contrast, ESNs upregulated APOBEC-3G and type I/III IFNs (IFNs-α,-β/-λ) in oral mucosal epithelial cells similar to their HIV-infected partners. The serodiscordant groups exhibited an increased expression of type I IFN-induced regulators, such as Trex and Foxo3, in oral epithelial cells. TLR7, TLR8 and TLR9 were expressed in oral epithelial cells of both ESNs and HIV-1-infected subjects. These findings revealed evidence of antiviral factors, type I/III interferon and regulatory factor expression only in the oral mucosal compartment of ESNs, while HIV-1-infected partners systemically and oral mucosal expressed the antiviral profile. PMID:27168019

  2. Multiple steps in the regulation of transcription-factor level and activity.

    PubMed Central

    Calkhoven, C F; Ab, G

    1996-01-01

    This review focuses on the regulation of transcription factors, many of which are DNA-binding proteins that recognize cis-regulatory elements of target genes and are the most direct regulators of gene transcription. Transcription factors serve as integration centres of the different signal-transduction pathways affecting a given gene. It is obvious that the regulation of these regulators themselves is of crucial importance for differential gene expression during development and in terminally differentiated cells. Transcription factors can be regulated at two, principally different, levels, namely concentration and activity, each of which can be modulated in a variety of ways. The concentrations of transcription factors, as of intracellular proteins in general, may be regulated at any of the steps leading from DNA to protein, including transcription, RNA processing, mRNA degradation and translation. The activity of a transcription factor is often regulated by (de) phosphorylation, which may affect different functions, e.g. nuclear localization DNA binding and trans-activation. Ligand binding is another mode of transcription-factor activation. It is typical for the large super-family of nuclear hormone receptors. Heterodimerization between transcription factors adds another dimension to the regulatory diversity and signal integration. Finally, non-DNA-binding (accessory) factors may mediate a diverse range of functions, e.g. serving as a bridge between the transcription factor and the basal transcription machinery, stabilizing the DNA-binding complex or changing the specificity of the target sequence recognition. The present review presents an overview of different modes of transcription-factor regulation, each illustrated by typical examples. PMID:8713055

  3. [Virulence factors in Pseudomonas aeruginosa: mechanisms and modes of regulation].

    PubMed

    Ben Haj Khalifa, Anis; Moissenet, Didier; Vu Thien, Hoang; Khedher, Mohamed

    2011-01-01

    Pseudomonas aeruginosa is a bacterium responsible for severe nosocomial infections, life-threatening infections in immunocompromised persons, and chronic infections in cystic fibrosis patients. The bacterium's virulence depends on a large number of cell-associated and extracellular factors. The virulence factors play an important pathological role in the colonization, the survival of the bacteria and the invasion of tissues. There are two types of virulence factors: (1) factors involved in the acute infection: these factors are either on the surface of P. aeruginosa, either secreted. The pili allow adherence to the epithelium. The exoenzyme S and other adhesins reinforce the adherence to epithelial cells. The exotoxin A is responsible of tissue necrosis. Phospholipase C is a thermolabile haemolysin. The pathogenic role of exoenzyme S is attributable to the disruption of normal cytoskeletal organization, the destruction of immunoglobulin G and A, leads to depolymerization of actin filaments and contributes to the resistance to macrophages. P. aeruginosa produces at least four proteases causing bleeding and tissue necrosis; (2) factors involved in the chronic infection: siderophores (pyoverdin and pyochelin), allow the bacteria to multiply in the absence of ferrous ions. The strains isolated from patients with cystic fibrosis have a pseudocapsule of alginate that protects the bacterium from phagocytosis, dehydration and antibiotics. Moreover, it improves adherence to epithelial cells forming a biofilm. Two different types of regulation systems control the expression of the majority of these virulence factors: the two-component transcriptional regulatory system and the quorum sensing system. These two mechanisms are necessary to the survival and the proliferation of this microorganism in the host. PMID:21896403

  4. Extracellular Superoxide Dismutase Regulates the Expression of Small GTPase Regulatory Proteins GEFs, GAPs, and GDI

    PubMed Central

    Laukkanen, Mikko O.; Cammarota, Francesca; Esposito, Tiziana; Salvatore, Marco; Castellone, Maria D.

    2015-01-01

    Extracellular superoxide dismutase (SOD3), which catalyzes the dismutation of superoxide anions to hydrogen peroxide at the cell membranes, regulates the cellular growth in a dose-dependent manner. This enzyme induces primary cell proliferation and immortalization at low expression levels whereas it activates cancer barrier signaling through the p53-p21 pathway at high expression levels, causing growth arrest, senescence, and apoptosis. Because previous reports suggested that the SOD3–induced reduction in the rates of cellular growth and migration also occurred in the absence of functional p53 signaling, in the current study we investigated the SOD3-induced growth-suppressive mechanisms in anaplastic thyroid cancer cells. Based on our data, the robust over-expression of SOD3 increased the level of phosphorylation of the EGFR, ERBB2, RYK, ALK, FLT3, and EPHA10 receptor tyrosine kinases with the consequent downstream activation of the SRC, FYN, YES, HCK, and LYN kinases. However, pull-down experiments focusing on the small GTPase RAS, RAC, CDC42, and RHO revealed a reduced level of growth and migration signal transduction, such as the lack of stimulation of the mitogen pathway, in the SOD3 over-expressing cells, which was confirmed by MEK1/2 and ERK1/2 Western blotting analysis. Interestingly, the mRNA expression analyses indicated that SOD3 regulated the expression of guanine nucleotide-exchange factors (RHO GEF16, RAL GEF RGL1), GTPase-activating proteins (ARFGAP ADAP2, RAS GAP RASAL1, RGS4), and a Rho guanine nucleotide-disassociation inhibitor (RHO GDI 2) in a dose dependent manner, thus controlling signaling through the small G protein GTPases. Therefore, our current data may suggest the occurrence of dose-dependent SOD3–driven control of the GTP loading of small G proteins indicating a novel growth regulatory mechanism of this enzyme. PMID:25751262

  5. Extracellular superoxide dismutase regulates the expression of small gtpase regulatory proteins GEFs, GAPs, and GDI.

    PubMed

    Laukkanen, Mikko O; Cammarota, Francesca; Esposito, Tiziana; Salvatore, Marco; Castellone, Maria D

    2015-01-01

    Extracellular superoxide dismutase (SOD3), which catalyzes the dismutation of superoxide anions to hydrogen peroxide at the cell membranes, regulates the cellular growth in a dose-dependent manner. This enzyme induces primary cell proliferation and immortalization at low expression levels whereas it activates cancer barrier signaling through the p53-p21 pathway at high expression levels, causing growth arrest, senescence, and apoptosis. Because previous reports suggested that the SOD3-induced reduction in the rates of cellular growth and migration also occurred in the absence of functional p53 signaling, in the current study we investigated the SOD3-induced growth-suppressive mechanisms in anaplastic thyroid cancer cells. Based on our data, the robust over-expression of SOD3 increased the level of phosphorylation of the EGFR, ERBB2, RYK, ALK, FLT3, and EPHA10 receptor tyrosine kinases with the consequent downstream activation of the SRC, FYN, YES, HCK, and LYN kinases. However, pull-down experiments focusing on the small GTPase RAS, RAC, CDC42, and RHO revealed a reduced level of growth and migration signal transduction, such as the lack of stimulation of the mitogen pathway, in the SOD3 over-expressing cells, which was confirmed by MEK1/2 and ERK1/2 Western blotting analysis. Interestingly, the mRNA expression analyses indicated that SOD3 regulated the expression of guanine nucleotide-exchange factors (RHO GEF16, RAL GEF RGL1), GTPase-activating proteins (ARFGAP ADAP2, RAS GAP RASAL1, RGS4), and a Rho guanine nucleotide-disassociation inhibitor (RHO GDI 2) in a dose dependent manner, thus controlling signaling through the small G protein GTPases. Therefore, our current data may suggest the occurrence of dose-dependent SOD3-driven control of the GTP loading of small G proteins indicating a novel growth regulatory mechanism of this enzyme. PMID:25751262

  6. Inverse regulation of human ERBB2 and epidermal growth factor receptors by tumor necrosis factor alpha.

    PubMed Central

    Kalthoff, H; Roeder, C; Gieseking, J; Humburg, I; Schmiegel, W

    1993-01-01

    Recombinant human tumor necrosis factor (TNF) alpha decreased the expression of ERBB2 mRNA by stimulating p55 TNF receptors of pancreatic tumor cells. This decrease contrasts with an increase in epidermal growth factor receptor (EGFR) mRNA. Both effects were selectively achieved by TNF-alpha or -beta, whereas interferon alpha or gamma or transforming growth factor beta showed no such effects. The inverse regulatory effects of TNF on ERBB2 and EGFR mRNA levels were evoked by different signaling pathways of p55 TNF receptors. The TNF-mediated ERBB2 mRNA decrease was followed by a reduction in protein. Four of five pancreatic tumor cell lines exhibited this down-regulation. This decrease of ERBB2 is a singular example of a modulation of this growth factor receptor by TNF. Overexpression of ERBB2 has been reported to cause resistance to TNF and other cytotoxic cytokines. In our study we show that the TNF-mediated down-regulation of ERBB2 in pancreatic tumor cells is accompanied by an increase in growth inhibition at low doses of TNF. The simultaneous alteration of the ERBB2/EGFR balance by TNF represents a striking model of cytokine receptor transregulation in the growth control of malignant pancreatic epithelial cells. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8105469

  7. Autophagy Regulatory Network — A systems-level bioinformatics resource for studying the mechanism and regulation of autophagy

    PubMed Central

    Türei, Dénes; Földvári-Nagy, László; Fazekas, Dávid; Módos, Dezső; Kubisch, János; Kadlecsik, Tamás; Demeter, Amanda; Lenti, Katalin; Csermely, Péter; Vellai, Tibor; Korcsmáros, Tamás

    2015-01-01

    Autophagy is a complex cellular process having multiple roles, depending on tissue, physiological, or pathological conditions. Major post-translational regulators of autophagy are well known, however, they have not yet been collected comprehensively. The precise and context-dependent regulation of autophagy necessitates additional regulators, including transcriptional and post-transcriptional components that are listed in various datasets. Prompted by the lack of systems-level autophagy-related information, we manually collected the literature and integrated external resources to gain a high coverage autophagy database. We developed an online resource, Autophagy Regulatory Network (ARN; http://autophagy-regulation.org), to provide an integrated and systems-level database for autophagy research. ARN contains manually curated, imported, and predicted interactions of autophagy components (1,485 proteins with 4,013 interactions) in humans. We listed 413 transcription factors and 386 miRNAs that could regulate autophagy components or their protein regulators. We also connected the above-mentioned autophagy components and regulators with signaling pathways from the SignaLink 2 resource. The user-friendly website of ARN allows researchers without computational background to search, browse, and download the database. The database can be downloaded in SQL, CSV, BioPAX, SBML, PSI-MI, and in a Cytoscape CYS file formats. ARN has the potential to facilitate the experimental validation of novel autophagy components and regulators. In addition, ARN helps the investigation of transcription factors, miRNAs and signaling pathways implicated in the control of the autophagic pathway. The list of such known and predicted regulators could be important in pharmacological attempts against cancer and neurodegenerative diseases. PMID:25635527

  8. Identification of the Staphylococcus aureus vfrAB Operon, a Novel Virulence Factor Regulatory Locus

    PubMed Central

    Daly, Seth M.; Hall, Pamela R.; Bayles, Kenneth W.

    2014-01-01

    During a screen of the Nebraska Transposon Mutant Library, we identified 71 mutations in the Staphylococcus aureus genome that altered hemolysis on blood agar medium. Although many of these mutations disrupted genes known to affect the production of alpha-hemolysin, two of them were associated with an apparent operon, designated vfrAB, that had not been characterized previously. Interestingly, a ΔvfrB mutant exhibited only minor effects on the transcription of the hla gene, encoding alpha-hemolysin, when grown in broth, as well as on RNAIII, a posttranscriptional regulatory RNA important for alpha-hemolysin translation, suggesting that VfrB may function at the posttranscriptional level. Indeed, a ΔvfrB mutant had increased aur and sspAB protease expression under these conditions. However, disruption of the known secreted proteases in the ΔvfrB mutant did not restore hemolytic activity in the ΔvfrB mutant on blood agar. Further analysis revealed that, in contrast to the minor effects of VfrB on hla transcription when strains were cultured in liquid media, the level of hla transcription was decreased 50-fold in the absence of VfrB on solid media. These results demonstrate that while VfrB represses protease expression when strains are grown in broth, hla regulation is highly responsive to factors associated with growth on solid media. Intriguingly, the ΔvfrB mutant displayed increased pathogenesis in a model of S. aureus dermonecrosis, further highlighting the complexity of VfrB-dependent virulence regulation. The results of this study describe a phenotype associated with a class of highly conserved yet uncharacterized proteins found in Gram-positive bacteria, and they shed new light on the regulation of virulence factors necessary for S. aureus pathogenesis. PMID:24549328

  9. Extending the dynamic range of transcription factor action by translational regulation.

    PubMed

    Sokolowski, Thomas R; Walczak, Aleksandra M; Bialek, William; Tkačik, Gašper

    2016-02-01

    A crucial step in the regulation of gene expression is binding of transcription factor (TF) proteins to regulatory sites along the DNA. But transcription factors act at nanomolar concentrations, and noise due to random arrival of these molecules at their binding sites can severely limit the precision of regulation. Recent work on the optimization of information flow through regulatory networks indicates that the lower end of the dynamic range of concentrations is simply inaccessible, overwhelmed by the impact of this noise. Motivated by the behavior of homeodomain proteins, such as the maternal morphogen Bicoid in the fruit fly embryo, we suggest a scheme in which transcription factors also act as indirect translational regulators, binding to the mRNA of other regulatory proteins. Intuitively, each mRNA molecule acts as an independent sensor of the input concentration, and averaging over these multiple sensors reduces the noise. We analyze information flow through this scheme and identify conditions under which it outperforms direct transcriptional regulation. Our results suggest that the dual role of homeodomain proteins is not just a historical accident, but a solution to a crucial physics problem in the regulation of gene expression. PMID:26986359

  10. Extending the dynamic range of transcription factor action by translational regulation

    NASA Astrophysics Data System (ADS)

    Sokolowski, Thomas R.; Walczak, Aleksandra M.; Bialek, William; Tkačik, Gašper

    2016-02-01

    A crucial step in the regulation of gene expression is binding of transcription factor (TF) proteins to regulatory sites along the DNA. But transcription factors act at nanomolar concentrations, and noise due to random arrival of these molecules at their binding sites can severely limit the precision of regulation. Recent work on the optimization of information flow through regulatory networks indicates that the lower end of the dynamic range of concentrations is simply inaccessible, overwhelmed by the impact of this noise. Motivated by the behavior of homeodomain proteins, such as the maternal morphogen Bicoid in the fruit fly embryo, we suggest a scheme in which transcription factors also act as indirect translational regulators, binding to the mRNA of other regulatory proteins. Intuitively, each mRNA molecule acts as an independent sensor of the input concentration, and averaging over these multiple sensors reduces the noise. We analyze information flow through this scheme and identify conditions under which it outperforms direct transcriptional regulation. Our results suggest that the dual role of homeodomain proteins is not just a historical accident, but a solution to a crucial physics problem in the regulation of gene expression.

  11. Cofunctional Subpathways Were Regulated by Transcription Factor with Common Motif, Common Family, or Common Tissue

    PubMed Central

    Su, Fei; Shang, Desi; Xu, Yanjun; Feng, Li; Yang, Haixiu; Liu, Baoquan; Su, Shengyang; Chen, Lina; Li, Xia

    2015-01-01

    Dissecting the characteristics of the transcription factor (TF) regulatory subpathway is helpful for understanding the TF underlying regulatory function in complex biological systems. To gain insight into the influence of TFs on their regulatory subpathways, we constructed a global TF-subpathways network (TSN) to analyze systematically the regulatory effect of common-motif, common-family, or common-tissue TFs on subpathways. We performed cluster analysis to show that the common-motif, common-family, or common-tissue TFs that regulated the same pathway classes tended to cluster together and contribute to the same biological function that led to disease initiation and progression. We analyzed the Jaccard coefficient to show that the functional consistency of subpathways regulated by the TF pairs with common motif, common family, or common tissue was significantly greater than the random TF pairs at the subpathway level, pathway level, and pathway class level. For example, HNF4A (hepatocyte nuclear factor 4, alpha) and NR1I3 (nuclear receptor subfamily 1, group I, member 3) were a pair of TFs with common motif, common family, and common tissue. They were involved in drug metabolism pathways and were liver-specific factors required for physiological transcription. In short, we inferred that the cofunctional subpathways were regulated by common-motif, common-family, or common-tissue TFs. PMID:26688819

  12. Social insect genomes exhibit dramatic evolution in gene composition and regulation while preserving regulatory features linked to sociality.

    PubMed

    Simola, Daniel F; Wissler, Lothar; Donahue, Greg; Waterhouse, Robert M; Helmkampf, Martin; Roux, Julien; Nygaard, Sanne; Glastad, Karl M; Hagen, Darren E; Viljakainen, Lumi; Reese, Justin T; Hunt, Brendan G; Graur, Dan; Elhaik, Eran; Kriventseva, Evgenia V; Wen, Jiayu; Parker, Brian J; Cash, Elizabeth; Privman, Eyal; Childers, Christopher P; Muñoz-Torres, Monica C; Boomsma, Jacobus J; Bornberg-Bauer, Erich; Currie, Cameron R; Elsik, Christine G; Suen, Garret; Goodisman, Michael A D; Keller, Laurent; Liebig, Jürgen; Rawls, Alan; Reinberg, Danny; Smith, Chris D; Smith, Chris R; Tsutsui, Neil; Wurm, Yannick; Zdobnov, Evgeny M; Berger, Shelley L; Gadau, Jürgen

    2013-08-01

    Genomes of eusocial insects code for dramatic examples of phenotypic plasticity and social organization. We compared the genomes of seven ants, the honeybee, and various solitary insects to examine whether eusocial lineages share distinct features of genomic organization. Each ant lineage contains ∼4000 novel genes, but only 64 of these genes are conserved among all seven ants. Many gene families have been expanded in ants, notably those involved in chemical communication (e.g., desaturases and odorant receptors). Alignment of the ant genomes revealed reduced purifying selection compared with Drosophila without significantly reduced synteny. Correspondingly, ant genomes exhibit dramatic divergence of noncoding regulatory elements; however, extant conserved regions are enriched for novel noncoding RNAs and transcription factor-binding sites. Comparison of orthologous gene promoters between eusocial and solitary species revealed significant regulatory evolution in both cis (e.g., Creb) and trans (e.g., fork head) for nearly 2000 genes, many of which exhibit phenotypic plasticity. Our results emphasize that genomic changes can occur remarkably fast in ants, because two recently diverged leaf-cutter ant species exhibit faster accumulation of species-specific genes and greater divergence in regulatory elements compared with other ants or Drosophila. Thus, while the "socio-genomes" of ants and the honeybee are broadly characterized by a pervasive pattern of divergence in gene composition and regulation, they preserve lineage-specific regulatory features linked to eusociality. We propose that changes in gene regulation played a key role in the origins of insect eusociality, whereas changes in gene composition were more relevant for lineage-specific eusocial adaptations. PMID:23636946

  13. Does the Transcription Factor NemR Use a Regulatory Sulfenamide Bond to Sense Bleach?

    PubMed

    Gray, Michael Jeffrey; Li, Yan; Leichert, Lars Ingo-Ole; Xu, Zhaohui; Jakob, Ursula

    2015-09-20

    Reactive chlorine species (RCS), such as hypochlorous acid (i.e., bleach), are antimicrobial oxidants produced by the innate immune system. Like many redox-regulated transcription factors, the Escherichia coli repressor NemR responds to RCS by using the reversible oxidation of highly conserved cysteines to alter its DNA-binding affinity. However, earlier work showed that RCS response in NemR does not depend on any commonly known oxidative cysteine modifications. We have now determined the crystal structure of NemR, showing that the regulatory cysteine, Cys106, is in close proximity to a highly conserved lysine (Lys175). We used crystallographic, biochemical, and mass spectrometric analyses to analyze the role of this lysine residue in RCS sensing. Based on our results, we hypothesize that RCS treatment of NemR results in the formation of a reversible Cys106-Lys175 sulfenamide bond. This is, to our knowledge, the first description of a protein whose function is regulated by a cysteine-lysine sulfenamide thiol switch, constituting a novel addition to the biological repertoire of functional redox switches. PMID:25867078

  14. Differential roles of epigenetic changes and Foxp3 expression in regulatory T cell-specific transcriptional regulation

    PubMed Central

    Morikawa, Hiromasa; Ohkura, Naganari; Vandenbon, Alexis; Itoh, Masayoshi; Nagao-Sato, Sayaka; Kawaji, Hideya; Lassmann, Timo; Carninci, Piero; Hayashizaki, Yoshihide; Forrest, Alistair R. R.; Standley, Daron M.; Date, Hiroshi; Sakaguchi, Shimon; Forrest, Alistair R.R.; Kawaji, Hideya; Rehli, Michael; Baillie, J. Kenneth; de Hoon, Michiel J.L.; Haberle, Vanja; Lassmann, Timo; Kulakovskiy, Ivan V.; Lizio, Marina; Itoh, Masayoshi; Andersson, Robin; Mungall, Christopher J.; Meehan, Terrence F.; Schmeier, Sebastian; Bertin, Nicolas; Jørgensen, Mette; Dimont, Emmanuel; Arner, Erik; Schmidl, Christian; Schaefer, Ulf; Medvedeva, Yulia A.; Plessy, Charles; Vitezic, Morana; Severin, Jessica; Semple, Colin A.; Ishizu, Yuri; Francescatto, Margherita; Alam, Intikhab; Albanese, Davide; Altschuler, Gabriel M.; Archer, John A.C.; Arner, Peter; Babina, Magda; Baker, Sarah; Balwierz, Piotr J.; Beckhouse, Anthony G.; Pradhan-Bhatt, Swati; Blake, Judith A.; Blumenthal, Antje; Bodega, Beatrice; Bonetti, Alessandro; Briggs, James; Brombacher, Frank; Burroughs, A. Maxwell; Califano, Andrea; Cannistraci, Carlo V.; Carbajo, Daniel; Chen, Yun; Chierici, Marco; Ciani, Yari; Clevers, Hans C.; Dalla, Emiliano; Davis, Carrie A.; Deplancke, Bart; Detmar, Michael; Diehl, Alexander D.; Dohi, Taeko; Drabløs, Finn; Edge, Albert S.B.; Edinger, Matthias; Ekwall, Karl; Endoh, Mitsuhiro; Enomoto, Hideki; Fagiolini, Michela; Fairbairn, Lynsey; Fang, Hai; Farach-Carson, Mary C.; Faulkner, Geoffrey J.; Favorov, Alexander V.; Fisher, Malcolm E.; Frith, Martin C.; Fujita, Rie; Fukuda, Shiro; Furlanello, Cesare; Furuno, Masaaki; Furusawa, Jun-ichi; Geijtenbeek, Teunis B.; Gibson, Andrew; Gingeras, Thomas; Goldowitz, Daniel; Gough, Julian; Guhl, Sven; Guler, Reto; Gustincich, Stefano; Ha, Thomas J.; Hamaguchi, Masahide; Hara, Mitsuko; Harbers, Matthias; Harshbarger, Jayson; Hasegawa, Akira; Hasegawa, Yuki; Hashimoto, Takehiro; Herlyn, Meenhard; Hitchens, Kelly J.; Sui, Shannan J. Ho; Hofmann, Oliver M.; Hoof, Ilka; Hori, Fumi; Huminiecki, Lukasz; Iida, Kei; Ikawa, Tomokatsu; Jankovic, Boris R.; Jia, Hui; Joshi, Anagha; Jurman, Giuseppe; Kaczkowski, Bogumil; Kai, Chieko; Kaida, Kaoru; Kaiho, Ai; Kajiyama, Kazuhiro; Kanamori-Katayama, Mutsumi; Kasianov, Artem S.; Kasukawa, Takeya; Katayama, Shintaro; Kato, Sachi; Kawaguchi, Shuji; Kawamoto, Hiroshi; Kawamura, Yuki I.; Kawashima, Tsugumi; Kempfle, Judith S.; Kenna, Tony J.; Kere, Juha; Khachigian, Levon M.; Kitamura, Toshio; Klinken, S. Peter; Knox, Alan J.; Kojima, Miki; Kojima, Soichi; Kondo, Naoto; Koseki, Haruhiko; Koyasu, Shigeo; Krampitz, Sarah; Kubosaki, Atsutaka; Kwon, Andrew T.; Laros, Jeroen F.J.; Lee, Weonju; Lennartsson, Andreas; Li, Kang; Lilje, Berit; Lipovich, Leonard; Mackay-sim, Alan; Manabe, Ri-ichiroh; Mar, Jessica C.; Marchand, Benoit; Mathelier, Anthony; Mejhert, Niklas; Meynert, Alison; Mizuno, Yosuke; Morais, David A. de Lima; Morikawa, Hiromasa; Morimoto, Mitsuru; Moro, Kazuyo; Motakis, Efthymios; Motohashi, Hozumi; Mummery, Christine L.; Murata, Mitsuyoshi; Nagao-Sato, Sayaka; Nakachi, Yutaka; Nakahara, Fumio; Nakamura, Toshiyuki; Nakamura, Yukio; Nakazato, Kenichi; van Nimwegen, Erik; Ninomiya, Noriko; Nishiyori, Hiromi; Noma, Shohei; Nozaki, Tadasuke; Ogishima, Soichi; Ohkura, Naganari; Ohmiya, Hiroko; Ohno, Hiroshi; Ohshima, Mitsuhiro; Okada-Hatakeyama, Mariko; Okazaki, Yasushi; Orlando, Valerio; Ovchinnikov, Dmitry A.; Pain, Arnab; Passier, Robert; Patrikakis, Margaret; Persson, Helena; Piazza, Silvano; Prendergast, James G.D.; Rackham, Owen J.L.; Ramilowski, Jordan A.; Rashid, Mamoon; Ravasi, Timothy; Rizzu, Patrizia; Roncador, Marco; Roy, Sugata; Rye, Morten B.; Saijyo, Eri; Sajantila, Antti; Saka, Akiko; Sakaguchi, Shimon; Sakai, Mizuho; Sato, Hiroki; Satoh, Hironori; Savvi, Suzana; Saxena, Alka; Schneider, Claudio; Schultes, Erik A.; Schulze-Tanzil, Gundula G.; Schwegmann, Anita; Sengstag, Thierry; Sheng, Guojun; Shimoji, Hisashi; Shimoni, Yishai; Shin, Jay W.; Simon, Christophe; Sugiyama, Daisuke; Sugiyama, Takaaki; Suzuki, Masanori; Swoboda, Rolf K.; 't Hoen, Peter A.C.; Tagami, Michihira; Takahashi, Naoko; Takai, Jun; Tanaka, Hiroshi; Tatsukawa, Hideki; Tatum, Zuotian; Thompson, Mark; Toyoda, Hiroo; Toyoda, Tetsuro; Valen, Eivind; van de Wetering, Marc; van den Berg, Linda M.; Verardo, Roberto; Vijayan, Dipti; Vorontsov, Ilya E.; Wasserman, Wyeth W.; Watanabe, Shoko; Wells, Christine A.; Winteringham, Louise N.; Wolvetang, Ernst; Wood, Emily J.; Yamaguchi, Yoko; Yamamoto, Masayuki; Yoneda, Misako; Yonekura, Yohei; Yoshida, Shigehiro; Zabierowski, Suzan E.; Zhang, Peter G.

    2014-01-01

    Naturally occurring regulatory T (Treg) cells, which specifically express the transcription factor forkhead box P3 (Foxp3), are engaged in the maintenance of immunological self-tolerance and homeostasis. By transcriptional start site cluster analysis, we assessed here how genome-wide patterns of DNA methylation or Foxp3 binding sites were associated with Treg-specific gene expression. We found that Treg-specific DNA hypomethylated regions were closely associated with Treg up-regulated transcriptional start site clusters, whereas Foxp3 binding regions had no significant correlation with either up- or down-regulated clusters in nonactivated Treg cells. However, in activated Treg cells, Foxp3 binding regions showed a strong correlation with down-regulated clusters. In accordance with these findings, the above two features of activation-dependent gene regulation in Treg cells tend to occur at different locations in the genome. The results collectively indicate that Treg-specific DNA hypomethylation is instrumental in gene up-regulation in steady state Treg cells, whereas Foxp3 down-regulates the expression of its target genes in activated Treg cells. Thus, the two events seem to play distinct but complementary roles in Treg-specific gene expression. PMID:24706905

  15. An essential regulatory role for macrophage migration inhibitory factor in T-cell activation.

    PubMed Central

    Bacher, M; Metz, C N; Calandra, T; Mayer, K; Chesney, J; Lohoff, M; Gemsa, D; Donnelly, T; Bucala, R

    1996-01-01

    The protein known as macrophage migration inhibitory factor (MIF) was one of the first cytokines to be discovered and was described 30 years ago to be a T-cell-derived factor that inhibited the random migration of macrophages in vitro. A much broader role for MIF has emerged recently as a result of studies that have demonstrated it to be released from the anterior pituitary gland in vivo. MIF also is the first protein that has been identified to be secreted from monocytes/macrophages upon glucocorticoid stimulation. Once released, MIF acts to "override" or counter-regulate the suppressive effects of glucocorticoids on macrophage cytokine production. We report herein that MIF plays an important regulatory role in the activation of T cells induced by mitogenic or antigenic stimuli. Activated T cells produce MIF and neutralizing anti-MIF antibodies inhibit T-cell proliferation and interleukin 2 production in vitro, and suppress antigen-driven T-cell activation and antibody production in vivo. T cells also release MIF in response to glucocorticoid stimulation and MIF acts to override glucocorticoid inhibition of T-cell proliferation and interleukin 2 and interferon gamma production. These studies indicate that MIF acts in concert with glucocorticoids to control T-cell activation and assign a previously unsuspected but critical role for MIF in antigen-specific immune responses. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8755565

  16. IκB Kinase ε Targets Interferon Regulatory Factor 1 in Activated T Lymphocytes

    PubMed Central

    Sgarbanti, Marco; Marsili, Giulia; Remoli, Anna Lisa; Stellacci, Emilia; Mai, Antonello; Rotili, Dante; Perrotti, Edvige; Acchioni, Chiara; Orsatti, Roberto; Iraci, Nunzio; Ferrari, Mathieu; Borsetti, Alessandra

    2014-01-01

    IκB kinase ε (IKK-ε) has an essential role as a regulator of innate immunity, functioning downstream of pattern recognition receptors to modulate NF-κB and interferon (IFN) signaling. In the present study, we investigated IKK-ε activation following T cell receptor (TCR)/CD28 stimulation of primary CD4+ T cells and its role in the stimulation of a type I IFN response. IKK-ε was activated following TCR/CD28 stimulation of primary CD4+ T cells; however, in T cells treated with poly(I·C), TCR/CD28 costimulation blocked induction of IFN-β transcription. We demonstrated that IKK-ε phosphorylated the transcription factor IFN regulatory factor 1 (IRF-1) at amino acid (aa) 215/219/221 in primary CD4+ T cells and blocked its transcriptional activity. At the mechanistic level, IRF-1 phosphorylation impaired the physical interaction between IRF-1 and the NF-κB RelA subunit and interfered with PCAF-mediated acetylation of NF-κB RelA. These results demonstrate that TCR/CD28 stimulation of primary T cells stimulates IKK-ε activation, which in turn contributes to suppression of IFN-β production. PMID:24396068

  17. Interferon regulatory factor 7 is activated by a viral oncoprotein through RIP-dependent ubiquitination.

    PubMed

    Huye, Leslie E; Ning, Shunbin; Kelliher, Michelle; Pagano, Joseph S

    2007-04-01

    As a key mediator of type I interferon (IFN) (IFN-alpha/beta) responses, IFN regulatory factor 7 (IRF7) is essential to host immune defenses. Activation of IRF7 generally requires virus-induced C-terminal phosphorylation, which leads to its nuclear accumulation and activation of target genes. Here we use the Epstein-Barr virus (EBV) oncoprotein LMP1, which activates IRF7, to identify factors involved in IRF7 activation. We demonstrate for the first time that RIP activates IRF7 and that RIP and IRF7 interact under physiological conditions in EBV-positive Burkitt's lymphoma cells. We provide evidence that both RIP and IRF7 are ubiquitinated in these cells and that IRF7 preferentially interacts with ubiquitinated RIP. RIP is required for full activation of IRF7 by LMP1, with LMP1 stimulating the ubiquitination of RIP and its interaction with IRF7. Moreover, LMP1 stimulates RIP-dependent K63-linked ubiquitination of IRF7, which regulates protein function rather than proteasomal degradation of proteins. We suggest that RIP may serve as a general activator of IRF7, responding to and transmitting the signals from various stimuli, and that ubiquitination may be a general mechanism for enhancing the activity of IRF7. PMID:17296724

  18. BRCA1 EXON 11, a CERES (composite regulatory element of splicing) element involved in splice regulation.

    PubMed

    Tammaro, Claudia; Raponi, Michela; Wilson, David I; Baralle, Diana

    2014-01-01

    Unclassified variants (UV) of BRCA1 can affect normal pre-mRNA splicing. Here, we investigate the UV c.693G>A, a "silent" change in BRCA1 exon 11, which we have found induces aberrant splicing in patient carriers and in vitro. Using a minigene assay, we show that the UV c.693G>A has a strong effect on the splicing isoform ratio of BRCA1. Systematic site-directed mutagenesis of the area surrounding the nucleotide position c.693G>A induced variable changes in the level of exon 11 inclusion/exclusion in the mRNA, pointing to the presence of a complex regulatory element with overlapping enhancer and silencer functions. Accordingly, protein binding analysis in the region detected several splicing regulatory factors involved, including SRSF1, SRSF6 and SRSF9, suggesting that this sequence represents a composite regulatory element of splicing (CERES). PMID:25056543

  19. Regulatory T-cell suppressor program co-opts transcription factor IRF4 to control TH2 responses

    PubMed Central

    Zheng, Ye; Chaudhry, Ashutosh; Kas, Arnold; deRoos, Paul; Kim, Jeong M.; Chu, Tin-Tin; Corcoran, Lynn; Treuting, Piper; Klein, Ulf; Rudensky, Alexander Y.

    2010-01-01

    In the course of infection or autoimmunity, particular transcription factors orchestrate the differentiation of TH1, TH2 or TH17 effector cells, the responses of which are limited by a distinct lineage of suppressive regulatory T cells (Treg). Treg cell differentiation and function are guided by the transcription factor Foxp3, and their deficiency due to mutations in Foxp3 results in aggressive fatal autoimmune disease associated with sharply augmented TH1 and TH2 cytokine production1–3. Recent studies suggested that Foxp3 regulates the bulk of the Foxp3-dependent transcriptional program indirectly through a set of transcriptional regulators serving as direct Foxp3 targets4,5. Here we show that in mouse Treg cells, high amounts of interferon regulatory factor-4 (IRF4), a transcription factor essential for TH2 effector cell differentiation, is dependent on Foxp3 expression. We proposed that IRF4 expression endows Treg cells with the ability to suppress TH2 responses. Indeed, ablation of a conditional Irf4 allele in Treg cells resulted in selective dysregulation of TH2 responses, IL4-dependent immunoglobulin isotype production, and tissue lesions with pronounced plasma cell infiltration, in contrast to the mononuclear-cell-dominated pathology typical of mice lacking Treg cells. Our results indicate that Treg cells use components of the transcriptional machinery, promoting a particular type of effector CD4+ T cell differentiation, to efficiently restrain the corresponding type of the immune response. PMID:19182775

  20. Fibroblast Growth Factor Signaling in Metabolic Regulation

    PubMed Central

    Nies, Vera J. M.; Sancar, Gencer; Liu, Weilin; van Zutphen, Tim; Struik, Dicky; Yu, Ruth T.; Atkins, Annette R.; Evans, Ronald M.; Jonker, Johan W.; Downes, Michael Robert

    2016-01-01

    The prevalence of obesity is a growing health problem. Obesity is strongly associated with several comorbidities, such as non-alcoholic fatty liver disease, certain cancers, insulin resistance, and type 2 diabetes, which all reduce life expectancy and life quality. Several drugs have been put forward in order to treat these diseases, but many of them have detrimental side effects. The unexpected role of the family of fibroblast growth factors in the regulation of energy metabolism provides new approaches to the treatment of metabolic diseases and offers a valuable tool to gain more insight into metabolic regulation. The known beneficial effects of FGF19 and FGF21 on metabolism, together with recently discovered similar effects of FGF1 suggest that FGFs and their derivatives carry great potential as novel therapeutics to treat metabolic conditions. To facilitate the development of new therapies with improved targeting and minimal side effects, a better understanding of the molecular mechanism of action of FGFs is needed. In this review, we will discuss what is currently known about the physiological roles of FGF signaling in tissues important for metabolic homeostasis. In addition, we will discuss current concepts regarding their pharmacological properties and effector tissues in the context of metabolic disease. Also, the recent progress in the development of FGF variants will be reviewed. Our goal is to provide a comprehensive overview of the current concepts and consensuses regarding FGF signaling in metabolic health and disease and to provide starting points for the development of FGF-based therapies against metabolic conditions. PMID:26834701

  1. Understanding Transcription Factor Regulation by Integrating Gene Expression and DNase I Hypersensitive Sites

    PubMed Central

    Wang, Guohua; Wang, Fang; Huang, Qian; Li, Yu; Liu, Yunlong; Wang, Yadong

    2015-01-01

    Transcription factors are proteins that bind to DNA sequences to regulate gene transcription. The transcription factor binding sites are short DNA sequences (5–20 bp long) specifically bound by one or more transcription factors. The identification of transcription factor binding sites and prediction of their function continue to be challenging problems in computational biology. In this study, by integrating the DNase I hypersensitive sites with known position weight matrices in the TRANSFAC database, the transcription factor binding sites in gene regulatory region are identified. Based on the global gene expression patterns in cervical cancer HeLaS3 cell and HelaS3-ifnα4h cell (interferon treatment on HeLaS3 cell for 4 hours), we present a model-based computational approach to predict a set of transcription factors that potentially cause such differential gene expression. Significantly, 6 out 10 predicted functional factors, including IRF, IRF-2, IRF-9, IRF-1 and IRF-3, ICSBP, belong to interferon regulatory factor family and upregulate the gene expression levels responding to the interferon treatment. Another factor, ISGF-3, is also a transcriptional activator induced by interferon alpha. Using the different transcription factor binding sites selected criteria, the prediction result of our model is consistent. Our model demonstrated the potential to computationally identify the functional transcription factors in gene regulation. PMID:26425553

  2. LEAFY COTYLEDON1-CASEIN KINASE I-TCP15-PHYTOCHROME INTERACTING FACTOR4 Network Regulates Somatic Embryogenesis by Regulating Auxin Homeostasis1[OPEN

    PubMed Central

    Min, Ling; Hu, Qin; Li, Yaoyao; Xu, Jiao; Ma, Yizan; Zhu, Longfu; Yang, Xiyan; Zhang, Xianlong

    2015-01-01

    Somatic embryogenesis (SE) is an efficient tool for the propagation of plant species and also, a useful model for studying the regulatory networks in embryo development. However, the regulatory networks underlying the transition from nonembryogenic callus to somatic embryos during SE remain poorly understood. Here, we describe an upland cotton (Gossypium hirsutum) CASEIN KINASE I gene, GhCKI, which is a unique key regulatory factor that strongly affects SE. Overexpressing GhCKI halted the formation of embryoids and plant regeneration because of a block in the transition from nonembryogenic callus to somatic embryos. In contrast, defective GhCKI in plants facilitated SE. To better understand the mechanism by which GhCKI regulates SE, the regulatory network was analyzed. A direct upstream negative regulator protein, cotton LEAFY COTYLEDON1, was identified to be targeted to a cis-element, CTTTTC, in the promoter of GhCKI. Moreover, GhCKI interacted with and phosphorylated cotton CINCINNATA-like TEOSINTE BRANCHED1-CYCLOIDEA-PCF transcription factor15 by coordinately regulating the expression of cotton PHYTOCHROME INTERACTING FACTOR4, finally disrupting auxin homeostasis, which led to increased cell proliferation and aborted somatic embryo formation in GhCKI-overexpressing somatic cells. Our results show a complex process of SE that is negatively regulated by GhCKI through a complex regulatory network. PMID:26491146

  3. Enhancement of alkaloid production in opium and California poppy by transactivation using heterologous regulatory factors.

    PubMed

    Apuya, Nestor R; Park, Joon-Hyun; Zhang, Liping; Ahyow, Maurice; Davidow, Patricia; Van Fleet, Jennifer; Rarang, Joel C; Hippley, Matthew; Johnson, Thomas W; Yoo, Hye-Dong; Trieu, Anthony; Krueger, Shannon; Wu, Chuan-yin; Lu, Yu-ping; Flavell, Richard B; Bobzin, Steven C

    2008-02-01

    Genes encoding regulatory factors isolated from Arabidopsis, soybean and corn have been screened to identify those that modulate the expression of genes encoding for enzymes involved in the biosynthesis of morphinan alkaloids in opium poppy (Papaver somniferum) and benzophenanthridine alkaloids in California poppy (Eschscholzia californica). In opium poppy, the over-expression of selected regulatory factors increased the levels of PsCOR (codeinone reductase), Ps4'OMT (S-adenosyl-l-methionine:3'-hydroxy-N-methylcoclaurine 4'-O-methyltransferase) and Ps6OMT [(R,S)-norcoclaurine 6-O-methyltransferase] transcripts by 10- to more than 100-fold. These transcriptional activations translated into an enhancement of alkaloid production in opium poppy of up to at least 10-fold. In California poppy, the transactivation effect of regulatory factor WRKY1 resulted in an increase of up to 60-fold in the level of EcCYP80B1 [(S)-N-methylcoclaurine 3'-hydroxylase] and EcBBE (berberine bridge enzyme) transcripts. As a result, the accumulations of selected alkaloid intermediates were enhanced up to 30-fold. The transactivation effects of other regulatory factors led to the accumulation of the same intermediates. These regulatory factors also led to the production of new alkaloids in California poppy callus culture. PMID:17961129

  4. Molecular cloning and characterization of interferon regulatory factor 9 (IRF9) in Japanese flounder, Paralichthys olivaceus.

    PubMed

    Hu, Guo-Bin; Zhao, Ming-Yu; Lin, Jing-Yun; Liu, Qiu-Ming; Zhang, Shi-Cui

    2014-08-01

    Interferon regulatory factor 9 (IRF9) in mammals is known to be involved in antiviral response. In this study, we studied the structure, mRNA tissue distribution and regulation of IRF9 from Japanese flounder, Paralichthys olivaceus. The cDNA sequence of IRF9 is 3305 bp long, containing an open reading frame (ORF) of 1308 bp that encodes a peptide of 435 amino acids. The predicted protein sequence shares 33.7-72.0% identity to other fish IRF9s. Japanese flounder IRF9 possesses a DNA-binding domain (DBD), an IRF association domain (IAD), two nuclear localization signals (NLSs) and a proline-rich domain (PRD). The IRF9 transcripts were detectable in all examined tissues of healthy Japanese flounders, with higher levels in the head kidney, kidney, liver and spleen. The IRF9 mRNA levels were up-regulated in the gills, head kidney, spleen and muscle when challenged with polyinosinic:polycytidylic acid (poly I:C) or lymphocystis disease virus (LCDV). The up-regulations were stronger and arose earlier in the case of poly I:C treatment in most tested organs in a 7-day time course, with maximum increases ranging from 1.37- to 8.59-fold and peak time points from 3 h to 3 d post injection depending on different organs, relative to those in the case of LCDV treatment which ranged from 1.32- to 3.21-fold and from 18 h to 3 d post injection, respectively. The highest and earliest inductions were detected in the spleen in both challenge cases, while the inductions by LCDV in the muscle were quite faint. These results demonstrate a role of Japanese flounder IRF9 in the host's antiviral responses. PMID:24837327

  5. Statin effects on regulatory and proinflammatory factors in chronic idiopathic urticaria.

    PubMed

    Azor, M H; dos Santos, J C; Futata, E A; de Brito, C A; Maruta, C W; Rivitti, E A; da Silva Duarte, A J; Sato, M N

    2011-11-01

    Immunological dysfunction has been described to occur in chronic idiopathic urticaria (CIU), most notably in association with an inflammatory process. Some pharmacological agents as statins--drugs used in hypercholesterolaemia--display a broad effect on the immune response and thus should be tested in vitro in CIU. Our main objectives were to evaluate the effects of statins on the innate and adaptive immune response in CIU. Simvastatin or lovastatin have markedly inhibited the peripheral blood mononuclear cells (PBMC) proliferative response induced by T and B cell mitogens, superantigen or recall antigen. Simvastatin arrested phytohaemaglutinin (PHA)-induced T cells at the G0/G1 phase, inhibiting T helper type 1 (Th1), Th2, interleukin (IL)-10 and IL-17A cytokine secretion in both patients and healthy control groups. Up-regulation of suppressor of cytokine signalling 3 (SOCS3) mRNA expression in PHA-stimulated PBMCs from CIU patients was not modified by simvastatin, in contrast to the enhancing effect in the control group. Statin exhibited a less efficient inhibition effect on cytokine production [IL-6 and macrophage inflammatory protein (MIP)-1α] induced by Toll-like receptor (TLR)-4, to which a statin preincubation step was required. Furthermore, statin did not affect the tumour necrosis factor (TNF)-α secretion by lipopolysaccharide (LPS)-stimulated PBMC or CD14+ cells in CIU patients. In addition, LPS-activated PBMC from CIU patients showed impaired indoleamine 2,3-dioxygenase (IDO) mRNA expression compared to healthy control, which remained at decreased levels with statin treatment. Statins exhibited a marked down-regulatory effect in T cell functions, but were not able to control TLR-4 activation in CIU patients. The unbalanced regulatory SOCS3 and IDO expressions in CIU may contribute to the pathogenesis of the disease. PMID:21985375

  6. Imbalanced signal transduction in regulatory T cells expressing the transcription factor FoxP3.

    PubMed

    Yan, Dapeng; Farache, Julia; Mingueneau, Michael; Mathis, Diane; Benoist, Christophe

    2015-12-01

    FoxP3(+) T regulatory (Treg) cells have a fundamental role in immunological tolerance, with transcriptional and functional phenotypes that demarcate them from conventional CD4(+) T cells (Tconv). Differences between these two lineages in the signaling downstream of T-cell receptor-triggered activation have been reported, and there are different requirements for some signaling factors. Seeking a comprehensive view, we found that Treg cells have a broadly dampened activation of several pathways and signaling nodes upon TCR-mediated activation, with low phosphorylation of CD3ζ, SLP76, Erk1/2, AKT, or S6 and lower calcium flux. In contrast, STAT phosphorylation triggered by interferons, IL2 or IL6, showed variations between Treg and Tconv in magnitude or choice of preferential STAT activation but no general Treg signaling defect. Much, but not all, of the Treg/Tconv difference in TCR-triggered responses could be attributed to lower responsiveness of antigen-experienced cells with CD44(hi) or CD62L(lo) phenotypes, which form a greater proportion of the Treg pool. Candidate regulators were tested, but the Treg/Tconv differential could not be explained by overexpression in Treg cells of the signaling modulator CD5, the coinhibitors PD-1 and CTLA4, or the regulatory phosphatase DUSP4. However, transcriptome profiling in Dusp4-deficient mice showed that DUSP4 enhances the expression of a segment of the canonical Treg transcriptional signature, which partially overlaps with the TCR-dependent Treg gene set. Thus, Treg cells, likely because of their intrinsically higher reactivity to self, tune down TCR signals but seem comparatively more attuned to cytokines or other intercellular signals. PMID:26627244

  7. Identification of novel regulatory factor X (RFX) target genes by comparative genomics in Drosophila species

    PubMed Central

    Laurençon, Anne; Dubruille, Raphaëlle; Efimenko, Evgeni; Grenier, Guillaume; Bissett, Ryan; Cortier, Elisabeth; Rolland, Vivien; Swoboda, Peter; Durand, Bénédicte

    2007-01-01

    Background Regulatory factor X (RFX) transcription factors play a key role in ciliary assembly in nematode, Drosophila and mouse. Using the tremendous advantages of comparative genomics in closely related species, we identified novel genes regulated by dRFX in Drosophila. Results We first demonstrate that a subset of known ciliary genes in Caenorhabditis elegans and Drosophila are regulated by dRFX and have a conserved RFX binding site (X-box) in their promoters in two highly divergent Drosophila species. We then designed an X-box consensus sequence and carried out a genome wide computer screen to identify novel genes under RFX control. We found 412 genes that share a conserved X-box upstream of the ATG in both species, with 83 genes presenting a more restricted consensus. We analyzed 25 of these 83 genes, 16 of which are indeed RFX target genes. Two of them have never been described as involved in ciliogenesis. In addition, reporter construct expression analysis revealed that three of the identified genes encode proteins specifically localized in ciliated endings of Drosophila sensory neurons. Conclusion Our X-box search strategy led to the identification of novel RFX target genes in Drosophila that are involved in sensory ciliogenesis. We also established a highly valuable Drosophila cilia and basal body dataset. These results demonstrate the accuracy of the X-box screen and will be useful for the identification of candidate genes for human ciliopathies, as several human homologs of RFX target genes are known to be involved in diseases, such as Bardet-Biedl syndrome. PMID:17875208

  8. Synergetic regulatory networks mediated by oncogene-driven microRNAs and transcription factors in serous ovarian cancer

    PubMed Central

    Zhao, Min; Sun, Jingchun; Zhao, Zhongming

    2013-01-01

    Although high-grade serous ovarian cancer (OVC) is the most lethal gynecologic malignancy in women, little is known about the regulatory mechanisms in the cellular processes that lead to this cancer. Recently, accumulated lines of evidence have shown that the interplay between transcription factors (TFs) and microRNAs (miRNAs) is critical in cellular regulation during tumorigenesis. A comprehensive investigation of TFs and miRNAs, and their target genes, may provide a deeper understanding of the regulatory mechanisms in the pathology of OVC. In this study, we have integrated three complementary algorithms into a framework, aiming to infer the regulation by miRNAs and TFs in conjunction with gene expression profiles. We demonstrated the utility of our framework by inferring 67 OVC-specific regulatory feed-forward loops (FFL) initiated by miRNAs or TFs in high-grade serous OVC. By analyzing these regulatory behaviors, we found that all the 67 FFLs are consistent in their regulatory effects on genes that jointly targeted by miRNAs and TFs. Remarkably, we unveiled an unbalanced distribution of FFLs with different oncogenic effects. In total, 31 of the 67 coherent FFLs were mainly initiated by oncogenes. On the contrary, only 4 of the FFLs were initiated by tumor suppressor genes. These overwhelmingly observed oncogenic genes were further detected in a sub-network with 32 FFLs centered by miRNA let-7b and TF TCF7L1 to regulate cell differentiation. Closer inspection of 32 FFLs revealed that 75% of the miRNAs reportedly play functional roles in cell differentiation, especially when enriched in epithelial–mesenchymal transitions. This study provides a comprehensive pathophysiological overview of recurring coherent circuits in OVC that are co-regulated by miRNAs and TFs. The prevalence of oncogenic coherent FFLs in serous OVC suggests that oncogene-driven regulatory motifs could cooperatively act upon critical cellular process such as cell differentiation in a highly

  9. Human papillomavirus 16 E6 oncoprotein binds to interferon regulatory factor-3 and inhibits its transcriptional activity

    PubMed Central

    Ronco, Lucienne V.; Karpova, Alla Y.; Vidal, Marc; Howley, Peter M.

    1998-01-01

    Interferon regulatory factor-3 (IRF-3) was found to specifically interact with HPV16 E6 in a yeast two-hybrid screen. IRF-3 is activated by the presence of double-stranded RNA or by virus infection to form a stable complex with other transcriptional regulators that bind to the regulatory elements of the IFNβ promoter. We show that IRF-3 is a potent transcriptional activator and demonstrate that HPV16 E6 can inhibit its transactivation function. The expression of HPV16 E6 in primary human keratinocytes inhibits the induction of IFNβ mRNA following Sendai virus infection. The binding of HPV16 E6 to IRF-3 does not result in its ubiquitination or degradation. We propose that the interaction of E6 with IRF-3 and the inhibition of IRF-3’s transcriptional activity may provide the virus a means to circumvent the normal antiviral response of an HPV16-infected cell. PMID:9649509

  10. Scientific foundation of regulating ionizing radiation: application of metrics for evaluation of regulatory science information.

    PubMed

    Moghissi, A Alan; Gerraa, Vikrham Kumar; McBride, Dennis K; Swetnam, Michael

    2014-11-01

    This paper starts by describing the historical evolution of assessment of biologic effects of ionizing radiation leading to the linear non-threshold (LNT) system currently used to regulate exposure to ionizing radiation. The paper describes briefly the concept of Best Available Science (BAS) and Metrics for Evaluation of Scientific Claims (MESC) derived for BAS. It identifies three phases of regulatory science consisting of the initial phase, when the regulators had to develop regulations without having the needed scientific information; the exploratory phase, when relevant tools were developed; and the standard operating phase, when the tools were applied to regulations. Subsequently, an attempt is made to apply the BAS/MESC system to various stages of LNT. This paper then compares the exposure limits imposed by regulatory agencies and also compares them with naturally occurring radiation at several cities. Controversies about LNT are addressed, including judgments of the U.S. National Academies and their French counterpart. The paper concludes that, based on the BAS/MESC system, there is no disagreement between the two academies on the scientific foundation of LNT; instead, the disagreement is based on their judgment or speculation. PMID:25271928

  11. Combinatorial regulation of tissue specification by GATA and FOG factors

    PubMed Central

    Chlon, Timothy M.; Crispino, John D.

    2012-01-01

    The development of complex organisms requires the formation of diverse cell types from common stem and progenitor cells. GATA family transcriptional regulators and their dedicated co-factors, termed Friend of GATA (FOG) proteins, control cell fate and differentiation in multiple tissue types from Drosophila to man. FOGs can both facilitate and antagonize GATA factor transcriptional regulation depending on the factor, cell, and even the specific gene target. In this review, we highlight recent studies that have elucidated mechanisms by which FOGs regulate GATA factor function and discuss how these factors use these diverse modes of gene regulation to control cell lineage specification throughout metazoans. PMID:23048181

  12. The C-terminal helix in subdomain 4 of the regulatory light chain is essential for myosin regulation.

    PubMed Central

    Rowe, T; Kendrick-Jones, J

    1993-01-01

    In vertebrate smooth/non-muscle myosins, phosphorylation of the regulatory light chains by a specific calmodulin-activated kinase controls both myosin head interaction with actin and assembly of the myosin into filaments. Previous studies have shown that the C-terminal domain of the regulatory light chain is crucial for the regulation of these myosin functions. To further dissect the role of this region of the light chain in myosin regulation, a series of chicken smooth muscle myosin regulatory light chain mutants has been constructed with successive C-terminal deletions. These mutants were synthesized in Escherichia coli and analysed by their ability to restore Ca2+ regulation to scallop myosin that had been stripped of its native regulatory light chains ('desensitized'). The results show that regulatory light chain mutants with deletions in the C-terminal helix in subdomain 4 were able to reform the regulatory Ca2+ binding site on the scallop myosin head, but had lost the ability to suppress scallop myosin filament assembly and interaction with actin in the absence of Ca2+. Further deletions in the C-terminal domain led to a gradual loss of ability to restore the regulatory Ca2+ binding site. Thus, the regions in the C-terminal half of the regulatory light chain responsible for myosin regulation can be identified. Images PMID:8223496

  13. RpoN Regulates Virulence Factors of Pseudomonas aeruginosa via Modulating the PqsR Quorum Sensing Regulator

    PubMed Central

    Cai, Zhao; Liu, Yang; Chen, Yicai; Yam, Joey Kuok Hoong; Chew, Su Chuen; Chua, Song Lin; Wang, Ke; Givskov, Michael; Yang, Liang

    2015-01-01

    The alternative sigma factor RpoN regulates many cell functions, such as motility, quorum sensing, and virulence in the opportunistic pathogen Pseudomonas aeruginosa (P. aeruginosa). P. aeruginosa often evolves rpoN-negative variants during the chronic infection in cystic fibrosis patients. It is unclear how RpoN interacts with other regulatory mechanisms to control virulence of P. aeruginosa. In this study, we show that RpoN modulates the function of PqsR, a quorum sensing receptor regulating production of virulence factors including the phenazine pyocyanin. The ∆rpoN mutant is able to synthesize 4-quinolone signal molecule HHQ but unable to activate PqsR and Pseudomonas quinolone signal (pqs) quorum sensing. The ∆rpoN mutant produces minimal level of pyocyanin and is unable to produce the anti-staphylococcal agents. Providing pqsR in trans in the ∆rpoN mutant restores its pqs quorum sensing and virulence factor production to the wild-type level. Our study provides evidence that RpoN has a regulatory effect on P. aeruginosa virulence through modulating the function of the PqsR quorum sensing regulator. PMID:26633362

  14. Mapping regulatory factors by immunoprecipitation from native chromatin

    PubMed Central

    Orsi, Guillermo A.; Kasinathan, Sivakanthan; Zentner, Gabriel E.; Henikoff, Steven; Ahmad, Kami

    2015-01-01

    Occupied Regions of Genomes from Affinity-purified Naturally Isolated Chromatin (ORGANIC) is a high-resolution method that can be used to quantitatively map protein-DNA interactions with high specificity and sensitivity. This method uses micrococcal nuclease (MNase) digestion of chromatin and low-salt solubilization to preserve protein-DNA complexes followed by immunoprecipitation and paired-end sequencing for genome-wide mapping of binding sites. In this Unit, we describe methods for isolation of nuclei and MNase digestion of unfixed chromatin, immunoprecipitation of protein-DNA complexes, and high-throughput sequencing to map sites of bound factors. PMID:25827087

  15. The regulatory role of hepatoma-derived growth factor as an angiogenic factor in the eye

    PubMed Central

    LeBlanc, Michelle E.; Wang, Weiwen; Chen, Xiuping; Ji, Yanli; Shakya, Akhalesh; Shen, Chen; Zhang, Chenming; Gonzalez, Vivianne; Brewer, Megan; Ma, Jian-xing; Wen, Rong; Zhang, Fangliang

    2016-01-01

    Purpose Hepatoma-derived growth factor (HDGF) is a mitogen that promotes endothelial proliferation and neuronal survival. Using a unique technology of ligandomics, we recently identified HDGF as a retinal endothelial binding protein. The purpose of this study is to examine the role of HDGF in regulating ocular vasculature and the expression of HDGF in the retina. Methods HDGF expression in the retinal was analyzed with western blot and immunohistochemistry. Angiogenic activity was investigated in human retinal microvascular endothelial cells (HRMVECs) with in vitro endothelial proliferation, migration, and permeability assays. In vivo angiogenic activity was quantified with a corneal pocket assay. The Evans blue assay and western blot using anti-mouse albumin were performed to detect the capacity of HDGF to induce retinal vascular leakage. Results Immunohistochemistry revealed that HDGF is expressed in the retina with a distinct pattern. HDGF was detected in retinal ganglion cells and the inner nuclear layer but not in the inner plexiform layer, suggesting that HDGF is expressed in the nucleus, but not in the cytoplasm, of retinal neurons. In contrast to family member HDGF-related protein 3 (HRP-3) that has no expression in photoreceptors, HDGF is also present in the outer nuclear layer and the inner and outer segments of photoreceptors. This suggests that HDGF is expressed in the nucleus as well as the cytoplasm of photoreceptors. In vitro functional assays showed that HDGF induced the proliferation, migration, and permeability of HRMVECs. Corneal pocket assay indicated that HDGF directly stimulated angiogenesis in vivo. Intravitreal injection of HDGF significantly induced retinal vascular leakage. Conclusions These results suggest that HDGF is an angiogenic factor that regulates retinal vasculature in physiologic and pathological conditions. Identification of HDGF by ligandomics and its independent characterization in this study also support the validity of this

  16. [Genetic diagnostics as a legislation project. Regulatory initiatives and main areas of regulation].

    PubMed

    Damm, Reinhard

    2007-02-01

    The legislation project of a law on genetic diagnostics appears to have come to a standstill; however, it should be taken up again. The national and international discussion underlines the need for regulation. This assessment is based on the dynamic developments in the field of biological and medical sciences and the resulting problems for medical practice, the healthcare system, commercial in terests and, not least, patients, volunteers and clients. The German legislators cannot only build on the preparatory work of political advisory institutions and commissions; besides current legislation in neighbouring countries, several regulatory drafts have been prepared in Germany, which provide important normative material for legislative work. However, these drafts also reflect the conflicts of interest and assessment arising from such a project. Legislation on genetic diagnostics is not only concerned with differing focal points of regulation and numerous questions of detail but also with decisions on fundamental normative orientations and principles of regulation. PMID:17225988

  17. Auxin Response Factor SlARF2 Is an Essential Component of the Regulatory Mechanism Controlling Fruit Ripening in Tomato.

    PubMed

    Hao, Yanwei; Hu, Guojian; Breitel, Dario; Liu, Mingchun; Mila, Isabelle; Frasse, Pierre; Fu, Yongyao; Aharoni, Asaph; Bouzayen, Mondher; Zouine, Mohamed

    2015-12-01

    Ethylene is the main regulator of climacteric fruit ripening, by contrast the putative role of other phytohormones in this process remains poorly understood. The present study brings auxin signaling components into the mechanism regulating tomato fruit ripening through the functional characterization of Auxin Response Factor2 (SlARF2) which encodes a downstream component of auxin signaling. Two paralogs, SlARF2A and SlARF2B, are found in the tomato genome, both displaying a marked ripening-associated expression but distinct responsiveness to ethylene and auxin. Down-regulation of either SlARF2A or SlARF2B resulted in ripening defects while simultaneous silencing of both genes led to severe ripening inhibition suggesting a functional redundancy among the two ARFs. Tomato fruits under-expressing SlARF2 produced less climacteric ethylene and exhibited a dramatic down-regulation of the key ripening regulators RIN, CNR, NOR and TAGL1. Ethylene treatment failed to reverse the non-ripening phenotype and the expression of ethylene signaling and biosynthesis genes was strongly altered in SlARF2 down-regulated fruits. Although both SlARF proteins are transcriptional repressors the data indicate they work as positive regulators of tomato fruit ripening. Altogether, the study defines SlARF2 as a new component of the regulatory network controlling the ripening process in tomato. PMID:26716451

  18. Auxin Response Factor SlARF2 Is an Essential Component of the Regulatory Mechanism Controlling Fruit Ripening in Tomato

    PubMed Central

    Hao, Yanwei; Hu, Guojian; Breitel, Dario; Liu, Mingchun; Mila, Isabelle; Frasse, Pierre; Fu, Yongyao; Aharoni, Asaph; Bouzayen, Mondher; Zouine, Mohamed

    2015-01-01

    Ethylene is the main regulator of climacteric fruit ripening, by contrast the putative role of other phytohormones in this process remains poorly understood. The present study brings auxin signaling components into the mechanism regulating tomato fruit ripening through the functional characterization of Auxin Response Factor2 (SlARF2) which encodes a downstream component of auxin signaling. Two paralogs, SlARF2A and SlARF2B, are found in the tomato genome, both displaying a marked ripening-associated expression but distinct responsiveness to ethylene and auxin. Down-regulation of either SlARF2A or SlARF2B resulted in ripening defects while simultaneous silencing of both genes led to severe ripening inhibition suggesting a functional redundancy among the two ARFs. Tomato fruits under-expressing SlARF2 produced less climacteric ethylene and exhibited a dramatic down-regulation of the key ripening regulators RIN, CNR, NOR and TAGL1. Ethylene treatment failed to reverse the non-ripening phenotype and the expression of ethylene signaling and biosynthesis genes was strongly altered in SlARF2 down-regulated fruits. Although both SlARF proteins are transcriptional repressors the data indicate they work as positive regulators of tomato fruit ripening. Altogether, the study defines SlARF2 as a new component of the regulatory network controlling the ripening process in tomato. PMID:26716451

  19. Discovery of Transcription Factors and Regulatory Regions Driving In Vivo Tumor Development by ATAC-seq and FAIRE-seq Open Chromatin Profiling

    PubMed Central

    Davie, Kristofer; Jacobs, Jelle; Atkins, Mardelle; Potier, Delphine; Christiaens, Valerie; Halder, Georg; Aerts, Stein

    2015-01-01

    Genomic enhancers regulate spatio-temporal gene expression by recruiting specific combinations of transcription factors (TFs). When TFs are bound to active regulatory regions, they displace canonical nucleosomes, making these regions biochemically detectable as nucleosome-depleted regions or accessible/open chromatin. Here we ask whether open chromatin profiling can be used to identify the entire repertoire of active promoters and enhancers underlying tissue-specific gene expression during normal development and oncogenesis in vivo. To this end, we first compare two different approaches to detect open chromatin in vivo using the Drosophila eye primordium as a model system: FAIRE-seq, based on physical separation of open versus closed chromatin; and ATAC-seq, based on preferential integration of a transposon into open chromatin. We find that both methods reproducibly capture the tissue-specific chromatin activity of regulatory regions, including promoters, enhancers, and insulators. Using both techniques, we screened for regulatory regions that become ectopically active during Ras-dependent oncogenesis, and identified 3778 regions that become (over-)activated during tumor development. Next, we applied motif discovery to search for candidate transcription factors that could bind these regions and identified AP-1 and Stat92E as key regulators. We validated the importance of Stat92E in the development of the tumors by introducing a loss of function Stat92E mutant, which was sufficient to rescue the tumor phenotype. Additionally we tested if the predicted Stat92E responsive regulatory regions are genuine, using ectopic induction of JAK/STAT signaling in developing eye discs, and observed that similar chromatin changes indeed occurred. Finally, we determine that these are functionally significant regulatory changes, as nearby target genes are up- or down-regulated. In conclusion, we show that FAIRE-seq and ATAC-seq based open chromatin profiling, combined with motif

  20. Regulatory architecture determines optimal regulation of gene expression in metabolic pathways

    PubMed Central

    Chubukov, Victor; Zuleta, Ignacio A.; Li, Hao

    2012-01-01

    In response to environmental changes, the connections (“arrows”) in gene regulatory networks determine which genes modulate their expression, but the quantitative parameters of the network (“the numbers on the arrows”) are equally important in determining the resulting phenotype. What are the objectives and constraints by which evolution determines these parameters? We explore these issues by analyzing gene expression changes in a number of yeast metabolic pathways in response to nutrient depletion. We find that a striking pattern emerges that couples the regulatory architecture of the pathway to the gene expression response. In particular, we find that pathways controlled by the intermediate metabolite activation (IMA) architecture, in which an intermediate metabolite activates transcription of pathway genes, exhibit the following response: the enzyme immediately downstream of the regulatory metabolite is under the strongest transcriptional control, whereas the induction of the enzymes upstream of the regulatory intermediate is relatively weak. This pattern of responses is absent in pathways not controlled by an IMA architecture. The observation can be explained by the constraint imposed by the fundamental feedback structure of the network, which places downstream enzymes under a negative feedback loop and upstream ones under a positive feedback loop. This general design principle for transcriptional control of a metabolic pathway can be derived from a simple cost/benefit model of gene expression, in which the observed pattern is an optimal solution. Our results suggest that the parameters regulating metabolic enzyme expression are optimized by evolution, under the strong constraint of the underlying regulatory architecture. PMID:22416120

  1. Positive regulatory domain I binding factor 1 silences class II transactivator expression in multiple myeloma cells.

    PubMed

    Ghosh, N; Gyory, I; Wright, G; Wood, J; Wright, K L

    2001-05-01

    The major histocompatibility complex (MHC) class II transactivator (CIITA) acts as a master switch to activate expression of the genes required for MHC-II antigen presentation. During B-cell to plasma cell differentiation, MHC-II expression is actively silenced, but the mechanism has been unknown. In plasma cell tumors such as multiple myeloma the repression of MHC-II is associated with the loss of CIITA. We have identified that positive regulatory domain I binding factor 1 (PRDI-BF1), a transcriptional repressor, inhibits CIITA expression in multiple myeloma cell lines. Repression of CIITA depends on the DNA binding activity of PRDI-BF1 and its specific binding site in the CIITA promoter. Deletion of a histone deacetylase recruitment domain in PRDI-BF1 does not inhibit repression of CIITA nor does blocking histone deacetylase activity. This is in contrast to PRDI-BF1 repression of the c-myc promoter. Repression of CIITA requires either the N-terminal acidic and conserved PR motif or the proline-rich domain. PRDI-BF1 has been shown to be a key regulator of B-cell and macrophage differentiation. These findings now indicate that PRDI-BF1 has at least two mechanisms of repression whose function is dependent on the nature of the target promoter. Importantly, PRDI-BF1 is defined as the key molecule in silencing CIITA and thus MHC-II in multiple myeloma cells. PMID:11279146

  2. Interferon Regulatory Factor 6 Has a Protective Role in the Host Response to Endotoxic Shock

    PubMed Central

    Volk, Paige; Moreland, Jessica G.; Dunnwald, Martine

    2016-01-01

    Interferon Regulatory Factor (IRF) 6, a member of the IRF family, is essential for epidermal and orofacial embryonic development. Irf6 is strongly expressed in keratinocytes, in which it regulates epidermal proliferation, differentiation, and migration. A recent role for Irf6 in Toll-like receptor 2-dependent chemokine gene expression was also reported in an epithelial cell line. However, a function for Irf6 in innate immune cells was not previously reported. In the present study, we investigated the expression and function of Irf6 in bone marrow-derived neutrophils and macrophages. We show here, using a conditional knockout of Irf6 in lysosymeM expressing cells, that Irf6 is required for resistance to LPS-induced endotoxic shock. In addition, Irf6-deficient bone marrow-derived neutrophils exhibited increased chemotactic index and velocity compared with wild-type cells in vitro. TLR4-specific KC and IL6 secretions were upregulated in Irf6-deficient bone marrow-derived macrophages in vitro. These cells also exhibited an increased level of phosphorylated IkBa. Collectively, our findings suggest a role for Irf6 in the resistance to endotoxic shock due to NFk-B-mediated alteration of cytokine production. PMID:27035130

  3. Activation of Interferon Regulatory Factor 3 Is Inhibited by the Influenza A Virus NS1 Protein

    PubMed Central

    Talon, Julie; Horvath, Curt M.; Polley, Rosalind; Basler, Christopher F.; Muster, Thomas; Palese, Peter; García-Sastre, Adolfo

    2000-01-01

    We present a novel mechanism by which viruses may inhibit the alpha/beta interferon (IFN-α/β) cascade. The double-stranded RNA (dsRNA) binding protein NS1 of influenza virus is shown to prevent the potent antiviral interferon response by inhibiting the activation of interferon regulatory factor 3 (IRF-3), a key regulator of IFN-α/β gene expression. IRF-3 activation and, as a consequence, IFN-β mRNA induction are inhibited in wild-type (PR8) influenza virus-infected cells but not in cells infected with an isogenic virus lacking the NS1 gene (delNS1 virus). Furthermore, NS1 is shown to be a general inhibitor of the interferon signaling pathway. Inhibition of IRF-3 activation can be achieved by the expression of wild-type NS1 in trans, not only in delNS1 virus-infected cells but also in cells infected with a heterologous RNA virus (Newcastle disease virus). We propose that inhibition of IRF-3 activation by a dsRNA binding protein significantly contributes to the virulence of influenza A viruses and possibly to that of other viruses. PMID:10933707

  4. FootprintDB: Analysis of Plant Cis-Regulatory Elements, Transcription Factors, and Binding Interfaces.

    PubMed

    Contreras-Moreira, Bruno; Sebastian, Alvaro

    2016-01-01

    FootprintDB is a database and search engine that compiles regulatory sequences from open access libraries of curated DNA cis-elements and motifs, and their associated transcription factors (TFs). It systematically annotates the binding interfaces of the TFs by exploiting protein-DNA complexes deposited in the Protein Data Bank. Each entry in footprintDB is thus a DNA motif linked to the protein sequence of the TF(s) known to recognize it, and in most cases, the set of predicted interface residues involved in specific recognition. This chapter explains step-by-step how to search for DNA motifs and protein sequences in footprintDB and how to focus the search to a particular organism. Two real-world examples are shown where this software was used to analyze transcriptional regulation in plants. Results are described with the aim of guiding users on their interpretation, and special attention is given to the choices users might face when performing similar analyses. PMID:27557773

  5. Activation of Vago by interferon regulatory factor (IRF) suggests an interferon system-like antiviral mechanism in shrimp

    PubMed Central

    Li, Chaozheng; Li, Haoyang; Chen, Yixiao; Chen, Yonggui; Wang, Sheng; Weng, Shao-Ping; Xu, Xiaopeng; He, Jianguo

    2015-01-01

    There is a debate on whether invertebrates possess an antiviral immunity similar to the interferon (IFN) system of vertebrates. The Vago gene from arthropods encodes a viral-activated secreted peptide that restricts virus infection through activating the JAK-STAT pathway and is considered to be a cytokine functionally similar to IFN. In this study, the first crustacean IFN regulatory factor (IRF)-like gene was identified in Pacific white shrimp, Litopenaeus vannamei. The L. vannamei IRF showed similar protein nature to mammalian IRFs and could be activated during virus infection. As a transcriptional regulatory factor, L. vannamei IRF could activate the IFN-stimulated response element (ISRE)-containing promoter to regulate the expression of mammalian type I IFNs and initiate an antiviral state in mammalian cells. More importantly, IRF could bind the 5′-untranslated region of L. vannamei Vago4 gene and activate its transcription, suggesting that shrimp Vago may be induced in a similar manner to that of IFNs and supporting the opinion that Vago might function as an IFN-like molecule in invertebrates. These suggested that shrimp might possess an IRF-Vago-JAK/STAT regulatory axis, which is similar to the IRF-IFN-JAK/STAT axis of vertebrates, indicating that invertebrates might possess an IFN system-like antiviral mechanism. PMID:26459861

  6. Regulatory T Cells in HIV Infection: Can Immunotherapy Regulate the Regulator?

    PubMed Central

    Jenabian, Mohammad-Ali; Ancuta, Petronela; Gilmore, Norbert; Routy, Jean-Pierre

    2012-01-01

    Regulatory T cells (Tregs) have a dominant role in self-tolerance and control of autoimmune diseases. These cells also play a pivotal role in chronic viral infections and cancer by limiting immune activation and specific immune response. The role of Tregs in HIV pathogenesis remains poorly understood as their function, changes according to the phases of infection. Tregs can suppress anti-HIV specific responses and conversely can have a beneficial role by reducing the deleterious impact of immune activation. We review the frequency, function and homing potential of Tregs in the blood and lymphoid tissues as well as their interaction with dendritic cells in the context of HIV infection. We also examine the new insights generated by recombinant IL-2 and IL-7 clinical trials in HIV-infected adults, including the immunomodulatory effects of Tregs. Based on their detrimental role in limiting anti-HIV responses, we propose Tregs as potential targets for immunotherapeutic strategies aimed at decreasing Tregs frequency and/or immunosuppressive function. However, such approaches require a better understanding of the time upon infection when interfering with Treg function may not cause a deleterious state of hyperimmune activation. PMID:23251223

  7. An information transmission model for transcription factor binding at regulatory DNA sites

    PubMed Central

    2012-01-01

    Background Computational identification of transcription factor binding sites (TFBSs) is a rapid, cost-efficient way to locate unknown regulatory elements. With increased potential for high-throughput genome sequencing, the availability of accurate computational methods for TFBS prediction has never been as important as it currently is. To date, identifying TFBSs with high sensitivity and specificity is still an open challenge, necessitating the development of novel models for predicting transcription factor-binding regulatory DNA elements. Results Based on the information theory, we propose a model for transcription factor binding of regulatory DNA sites. Our model incorporates position interdependencies in effective ways. The model computes the information transferred (TI) between the transcription factor and the TFBS during the binding process and uses TI as the criterion to determine whether the sequence motif is a possible TFBS. Based on this model, we developed a computational method to identify TFBSs. By theoretically proving and testing our model using both real and artificial data, we found that our model provides highly accurate predictive results. Conclusions In this study, we present a novel model for transcription factor binding regulatory DNA sites. The model can provide an increased ability to detect TFBSs. PMID:22672438

  8. Regulatory SNPs and transcriptional factor binding sites in ADRBK1, AKT3, ATF3, DIO2, TBXA2R and VEGFA

    PubMed Central

    Buroker, Norman E

    2014-01-01

    Abstract Regulatory single nucleotide polymorphisms (rSNPs) which change the transcriptional factor binding sites (TFBS) for transcriptional factors (TFs) to bind DNA were reviewed for the ADRBK1 (GRK2), AKT3, ATF3, DIO2, TBXA2R and VEGFA genes. Changes in the TFBS where TFs attach to regulate these genes may result in human sickness and disease. The highlights of this previous work were reviewed for these genes. PMID:25483406

  9. Regulation of human PTCH1b expression by different 5' untranslated region cis-regulatory elements

    PubMed Central

    Ozretić, Petar; Bisio, Alessandra; Musani, Vesna; Trnski, Diana; Sabol, Maja; Levanat, Sonja; Inga, Alberto

    2015-01-01

    PTCH1 gene codes for a 12-pass transmembrane receptor with a negative regulatory role in the Hedgehog-Gli signaling pathway. PTCH1 germline mutations cause Gorlin syndrome, a disorder characterized by developmental abnormalities and tumor susceptibility. The autosomal dominant inheritance, and the evidence for PTCH1 haploinsufficiency, suggests that fine-tuning systems of protein patched homolog 1 (PTC1) levels exist to properly regulate the pathway. Given the role of 5' untranslated region (5'UTR) in protein expression, our aim was to thoroughly explore cis-regulatory elements in the 5'UTR of PTCH1 transcript 1b. The (CGG)n polymorphism was the main potential regulatory element studied so far but with inconsistent results and no clear association between repeat number and disease risk. Using luciferase reporter constructs in human cell lines here we show that the number of CGG repeats has no strong impact on gene expression, both at mRNA and protein levels. We observed variability in the length of 5'UTR and changes in abundance of the associated transcripts after pathway activation. We show that upstream AUG codons (uAUGs) present only in longer 5'UTRs could negatively regulate the amount of PTC1 isoform L (PTC1-L). The existence of an internal ribosome entry site (IRES) observed using different approaches and mapped in the region comprising the CGG repeats, would counteract the effect of the uAUGs and enable synthesis of PTC1-L under stressful conditions, such as during hypoxia. Higher relative translation efficiency of PTCH1b mRNA in HEK 293T cultured hypoxia was observed by polysomal profiling and Western blot analyses. All our results point to an exceptionally complex and so far unexplored role of 5'UTR PTCH1b cis-element features in the regulation of the Hedgehog-Gli signaling pathway. PMID:25826662

  10. Regulation of Cell Fate Determination by Single-Repeat R3 MYB Transcription Factors in Arabidopsis

    SciTech Connect

    Wang, Shucai; Chen, Jay

    2014-01-01

    MYB transcription factors regulate multiple aspects of plant growth and development. Among the large family of MYB transcription factors, single-repeat R3 MYB are characterized by their short sequence (<120 amino acids) consisting largely of the single MYB DNA-binding repeat. In the model plant Arabidopsis, R3 MYBs mediate lateral inhibition during epidermal patterning and are best characterized for their regulatory roles in trichome and root hair development. R3 MYBs act as negative regulators for trichome formation but as positive regulators for root hair development. In this article, we provide a comprehensive review on the role of R3 MYBs in the regulation of cell type specification in the model plant Arabidopsis.

  11. Novel alleles of the transforming growth factor β-1 regulatory region and exon 1.

    PubMed

    Arrieta-Bolaños, E; Madrigal, J A; Shaw, B E

    2015-06-01

    Transforming growth factor β-1, encoded by the TGFB1 gene, is a cytokine that plays a central role in many physiologic and pathogenic processes with pleiotropic effects. Regulatory activity for this gene has been shown for 3.0 kb between positions -2665 and +423 from its translational start site. At least 17 TGFB1 regulatory region and exon 1 alleles have been defined on the basis of 18 polymorphic sites. Polymorphisms in TGFB1's regulatory region have been associated with differential levels of expression of this cytokine and to genetic risk in cancer and transplantation. In this report, we present 19 novel TGFB1 regulatory region and exon 1 alleles: p018-p036. Amplification of TGFB1's regulatory region was performed with an in-house protocol, and novel alleles were defined by either allele-specific amplification and/or molecular cloning of the amplicons, followed by sequencing in isolation. Three of these novel alleles (p018, p019, and p020) are shown to be formed by novel combinations of the aforementioned known polymorphic positions. Another 16 novel alleles are shown to carry additional known and unknown single-nucleotide polymorphisms. Polymorphism in TGFB1's regulatory region could have an impact on important processes, including embryogenesis, hematopoiesis, carcinogenesis, angiogenesis, fibrosis, immune responses, and transplantation, making its characterization necessary. PMID:25808355

  12. Imogene: identification of motifs and cis-regulatory modules underlying gene co-regulation

    PubMed Central

    Rouault, Hervé; Santolini, Marc; Schweisguth, François; Hakim, Vincent

    2014-01-01

    Cis-regulatory modules (CRMs) and motifs play a central role in tissue and condition-specific gene expression. Here we present Imogene, an ensemble of statistical tools that we have developed to facilitate their identification and implemented in a publicly available software. Starting from a small training set of mammalian or fly CRMs that drive similar gene expression profiles, Imogene determines de novo cis-regulatory motifs that underlie this co-expression. It can then predict on a genome-wide scale other CRMs with a regulatory potential similar to the training set. Imogene bypasses the need of large datasets for statistical analyses by making central use of the information provided by the sequenced genomes of multiple species, based on the developed statistical tools and explicit models for transcription factor binding site evolution. We test Imogene on characterized tissue-specific mouse developmental CRMs. Its ability to identify CRMs with the same specificity based on its de novo created motifs is comparable to that of previously evaluated ‘motif-blind’ methods. We further show, both in flies and in mammals, that Imogene de novo generated motifs are sufficient to discriminate CRMs related to different developmental programs. Notably, purely relying on sequence data, Imogene performs as well in this discrimination task as a previously reported learning algorithm based on Chromatin Immunoprecipitation (ChIP) data for multiple transcription factors at multiple developmental stages. PMID:24682824

  13. A Csr-type regulatory system, including small non-coding RNAs, regulates the global virulence regulator RovA of Yersinia pseudotuberculosis through RovM.

    PubMed

    Heroven, Ann Kathrin; Böhme, Katja; Rohde, Manfred; Dersch, Petra

    2008-06-01

    The MarR-type regulator RovA controls expression of virulence genes of Yersinia pseudotuberculosis in response to environmental signals. Using a genetic strategy to discover components that influence rovA expression, we identified new regulatory factors with homology to components of the carbon storage regulator system (Csr). We showed that overexpression of a CsrB- or a CsrC-type RNA activates rovA, whereas a CsrA-like protein represses RovA synthesis. We further demonstrate that influence of the Csr system on rovA is indirect and occurs through control of the LysR regulator RovM, which inhibits rovA transcription. The CsrA protein had also a major influence on the motility of Yersinia, which was independent of RovM. The CsrB and CsrC RNAs are differentially expressed in Yersinia. CsrC is highly induced in complex but not in minimal media, indicating that medium-dependent rovM expression is mediated through CsrC. CsrB synthesis is generally very low. However, overexpression of the response regulator UvrY was found to activate CsrB production, which in turn represses CsrC synthesis independent of the growth medium. In summary, the post-transcriptional Csr-type components were shown to be key regulators in the co-ordinated environmental control of physiological processes and virulence factors, which are crucial for the initiation of Yersinia infections. PMID:18430141

  14. A trans-acting Variant within the Transcription Factor RIM101 Interacts with Genetic Background to Determine its Regulatory Capacity

    PubMed Central

    Read, Timothy; Richmond, Phillip A.; Dowell, Robin D.

    2016-01-01

    Most genetic variants associated with disease occur within regulatory regions of the genome, underscoring the importance of defining the mechanisms underlying differences in regulation of gene expression between individuals. We discovered a pair of co-regulated, divergently oriented transcripts, AQY2 and ncFRE6, that are expressed in one strain of Saccharomyces cerevisiae, ∑1278b, but not in another, S288c. By combining classical genetics techniques with high-throughput sequencing, we identified a trans-acting single nucleotide polymorphism within the transcription factor RIM101 that causes the background-dependent expression of both transcripts. Subsequent RNA-seq experiments revealed that RIM101 regulates many more targets in S288c than in ∑1278b and that deletion of RIM101 in both backgrounds abrogates the majority of differential expression between the strains. Strikingly, only three transcripts undergo a significant change in expression after swapping RIM101 alleles between backgrounds, implying that the differences in the RIM101 allele lead to a remarkably focused transcriptional response. However, hundreds of RIM101-dependent targets undergo a subtle but consistent shift in expression in the S288c RIM101-swapped strain, but not its ∑1278b counterpart. We conclude that ∑1278b may harbor a variant(s) that buffers against widespread transcriptional dysregulation upon introduction of a non-native RIM101 allele, emphasizing the importance of accounting for genetic background when assessing the impact of a regulatory variant. PMID:26751950

  15. Insights into the Interferon Regulatory Factor Activation from the Crystal Structure of Dimeric IRF5

    SciTech Connect

    Chen, W.; Lam, S; Srinath, H; Jiang, Z; Correia, J; Schiffer, C; Fitzgerald, K; Lin, K; Royer, Jr., W

    2008-01-01

    The interferon regulatory factors (IRFs) are involved in the innate immune response and are activated by phosphorylation. The structure of a pseudophosphorylated IRF5 activation domain now reveals structural changes in the activated form that would turn an autoinhibitory region into a dimerization interface. In vivo analysis supports the relevance of such a dimer to transcriptional activation.

  16. Myogenic regulatory factor (MRF) expression is affected by exercise in postnatal chicken skeletal muscles.

    PubMed

    Yin, Huadong; Li, Diyan; Wang, Yan; Zhao, Xiaoling; Liu, Yiping; Yang, Zhiqin; Zhu, Qing

    2015-05-01

    The MyoD1, MyoG, Myf5, and Mrf4 proteins belong to the family of muscle regulatory factors (MRFs) and play important roles in skeletal muscle hyperplasia and hypertrophy. We hypothesized that exercise would affect MRF mRNA and protein abundance in postnatal chicken skeletal muscle driving molecular changes that could ultimately lead to increased muscle fiber diameter. At day (d) 43, twelve hundred chickens with similar body weight were randomly assigned to cage, pen, and free-range groups. The MRF mRNA abundance was measured in the pectoralis major and thigh muscle at d56, d70, and d84, and the protein levels of MRFs were determined from the thigh muscle at d84. The results showed no significant difference in mRNA of the MRFs among the three groups at d56 (P>0.05). At d84, chicken in the pen and free-range group showed higher MyoD1, MyoG, Myf5, and Mrf4 mRNA abundance compared to the caged chickens (P<0.05). Free-range chickens had higher Mrf4 and MyoG expression than those in penned ones (P<0.05). Protein abundances of all four factors were lowest in the caged group, and Mrf4 and MyoG protein quantities were greatest in free-range chickens (P<0.05), but Myf5 and MyoD1 protein abundance did not differ between penned and caged groups. The results suggested that exercise up-regulated MRF expression in the postnatal skeletal muscles, which led to an increase in muscle fiber diameter, and eventually affected the meat quality of the skeletal muscles in adult chickens. PMID:25701607

  17. Smad ubiquitination regulatory factor 2 expression is enhanced in hypertrophic scar fibroblasts from burned children

    PubMed Central

    Finnerty, Celeste C; He, Jing; Herndon, David N

    2013-01-01

    Transforming growth factor-β1 (TGF-β1) plays a key role in hypertrophic scar formation. A lot of studies have shown that TGF-β1 stimulates fibroblast proliferation, collagen production, and α-smooth muscle actin (α-SMA) expression, inhibits matrix degradation and eventually leads to scar formation. Smad proteins are important intracellular mediators of TGF-β1 signaling, and Smad ubiquitination regulatory factor 2 (Smurf2), an ubiquitin ligase for Smads, plays critical roles in the regulation of TGF-β1/Smad signaling. It was reported that Smurf2 was abnormally expressed during the process of liver fibrosis and lung fibrosis. Hypertrophic scarring is a fibroproliferative disorder of the dermis that occurs following wounding. However, little is known about the expression of Smurf2 in hypertrophic scarring. We hypothesized that TGF-β1 signaling cannot be disrupted after wound epithelialization probably due to abnormal expression of Smurf2 in hypertrophic scar fibroblasts. In the present study, we found that hypertrophic scar fibroblasts exhibited increased Smurf2 protein and mRNA levels compared with normal fibroblasts, and the expression of Smurf2 gradually increased in hypertrophic scar fibroblasts after TGF-β1 stimulation. Furthermore, we transfected Smurf2 siRNA into hypertrophic scar fibroblasts, and we found that silencing the expression of Smurf2 in hypertrophic scar fibroblasts dramatically reduced TGF-β1 production, inhibited TGF-β1-induced α-SMA expression and inhibited TGF-β1-induced collagen I synthesis. Our results suggest that the enhanced expression of Smurf2 is involved in the progression of hypertrophic scarring. PMID:21920670

  18. Characterization of Amphioxus IFN Regulatory Factor Family Reveals an Archaic Signaling Framework for Innate Immune Response.

    PubMed

    Yuan, Shaochun; Zheng, Tingting; Li, Peiyi; Yang, Rirong; Ruan, Jie; Huang, Shengfeng; Wu, Zhenxin; Xu, Anlong

    2015-12-15

    The IFN regulatory factor (IRF) family encodes transcription factors that play important roles in immune defense, stress response, reproduction, development, and carcinogenesis. Although the origin of the IRF family has been dated back to multicellular organisms, invertebrate IRFs differ from vertebrate IRFs in genomic structure and gene synteny, and little is known about their functions. Through comparison of multiple amphioxus genomes, in this study we suggested that amphioxus contains nine IRF members, whose orthologs are supposed to be shared among three amphioxus species. As the orthologs to the vertebrate IRF1 and IRF4 subgroups, Branchiostoma belcheri tsingtauense (bbt)IRF1 and bbtIRF8 bind the IFN-stimulated response element (ISRE) and were upregulated when amphioxus intestinal cells were stimulated with poly(I:C). As amphioxus-specific IRFs, both bbtIRF3 and bbtIRF7 bind ISRE. When activated, they can be phosphorylated by bbtTBK1 and then translocate into nucleus for target gene transcription. As transcriptional repressors, bbtIRF2 and bbtIRF4 can inhibit the transcriptional activities of bbtIRF1, 3, 7, and 8 by competing for the binding of ISRE. Interestingly, amphioxus IRF2, IRF8, and Rel were identified as target genes of bbtIRF1, bbtIRF7, and bbtIRF3, respectively, suggesting a dynamic feedback regulation among amphioxus IRF and NF-κB. Collectively, to our knowledge we present for the first time an archaic IRF signaling framework in a basal chordate, shedding new insights into the origin and evolution of vertebrate IFN-based antiviral networks. PMID:26573836

  19. Bacterial lipopolysaccharide down-regulates expression of GTP cyclohydrolase I feedback regulatory protein.

    PubMed

    Werner, Ernst R; Bahrami, Soheyl; Heller, Regine; Werner-Felmayer, Gabriele

    2002-03-22

    GTP cyclohydrolase I feedback regulatory protein (GFRP) is a 9.7-kDa protein regulating GTP cyclohydrolase I activity in dependence of tetrahydrobiopterin and phenylalanine concentrations, thus enabling stimulation of tetrahydrobiopterin biosynthesis by phenylalanine to ensure its efficient metabolism by phenylalanine hydroxylase. Here, we were interested in regulation of GFRP expression by proinflammatory cytokines and stimuli, which are known to induce GTP cyclohydrolase I expression. Recombinant human GFRP stimulated recombinant human GTP cyclohydrolase I in the presence of phenylalanine and mediated feedback inhibition by tetrahydrobiopterin. Levels of GFRP mRNA in human myelomonocytoma (THP-1) cells remained unaltered by treatment of cells with interferon-gamma or interleukin-1beta, but were significantly down-regulated by bacterial lipopolysaccharide (LPS, 1 microg/ml), without or with cotreatment by interferon-gamma, which strongly up-regulated GTP cyclohydrolase I expression and activity. GFRP expression was also suppressed in human umbilical vein endothelial cells treated with 1 microg/ml LPS, as well as in rat tissues 7 h post intraperitoneal injection of 10 mg/kg LPS. THP-1 cells stimulated with interferon-gamma alone showed increased pteridine synthesis by addition of phenylalanine to the culture medium. Cells stimulated with interferon-gamma plus LPS, in contrast, showed phenylalanine-independent pteridine synthesis. These results demonstrate that LPS down-regulates expression of GFRP, thus rendering pteridine synthesis independent of metabolic control by phenylalanine. PMID:11799107

  20. Interplay of microRNA and epigenetic regulation in the human regulatory network.

    PubMed

    Osella, Matteo; Riba, Andrea; Testori, Alessandro; Corà, Davide; Caselle, Michele

    2014-01-01

    The expression of protein-coding genes is controlled by a complex network of regulatory interactions. It is becoming increasingly appreciated that post-transcriptional repression by microRNAs, a class of small non-coding RNAs, is a key layer of regulation in several biological processes. In this contribution, we discuss the interplay between microRNAs and epigenetic regulators. Among the mixed genetic circuits composed by these two different kinds of regulation, it seems that a central role is played by double-negative feedback loops in which a microRNA inhibits an epigenetic regulator and in turn is controlled at the epigenetic level by the same regulator. We discuss a few relevant properties of this class of network motifs and their potential role in cell differentiation. In particular, using mathematical modeling we show how this particular circuit can exhibit a switch-like behavior between two alternative steady states, while being robust to stochastic transitions between these two states, a feature presumably required for circuits involved in cell fate decision. Finally, we present a list of putative double-negative feedback loops from a literature survey combined with bioinformatic analysis, and discuss in detail a few examples. PMID:25339974

  1. The transcription factor GATA-6 regulates pathological cardiac hypertrophy

    PubMed Central

    van Berlo, Jop H.; Elrod, John W.; van den Hoogenhof, Maarten M.G.; York, Allen J.; Aronow, Bruce J.; Duncan, Stephen A.; Molkentin, Jeffery D.

    2010-01-01

    Rationale The transcriptional code that programs maladaptive cardiac hypertrophy involves the zinc finger-containing DNA binding factor GATA-4. The highly related transcription factor GATA-6 is also expressed in the adult heart, although its role in controlling the hypertrophic program is unknown. Objective To determine the role of GATA-6 in cardiac hypertrophy and homeostasis. Methods and Results Here we performed a cardiomyocyte-specific conditional gene targeting approach for Gata6, as well as a transgenic approach to overexpress GATA-6 in the mouse heart. Deletion of Gata6-loxP with Nkx2.5-cre produced late embryonic lethality with heart defects, while deletion with β-myosin heavy chain-cre (βMHC-cre) produced viable adults with greater than 95% loss of GATA-6 protein in the heart. These later mice were subjected to pressure overload induced hypertrophy for 2 and 6 weeks, which showed a significant reduction in cardiac hypertrophy similar to that observed Gata4 heart-specific deleted mice. Gata6-deleted mice subjected to pressure overload also developed heart failure while control mice maintained proper cardiac function. Gata6-deleted mice also developed less cardiac hypertrophy following 2 weeks of angiotensin II/phenylephrine infusion. Controlled GATA-6 overexpression in the heart induced hypertrophy with aging and predisposed to greater hypertrophy with pressure overload stimulation. Combinatorial deletion of Gata4 and Gata6 from the adult heart resulted in dilated cardiomyopathy and lethality by 16 weeks of age. Mechanistically, deletion of Gata6 from the heart resulted in fundamental changes in the levels of key regulatory genes and myocyte differentiation-specific genes. Conclusions These results indicate that GATA-6 is both necessary and sufficient for regulating the cardiac hypertrophic response and differentiated gene expression, both alone and in coordination with GATA-4. PMID:20705924

  2. PcFKH1, a novel regulatory factor from the forkhead family, controls the biosynthesis of penicillin in Penicillium chrysogenum.

    PubMed

    Domínguez-Santos, Rebeca; García-Estrada, Carlos; Kosalková, Katarina; Prieto, Carlos; Santamarta, Irene; Martín, Juan-Francisco

    2015-08-01

    Penicillin biosynthesis in Penicillium chrysogenum (re-identified as Penicillium rubens) is a good example of a biological process subjected to complex global regulatory networks and serves as a model to study fungal secondary metabolism. The winged-helix family of transcription factors recently described, which includes the forkhead type of proteins, is a key type of regulatory proteins involved in this process. In yeasts and humans, forkhead transcription factors are involved in different processes (cell cycle regulation, cell death control, pre-mRNA processing and morphogenesis); one member of this family of proteins has been identified in the P. chrysogenum genome (Pc18g00430). In this work, we have characterized this novel transcription factor (named PcFKH1) by generating knock-down mutants and overexpression strains. Results clearly indicate that PcFKH1 positively controls antibiotic biosynthesis through the specific interaction with the promoter region of the penDE gene, thus regulating penDE mRNA levels. PcFKH1 also binds to the pcbC promoter, but with low affinity. In addition, it also controls other ancillary genes of the penicillin biosynthetic process, such as phlA (encoding phenylacetyl CoA ligase) and ppt (encoding phosphopantetheinyl transferase). PcFKH1 also plays a role in conidiation and spore pigmentation, but it does not seem to be involved in hyphal morphology or cell division in the improved laboratory reference strain Wisconsin 54-1255. A genome-wide analysis of processes putatively coregulated by PcFKH1 and PcRFX1 (another winged-helix transcription factor) in P. chrysogenum provided evidence of the global effect of these transcription factors in P. chrysogenum metabolism. PMID:26049046

  3. Regulatory advice and drug development--a case study in negotiating with regulators.

    PubMed

    Seldrup, Jørgen

    2011-06-15

    Regulatory guidance on the development of drugs has existed for well over half a century in some territories. As drug development grew to become global so was born the need for harmonization. Beginning in the 1990 s, the International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) developed guidelines which were adopted by the Food and Drug Administration (FDA) in the U.S.A., the European Medicines Agency (EMA) in the European Union and the Pharmaceuticals and Medical Devices Agency (PMDA) in Japan. These guidelines are generally not disease specific. A visit to the web sites of any of the aforementioned Agencies or, for that matter other regulatory agencies outside of these, will witness a plethora of additional/separate guidances, some of which are disease specific. In addition to such written guidances, more specific advice (for example, on a drug development program at the end of Phase II) may be requested from the Regulator. Despite the harmonization efforts expressed through ICH, the actual advice given by different regulatory authorities in practical situations, however, may be inconsistent. This paper will describe a case of seeking advice on a Phase III programme from the FDA and the EMA, obtaining different opinions and developing an innovative solution to satisfy both Authorities without necessarily extending development time significantly. The case is chronic kidney disease; the issues concern study design (non-inferiority, margin, etc.); the solution required a non-traditional design and associated sample size considerations. We conclude with some general advice on 'talking to the regulator'. This work was originally presented as a Poster at the Statistical Methods in Biopharmacy, 6th International Meeting, Paris, 21-22 September 2009. PMID:21365671

  4. Self-perceived successful weight regulators are less affected by self-regulatory depletion in the domain of eating behavior.

    PubMed

    Friese, Malte; Engeler, Michèle; Florack, Arnd

    2015-01-01

    Weight loss and maintenance goals are highly prevalent in many affluent societies, but many weight regulators are not successful in the long term. Research started to reveal psychological mechanisms that help successful weight regulators in being successful. In the present study, we tested the assumption that these mechanisms facilitate successful self-regulation particularly under conditions of self-regulatory depletion. Participants exerted or did not exert self-control in a first task before engaging in a taste test of a tempting but unhealthy food. Participants who had initially exerted self-control ate more than participants in the control condition. This effect was reduced in self-perceived successful weight regulators as compared to perceived unsuccessful self-regulators. A reduced susceptibility to self-regulatory depletion may be an important contributor to long-term weight regulation success in successful weight regulators. PMID:25464058

  5. Overexpression of E2F mRNAs Associated with Gastric Cancer Progression Identified by the Transcription Factor and miRNA Co-Regulatory Network Analysis

    PubMed Central

    Zhang, XiaoTian; Ni, ZhaoHui; Duan, ZiPeng; Xin, ZhuoYuan; Wang, HuaiDong; Tan, JiaYi; Wang, GuoQing; Li, Fan

    2015-01-01

    Gene expression is regulated at the transcription and translation levels; thus, both transcription factors (TFs) and microRNAs (miRNA) play roles in regulation of gene expression. This study profiled differentially expressed mRNAs and miRNAs in gastric cancer tissues to construct a TF and miRNA co-regulatory network in order to identify altered genes in gastric cancer progression. A total of 70 cases gastric cancer and paired adjacent normal tissues were subjected to cDNA and miRNA microarray analyses. We obtained 887 up-regulated and 93 down-regulated genes and 41 down-regulated and 4 up-regulated miRNAs in gastric cancer tissues. Using the Transcriptional Regulatory Element Database, we obtained 105 genes that are regulated by the E2F family of genes and using Targetscan, miRanda, miRDB and miRWalk tools, we predicted potential targeting genes of these 45 miRNAs. We then built up the E2F-related TF and miRNA co-regulatory gene network and identified 9 hub-genes. Furthermore, we found that levels of E2F1, 2, 3, 4, 5, and 7 mRNAs associated with gastric cancer cell invasion capacity, and has associated with tumor differentiation. These data showed Overexpression of E2F mRNAs associated with gastric cancer progression. PMID:25646628

  6. STAT5 proteins are involved in down-regulation of iron regulatory protein 1 gene expression by nitric oxide.

    PubMed

    Starzynski, Rafal Radoslaw; Gonçalves, Ana Sofia; Muzeau, Françoise; Tyrolczyk, Zofia; Smuda, Ewa; Drapier, Jean-Claude; Beaumont, Carole; Lipinski, Pawel

    2006-12-01

    RNA-binding activity of IRP1 (iron regulatory protein 1) is regulated by the insertion/extrusion of a [4Fe-4S] cluster into/from the IRP1 molecule. NO (nitic oxide), whose ability to activate IRP1 by removing its [4Fe-4S] cluster is well known, has also been shown to down-regulate expression of the IRP1 gene. In the present study, we examine whether this regulation occurs at the transcriptional level. Analysis of the mouse IRP1 promoter sequence revealed two conserved putative binding sites for transcription factor(s) regulated by NO and/or changes in intracellular iron level: Sp1 (promoter-selective transcription factor 1) and MTF1 (metal transcription factor 1), plus GAS (interferon-gamma-activated sequence), a binding site for STAT (signal transducer and activator of transcription) proteins. In order to define the functional activity of these sequences, reporter constructs were generated through the insertion of overlapping fragments of the mouse IRP1 promoter upstream of the luciferase gene. Transient expression assays following transfection of HuH7 cells with these plasmids revealed that while both the Sp1 and GAS sequences are involved in basal transcriptional activity of the IRP1 promoter, the role of the latter is predominant. Analysis of protein binding to these sequences in EMSAs (electrophoretic mobility-shift assays) using nuclear extracts from mouse RAW 264.7 macrophages stimulated to synthesize NO showed a significant decrease in the formation of Sp1-DNA and STAT-DNA complexes, compared with controls. We have also demonstrated that the GAS sequence is involved in NO-dependent down-regulation of IRP1 transcription. Further analysis revealed that levels of STAT5a and STAT5b in the nucleus and cytosol of NO-producing macrophages are substantially lower than in control cells. These findings provide evidence that STAT5 proteins play a role in NO-mediated down-regulation of IRP1 gene expression. PMID:16886906

  7. STAT5 proteins are involved in down-regulation of iron regulatory protein 1 gene expression by nitric oxide

    PubMed Central

    Starzynski, Rafal Radoslaw; Gonçalves, Ana Sofia; Muzeau, Françoise; Tyrolczyk, Zofia; Smuda, Ewa; Drapier, Jean-Claude; Beaumont, Carole; Lipinski, Pawel

    2006-01-01

    RNA-binding activity of IRP1 (iron regulatory protein 1) is regulated by the insertion/extrusion of a [4Fe-4S] cluster into/from the IRP1 molecule. NO (nitic oxide), whose ability to activate IRP1 by removing its [4Fe-4S] cluster is well known, has also been shown to down-regulate expression of the IRP1 gene. In the present study, we examine whether this regulation occurs at the transcriptional level. Analysis of the mouse IRP1 promoter sequence revealed two conserved putative binding sites for transcription factor(s) regulated by NO and/or changes in intracellular iron level: Sp1 (promoter-selective transcription factor 1) and MTF1 (metal transcription factor 1), plus GAS (interferon-γ-activated sequence), a binding site for STAT (signal transducer and activator of transcription) proteins. In order to define the functional activity of these sequences, reporter constructs were generated through the insertion of overlapping fragments of the mouse IRP1 promoter upstream of the luciferase gene. Transient expression assays following transfection of HuH7 cells with these plasmids revealed that while both the Sp1 and GAS sequences are involved in basal transcriptional activity of the IRP1 promoter, the role of the latter is predominant. Analysis of protein binding to these sequences in EMSAs (electrophoretic mobility-shift assays) using nuclear extracts from mouse RAW 264.7 macrophages stimulated to synthesize NO showed a significant decrease in the formation of Sp1–DNA and STAT–DNA complexes, compared with controls. We have also demonstrated that the GAS sequence is involved in NO-dependent down-regulation of IRP1 transcription. Further analysis revealed that levels of STAT5a and STAT5b in the nucleus and cytosol of NO-producing macrophages are substantially lower than in control cells. These findings provide evidence that STAT5 proteins play a role in NO-mediated down-regulation of IRP1 gene expression. PMID:16886906

  8. metagene Profiles Analyses Reveal Regulatory Element's Factor-Specific Recruitment Patterns.

    PubMed

    Joly Beauparlant, Charles; Lamaze, Fabien C; Deschênes, Astrid; Samb, Rawane; Lemaçon, Audrey; Belleau, Pascal; Bilodeau, Steve; Droit, Arnaud

    2016-08-01

    ChIP-Sequencing (ChIP-Seq) provides a vast amount of information regarding the localization of proteins across the genome. The aggregation of ChIP-Seq enrichment signal in a metagene plot is an approach commonly used to summarize data complexity and to obtain a high level visual representation of the general occupancy pattern of a protein. Here we present the R package metagene, the graphical interface Imetagene and the companion package similaRpeak. Together, they provide a framework to integrate, summarize and compare the ChIP-Seq enrichment signal from complex experimental designs. Those packages identify and quantify similarities or dissimilarities in patterns between large numbers of ChIP-Seq profiles. We used metagene to investigate the differential occupancy of regulatory factors at noncoding regulatory regions (promoters and enhancers) in relation to transcriptional activity in GM12878 B-lymphocytes. The relationships between occupancy patterns and transcriptional activity suggest two different mechanisms of action for transcriptional control: i) a "gradient effect" where the regulatory factor occupancy levels follow transcription and ii) a "threshold effect" where the regulatory factor occupancy levels max out prior to reaching maximal transcription. metagene, Imetagene and similaRpeak are implemented in R under the Artistic license 2.0 and are available on Bioconductor. PMID:27538250

  9. metagene Profiles Analyses Reveal Regulatory Element’s Factor-Specific Recruitment Patterns

    PubMed Central

    Samb, Rawane; Lemaçon, Audrey; Bilodeau, Steve; Droit, Arnaud

    2016-01-01

    ChIP-Sequencing (ChIP-Seq) provides a vast amount of information regarding the localization of proteins across the genome. The aggregation of ChIP-Seq enrichment signal in a metagene plot is an approach commonly used to summarize data complexity and to obtain a high level visual representation of the general occupancy pattern of a protein. Here we present the R package metagene, the graphical interface Imetagene and the companion package similaRpeak. Together, they provide a framework to integrate, summarize and compare the ChIP-Seq enrichment signal from complex experimental designs. Those packages identify and quantify similarities or dissimilarities in patterns between large numbers of ChIP-Seq profiles. We used metagene to investigate the differential occupancy of regulatory factors at noncoding regulatory regions (promoters and enhancers) in relation to transcriptional activity in GM12878 B-lymphocytes. The relationships between occupancy patterns and transcriptional activity suggest two different mechanisms of action for transcriptional control: i) a “gradient effect” where the regulatory factor occupancy levels follow transcription and ii) a “threshold effect” where the regulatory factor occupancy levels max out prior to reaching maximal transcription. metagene, Imetagene and similaRpeak are implemented in R under the Artistic license 2.0 and are available on Bioconductor. PMID:27538250

  10. Sterol regulatory element-binding proteins are regulators of the NIS gene in thyroid cells.

    PubMed

    Ringseis, Robert; Rauer, Christine; Rothe, Susanne; Gessner, Denise K; Schütz, Lisa-Marie; Luci, Sebastian; Wen, Gaiping; Eder, Klaus

    2013-05-01

    The uptake of iodide into the thyroid, an essential step in thyroid hormone synthesis, is an active process mediated by the sodium-iodide symporter (NIS). Despite its strong dependence on TSH, the master regulator of the thyroid, the NIS gene was also reported to be regulated by non-TSH signaling pathways. In the present study we provide evidence that the rat NIS gene is subject to regulation by sterol regulatory element-binding proteins (SREBPs), which were initially identified as master transcriptional regulators of lipid biosynthesis and uptake. Studies in FRTL-5 thyrocytes revealed that TSH stimulates expression and maturation of SREBPs and expression of classical SREBP target genes involved in lipid biosynthesis and uptake. Almost identical effects were observed when the cAMP agonist forskolin was used instead of TSH. In TSH receptor-deficient mice, in which TSH/cAMP-dependent gene regulation is blocked, the expression of SREBP isoforms in the thyroid was markedly reduced when compared with wild-type mice. Sterol-mediated inhibition of SREBP maturation and/or RNA interference-mediated knockdown of SREBPs reduced expression of NIS and NIS-specific iodide uptake in FRTL-5 cells. Conversely, overexpression of active SREBPs caused a strong activation of the 5'-flanking region of the rat NIS gene mediated by binding to a functional SREBP binding site located in the 5'-untranslated region of the rat NIS gene. These findings show that TSH acts as a regulator of SREBP expression and maturation in thyroid epithelial cells and that SREBPs are novel transcriptional regulators of NIS. PMID:23542164

  11. Prediction of Regulatory Interactions from Genome Sequences Using a Biophysical Model for the Arabidopsis LEAFY Transcription Factor[C][W

    PubMed Central

    Moyroud, Edwige; Minguet, Eugenio Gómez; Ott, Felix; Yant, Levi; Posé, David; Monniaux, Marie; Blanchet, Sandrine; Bastien, Olivier; Thévenon, Emmanuel; Weigel, Detlef; Schmid, Markus; Parcy, François

    2011-01-01

    Despite great advances in sequencing technologies, generating functional information for nonmodel organisms remains a challenge. One solution lies in an improved ability to predict genetic circuits based on primary DNA sequence in combination with detailed knowledge of regulatory proteins that have been characterized in model species. Here, we focus on the LEAFY (LFY) transcription factor, a conserved master regulator of floral development. Starting with biochemical and structural information, we built a biophysical model describing LFY DNA binding specificity in vitro that accurately predicts in vivo LFY binding sites in the Arabidopsis thaliana genome. Applying the model to other plant species, we could follow the evolution of the regulatory relationship between LFY and the AGAMOUS (AG) subfamily of MADS box genes and show that this link predates the divergence between monocots and eudicots. Remarkably, our model succeeds in detecting the connection between LFY and AG homologs despite extensive variation in binding sites. This demonstrates that the cis-element fluidity recently observed in animals also exists in plants, but the challenges it poses can be overcome with predictions grounded in a biophysical model. Therefore, our work opens new avenues to deduce the structure of regulatory networks from mere inspection of genomic sequences. PMID:21515819

  12. Interferon regulatory factor 5 genetic variants are associated with cardiovascular disease in patients with rheumatoid arthritis

    PubMed Central

    2014-01-01

    Introduction Rheumatoid arthritis (RA) is a complex polygenic inflammatory disease associated with accelerated atherosclerosis and increased cardiovascular (CV) disease risk. Interferon regulatory factor 5 (IRF5) is a regulator of type I interferon induction. Recently, researchers have described an association between multiple single-nucleotide polymorphisms of the IRF5 gene and some rheumatic disorders. In this study, we aimed to evaluate whether three different haplotype blocks within the IRF5 locus which have been shown to alter the protein function are involved in the risk of CV events occurring in Spanish RA patients. Methods Three IRF5 polymorphisms (rs2004640, rs2070197 and rs10954213) representative of each haplotype group were genotyped by performing TaqMan assays using a 7900HT Fast Real-Time PCR System with tissue from a total of 2,137 Spanish patients diagnosed with RA. Among them, 390 (18.2%) had experienced CV events. The relationship of IRF5 genotypes and haplotypes to CV events was tested using Cox regression. Results Male sex, age at RA diagnosis and most traditional risk factors (hypertension, dyslipidemia and smoking habit) were associated with increased risk for CV events in the RA population. Interestingly, a protective effect of both IRF5 rs2004640 GG and IRF5 rs10954213 GG genotypes against the risk for CV events after adjusting the results for sex, age at RA diagnosis and traditional CV disease risk factors was observed (hazard ratio (HR) = 0.6, 95% confidence interval (CI) = 0.38 to 0.92, P = 0.02; and HR = 0.58, 95% CI = 0.36 to 0.95, P = 0.03, respectively). Moreover, we detected a protective effect of the GTG haplotype against the risk for CV events after adjusting the results for potential confounding factors (HR = 0.72, 95% CI = 0.56 to 0.93, P = 0.012). Conclusions Our results reveal that IRF5 gene variants are associated with risk of CV events in patients with RA. PMID:25011482

  13. Regulatory role of the 90-kDa-heat-shock protein (Hsp90) and associated factors on gene expression.

    PubMed

    Erlejman, Alejandra G; Lagadari, Mariana; Toneatto, Judith; Piwien-Pilipuk, Graciela; Galigniana, Mario D

    2014-02-01

    The term molecular chaperone was first used to describe the ability of nucleoplasmin to prevent the aggregation of histones with DNA during the assembly of nucleosomes. Subsequently, the name was extended to proteins that mediate the post-translational assembly of oligomeric complexes protecting them from denaturation and/or aggregation. Hsp90 is a 90-kDa molecular chaperone that represents the major soluble protein of the cell. In contrast to most conventional chaperones, Hsp90 functions as a refined sensor of protein function and its principal role in the cell is to facilitate biological activity to properly folded client proteins that already have a preserved tertiary structure. Consequently, Hsp90 is related to basic cell functions such as cytoplasmic transport of soluble proteins, translocation of client proteins to organelles, and regulation of the biological activity of key signaling factors such as protein kinases, ubiquitin ligases, steroid receptors, cell cycle regulators, and transcription factors. A growing amount of evidence links the protective action of this molecular chaperone to mechanisms related to posttranslational modifications of soluble nuclear factors as well as histones. In this article, we discuss some aspects of the regulatory action of Hsp90 on transcriptional regulation and how this effect could have impacted genetic assimilation mechanism in some organisms. PMID:24389346

  14. Transcription factors GAF and HSF act at distinct regulatory steps to modulate stress-induced gene activation

    PubMed Central

    Fuda, Nicholas J.; Mahat, Dig B.; Core, Leighton J.; Guertin, Michael J.

    2016-01-01

    The coordinated regulation of gene expression at the transcriptional level is fundamental to development and homeostasis. Inducible systems are invaluable when studying transcription because the regulatory process can be triggered instantaneously, allowing the tracking of ordered mechanistic events. Here, we use precision run-on sequencing (PRO-seq) to examine the genome-wide heat shock (HS) response in Drosophila and the function of two key transcription factors on the immediate transcription activation or repression of all genes regulated by HS. We identify the primary HS response genes and the rate-limiting steps in the transcription cycle that GAGA-associated factor (GAF) and HS factor (HSF) regulate. We demonstrate that GAF acts upstream of promoter-proximally paused RNA polymerase II (Pol II) formation (likely at the step of chromatin opening) and that GAF-facilitated Pol II pausing is critical for HS activation. In contrast, HSF is dispensable for establishing or maintaining Pol II pausing but is critical for the release of paused Pol II into the gene body at a subset of highly activated genes. Additionally, HSF has no detectable role in the rapid HS repression of thousands of genes. PMID:27492368

  15. Dynamic regulation of Gata factor levels is more important than their identity.

    PubMed

    Ferreira, Rita; Wai, Albert; Shimizu, Ritsuko; Gillemans, Nynke; Rottier, Robbert; von Lindern, Marieke; Ohneda, Kinuko; Grosveld, Frank; Yamamoto, Masayuki; Philipsen, Sjaak

    2007-06-15

    Three Gata transcription factors (Gata1, -2, and -3) are essential for hematopoiesis. These factors are thought to play distinct roles because they do not functionally replace each other. For instance, Gata2 messenger RNA (mRNA) expression is highly elevated in Gata1-null erythroid cells, yet this does not rescue the defect. Here, we test whether Gata2 and -3 transgenes rescue the erythroid defect of Gata1-null mice, if expressed in the appropriate spatiotemporal pattern. Gata1, -2, and -3 transgenes driven by beta-globin regulatory elements, directing expression to late stages of differentiation, fail to rescue erythropoiesis in Gata1-null mutants. In contrast, when controlled by Gata1 regulatory elements, directing expression to the early stages of differentiation, Gata1, -2, and -3 do rescue the Gata1-null phenotype. The dramatic increase of endogenous Gata2 mRNA in Gata1-null progenitors is not reflected in Gata2 protein levels, invoking translational regulation. Our data show that the dynamic spatiotemporal regulation of Gata factor levels is more important than their identity and provide a paradigm for developmental control mechanisms that are hard-wired in cis-regulatory elements. PMID:17327407

  16. Up-regulation of miR-98 and unraveling regulatory mechanisms in gestational diabetes mellitus.

    PubMed

    Cao, Jing-Li; Zhang, Lu; Li, Jian; Tian, Shi; Lv, Xiao-Dan; Wang, Xue-Qin; Su, Xing; Li, Ying; Hu, Yi; Ma, Xu; Xia, Hong-Fei

    2016-01-01

    MiR-98 expression was up-regulated in kidney in response to early diabetic nephropathy in mouse and down-regulated in muscle in type 2 diabetes in human. However, the expression prolife and functional role of miR-98 in human gestational diabetes mellitus (GDM) remained unclear. Here, we investigated its expression and function in placental tissues from GDM patients and the possible molecular mechanisms. The results showed that miR-98 was up-regulated in placentas from GDM patients compared with normal placentas. MiR-98 over-expression increased global DNA methylational level and miR-98 knockdown reduced global DNA methylational level. Further investigation revealed that miR-98 could inhibit Mecp2 expression by binding the 3'-untranslated region (UTR) of methyl CpG binding protein 2 (Mecp2), and then led to the expression dysregulation of canonical transient receptor potential 3 (Trpc3), a glucose uptake related gene. More importantly, in vivo analysis found that the expression level of Mecp2 and Trpc3 in placental tissues from GDM patients, relative to the increase of miR-98, was diminished, especially for GDM patients over the age of 35 years. Collectively, up-regulation of miR-98 in the placental tissues of human GDM is linked to the global DNA methylation via targeting Mecp2, which may imply a novel regulatory mechanism in GDM. PMID:27573367

  17. Up-regulation of miR-98 and unraveling regulatory mechanisms in gestational diabetes mellitus

    PubMed Central

    Cao, Jing-Li; Zhang, Lu; Li, Jian; Tian, Shi; Lv, Xiao-Dan; Wang, Xue-Qin; Su, Xing; Li, Ying; Hu, Yi; Ma, Xu; Xia, Hong-Fei

    2016-01-01

    MiR-98 expression was up-regulated in kidney in response to early diabetic nephropathy in mouse and down-regulated in muscle in type 2 diabetes in human. However, the expression prolife and functional role of miR-98 in human gestational diabetes mellitus (GDM) remained unclear. Here, we investigated its expression and function in placental tissues from GDM patients and the possible molecular mechanisms. The results showed that miR-98 was up-regulated in placentas from GDM patients compared with normal placentas. MiR-98 over-expression increased global DNA methylational level and miR-98 knockdown reduced global DNA methylational level. Further investigation revealed that miR-98 could inhibit Mecp2 expression by binding the 3′-untranslated region (UTR) of methyl CpG binding protein 2 (Mecp2), and then led to the expression dysregulation of canonical transient receptor potential 3 (Trpc3), a glucose uptake related gene. More importantly, in vivo analysis found that the expression level of Mecp2 and Trpc3 in placental tissues from GDM patients, relative to the increase of miR-98, was diminished, especially for GDM patients over the age of 35 years. Collectively, up-regulation of miR-98 in the placental tissues of human GDM is linked to the global DNA methylation via targeting Mecp2, which may imply a novel regulatory mechanism in GDM. PMID:27573367

  18. Homologous pairs of regulatory proteins control activity of Bacillus subtilis transcription factor sigma(b) in response to environmental stress.

    PubMed Central

    Kang, C M; Brody, M S; Akbar, S; Yang, X; Price, C W

    1996-01-01

    In Bacillus subtilis, activity of the general stress transcription factor sigma B is controlled posttranslationally by a regulatory network that transmits signals of environmental and metabolic stress. These signals include heat, ethanol, or osmotic challenge, or a sharp decrease in cellular energy levels, and all ultimately control sigma B activity by influencing the binding decision of the RsbW anti-sigma factor. In the absence of stress, RsbW binds to sigma B and prevents its association with RNA polymerase core enzyme. However, following stress, RsbW binds instead to the RsbV anti-anti-sigma factor, thereby releasing sigma B to direct transcription of its target genes. These two principal regulators of sigmaB activity are encoded in the eight-gene sigB operon, which has the gene order rsbR-rsbS-rsbT-rsbU-rsbV-rsbW-sig B-rsbX (where rsb stands for regulator of sigma B). Notably, the predicted rsbS product has significant amino acid identity to the RsbV anti-anti-sigma factor and the predicted rsbT product resembles the RsbW anti-sigma factor. To determine the roles of rsbS and rsbT, null or missense mutations were constructed in the chromosomal copies or each and tested for their effects on expression of a sigma B-dependent reporter fusion. On the basis of this genetic analysis, our principal conclusions are that (i) the rsbS product is a negative regulator of or" activity, (ii) the rsbT product is a positive regulator, (iii) RsbS requires RsbT for function, and (iv) the RsbS-RsbT and RsbV-RsbW pairs act hierarchically by a common mechanism in which key protein-protein interactions are controlled by phosphorylation events. PMID:8682789

  19. Regulated tissue-specific alternative splicing of enhanced green fluorescent protein transgenes conferred by alpha-tropomyosin regulatory elements in transgenic mice.

    PubMed

    Ellis, Peter D; Smith, Christopher W J; Kemp, Paul

    2004-08-27

    The mutually exclusive exons 2 and 3 of alpha-tropomyosin (alphaTM) have been used as a model system for strictly regulated alternative splicing. Exon 2 inclusion is only observed at high levels in smooth muscle (SM) tissues, whereas striated muscle and non-muscle cells use predominantly exon 3. Experiments in cell culture have shown that exon 2 selection results from repression of exon 3 and that this repression is mediated by regulatory elements flanking exon 3. We have now tested the cell culture-derived model in transgenic mice. We show that by harnessing the intronic splicing regulatory elements, expression of an enhanced green fluorescent protein transgene with a constitutively active promoter can be restricted to SM cells. Splicing of both endogenous alphaTM and a series of transgenes carrying regulatory element mutations was analyzed by reverse transcriptasePCR. These studies indicated that although SM-rich tissues are equipped to regulate splicing of high levels of endogenous or transgene alphaTM RNA, other non-SM tissues such as spleen, which express lower amounts of alphaTM, also splice significant proportions of exon 2, and this splicing pattern can be recapitulated by transgenes expressed at low levels. We confirm the importance in vivo of the negatively acting regulatory elements for regulated skipping of exon 3. Moreover, we provide evidence that some of the regulatory factors responsible for exon 3 skipping appear to be titratable, with loss of regulated splicing sometimes being associated with high transgene expression levels. PMID:15194683

  20. Regulation of scallop myosin by the regulatory light chain depends on a single glycine residue.

    PubMed Central

    Jancso, A; Szent-Györgyi, A G

    1994-01-01

    Specific Ca2+ binding and Ca2+ activation of ATPase activity in scallop myosin require a regulatory light chain (RLC) from regulated (molluscan or vertebrate smooth) myosin; hybrids containing vertebrate skeletal RLCs do not bind Ca2+ and their ATPase activity is inhibited. Chimeras between scallop and chicken skeletal RLCs restore Ca2+ sensitivity to RLC-free myosin provided that residues 81-117 are derived from scallop. Six mutants (R90M, A94K, D98P, N105K, M116Q, and G117C) were generated by replacing amino acids of the scallop RLC with the corresponding skeletal RLC residues in positions conserved in either regulated or nonregulated myosins. Ca2+ binding was abolished by a G117C and a G117A mutation; however, these mutants have a decreased affinity for the heavy chain. None of the other mutations affected RLC function. Replacement of the respective cysteine with glycine in the skeletal RLC has markedly changed the regulatory properties of the molecule. The single cysteine to glycine mutation conferred to this light chain the ability to restore Ca2+ binding and regulated ATPase activity, although Ca2+ activation of the actin-activated ATPase was lower than with scallop RLC. The presence of amino acids other than glycine at this position in vertebrate skeletal myosin RLCs may explain why these are not fully functional in the scallop system. The results are in agreement with x-ray crystallography data showing the central role of G117 in stabilizing the Ca(2+)-binding site of scallop myosin. Images PMID:8090720

  1. A Positive Regulatory Loop between a Wnt-Regulated Non-coding RNA and ASCL2 Controls Intestinal Stem Cell Fate.

    PubMed

    Giakountis, Antonis; Moulos, Panagiotis; Zarkou, Vasiliki; Oikonomou, Christina; Harokopos, Vaggelis; Hatzigeorgiou, Artemis G; Reczko, Martin; Hatzis, Pantelis

    2016-06-21

    The canonical Wnt pathway plays a central role in stem cell maintenance, differentiation, and proliferation in the intestinal epithelium. Constitutive, aberrant activity of the TCF4/β-catenin transcriptional complex is the primary transforming factor in colorectal cancer. We identify a nuclear long non-coding RNA, termed WiNTRLINC1, as a direct target of TCF4/β-catenin in colorectal cancer cells. WiNTRLINC1 positively regulates the expression of its genomic neighbor ASCL2, a transcription factor that controls intestinal stem cell fate. WiNTRLINC1 interacts with TCF4/β-catenin to mediate the juxtaposition of its promoter with the regulatory regions of ASCL2. ASCL2, in turn, regulates WiNTRLINC1 transcriptionally, closing a feedforward regulatory loop that controls stem cell-related gene expression. This regulatory circuitry is highly amplified in colorectal cancer and correlates with increased metastatic potential and decreased patient survival. Our results uncover the interplay between non-coding RNA-mediated regulation and Wnt signaling and point to the diagnostic and therapeutic potential of WiNTRLINC1. PMID:27292638

  2. Protecting the public or setting the bar too high? Understanding the causes and consequences of regulatory actions of front-line regulators and specialized drug shop operators in Kenya

    PubMed Central

    Wafula, Francis; Molyneux, Catherine; Mackintosh, Maureen; Goodman, Catherine

    2013-01-01

    The problem of poor regulatory compliance has been widely reported across private health providers in developing countries. Less known are the underlying reasons for poor compliance, especially with regards to the roles played by front-line regulatory staff, and the regulatory institution as a whole. We designed a qualitative study to address this gap, with the study questions and tools drawing on a conceptual framework informed by theoretical literature on regulation. Data were collected from specialized drug shops (SDSs) in two rural districts in Western Kenya in 2011 through eight focus group discussions, and from regulatory staff from organizations governing the pharmaceutical sector through a total of 24 in-depth interviews. We found that relationships between front-line regulators and SDS operators were a strong influence on regulatory behaviour, often resulting in non-compliance and perverse outcomes such as corruption. It emerged that separate regulatory streams operated in urban and rural locations, based mainly on differing relationships between the front-line regulators and SDS operators, and on broader factors such as the competition environment and community expectations. Effective incentive structures for regulatory staff were either absent, or poorly linked to performance in regulatory organizations, resulting in divergences between the purposes of the regulatory organization and activities of front-line staff. Given the rural-urban differences in the practice environment, the introduction of lower retail practice requirements for rural SDSs could be considered. This would allow illegally operated shops to be brought within the regulatory framework, facilitating good quality provision of essential commodities to marginalized areas, without lowering the practice requirements for the better complying urban SDSs. In addition, regulatory organizations need to devise incentives that better link the level of effort to rewards such as professional

  3. Protecting the public or setting the bar too high? Understanding the causes and consequences of regulatory actions of front-line regulators and specialized drug shop operators in Kenya.

    PubMed

    Wafula, Francis; Molyneux, Catherine; Mackintosh, Maureen; Goodman, Catherine

    2013-11-01

    The problem of poor regulatory compliance has been widely reported across private health providers in developing countries. Less known are the underlying reasons for poor compliance, especially with regards to the roles played by front-line regulatory staff, and the regulatory institution as a whole. We designed a qualitative study to address this gap, with the study questions and tools drawing on a conceptual framework informed by theoretical literature on regulation. Data were collected from specialized drug shops (SDSs) in two rural districts in Western Kenya in 2011 through eight focus group discussions, and from regulatory staff from organizations governing the pharmaceutical sector through a total of 24 in-depth interviews. We found that relationships between front-line regulators and SDS operators were a strong influence on regulatory behaviour, often resulting in non-compliance and perverse outcomes such as corruption. It emerged that separate regulatory streams operated in urban and rural locations, based mainly on differing relationships between the front-line regulators and SDS operators, and on broader factors such as the competition environment and community expectations. Effective incentive structures for regulatory staff were either absent, or poorly linked to performance in regulatory organizations, resulting in divergences between the purposes of the regulatory organization and activities of front-line staff. Given the rural-urban differences in the practice environment, the introduction of lower retail practice requirements for rural SDSs could be considered. This would allow illegally operated shops to be brought within the regulatory framework, facilitating good quality provision of essential commodities to marginalized areas, without lowering the practice requirements for the better complying urban SDSs. In addition, regulatory organizations need to devise incentives that better link the level of effort to rewards such as professional

  4. Structure of the regulatory domain of the LysR family regulator NMB2055 (MetR-like protein) from Neisseria meningitidis

    PubMed Central

    Sainsbury, Sarah; Ren, Jingshan; Saunders, Nigel J.; Stuart, David I.; Owens, Raymond J.

    2012-01-01

    The crystal structure of the regulatory domain of NMB2055, a putative MetR regulator from Neisseria meningitidis, is reported at 2.5 Å resolution. The structure revealed that there is a disulfide bond inside the predicted effector-binding pocket of the regulatory domain. Mutation of the cysteines (Cys103 and Cys106) that form the disulfide bond to serines resulted in significant changes to the structure of the effector pocket. Taken together with the high degree of conservation of these cysteine residues within MetR-related transcription factors, it is suggested that the Cys103 and Cys106 residues play an important role in the function of MetR regulators. PMID:22750853

  5. Activation of Sterol Regulatory Element Binding Factors by Fenofibrate and Gemfibrozil Stimulates Myelination in Zebrafish

    PubMed Central

    Ashikawa, Yoshifumi; Nishimura, Yuhei; Okabe, Shiko; Sasagawa, Shota; Murakami, Soichiro; Yuge, Mizuki; Kawaguchi, Koki; Kawase, Reiko; Tanaka, Toshio

    2016-01-01

    Oligodendrocytes are major myelin-producing cells and play essential roles in the function of a healthy nervous system. However, they are also one of the most vulnerable neural cell types in the central nervous system (CNS), and myelin abnormalities in the CNS are found in a wide variety of neurological disorders, including multiple sclerosis, adrenoleukodystrophy, and schizophrenia. There is an urgent need to identify small molecular weight compounds that can stimulate myelination. In this study, we performed comparative transcriptome analysis to identify pharmacodynamic effects common to miconazole and clobetasol, which have been shown to stimulate myelination by mouse oligodendrocyte progenitor cells (OPCs). Of the genes differentially expressed in both miconazole- and clobetasol-treated mouse OPCs compared with untreated cells, we identified differentially expressed genes (DEGs) common to both drug treatments. Gene ontology analysis revealed that these DEGs are significantly associated with the sterol biosynthetic pathway, and further bioinformatics analysis suggested that sterol regulatory element binding factors (SREBFs) might be key upstream regulators of the DEGs. In silico screening of a public database for chemicals associated with SREBF activation identified fenofibrate, a peroxisome proliferator-activated receptor α (PPARα) agonist, as a drug that increases the expression of known SREBF targets, raising the possibility that fenofibrate may also stimulate myelination. To test this, we performed in vivo imaging of zebrafish expressing a fluorescent reporter protein under the control of the myelin basic protein (mbp) promoter. Treatment of zebrafish with fenofibrate significantly increased expression of the fluorescent reporter compared with untreated zebrafish. This increase was attenuated by co-treatment with fatostatin, a specific inhibitor of SREBFs, confirming that the fenofibrate effect was mediated via SREBFs. Furthermore, incubation of zebrafish

  6. Regulatory mechanisms underlying sepsis progression in patients with tumor necrosis factor-α genetic variations

    PubMed Central

    LIU, YANGZHOU; HAN, NING; LI, QINCHUAN; LI, ZENGCHUN

    2016-01-01

    The present study aimed to investigate the regulatory mechanisms underlying sepsis progression in patients with tumor necrosis factor (TNF)-α genetic variations. The GSE5760 expression profile data, which was downloaded from the Gene Expression Omnibus database, contained 30 wild-type (WT) and 28 mutation (MUT) samples. Differentially expressed genes (DEGs) between the two types of samples were identified using the Student's t-test, and the corresponding microRNAs (miRNAs) were screened using WebGestalt software. An integrated miRNA-DEG network was constructed using the Cytoscape software, based on the interactions between the DEGs, as identified using the Search Tool for the Retrieval of Interacting Genes/Proteins database, and the correlation between miRNAs and their target genes. Furthermore, Gene Ontology and pathway enrichment analyses were conducted for the DEGs using the Database for Annotation, Visualization and Integrated Discovery and the KEGG Orthology Based Annotation System, respectively. A total of 390 DEGS between the WT and MUT samples, along with 11 -associated miRNAs, were identified. The integrated miRNA-DEG network consisted of 38 DEGs and 11 miRNAs. Within this network, COPS2 was found to be associated with transcriptional functions, while FUS was found to be involved in mRNA metabolic processes. Other DEGs, including FBXW7 and CUL3, were enriched in the ubiquitin-mediated proteolysis pathway. In addition, miR-15 was predicted to target COPS2 and CUL3. The results of the present study suggested that COPS2, FUS, FBXW7 and CUL3 may be associated with sepsis in patients with TNF-α genetic variations. In the progression of sepsis, FBXW7 and CUL3 may participate in the ubiquitin-mediated proteolysis pathway, whereas COPS2 may regulate the phosphorylation and ubiquitination of the FUS protein. Furthermore, COPS2 and CUL3 may be novel targets of miR-15. PMID:27347057

  7. IRF-7, a new interferon regulatory factor associated with Epstein-Barr virus latency.

    PubMed Central

    Zhang, L; Pagano, J S

    1997-01-01

    The Epstein-Barr virus (EBV) BamHI Q promoter (Qp) is the only promoter used for the transcription of Epstein-Barr virus nuclear antigen 1 (EBNA-1) mRNA in cells in the most restricted (type I) latent infection state. However, Qp is inactive in type III latency. With the use of the yeast one-hybrid system, a new cellular gene has been identified that encodes proteins which bind to sequence in Qp. The deduced amino acid sequence of the gene has significant homology to the interferon regulatory factors (IRFs). This new gene and products including two splicing variants are designated IRF-7A, IRF-7B, and IRF-7C. The expression of IRF-7 is predominantly in spleen, thymus, and peripheral blood leukocytes (PBL). IRF-7 proteins were identified in primary PBL with specific antiserum against IRF-7B protein. IRF-7s can bind to interferon-stimulated response element (ISRE) sequence and repress transcriptional activation by both interferon and IRF-1. Additionally, a functional viral ISRE sequence, 5'-GCGAAAACGAAAGT-3', has been identified in Qp. Finally, the expression of IRF-7 is consistently high in type III latency cells and almost undetectable in type I latency, corresponding to the activity of endogenous Qp in these latency states and the ability of the IRF-7 proteins to repress Qp-reporter constructs. The identification of a functional viral ISRE and association of IRF-7 with type III latency may be relevant to the mechanism of regulation of Qp. PMID:9315633

  8. Glucitol induction in Bacillus subtilis is mediated by a regulatory factor, GutR.

    PubMed Central

    Ye, R; Rehemtulla, S N; Wong, S L

    1994-01-01

    Expression of the glucitol dehydrogenase gene (gutB) is suggested to be regulated both positively and negatively in Bacillus subtilis. A mutation in the gutR locus results in the constitutive expression of gutB. The exact nature of this mutation and the function of gutR are still unknown. Cloning and characterization of gutR indicated that this gene is located immediately upstream of gutB and is transcribed in the opposite direction relative to gutB. GutR is suggested to be a 95-kDa protein with a putative helix-turn-helix motif and a nucleotide binding domain at the N-terminal region. At the C-terminal region, a short sequence of GutR shows homology with two proteins, Cyc8 (glucose repression mediator protein) and GsiA (glucose starvation-inducible protein), known to be directly or indirectly involved in catabolite repression. Part of the C-terminal conserved sequence from these proteins shows all the features observed in the tetratricopeptide motif found in many eucaryotic proteins. To study the functional role of gutR, chromosomal gutR was insertionally inactivated. A total loss of glucitol inducibility was observed. Reintroduction of a functional gutR to the GutR-deficient strain through integration at the amyE locus restores the inducibility. Therefore, GutR serves as a regulatory factor to modulate glucitol induction. The nature of the gutR1 mutation was also determined. A single amino acid change (serine-289 to arginine-289) near the putative nucleotide binding motif B in GutR is responsible for the observed phenotype. Possible models for the action of GutR are discussed. Images PMID:8195087

  9. Identification of the transcription factor ZEB1 as a central component of the adipogenic gene regulatory network

    PubMed Central

    Gubelmann, Carine; Schwalie, Petra C; Raghav, Sunil K; Röder, Eva; Delessa, Tenagne; Kiehlmann, Elke; Waszak, Sebastian M; Corsinotti, Andrea; Udin, Gilles; Holcombe, Wiebke; Rudofsky, Gottfried; Trono, Didier; Wolfrum, Christian; Deplancke, Bart

    2014-01-01

    Adipose tissue is a key determinant of whole body metabolism and energy homeostasis. Unraveling the regulatory mechanisms underlying adipogenesis is therefore highly relevant from a biomedical perspective. Our current understanding of fat cell differentiation is centered on the transcriptional cascades driven by the C/EBP protein family and the master regulator PPARγ. To elucidate further components of the adipogenic gene regulatory network, we performed a large-scale transcription factor (TF) screen overexpressing 734 TFs in mouse pre-adipocytes and probed their effect on differentiation. We identified 22 novel pro-adipogenic TFs and characterized the top ranking TF, ZEB1, as being essential for adipogenesis both in vitro and in vivo. Moreover, its expression levels correlate with fat cell differentiation potential in humans. Genomic profiling further revealed that this TF directly targets and controls the expression of most early and late adipogenic regulators, identifying ZEB1 as a central transcriptional component of fat cell differentiation. DOI: http://dx.doi.org/10.7554/eLife.03346.001 PMID:25163748

  10. Establishing a framework for the Ad/abaxial regulatory network of Arabidopsis: ascertaining targets of class III homeodomain leucine zipper and KANADI regulation.

    PubMed

    Reinhart, Brenda J; Liu, Tie; Newell, Nicole R; Magnani, Enrico; Huang, Tengbo; Kerstetter, Randall; Michaels, Scott; Barton, M Kathryn

    2013-09-01

    The broadly conserved Class III homeodomain leucine zipper (HD-ZIPIII) and KANADI transcription factors have opposing and transformational effects on polarity and growth in all tissues and stages of the plant's life. To obtain a comprehensive understanding of how these factors work, we have identified transcripts that change in response to induced HD-ZIPIII or KANADI function. Additional criteria used to identify high-confidence targets among this set were presence of an adjacent HD-ZIPIII binding site, expression enriched within a subdomain of the shoot apical meristem, mutant phenotype showing defect in polar leaf and/or meristem development, physical interaction between target gene product and HD-ZIPIII protein, opposite regulation by HD-ZIPIII and KANADI, and evolutionary conservation of the regulator-target relationship. We find that HD-ZIPIII and KANADI regulate tissue-specific transcription factors involved in subsidiary developmental decisions, nearly all major hormone pathways, and new actors (such as indeterminate domain4) in the ad/abaxial regulatory network. Multiple feedback loops regulating HD-ZIPIII and KANADI are identified, as are mechanisms through which HD-ZIPIII and KANADI oppose each other. This work lays the foundation needed to understand the components, structure, and workings of the ad/abaxial regulatory network directing basic plant growth and development. PMID:24076978

  11. GTP cyclohydrolase I feedback regulatory protein is expressed in serotonin neurons and regulates tetrahydrobiopterin biosynthesis.

    PubMed

    Kapatos, G; Hirayama, K; Shimoji, M; Milstien, S

    1999-02-01

    Tetrahydrobiopterin, the coenzyme required for hydroxylation of phenylalanine, tyrosine, and tryptophan, regulates its own synthesis through feedback inhibition of GTP cyclohydrolase I (GTPCH) mediated by a regulatory subunit, the GTP cyclohydrolase feedback regulatory protein (GFRP). In the liver, L-phenylalanine specifically stimulates tetrahydrobiopterin synthesis by displacing tetrahydrobiopterin from the GTPCH-GFRP complex. To explore the role of this regulatory system in rat brain, we examined the localization of GFRP mRNA using double-label in situ hybridization. GFRP mRNA expression was abundant in serotonin neurons of the dorsal raphe nucleus but was undetectable in dopamine neurons of the midbrain or norepinephrine neurons of the locus coeruleus. Simultaneous nuclease protection assays for GFRP and GTPCH mRNAs showed that GFRP mRNA is most abundant within the brainstem and that the ratio of GFRP to GTPCH mRNA is much higher than in the ventral midbrain. Two species of GFRP mRNA differing by approximately 20 nucleotides in length were detected in brainstem but not in other tissues, with the longer, more abundant form being common to other brain regions. It is interesting that the pineal and adrenal glands did not contain detectable levels of GFRP mRNA, although GTPCH mRNA was abundant in both. Primary neuronal cultures were used to examine the role of GFRP-mediated regulation of GTPCH on tetrahydrobiopterin synthesis within brainstem serotonin neurons and midbrain dopamine neurons. L-Phenylalanine increased tetrahydrobiopterin levels in serotonin neurons to a maximum of twofold in a concentration-dependent manner, whereas D-phenylalanine and L-tryptophan were without effect. In contrast, tetrahydrobiopterin levels within cultured dopamine neurons were not altered by L-phenylalanine. The time course of this effect was very rapid, with a maximal response observed within 60 min. Inhibitors of tetrahydrobiopterin biosynthesis prevented the L

  12. The function and regulation of the GATA factor ELT-2 in the C. elegans endoderm.

    PubMed

    Wiesenfahrt, Tobias; Berg, Janette Y; Osborne Nishimura, Erin; Robinson, Adam G; Goszczynski, Barbara; Lieb, Jason D; McGhee, James D

    2016-02-01

    ELT-2 is the major regulator of genes involved in differentiation, maintenance and function of C. elegans intestine from the early embryo to mature adult. elt-2 responds to overexpression of the GATA transcription factors END-1 and END-3, which specify the intestine, as well as to overexpression of the two GATA factors that are normally involved in intestinal differentiation, ELT-7 and ELT-2 itself. Little is known about the molecular mechanisms underlying these interactions, how ELT-2 levels are maintained throughout development or how such systems respond to developmental perturbations. Here, we analyse elt-2 gene regulation through transgenic reporter assays, ELT-2 ChIP and characterisation of in vitro DNA-protein interactions. Our results indicate that elt-2 is controlled by three discrete regulatory regions conserved between C. elegans and C. briggsae that span >4 kb of 5' flanking sequence. These regions are superficially interchangeable but have quantitatively different enhancer properties, and their combined activities indicate inter-region synergies. Their regulatory activity is mediated by a small number of conserved TGATAA sites that are largely interchangeable and interact with different endodermal GATA factors with only modest differences in affinity. The redundant molecular mechanism that forms the elt-2 regulatory network is robust and flexible, as loss of end-3 halves ELT-2 levels in the early embryo but levels fully recover by the time of hatching. When ELT-2 is expressed under the control of end-1 regulatory elements, in addition to its own endogenous promoter, it can replace the complete set of endoderm-specific GATA factors: END-1, END-3, ELT-7 and (the probably non-functional) ELT-4. Thus, in addition to controlling gene expression during differentiation, ELT-2 is capable of specifying the entire C. elegans endoderm. PMID:26700680

  13. Angiogenic growth factor axis in autophagy regulation.

    PubMed

    Stanton, Marissa J; Dutta, Samikshan; Polavaram, Navatha Shree; Roy, Sohini; Muders, Michael H; Datta, Kaustubh

    2013-05-01

    Understanding the molecular mechanisms promoting therapy resistance is important. Previously, we reported that VEGFC can promote cancer cell survival during stress via interaction with its receptor NRP2. While examining the molecular mechanisms involved in this survival, we performed a microarray study in which we identified two genes, WDFY1 and LAMP2, which have been suggested to function in autophagy. Our subsequent studies further confirmed the regulation of autophagy by the VEGFC-NRP2 axis in cancer during starvation- and chemotherapy-induced stress. We are currently in the process of determining the mechanism(s) through which WDFY1 and LAMP2 control autophagy; however, we did observe an increase in MTOR complex 1 (MTORC1) activity after the depletion of the VEGFC-NRP2 axis. It would therefore be interesting to study whether WDFY1 and LAMP2 can influence MTORC1 activity and regulate autophagy. Taken together, our data suggest that targeting the VEGFC-NRP2 axis in combination with chemotherapy could be an effective treatment for advanced cancers. PMID:23388383

  14. Notch1 regulated autophagy controls survival and suppressor activity of activated murine T-regulatory cells

    PubMed Central

    Marcel, Nimi; Sarin, Apurva

    2016-01-01

    Cell survival is one of several processes regulated by the Notch pathway in mammalian cells. Here we report functional outcomes of non-nuclear Notch signaling to activate autophagy, a conserved cellular response to nutrient stress, regulating survival in murine natural T-regulatory cells (Tregs), an immune subset controlling tolerance and inflammation. Induction of autophagy required ligand-dependent, Notch intracellular domain (NIC) activity, which controlled mitochondrial organization and survival of activated Tregs. Consistently, NIC immune-precipitated Beclin and Atg14, constituents of the autophagy initiation complex. Further, ectopic expression of an effector of autophagy (Atg3) or recombinant NIC tagged to a nuclear export signal (NIC-NES), restored autophagy and suppressor function in Notch1-/- Tregs. Furthermore, Notch1 deficiency in the Treg lineage resulted in immune hyperactivity, implicating Notch activity in Treg homeostasis. Notch1 integration with autophagy, revealed in these experiments, holds implications for Notch regulated cell-fate decisions governing differentiation. DOI: http://dx.doi.org/10.7554/eLife.14023.001 PMID:27267497

  15. Type One Protein Phosphatase 1 and Its Regulatory Protein Inhibitor 2 Negatively Regulate ABA Signaling

    PubMed Central

    Zhao, Yang; Xie, Shaojun; Batelli, Giorgia; Wang, Bangshing; Duan, Cheng-Guo; Wang, Xingang; Xing, Lu; Lei, Mingguang; Yan, Jun; Zhu, Xiaohong; Zhu, Jian-Kang

    2016-01-01

    The phytohormone abscisic acid (ABA) regulates plant growth, development and responses to biotic and abiotic stresses. The core ABA signaling pathway consists of three major components: ABA receptor (PYR1/PYLs), type 2C Protein Phosphatase (PP2C) and SNF1-related protein kinase 2 (SnRK2). Nevertheless, the complexity of ABA signaling remains to be explored. To uncover new components of ABA signal transduction pathways, we performed a yeast two-hybrid screen for SnRK2-interacting proteins. We found that Type One Protein Phosphatase 1 (TOPP1) and its regulatory protein, At Inhibitor-2 (AtI-2), physically interact with SnRK2s and also with PYLs. TOPP1 inhibited the kinase activity of SnRK2.6, and this inhibition could be enhanced by AtI-2. Transactivation assays showed that TOPP1 and AtI-2 negatively regulated the SnRK2.2/3/6-mediated activation of the ABA responsive reporter gene RD29B, supporting a negative role of TOPP1 and AtI-2 in ABA signaling. Consistent with these findings, topp1 and ati-2 mutant plants displayed hypersensitivities to ABA and salt treatments, and transcriptome analysis of TOPP1 and AtI-2 knockout plants revealed an increased expression of multiple ABA-responsive genes in the mutants. Taken together, our results uncover TOPP1 and AtI-2 as negative regulators of ABA signaling. PMID:26943172

  16. Mitochondrial Fusion and ERK Activity Regulate Steroidogenic Acute Regulatory Protein Localization in Mitochondria

    PubMed Central

    Duarte, Alejandra; Castillo, Ana Fernanda; Podestá, Ernesto J.; Poderoso, Cecilia

    2014-01-01

    The rate-limiting step in the biosynthesis of steroid hormones, known as the transfer of cholesterol from the outer to the inner mitochondrial membrane, is facilitated by StAR, the Steroidogenic Acute Regulatory protein. We have described that mitochondrial ERK1/2 phosphorylates StAR and that mitochondrial fusion, through the up-regulation of a fusion protein Mitofusin 2, is essential during steroidogenesis. Here, we demonstrate that mitochondrial StAR together with mitochondrial active ERK and PKA are necessary for maximal steroid production. Phosphorylation of StAR by ERK is required for the maintenance of this protein in mitochondria, observed by means of over-expression of a StAR variant lacking the ERK phosphorylation residue. Mitochondrial fusion regulates StAR levels in mitochondria after hormone stimulation. In this study, Mitofusin 2 knockdown and mitochondrial fusion inhibition in MA-10 Leydig cells diminished StAR mRNA levels and concomitantly mitochondrial StAR protein. Together our results unveil the requirement of mitochondrial fusion in the regulation of the localization and mRNA abundance of StAR. We here establish the relevance of mitochondrial phosphorylation events in the correct localization of this key protein to exert its action in specialized cells. These discoveries highlight the importance of mitochondrial fusion and ERK phosphorylation in cholesterol transport by means of directing StAR to the outer mitochondrial membrane to achieve a large number of steroid molecules per unit of StAR. PMID:24945345

  17. The kinase DYRK1A reciprocally regulates the differentiation of Th17 and regulatory T cells

    PubMed Central

    Khor, Bernard; Gagnon, John D; Goel, Gautam; Roche, Marly I; Conway, Kara L; Tran, Khoa; Aldrich, Leslie N; Sundberg, Thomas B; Paterson, Alison M; Mordecai, Scott; Dombkowski, David; Schirmer, Melanie; Tan, Pauline H; Bhan, Atul K; Roychoudhuri, Rahul; Restifo, Nicholas P; O'Shea, John J; Medoff, Benjamin D; Shamji, Alykhan F; Schreiber, Stuart L; Sharpe, Arlene H; Shaw, Stanley Y; Xavier, Ramnik J

    2015-01-01

    The balance between Th17 and T regulatory (Treg) cells critically modulates immune homeostasis, with an inadequate Treg response contributing to inflammatory disease. Using an unbiased chemical biology approach, we identified a novel role for the dual specificity tyrosine-phosphorylation-regulated kinase DYRK1A in regulating this balance. Inhibition of DYRK1A enhances Treg differentiation and impairs Th17 differentiation without affecting known pathways of Treg/Th17 differentiation. Thus, DYRK1A represents a novel mechanistic node at the branch point between commitment to either Treg or Th17 lineages. Importantly, both Treg cells generated using the DYRK1A inhibitor harmine and direct administration of harmine itself potently attenuate inflammation in multiple experimental models of systemic autoimmunity and mucosal inflammation. Our results identify DYRK1A as a physiologically relevant regulator of Treg cell differentiation and suggest a broader role for other DYRK family members in immune homeostasis. These results are discussed in the context of human diseases associated with dysregulated DYRK activity. DOI: http://dx.doi.org/10.7554/eLife.05920.001 PMID:25998054

  18. Extensive cross-regulation of post-transcriptional regulatory networks in Drosophila

    PubMed Central

    Stoiber, Marcus H.; Olson, Sara; May, Gemma E.; Duff, Michael O.; Manent, Jan; Obar, Robert; Guruharsha, K.G.; Bickel, Peter J.; Artavanis-Tsakonas, Spyros; Brown, James B.; Graveley, Brenton R.; Celniker, Susan E.

    2015-01-01

    In eukaryotic cells, RNAs exist as ribonucleoprotein particles (RNPs). Despite the importance of these complexes in many biological processes, including splicing, polyadenylation, stability, transportation, localization, and translation, their compositions are largely unknown. We affinity-purified 20 distinct RNA-binding proteins (RBPs) from cultured Drosophila melanogaster cells under native conditions and identified both the RNA and protein compositions of these RNP complexes. We identified “high occupancy target” (HOT) RNAs that interact with the majority of the RBPs we surveyed. HOT RNAs encode components of the nonsense-mediated decay and splicing machinery, as well as RNA-binding and translation initiation proteins. The RNP complexes contain proteins and mRNAs involved in RNA binding and post-transcriptional regulation. Genes with the capacity to produce hundreds of mRNA isoforms, ultracomplex genes, interact extensively with heterogeneous nuclear ribonuclear proteins (hnRNPs). Our data are consistent with a model in which subsets of RNPs include mRNA and protein products from the same gene, indicating the widespread existence of auto-regulatory RNPs. From the simultaneous acquisition and integrative analysis of protein and RNA constituents of RNPs, we identify extensive cross-regulatory and hierarchical interactions in post-transcriptional control. PMID:26294687

  19. Extensive cross-regulation of post-transcriptional regulatory networks in Drosophila

    SciTech Connect

    Stoiber, Marcus H.; Olson, Sara; May, Gemma E.; Duff, Michael O.; Manent, Jan; Obar, Robert; Guruharsha, K. G.; Bickel, Peter J.; Artavanis-Tsakonas, Spyros; Brown, James B.; Graveley, Brenton R.; Celniker, Susan E.

    2015-08-20

    In eukaryotic cells, RNAs exist as ribonucleoprotein particles (RNPs). Despite the importance of these complexes in many biological processes, including splicing, polyadenylation, stability, transportation, localization, and translation, their compositions are largely unknown. We affinity-purified 20 distinct RNA-binding proteins (RBPs) from cultured Drosophila melanogaster cells under native conditions and identified both the RNA and protein compositions of these RNP complexes. We identified “high occupancy target” (HOT) RNAs that interact with the majority of the RBPs we surveyed. HOT RNAs encode components of the nonsense-mediated decay and splicing machinery, as well as RNA-binding and translation initiation proteins. The RNP complexes contain proteins and mRNAs involved in RNA binding and post-transcriptional regulation. Genes with the capacity to produce hundreds of mRNA isoforms, ultracomplex genes, interact extensively with heterogeneous nuclear ribonuclear proteins (hnRNPs). Our data are consistent with a model in which subsets of RNPs include mRNA and protein products from the same gene, indicating the widespread existence of auto-regulatory RNPs. Lastly, from the simultaneous acquisition and integrative analysis of protein and RNA constituents of RNPs, we identify extensive cross-regulatory and hierarchical interactions in post-transcriptional control.

  20. Extensive cross-regulation of post-transcriptional regulatory networks in Drosophila

    DOE PAGESBeta

    Stoiber, Marcus H.; Olson, Sara; May, Gemma E.; Duff, Michael O.; Manent, Jan; Obar, Robert; Guruharsha, K. G.; Bickel, Peter J.; Artavanis-Tsakonas, Spyros; Brown, James B.; et al

    2015-08-20

    In eukaryotic cells, RNAs exist as ribonucleoprotein particles (RNPs). Despite the importance of these complexes in many biological processes, including splicing, polyadenylation, stability, transportation, localization, and translation, their compositions are largely unknown. We affinity-purified 20 distinct RNA-binding proteins (RBPs) from cultured Drosophila melanogaster cells under native conditions and identified both the RNA and protein compositions of these RNP complexes. We identified “high occupancy target” (HOT) RNAs that interact with the majority of the RBPs we surveyed. HOT RNAs encode components of the nonsense-mediated decay and splicing machinery, as well as RNA-binding and translation initiation proteins. The RNP complexes contain proteinsmore » and mRNAs involved in RNA binding and post-transcriptional regulation. Genes with the capacity to produce hundreds of mRNA isoforms, ultracomplex genes, interact extensively with heterogeneous nuclear ribonuclear proteins (hnRNPs). Our data are consistent with a model in which subsets of RNPs include mRNA and protein products from the same gene, indicating the widespread existence of auto-regulatory RNPs. Lastly, from the simultaneous acquisition and integrative analysis of protein and RNA constituents of RNPs, we identify extensive cross-regulatory and hierarchical interactions in post-transcriptional control.« less

  1. Stable inhibitory activity of regulatory T cells requires the transcription factor Helios.

    PubMed

    Kim, Hye-Jung; Barnitz, R Anthony; Kreslavsky, Taras; Brown, Flavian D; Moffett, Howell; Lemieux, Madeleine E; Kaygusuz, Yasemin; Meissner, Torsten; Holderried, Tobias A W; Chan, Susan; Kastner, Philippe; Haining, W Nicholas; Cantor, Harvey

    2015-10-16

    The maintenance of immune homeostasis requires regulatory T cells (T(regs)). Given their intrinsic self-reactivity, T(regs) must stably maintain a suppressive phenotype to avoid autoimmunity. We report that impaired expression of the transcription factor (TF) Helios by FoxP3(+) CD4 and Qa-1-restricted CD8 T(regs) results in defective regulatory activity and autoimmunity in mice. Helios-deficient T(regs) develop an unstable phenotype during inflammatory responses characterized by reduced FoxP3 expression and increased effector cytokine expression secondary to diminished activation of the STAT5 pathway. CD8 T(regs) also require Helios-dependent STAT5 activation for survival and to prevent terminal T cell differentiation. The definition of Helios as a key transcription factor that stabilizes T(regs) in the face of inflammatory responses provides a genetic explanation for a core property of T(regs). PMID:26472910

  2. Environmental factors regulating soil organic matter chlorination

    NASA Astrophysics Data System (ADS)

    Svensson, Teresia; Montelius, Malin; Reyier, Henrik; Rietz, Karolina; Karlsson, Susanne; Lindberg, Cecilia; Andersson, Malin; Danielsson, Åsa; Bastviken, David

    2016-04-01

    Natural chlorination of organic matter is common in soils. Despite the widespread abundance of soil chlorinated soil organic matter (SOM), frequently exceeding soil chloride abundance in surface soils, and a common ability of microorganisms to produce chlorinated SOM, we lack fundamental knowledge about dominating processes and organisms responsible for the chlorination. To take one step towards resolving the terrestrial chlorine (Cl) puzzle, this study aims to analyse how environmental factors influence chlorination of SOM. Four factors were chosen for this study: soil moisture (W), nitrogen (N), chloride (Cl) and organic matter quality (C). These factors are all known to be important for soil processes. Laboratory incubations with 36Cl as a Cl tracer were performed in a two soil incubation experiments. It was found that addition of chloride and nitrogen seem to hamper the chlorination. For the C treatment, on the other hand, the results show that chlorination is enhanced by increased availability of labile organic matter (glucose and maltose). Even higher chlorination was observed when nitrogen and water were added in combination with labile organic matter. The effect that more labile organic matter strongly stimulated the chlorination rates was confirmed by the second separate experiment. These results indicate that chlorination was not primarily a way to cut refractory organic matter into digestible molecules, representing one previous hypothesis, but is related with microbial metabolism in other ways that will be further discussed in our presentation.

  3. Pervasive Variation of Transcription Factor Orthologs Contributes to Regulatory Network Evolution

    PubMed Central

    Nadimpalli, Shilpa; Persikov, Anton V.; Singh, Mona

    2015-01-01

    Differences in transcriptional regulatory networks underlie much of the phenotypic variation observed across organisms. Changes to cis-regulatory elements are widely believed to be the predominant means by which regulatory networks evolve, yet examples of regulatory network divergence due to transcription factor (TF) variation have also been observed. To systematically ascertain the extent to which TFs contribute to regulatory divergence, we analyzed the evolution of the largest class of metazoan TFs, Cys2-His2 zinc finger (C2H2-ZF) TFs, across 12 Drosophila species spanning ~45 million years of evolution. Remarkably, we uncovered that a significant fraction of all C2H2-ZF 1-to-1 orthologs in flies exhibit variations that can affect their DNA-binding specificities. In addition to loss and recruitment of C2H2-ZF domains, we found diverging DNA-contacting residues in ~44% of domains shared between D. melanogaster and the other fly species. These diverging DNA-contacting residues, found in ~70% of the D. melanogaster C2H2-ZF genes in our analysis and corresponding to ~26% of all annotated D. melanogaster TFs, show evidence of functional constraint: they tend to be conserved across phylogenetic clades and evolve slower than other diverging residues. These same variations were rarely found as polymorphisms within a population of D. melanogaster flies, indicating their rapid fixation. The predicted specificities of these dynamic domains gradually change across phylogenetic distances, suggesting stepwise evolutionary trajectories for TF divergence. Further, whereas proteins with conserved C2H2-ZF domains are enriched in developmental functions, those with varying domains exhibit no functional enrichments. Our work suggests that a subset of highly dynamic and largely unstudied TFs are a likely source of regulatory variation in Drosophila and other metazoans. PMID:25748510

  4. [Regulation factors of stomach emptying in dogs].

    PubMed

    Krejs, G J; Hegglin, J; Säuberli, H; Largiadér, F; Schmid, P; Blum, A L

    1976-03-01

    Gastric emptying of organic acids was studied in 6 healthy mongrel dogs. After chronic esophagostomies were performed according to the method of Komarov, a total of 340 test meals were instilled. Each test meal consisted of 300 ml of 6 different organic acids with decreasing molecular weight and different concentrations. After the experiments were achieved, each dog underwent a proximal gastric vagotomy according to the method of Amdrup, and experiments with citric acid were repeated. The results may be summarized as follows: multiple stepwise regression analysis of the data is consistent with a model in which gastric emptying of organic acids is regulated by 3 receptors. The receptors respond to concentration of the organic acid, the actual volume, and the type of acid. The volume receptor is located in the corpus of the stomach because the effect of volume accelerates the emptying rate after proximal gastric vagotomy while the effects of concentration and type of acid remain unchanged. PMID:1270294

  5. Puffs and gene regulation--molecular insights into the Drosophila ecdysone regulatory hierarchy.

    PubMed

    Thummel, C S

    1990-12-01

    Sixteen years ago, Michael Ashburner and his colleagues proposed a hierarchical model for the genetic control of polytene chromosome puffing by the steroid hormone ecdysone. The recent molecular isolation and characterization of three early ecdysone-inducible genes has confirmed many aspects of this model--these genes are directly induced by ecdysone, repressed by ecdysone-induced proteins, and appear to encode DNA binding regulatory proteins. The three early genes are also remarkably similar in structure. They are all unusually long and complex, with multiple transcripts that direct the synthesis of several related proteins from each locus. Proteins encoded by two of the early genes bind to both early and late ecdysone-induced puffs, implying that they are key regulators in the hierarchy. PMID:2127884

  6. [ Super-enhancers. Are they regulators of regulatory genes of development and cancer?].

    PubMed

    Didych, D A; Tyulkina, D V; Pleshkan, V V; Alekseenko, I V; Sverdlov, E D

    2015-01-01

    Enhancers make up a huge class of genome regulatory elements that play an important role in the formation and maintenance of specific patterns of gene transcriptional activity in all types of cells. In recent years, high-throughput methods for the genome-wide epigenetic analysis of chromatin have made it possible to identify structural and functional features of enhancers and their role in the spatial and functional organization of the genome and in the formation and maintenance of cell identity, as well as in the pathogenesis of certain diseases. Special attention has been focused on genome regions called super-enhancers, or stretch enhancers, which consist of clusters of elements with properties of classic enhancers. This review considers current data on specific properties of super-enhancers and their role in the formation of interconnected autoregulatory circuits with positive feedback that regulates the most important genes, the activity of which underlies the formation and maintenance of specialized cellular functions. PMID:26710770

  7. Phosphorylation-Induced Dimerization of Interferon Regulatory Factor 7 Unmasks DNA Binding and a Bipartite Transactivation Domain

    PubMed Central

    Marié, Isabelle; Smith, Eric; Prakash, Arun; Levy, David E.

    2000-01-01

    Interferon regulatory factor 7 (IRF7) is an interferon (IFN)-inducible transcription factor required for activation of a subset of IFN-α genes that are expressed with delayed kinetics following viral infection. IRF7 is synthesized as a latent protein and is posttranslationally modified by protein phosphorylation in infected cells. Phosphorylation required a carboxyl-terminal regulatory domain that controlled the retention of the active protein exclusively in the nucleus, as well as its binding to specific DNA target sequences, multimerization, and ability to induce target gene expression. Transcriptional activation by IRF7 mapped to two distinct regions, both of which were required for full activity, while all functions were masked in latent IRF7 by an autoinhibitory domain mapping to an internal region. A conditionally active form of IRF7 was constructed by fusing IRF7 with the ligand-binding and dimerization domain of estrogen receptor (ER). Hormone-dependent dimerization of chimeric IRF7-ER stimulated DNA binding and transcriptional transactivation of endogenous target genes. These studies demonstrate the regulation of IRF7 activity by phosphorylation-dependent allosteric changes that result in dimerization and that facilitate nuclear retention, derepress transactivation, and allow specific DNA binding. PMID:11073981

  8. A Mathematical Model of the Immune and Neuroendocrine Systems Mutual Regulation under the Technogenic Chemical Factors Impact

    PubMed Central

    Zaitseva, N. V.; Kiryanov, D. A.; Lanin, D. V.; Chigvintsev, V. M.

    2014-01-01

    The concept of the triad regulatory metasystem, which includes the neuroendocrine and immune regulation systems, is currently generally accepted. Changes occurring in each of the regulatory systems in response to the impact of technogenic chemical factors are also well known. This paper presents mathematical models of the immune and neuroendocrine system functioning, using the interaction between these systems in response to bacterial invasion as an example, and changes in their performance under exposure to chemical factors, taking into account the stage of functional disorders in a producing organ, using the performance of the bone marrow as an example. PMID:24872840

  9. Identification of trans-acting factors regulating SamDC expression in Oryza sativa.

    PubMed

    Basu, Supratim; Roychoudhury, Aryadeep; Sengupta, Dibyendu N

    2014-03-01

    Abiotic stress affects the growth and productivity of crop plants; to cope with the adverse environmental conditions, plants have developed efficient defense machinery comprising of antioxidants like phenolics and flavonoids, and osmolytes like polyamines. SamDC is a key enzyme in the polyamine biosynthesis pathway in plants. In our present communication we have done in silico analysis of the promoter region of SamDC to look for the presence of different cis-regulatory elements contributing to its expression. Based on the presence of different cis-regulatory elements we completed comparative analysis of SamDC gene expression in rice lamina of IR-29 and Nonabokra by qPCR in response to the abiotic stress treatments of salinity, drought, cold and the biotic stress treatments of ABA and light. Additionally, to explore the role of the cis-regulatory elements in regulating the expression of SamDC gene in plants we comparatively analyzed the binding of rice nuclear proteins prepared from IR-29 and Nonabokra undergoing various stress treatments. The intensity of the complex formed was low and inducible in IR-29 in contrast to Nonabokra. Southwestern blot analysis helped in predicting the size of the trans-acting factors binding to these cis-elements. To our knowledge this is the first report on the comprehensive analysis of SamDC gene expression in rice and identification of the trans-acting factors regulating its expression. PMID:24530223

  10. Co-regulation of invected and engrailed by a complex array of regulatory sequences in Drosophila

    PubMed Central

    Cheng, Yuzhong; Brunner, Alayne L.; Kremer, Stefanie; DeVido, Sarah K.; Stefaniuk, Catherine M.; Kassis, Judith A.

    2014-01-01

    invected (inv) and engrailed (en) form a gene complex that extends about 115kb. These two genes encode highly related homeodomain proteins that are co-regulated in a complex manner throughout development. Our dissection of inv/en regulatory DNA shows that most enhancers are spread throughout a 62kb region. We used two types of constructs to analyze the function of this DNA: P-element based reporter constructs with small pieces of DNA fused to the en promoter driving lacZ expression and large constructs with HA-tagged en and inv inserted in the genome with the phiC31 system. In addition, we generated deletions of inv and en DNA in situ and assayed their effects on inv/en expression. Our results support and extend our knowledge of inv/en regulation. First, inv and en share regulatory DNA, most of which is flanking the en transcription unit. In support of this, a 79-kb HA-en transgene can rescue inv en double mutants to viable, fertile adults. In contrast, an 84-kb HA-inv transgene lacks most of the enhancers for inv/en expression. Second, there are multiple enhancers for inv/en stripes in embryos; some of these may be redundant but others play discrete roles at different stages of embryonic development. Finally, no small reporter construct gave expression in the posterior compartment of imaginal discs, a hallmark of inv/en expression. Robust expression of HA-en in the posterior compartment of imaginal discs is evident from the 79-kb HA-en transgene, while a 45-kb HA-en transgene gives weaker, variable imaginal disc expression. We suggest that the activity of the imaginal disc enhancer(s) is dependent on the chromatin structure of the inv/en domain. PMID:25172431

  11. Mining 3D genome structure populations identifies major factors governing the stability of regulatory communities

    PubMed Central

    Dai, Chao; Li, Wenyuan; Tjong, Harianto; Hao, Shengli; Zhou, Yonggang; Li, Qingjiao; Chen, Lin; Zhu, Bing; Alber, Frank; Jasmine Zhou, Xianghong

    2016-01-01

    Three-dimensional (3D) genome structures vary from cell to cell even in an isogenic sample. Unlike protein structures, genome structures are highly plastic, posing a significant challenge for structure-function mapping. Here we report an approach to comprehensively identify 3D chromatin clusters that each occurs frequently across a population of genome structures, either deconvoluted from ensemble-averaged Hi-C data or from a collection of single-cell Hi-C data. Applying our method to a population of genome structures (at the macrodomain resolution) of lymphoblastoid cells, we identify an atlas of stable inter-chromosomal chromatin clusters. A large number of these clusters are enriched in binding of specific regulatory factors and are therefore defined as ‘Regulatory Communities.' We reveal two major factors, centromere clustering and transcription factor binding, which significantly stabilize such communities. Finally, we show that the regulatory communities differ substantially from cell to cell, indicating that expression variability could be impacted by genome structures. PMID:27240697

  12. Cell Cycle and Apoptosis Regulatory Protein (CARP)-1 is Expressed inOsteoblasts and Regulated by PTH

    SciTech Connect

    Sharma, Sonali; Mahalingam, Chandrika D.; Das, Varsha; Levi, Edi; Rishi, Arun K.; Datta, Nabanita S.

    2013-07-12

    Highlights: •CARP-1 is identified for the first time in bone cells. •PTH downregulates CARP-1 expression in differentiated osteoblasts. •PTH displaces CARP-1 from nucleus to the cytoplasm in differentiated osteoblasts. •Downregulation of CARP-1 by PTH involves PKA, PKC and P-p38 MAPK pathways. -- Abstract: Bone mass is dependent on osteoblast proliferation, differentiation and life-span of osteoblasts. Parathyroid hormone (PTH) controls osteoblast cell cycle regulatory proteins and suppresses mature osteoblasts apoptosis. Intermittent administration of PTH increases bone mass but the mechanism of action are complex and incompletely understood. Cell Cycle and Apoptosis Regulatory Protein (CARP)-1 (aka CCAR1) is a novel transducer of signaling by diverse agents including cell growth and differentiation factors. To gain further insight into the molecular mechanism, we investigated involvement of CARP-1 in PTH signaling in osteoblasts. Immunostaining studies revealed presence of CARP-1 in osteoblasts and osteocytes, while a minimal to absent levels were noted in the chondrocytes of femora from 10 to 12-week old mice. Treatment of 7-day differentiated MC3T3-E1 clone-4 (MC-4) mouse osteoblastic cells and primary calvarial osteoblasts with PTH for 30 min to 5 h followed by Western blot analysis showed 2- to 3-fold down-regulation of CARP-1 protein expression in a dose- and time-dependent manner compared to the respective vehicle treated control cells. H-89, a Protein Kinase A (PKA) inhibitor, suppressed PTH action on CARP-1 protein expression indicating PKA-dependent mechanism. PMA, a Protein Kinase C (PKC) agonist, mimicked PTH action, and the PKC inhibitor, GF109203X, partially blocked PTH-dependent downregulation of CARP-1, implying involvement of PKC. U0126, a Mitogen-Activated Protein Kinase (MAPK) Kinase (MEK) inhibitor, failed to interfere with CARP-1 suppression by PTH. In contrast, SB203580, p38 inhibitor, attenuated PTH down-regulation of CARP-1

  13. Methionine Enkephalin (MENK) Inhibits tumor growth through regulating CD4+Foxp3+ Regulatory T cells (Tregs) in mice

    PubMed Central

    Li, Xuan; Meng, Yiming; Plotnikoff, Nicolas P; Youkilis, Gene; Griffin, Noreen; Wang, Enhua; Lu, Changlong; Shan, Fengping

    2015-01-01

    Methionine enkephalin (MENK), an endogenous neuropeptide, plays an crucial role in both neuroendocrine and immune systems. CD4+Foxp3+ regulatory T cells (Tregs) are identified as a major subpopulation of T lymphocytes in suppressing immune system to keep balanced immunity. The aim of this research work was to elucidate the mechanisms via which MENK interacts with Tregs in cancer situation. The influence of MENK on transforming growth factor-β (TGF-β) mediated conversion from naïve CD4+CD25- T cells to CD4+CD25+ Tregs was determined and the data from flow cytometry (FCM) analysis indicated that MENK effectively inhibited the expression of Foxp3 during the process of TGF-βinduction. Furthermore, this inhibiting process was accompanied by diminishing phosphorylation and nuclear translocation of Smad2/3, confirmed by western blot (WB) analysis and immunofluorescence (IF) at molecular level. We established sarcoma mice model with S180 to investigate whether MENK could modulate Tregs in tumor circumstance. Our findings showed that MENK delayed the development of tumor in S180 tumor bearing mice and down-regulated level of Tregs. Together, these novel findings reached a conclusion that MENK could inhibit Tregs activity directly and retard tumor development through down-regulating Tregs in mice. This work advances the deepening understanding of the influence of MENK on Tregs in cancer situation, and relation of MENK with immune system, supporting the implication of MENK as a new strategy for cancer immunotherapy. PMID:25701137

  14. Genome-wide targeting of the epigenetic regulatory protein CTCF to gene promoters by the transcription factor TFII-I

    PubMed Central

    Peña-Hernández, Rodrigo; Marques, Maud; Hilmi, Khalid; Zhao, Teijun; Saad, Amine; Alaoui-Jamali, Moulay A.; del Rincon, Sonia V.; Ashworth, Todd; Roy, Ananda L.; Emerson, Beverly M.; Witcher, Michael

    2015-01-01

    CCCTC-binding factor (CTCF) is a key regulator of nuclear chromatin structure and gene regulation. The impact of CTCF on transcriptional output is highly varied, ranging from repression to transcriptional pausing and transactivation. The multifunctional nature of CTCF may be directed solely through remodeling chromatin architecture. However, another hypothesis is that the multifunctional nature of CTCF is mediated, in part, through differential association with protein partners having unique functions. Consistent with this hypothesis, our mass spectrometry analyses of CTCF interacting partners reveal a previously undefined association with the transcription factor general transcription factor II-I (TFII-I). Biochemical fractionation of CTCF indicates that a distinct CTCF complex incorporating TFII-I is assembled on DNA. Unexpectedly, we found that the interaction between CTCF and TFII-I is essential for directing CTCF to the promoter proximal regulatory regions of target genes across the genome, particularly at genes involved in metabolism. At genes coregulated by CTCF and TFII-I, we find knockdown of TFII-I results in diminished CTCF binding, lack of cyclin-dependent kinase 8 (CDK8) recruitment, and an attenuation of RNA polymerase II phosphorylation at serine 5. Phenotypically, knockdown of TFII-I alters the cellular response to metabolic stress. Our data indicate that TFII-I directs CTCF binding to target genes, and in turn the two proteins cooperate to recruit CDK8 and enhance transcription initiation. PMID:25646466

  15. Tumor necrosis factor receptor associated factor 6 (TRAF6) regulation of development, function, and homeostasis of the immune system

    PubMed Central

    Walsh, Matthew C.; Lee, JangEun; Choi, Yongwon

    2016-01-01

    Summary Tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) is an adaptor protein that mediates a wide array of protein-protein interactions via its TRAF domain and a RING finger domain that possesses non-conventional E3 ubiquitin ligase activity. First identified nearly two decades ago as a mediator of IL-1 receptor (IL-1R)-mediated activation of NFκB, TRAF6 has since been identified as an actor downstream of multiple receptor families with immunoregulatory functions, including members of the TNFR superfamily, the toll-like receptor (TLR) family, tumor growth factor-β receptors (TGFβR), and T cell receptor (TCR). In addition to NFκB, TRAF6 may also direct activation of mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K), and interferon regulatory factor (IRF) pathways. In the context of the immune system, TRAF6-mediated signals have proven critical for the development, homeostasis, and/or activation of B cells, T cells, and myeloid cells, including macrophages, dendritic cells, and osteoclasts, as well as for organogenesis of thymic and secondary lymphoid tissues. In multiple cellular contexts, TRAF6 function is essential not only for proper activation of the immune system, but also for maintaining immune tolerance, and more recent works have begun to identify mechanisms of contextual specificity for TRAF6, involving both regulatory protein interactions, and messenger RNA regulation by microRNAs. PMID:26085208

  16. Dynamics of chromatin accessibility and gene regulation by MADS-domain transcription factors in flower development

    PubMed Central

    2014-01-01

    Background Development of eukaryotic organisms is controlled by transcription factors that trigger specific and global changes in gene expression programs. In plants, MADS-domain transcription factors act as master regulators of developmental switches and organ specification. However, the mechanisms by which these factors dynamically regulate the expression of their target genes at different developmental stages are still poorly understood. Results We characterized the relationship of chromatin accessibility, gene expression, and DNA binding of two MADS-domain proteins at different stages of Arabidopsis flower development. Dynamic changes in APETALA1 and SEPALLATA3 DNA binding correlated with changes in gene expression, and many of the target genes could be associated with the developmental stage in which they are transcriptionally controlled. We also observe dynamic changes in chromatin accessibility during flower development. Remarkably, DNA binding of APETALA1 and SEPALLATA3 is largely independent of the accessibility status of their binding regions and it can precede increases in DNA accessibility. These results suggest that APETALA1 and SEPALLATA3 may modulate chromatin accessibility, thereby facilitating access of other transcriptional regulators to their target genes. Conclusions Our findings indicate that different homeotic factors regulate partly overlapping, yet also distinctive sets of target genes in a partly stage-specific fashion. By combining the information from DNA-binding and gene expression data, we are able to propose models of stage-specific regulatory interactions, thereby addressing dynamics of regulatory networks throughout flower development. Furthermore, MADS-domain TFs may regulate gene expression by alternative strategies, one of which is modulation of chromatin accessibility. PMID:24581456

  17. Sterol regulatory element-binding proteins are transcriptional regulators of the thyroglobulin gene in thyroid cells.

    PubMed

    Wen, Gaiping; Eder, Klaus; Ringseis, Robert

    2016-08-01

    The genes encoding sodium/iodide symporter (NIS) and thyroid peroxidase (TPO), both of which are essential for thyroid hormone (TH) synthesis, were shown to be regulated by sterol regulatory element-binding proteins (SREBP)-1c and -2. In the present study we tested the hypothesis that transcription of a further gene essential for TH synthesis, the thyroglobulin (TG) gene, is under the control of SREBP. To test this hypothesis, we studied the influence of inhibition of SREBP maturation and SREBP knockdown on TG expression in FRTL-5 thyrocytes and explored transcriptional regulation of the TG promoter by reporter gene experiments in FRTL-5 and HepG2 cells, gel shift assays and chromatin immunoprecipitation. Inhibition of SREBP maturation by 25-hydroxycholesterol and siRNA-mediated knockdown of either SREBP-1c or SREBP-2 decreased mRNA and protein levels of TG in FRTL-5 thyrocytes. Reporter gene assays with wild-type and mutated TG promoter reporter truncation constructs revealed that the rat TG promoter is transcriptionally activated by nSREBP-1c and nSREBP-2. DNA-binding assays and chromatin immunoprecipitation assays showed that both nSREBP-1c and nSREBP-2 bind to a SREBP binding motif with characteristics of an E-box SRE at position -63 in the rat TG promoter. In connection with recent findings that NIS and TPO are regulated by SREBP in thyrocytes the present findings support the view that SREBP are regulators of essential steps of TH synthesis in the thyroid gland such as iodide uptake, iodide oxidation and iodination of tyrosyl residues of TG. This moreover suggests that SREBP may be molecular targets for pharmacological modulation of TH synthesis. PMID:27321819

  18. Fatigue risk management: Organizational factors at the regulatory and industry/company level.

    PubMed

    Gander, Philippa; Hartley, Laurence; Powell, David; Cabon, Philippe; Hitchcock, Edward; Mills, Ann; Popkin, Stephen

    2011-03-01

    This paper focuses on the development of fatigue risk management systems (FRMS) in the transport sector. The evolution of regulatory frameworks is traced, from uni-dimensional hours of service regulations through to frameworks that enable multi-dimensional FRMS. These regulatory changes reflect advances in understanding of human error in the aetiology of accidents, and in fatigue and safety science. Implementation of FRMS shifts the locus of responsibility for safety away from the regulator towards companies and individuals, and requires changes in traditional roles. Organizational, ethnic, and national culture need to be considered. Recent trends in the work environment have potential to adversely affect FRMS, including precarious employment and shortages of skilled labour. Essential components of an FRMS, and examples of FRMS in different transport modes, are described. It is vital that regulators, employer, and employees have an understanding of the causes and consequences of fatigue that is sufficient for them to meet their responsibilities in relation to FRMS. While there is a strong evidence base supporting the principles of FRMS, experience with implementation is more limited. The evidence base for effective implementation will expand, since FRMS is data-driven, and ongoing evaluation is integral. We strongly advocate that experience be shared wherever possible. PMID:21130218

  19. Roles of transcription factors and epigenetic modifications in differentiation and maintenance of regulatory T cells.

    PubMed

    Sekiya, Takashi; Nakatsukasa, Hiroko; Lu, Qianjin; Yoshimura, Akihiko

    2016-06-01

    Regulatory T (Treg) cells are an essential cell subset for the maintenance of immune homeostasis. Treg cells are characterized by a distinct pattern of gene expression, including the upregulation of immune-suppressive genes and the silencing of inflammatory genes. The molecular mechanisms involved in the development and maintenance of Tregs have been extensively investigated. We have identified essential transcription factors NR4a and Smad2/3 in the development of thymic Tregs and induced Tregs, respectively. This article reviews the roles of transcription factors in the differentiation, maintenance, and function of Treg cells. PMID:26970203

  20. The FasX Small Regulatory RNA Negatively Regulates the Expression of Two Fibronectin-Binding Proteins in Group A Streptococcus

    PubMed Central

    Danger, Jessica L.; Makthal, Nishanth; Kumaraswami, Muthiah

    2015-01-01

    ABSTRACT The group A Streptococcus (GAS; Streptococcus pyogenes) causes more than 700 million human infections each year. The success of this pathogen can be traced in part to the extensive arsenal of virulence factors that are available for expression in temporally and spatially specific manners. To modify the expression of these virulence factors, GAS use both protein- and RNA-based regulators, with the best-characterized RNA-based regulator being the small regulatory RNA (sRNA) FasX. FasX is a 205-nucleotide sRNA that contributes to GAS virulence by enhancing the expression of the thrombolytic secreted virulence factor streptokinase and by repressing the expression of the collagen-binding cell surface pili. Here, we have expanded the FasX regulon, showing that this sRNA also negatively regulates the expression of the adhesion- and internalization-promoting, fibronectin-binding proteins PrtF1 and PrtF2. FasX posttranscriptionally regulates the expression of PrtF1/2 through a mechanism that involves base pairing to the prtF1 and prtF2 mRNAs within their 5′ untranslated regions, overlapping the mRNA ribosome-binding sites. Thus, duplex formation between FasX and the prtF1 and prtF2 mRNAs blocks ribosome access, leading to an inhibition of mRNA translation. Given that FasX positively regulates the expression of the spreading factor streptokinase and negatively regulates the expression of the collagen-binding pili and of the fibronectin-binding PrtF1/2, our data are consistent with FasX functioning as a molecular switch that governs the transition of GAS between the colonization and dissemination stages of infection. IMPORTANCE More than half a million deaths each year are a consequence of infections caused by GAS. Insights into how this pathogen regulates the production of proteins during infection may facilitate the development of novel therapeutic or preventative regimens aimed at inhibiting this activity. Here, we have expanded insight into the regulatory

  1. Establishing a Framework for the Ad/Abaxial Regulatory Network of Arabidopsis: Ascertaining Targets of Class III HOMEODOMAIN LEUCINE ZIPPER and KANADI Regulation[W

    PubMed Central

    Reinhart, Brenda J.; Liu, Tie; Newell, Nicole R.; Magnani, Enrico; Huang, Tengbo; Kerstetter, Randall; Michaels, Scott; Barton, M. Kathryn

    2013-01-01

    The broadly conserved Class III HOMEODOMAIN LEUCINE ZIPPER (HD-ZIPIII) and KANADI transcription factors have opposing and transformational effects on polarity and growth in all tissues and stages of the plant's life. To obtain a comprehensive understanding of how these factors work, we have identified transcripts that change in response to induced HD-ZIPIII or KANADI function. Additional criteria used to identify high-confidence targets among this set were presence of an adjacent HD-ZIPIII binding site, expression enriched within a subdomain of the shoot apical meristem, mutant phenotype showing defect in polar leaf and/or meristem development, physical interaction between target gene product and HD-ZIPIII protein, opposite regulation by HD-ZIPIII and KANADI, and evolutionary conservation of the regulator–target relationship. We find that HD-ZIPIII and KANADI regulate tissue-specific transcription factors involved in subsidiary developmental decisions, nearly all major hormone pathways, and new actors (such as INDETERMINATE DOMAIN4) in the ad/abaxial regulatory network. Multiple feedback loops regulating HD-ZIPIII and KANADI are identified, as are mechanisms through which HD-ZIPIII and KANADI oppose each other. This work lays the foundation needed to understand the components, structure, and workings of the ad/abaxial regulatory network directing basic plant growth and development. PMID:24076978

  2. Developing self-regulation for dietary temptations: intervention effects on physical, self-regulatory and psychological outcomes.

    PubMed

    McKee, Heather C; Ntoumanis, Nikos

    2014-12-01

    We aimed to investigate whether a self-regulatory skills intervention can improve weight loss-related outcomes. Fifty-five participants (M BMI = 32.60 ± 4.86) were randomized into self-regulation training and advice groups and received two training workshops and weekly practice tasks. The self-regulation training group was trained to use six self-regulatory skills: Delayed gratification, thought control, goal setting, self-monitoring, mindfulness, and coping. The advice group received dietary and physical activity advice for weight loss. Physical, self-regulatory, and psychological measures were taken at baseline, end of intervention (week 8) and at follow-up (week 12). Using intention-to-treat analysis, weight, waist circumference, body fat and body mass index (BMI) were significantly reduced at follow-up for both groups. There were significant increases in all six self-regulatory skills and the psychological measures of self-efficacy, self-regulatory success, and physical self-worth for both groups. Results indicate that self-regulatory skills training might be as effective as dietary and physical activity advice in terms of weight loss and related outcomes. PMID:24523025

  3. Regulation of Airway Inflammation by G-protein Regulatory Motif Peptides of AGS3 protein

    PubMed Central

    Choi, IL-Whan; Ahn, Do Whan; Choi, Jang-Kyu; Cha, Hee-Jae; Ock, Mee Sun; You, EunAe; Rhee, SangMyung; Kim, Kwang Chul; Choi, Yung Hyun; Song, Kyoung Seob

    2016-01-01

    Respiratory diseases such as asthma, chronic obstructive pulmonary disease (COPD), and lung infections have critical consequences on mortality and morbidity in humans. The aims of the present study were to examine the mechanisms by which CXCL12 affects MUC1 transcription and airway inflammation, which depend on activator of G-protein signaling (AGS) 3 and to identify specific molecules that suppress CXCL12-induced airway inflammation by acting on G-protein-coupled receptors. Herein, AGS3 suppresses CXCL12-mediated upregulation of MUC1 and TNFα by regulating Gαi. We found that the G-protein regulatory (GPR) motif peptide in AGS3 binds to Gαi and downregulates MUC1 expression; in contrast, this motif upregulates TNFα expression. Mutated GPR Q34A peptide increased the expression of MUC1 and TGFβ but decreased the expression of TNFα and IL-6. Moreover, CXCR4-induced dendritic extensions in 2D and 3D matrix cultures were inhibited by the GPR Q34A peptide compared with a wild-type GPR peptide. The GPR Q34A peptide also inhibited CXCL12-induced morphological changes and inflammatory cell infiltration in the mouse lung, and production of inflammatory cytokines in bronchoalveolar lavage (BAL) fluid and the lungs. Our data indicate that the GPR motif of AGS3 is critical for regulating MUC1/Muc1 expression and cytokine production in the inflammatory microenvironment. PMID:27270970

  4. Notch and TGFβ form a positive regulatory loop and regulate EMT in epithelial ovarian cancer cells.

    PubMed

    Zhou, Jiesi; Jain, Saket; Azad, Abul K; Xu, Xia; Yu, Hai Chuan; Xu, Zhihua; Godbout, Roseline; Fu, YangXin

    2016-08-01

    Epithelial-mesenchymal transition (EMT) plays a critical role in the progression of epithelial ovarian cancer (EOC). However, the mechanisms that regulate EMT in EOC are not fully understood. Here, we report that activation of Notch1 induces EMT in EOC cells as evidenced by downregulation of E-cadherin and cytokeratins, upregulation of Slug and Snail, as well as morphological changes. Interestingly, activation of Notch1 increases TGFβ/Smad signaling by upregulating the expression of TGFβ and TGFβ type 1 receptor. Time course experiments demonstrate that inhibition of Notch by DAPT (a γ-secretase inhibitor) decreases TGFβ-induced phosphorylation of receptor Smads at late, but not at early, timepoints. These results suggest that Notch activation plays a role in sustaining TGFβ/Smad signaling in EOC cells. Furthermore, inhibition of Notch by DAPT decreases TGFβ induction of Slug and repression of E-cadherin and knockdown of Notch1 decreases TGFβ-induced repression of E-cadherin, indicating that Notch is required, at least in part, for TGFβ-induced EMT in EOC cells. On the other hand, TGFβ treatment increases the expression of Notch ligand Jagged1 and Notch target gene HES1 in EOC cells. Functionally, the combination of Notch1 activation and TGFβ treatment is more potent in promoting motility and migration of EOC cells than either stimulation alone. Taken together, our results indicate that Notch and TGFβ form a reciprocal positive regulatory loop and cooperatively regulate EMT and promote EOC cell motility and migration. PMID:27075926

  5. Sterol regulatory element binding protein-1 (SREBP-1)c promoter: Characterization and transcriptional regulation by mature SREBP-1 and liver X receptor α in goat mammary epithelial cells.

    PubMed

    Xu, H F; Luo, J; Wang, H P; Wang, H; Zhang, T Y; Tian, H B; Yao, D W; Loor, J J

    2016-02-01

    Sterol regulatory element binding protein-1 (SREBP-1) is a key transcription factor that regulates lipogenesis in rodent liver. Two isoforms (SREBP-1a and SREBP-1c) of SREBP-1 are transcribed by an alternative promoter on the same gene (SREBF1), and the isoforms differ only in their first exon. Although the regulatory effects of SREBP-1 on lipid and milk fat synthesis have received much attention in ruminants, SREBP-1c promoter and its regulatory mechanisms have not been characterized in the goat. In the present study, we cloned and sequenced a 2,012-bp fragment of the SREBP-1c 5'-flanking region from goat genomic DNA. A luciferase reporter assay revealed that SREBP-1c is transcriptionally activated by the liver X receptor α (LXRα) agonist T0901317, and is decreased by SREBP-1 small interfering (si)RNA. A 5' deletion analysis revealed a core promoter region located -395 to +1 bp upstream of the transcriptional start site (TSS). Site-directed mutagenesis of LXRα binding elements (LXRE1 and LXRE2) and sterol regulatory elements (SRE1 and SRE2) revealed that the full effects of T 4506585 require the presence of both LXRE and SRE. We also characterized a new SRE (SRE1) and demonstrated a direct role of SREBP-1 (auto-loop regulation) in maintaining its basal transcription activity. Results suggest that goat SREBP-1c gene is transcriptionally regulated by mature SREBP-1 (auto-loop circuit regulation) and LXRα in goat mammary epithelial cells. PMID:26709176

  6. Positive Regulatory Domain I-Binding Factor 1 mediates repression of the MHC Class II Transactivator (CIITA) type IV promoter

    PubMed Central

    Chen, Han; Gilbert, Carolyn A.; Hudson, John A.; Bolick, Sophia C.; Wright, Kenneth L.; Piskurich, Janet F.

    2006-01-01

    MHC class II transactivator (CIITA), a co-activator that controls MHC class II (MHC II) transcription, functions as the master regulator of MHC II expression. Persistent activity of the CIITA type III promoter (pIII), one of the four potential promoters of this gene, is responsible for constitutive expression of MHC II by B lymphocytes. In addition, IFN-γ induces expression of CIITA in these cells through the type IV promoter (pIV). Positive regulatory domain 1-binding factor 1 (PRDI-BF1), called B lymphocyte-induced maturation protein 1 (Blimp-1) in mice, represses the expression of CIITA pIII in plasma and multiple myeloma cells. To investigate regulation of CIITA pIV expression by PRDI-BF1 in the B lymphocyte lineage, protein/DNA binding studies, and functional promoter analyses were performed. PRDI-BF1 bound to the IRF-E site in CIITA pIV. Ectopic expression of either PRDI-BF1 or Blimp-1 repressed this promoter in B lymphocytes. In vitro binding and functional analyses of CIITA pIV demonstrated that the IFN regulatory factor-element (IRF-E) is the target of this repression. In vivo genomic footprint analysis demonstrated protein binding at the IRF-E site of CIITA pIV in U266 myeloma cells, which express PRDI-BF1. PRDI-BF1β, a truncated form of PRDI-BF1 that is co-expressed in myeloma cells, also bound to the IRF-E site and repressed CIITA pIV. These findings demonstrate for the first time that, in addition to silencing expression of CIITA pIII in B lymphocytes, PRDI-BF1 is capable of binding and suppressing CIITA pIV. PMID:16765445

  7. Identification of trans-acting factors regulating SamDC expression in Oryza sativa

    SciTech Connect

    Basu, Supratim; Roychoudhury, Aryadeep; Sengupta, Dibyendu N.

    2014-03-07

    Highlights: • Identification of cis elements responsible for SamDC expression by in silico analysis. • qPCR analysis of SamDC expression to abiotic and biotic stress treatments. • Detection of SamDC regulators using identified cis-elements as probe by EMSA. • Southwestern Blot analysis to predict the size of the trans-acting factors. - Abstract: Abiotic stress affects the growth and productivity of crop plants; to cope with the adverse environmental conditions, plants have developed efficient defense machinery comprising of antioxidants like phenolics and flavonoids, and osmolytes like polyamines. SamDC is a key enzyme in the polyamine biosynthesis pathway in plants. In our present communication we have done in silico analysis of the promoter region of SamDC to look for the presence of different cis-regulatory elements contributing to its expression. Based on the presence of different cis-regulatory elements we completed comparative analysis of SamDC gene expression in rice lamina of IR-29 and Nonabokra by qPCR in response to the abiotic stress treatments of salinity, drought, cold and the biotic stress treatments of ABA and light. Additionally, to explore the role of the cis-regulatory elements in regulating the expression of SamDC gene in plants we comparatively analyzed the binding of rice nuclear proteins prepared from IR-29 and Nonabokra undergoing various stress treatments. The intensity of the complex formed was low and inducible in IR-29 in contrast to Nonabokra. Southwestern blot analysis helped in predicting the size of the trans-acting factors binding to these cis-elements. To our knowledge this is the first report on the comprehensive analysis of SamDC gene expression in rice and identification of the trans-acting factors regulating its expression.

  8. Regulation of Specialized Metabolism by WRKY Transcription Factors

    PubMed Central

    Schluttenhofer, Craig; Yuan, Ling

    2015-01-01

    WRKY transcription factors (TFs) are well known for regulating plant abiotic and biotic stress tolerance. However, much less is known about how WRKY TFs affect plant-specialized metabolism. Analysis of WRKY TFs regulating the production of specialized metabolites emphasizes the values of the family outside of traditionally accepted roles in stress tolerance. WRKYs with conserved roles across plant species seem to be essential in regulating specialized metabolism. Overall, the WRKY family plays an essential role in regulating the biosynthesis of important pharmaceutical, aromatherapy, biofuel, and industrial components, warranting considerable attention in the forthcoming years. PMID:25501946

  9. Regulation of specialized metabolism by WRKY transcription factors.

    PubMed

    Schluttenhofer, Craig; Yuan, Ling

    2015-02-01

    WRKY transcription factors (TFs) are well known for regulating plant abiotic and biotic stress tolerance. However, much less is known about how WRKY TFs affect plant-specialized metabolism. Analysis of WRKY TFs regulating the production of specialized metabolites emphasizes the values of the family outside of traditionally accepted roles in stress tolerance. WRKYs with conserved roles across plant species seem to be essential in regulating specialized metabolism. Overall, the WRKY family plays an essential role in regulating the biosynthesis of important pharmaceutical, aromatherapy, biofuel, and industrial components, warranting considerable attention in the forthcoming years. PMID:25501946

  10. Multiple Transcription Factor Families Regulate Axon Growth and Regeneration

    PubMed Central

    Moore, Darcie L.; Goldberg, Jeffrey L.

    2011-01-01

    Understanding axon regenerative failure remains a major goal in neuroscience, and reversing this failure remains a major goal for clinical neurology. While an inhibitory CNS environment clearly plays a role, focus on molecular pathways within neurons has begun to yield fruitful insights. Initial steps forward investigated the receptors and signaling pathways immediately downstream of environmental cues, but recent work has also shed light on transcriptional control mechanisms that regulate intrinsic axon growth ability, presumably through whole cassettes of gene target regulation. Here we will discuss transcription factors that regulate neurite growth in vitro and in vivo, including p53, SnoN, E47, CREB, STAT3, NFAT, c-Jun, ATF3, Sox11, NFκB, and Kruppel-like factors (KLFs). Revealing the similarities and differences among the functions of these transcription factors may further our understanding of the mechanisms of transcriptional regulation in axon growth and regeneration. PMID:21674813

  11. An Arabidopsis Transcriptional Regulatory Map Reveals Distinct Functional and Evolutionary Features of Novel Transcription Factors.

    PubMed

    Jin, Jinpu; He, Kun; Tang, Xing; Li, Zhe; Lv, Le; Zhao, Yi; Luo, Jingchu; Gao, Ge

    2015-07-01

    Transcription factors (TFs) play key roles in both development and stress responses. By integrating into and rewiring original systems, novel TFs contribute significantly to the evolution of transcriptional regulatory networks. Here, we report a high-confidence transcriptional regulatory map covering 388 TFs from 47 families in Arabidopsis. Systematic analysis of this map revealed the architectural heterogeneity of developmental and stress response subnetworks and identified three types of novel network motifs that are absent from unicellular organisms and essential for multicellular development. Moreover, TFs of novel families that emerged during plant landing present higher binding specificities and are preferentially wired into developmental processes and these novel network motifs. Further unveiled connection between the binding specificity and wiring preference of TFs explains the wiring preferences of novel-family TFs. These results reveal distinct functional and evolutionary features of novel TFs, suggesting a plausible mechanism for their contribution to the evolution of multicellular organisms. PMID:25750178

  12. The transcription factors Sox10 and Myrf define an essential regulatory network module in differentiating oligodendrocytes.

    PubMed

    Hornig, Julia; Fröb, Franziska; Vogl, Michael R; Hermans-Borgmeyer, Irm; Tamm, Ernst R; Wegner, Michael

    2013-10-01

    Myelin is essential for rapid saltatory conduction and is produced by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. In both cell types the transcription factor Sox10 is an essential component of the myelin-specific regulatory network. Here we identify Myrf as an oligodendrocyte-specific target of Sox10 and map a Sox10 responsive enhancer to an evolutionarily conserved element in intron 1 of the Myrf gene. Once induced, Myrf cooperates with Sox10 to implement the myelination program as evident from the physical interaction between both proteins and the synergistic activation of several myelin-specific genes. This is strongly reminiscent of the situation in Schwann cells where Sox10 first induces and then cooperates with Krox20 during myelination. Our analyses indicate that the regulatory network for myelination in oligodendrocytes is organized along similar general principles as the one in Schwann cells, but is differentially implemented. PMID:24204311

  13. TCPs, WUSs, and WINDs: families of transcription factors that regulate shoot meristem formation, stem cell maintenance, and somatic cell differentiation

    PubMed Central

    Ikeda, Miho; Ohme-Takagi, Masaru

    2014-01-01

    In contrast to somatic mammalian cells, which cannot alter their fate, plant cells can dedifferentiate to form totipotent callus cells and regenerate a whole plant, following treatment with specific phytohormones. However, the regulatory mechanisms and key factors that control differentiation-dedifferentiation and cell totipotency have not been completely clarified in plants. Recently, several plant transcription factors that regulate meristem formation and dedifferentiation have been identified and include members of the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP), WUSCHEL (WUS), and WOUND INDUCED DEDIFFERENTIATION (WIND1) families. WUS and WIND positively control plant cell totipotency, while TCP negatively controls it. Interestingly, TCP is a transcriptional activator that acts as a negative regulator of shoot meristem formation, and WUS is a transcriptional repressor that positively maintains totipotency of the stem cells of the shoot meristem. We describe here the functions of TCP, WUS, and WIND transcription factors in the regulation of differentiation-dedifferentiation by positive and negative transcriptional regulators. PMID:25232356

  14. Transcription factor p63 bookmarks and regulates dynamic enhancers during epidermal differentiation

    PubMed Central

    Kouwenhoven, Evelyn N; Oti, Martin; Niehues, Hanna; van Heeringen, Simon J; Schalkwijk, Joost; Stunnenberg, Hendrik G; van Bokhoven, Hans; Zhou, Huiqing

    2015-01-01

    The transcription factor p63 plays a pivotal role in keratinocyte proliferation and differentiation in the epidermis. However, how p63 regulates epidermal genes during differentiation is not yet clear. Using epigenome profiling of differentiating human primary epidermal keratinocytes, we characterized a catalog of dynamically regulated genes and p63-bound regulatory elements that are relevant for epithelial development and related diseases. p63-bound regulatory elements occur as single or clustered enhancers, and remarkably, only a subset is active as defined by the co-presence of the active enhancer mark histone modification H3K27ac in epidermal keratinocytes. We show that the dynamics of gene expression correlates with the activity of p63-bound enhancers rather than with p63 binding itself. The activity of p63-bound enhancers is likely determined by other transcription factors that cooperate with p63. Our data show that inactive p63-bound enhancers in epidermal keratinocytes may be active during the development of other epithelial-related structures such as limbs and suggest that p63 bookmarks genomic loci during the commitment of the epithelial lineage and regulates genes through temporal- and spatial-specific active enhancers. PMID:26034101

  15. Transcription factor p63 bookmarks and regulates dynamic enhancers during epidermal differentiation.

    PubMed

    Kouwenhoven, Evelyn N; Oti, Martin; Niehues, Hanna; van Heeringen, Simon J; Schalkwijk, Joost; Stunnenberg, Hendrik G; van Bokhoven, Hans; Zhou, Huiqing

    2015-07-01

    The transcription factor p63 plays a pivotal role in keratinocyte proliferation and differentiation in the epidermis. However, how p63 regulates epidermal genes during differentiation is not yet clear. Using epigenome profiling of differentiating human primary epidermal keratinocytes, we characterized a catalog of dynamically regulated genes and p63-bound regulatory elements that are relevant for epithelial development and related diseases. p63-bound regulatory elements occur as single or clustered enhancers, and remarkably, only a subset is active as defined by the co-presence of the active enhancer mark histone modification H3K27ac in epidermal keratinocytes. We show that the dynamics of gene expression correlates with the activity of p63-bound enhancers rather than with p63 binding itself. The activity of p63-bound enhancers is likely determined by other transcription factors that cooperate with p63. Our data show that inactive p63-bound enhancers in epidermal keratinocytes may be active during the development of other epithelial-related structures such as limbs and suggest that p63 bookmarks genomic loci during the commitment of the epithelial lineage and regulates genes through temporal- and spatial-specific active enhancers. PMID:26034101

  16. 76 FR 40038 - Improving Government Regulations; Unified Agenda of Federal Regulatory and Deregulatory Actions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... minimal. Timetable: ] Action Date FR Cite NPRM 06/00/11 Regulatory Flexibility Analysis Required: Yes... be minimal. Timetable: Action Date FR Cite NPRM 06/00/11 Regulatory Flexibility Analysis Required.... Timetable: Action Date FR Cite NPRM 06/00/11 Regulatory Flexibility Analysis Required: Yes. Agency...

  17. Regulation of the endogenous VEGF-A gene by exogenous designed regulatory proteins

    PubMed Central

    Tachikawa, Kiyoshi; Schröder, Oliver; Frey, Gerhard; Briggs, Steven P.; Sera, Takashi

    2004-01-01

    We describe a facile method to activate or repress transcription of endogenous genes in a quantitative and specific manner by treatment with designed regulatory proteins (DRPs), in which artificial transcription factors (ATFs) are fused to cell-penetrating peptides (CPPs). Penetration of DRPs into cells is mediated by an N-terminal CPP fused to a nuclear localization signal; a DNA-binding domain and a transactivation domain follow. The DNA-binding domain was targeted to the vascular endothelial growth factor (VEGF)-A gene. An agonist DRP was rapidly taken up by cells and transported to the nucleus; soon after, the cells began transcribing the gene and secreting VEGF-A protein in a dose-dependent manner. Multiple copies of a short oligopeptide derived from a minimal transactivation domain of human β-catenin was stronger than VP-16. The SRDX domain from the plant transcription factor, SUPERMAN, changed the DRP to a hypoxia-induced antagonist of VEGF-A. DRPs combine many of the potential benefits of transgenes with those of recombinant proteins. PMID:15475575

  18. Regulation of the protein stability of EMT transcription factors

    PubMed Central

    Díaz, VM; Viñas-Castells, R; García de Herreros, A

    2014-01-01

    The epithelial to mesenchymal transition (EMT) consists of a rapid change of cell phenotype, characterized by the loss of epithelial characteristics and the acquisition of a more invasive phenotype. Transcription factors regulating EMT (Snail, Twist and Zeb) are extremely labile proteins, rapidly degraded by the proteasome system. In this review we analyze the current mechanisms controlling degradation of EMT transcription factors, focusing on the role of new E3 ubiquitin-ligases involved in EMT. We also summarize the regulation of the stability of these EMT transcription factors, specially observed in different stress conditions, such as hypoxia, chemotherapeutic drugs, oxidative stress or γ-irradiation. PMID:25482633

  19. C/EBPβ regulates transcription factors critical for proliferation and survival of multiple myeloma cells

    PubMed Central

    Pal, Rekha; Janz, Martin; Galson, Deborah L.; Gries, Margarete; Li, Shirong; Jöhrens, Korinna; Anagnostopoulos, Ioannis; Dörken, Bernd; Mapara, Markus Y.; Borghesi, Lisa; Kardava, Lela; Roodman, G. David; Milcarek, Christine

    2009-01-01

    CCAAT/enhancer-binding protein β (C/EBPβ), also known as nuclear factor–interleukin-6 (NF-IL6), is a transcription factor that plays an important role in the regulation of growth and differentiation of myeloid and lymphoid cells. Mice deficient in C/EBPβ show impaired generation of B lymphocytes. We show that C/EBPβ regulates transcription factors critical for proliferation and survival in multiple myeloma. Multiple myeloma cell lines and primary multiple myeloma cells strongly expressed C/EBPβ, whereas normal B cells and plasma cells had little or no detectable levels of C/EBPβ. Silencing of C/EBPβ led to down-regulation of transcription factors such as IRF4, XBP1, and BLIMP1 accompanied by a strong inhibition of proliferation. Further, silencing of C/EBPβ led to a complete down-regulation of antiapoptotic B-cell lymphoma 2 (BCL2) expression. In chromatin immunoprecipitation assays, C/EBPβ directly bound to the promoter region of IRF4, BLIMP1, and BCL2. Our data indicate that C/EBPβ is involved in the regulatory network of transcription factors that are critical for plasma cell differentiation and survival. Targeting C/EBPβ may provide a novel therapeutic strategy in the treatment of multiple myeloma. PMID:19717648

  20. A direct regulatory interaction between chaperonin TRiC and stress-responsive transcription factor HSF1.

    PubMed

    Neef, Daniel W; Jaeger, Alex M; Gomez-Pastor, Rocio; Willmund, Felix; Frydman, Judith; Thiele, Dennis J

    2014-11-01

    Heat shock transcription factor 1 (HSF1) is an evolutionarily conserved transcription factor that protects cells from protein-misfolding-induced stress and apoptosis. The mechanisms by which cytosolic protein misfolding leads to HSF1 activation have not been elucidated. Here, we demonstrate that HSF1 is directly regulated by TRiC/CCT, a central ATP-dependent chaperonin complex that folds cytosolic proteins. A small-molecule activator of HSF1, HSF1A, protects cells from stress-induced apoptosis, binds TRiC subunits in vivo and in vitro, and inhibits TRiC activity without perturbation of ATP hydrolysis. Genetic inactivation or depletion of the TRiC complex results in human HSF1 activation, and HSF1A inhibits the direct interaction between purified TRiC and HSF1 in vitro. These results demonstrate a direct regulatory interaction between the cytosolic chaperone machine and a critical transcription factor that protects cells from proteotoxicity, providing a mechanistic basis for signaling perturbations in protein folding to a stress-protective transcription factor. PMID:25437552

  1. Self-Regulation in Early Adolescence: Relations with Mother-Son Relationship Quality and Maternal Regulatory Support and Antagonism

    ERIC Educational Resources Information Center

    Moilanen, Kristin L.; Shaw, Daniel S.; Fitzpatrick, Amber

    2010-01-01

    The purpose of the current investigation was to examine relations among maternal regulatory support, maternal antagonism, and mother-son relationship quality in relation to boys' self-regulation during early adolescence. As part of a larger longitudinal study on 263 low-income, ethnically diverse boys, multiple informants and methods were used to…

  2. Regulatory Teaching and Self-Regulated Learning in College Students: Confirmatory Validation Study of the IATLP Scales

    ERIC Educational Resources Information Center

    de la Fuente, Jesus; Zapata, Lucia; Martinez-Vicente, J. M.; Cardelle-Elawar, Maria; Sander, Paul; Justicia, Fernando; Pichardo, M. C.; Garcia-Belen, A. B.

    2012-01-01

    Introduction: The purpose of this study was to empirically confirm two conceptual interactions proposed by the IATLP Scales: (1) the combination of the teacher's regulatory teaching and the student's self-regulated learning, in order to produce satisfaction with learning; (2) the relationship of this interaction with students' prior…

  3. Context-dependent function of regulatory elements and a switch in chromatin occupancy between GATA3 and GATA2 regulate Gata2 transcription during trophoblast differentiation.

    PubMed

    Ray, Soma; Dutta, Debasree; Rumi, M A Karim; Kent, Lindsey N; Soares, Michael J; Paul, Soumen

    2009-02-20

    GATA transcription factors are important regulators of tissue-specific gene expression during development. GATA2 and GATA3 have been implicated in the regulation of trophoblast-specific genes. However, the regulatory mechanisms of GATA2 expression in trophoblast cells are poorly understood. In this study, we demonstrate that Gata2 is transcriptionally induced during trophoblast giant cell-specific differentiation. Transcriptional induction is associated with displacement of GATA3-dependent nucleoprotein complexes by GATA2-dependent nucleoprotein complexes at two regulatory regions, the -3.9- and +9.5-kb regions, of the mouse Gata2 locus. Analyses with reporter genes showed that, in trophoblast cells, -3.9- and +9.5-kb regions function as transcriptional enhancers in GATA motif independent and dependent fashions, respectively. We also found that knockdown of GATA3 by RNA interference induces GATA2 in undifferentiated trophoblast cells. Interestingly, three other known GATA motif-dependent Gata2 regulatory elements, the -1.8-, -2.8-, and -77-kb regions, which are important to regulate Gata2 in hematopoietic cells are not occupied by GATA factors in trophoblast cells. These elements do not show any enhancer activity and also possess inaccessible chromatin structure in trophoblast cells indicating a context-dependent function. Our results indicate that GATA3 directly represses Gata2 in undifferentiated trophoblast cells, and a switch in chromatin occupancy between GATA3 and GATA2 (GATA3/GATA2 switch) induces transcription during trophoblast differentiation. We predict that this GATA3/GATA2 switch is an important mechanism for the transcriptional regulation of other trophoblast-specific genes. PMID:19106099

  4. The role of personal self-regulation and regulatory teaching to predict motivational-affective variables, achievement, and satisfaction: a structural model.

    PubMed

    De la Fuente, Jesus; Zapata, Lucía; Martínez-Vicente, Jose M; Sander, Paul; Cardelle-Elawar, María

    2015-01-01

    The present investigation examines how personal self-regulation (presage variable) and regulatory teaching (process variable of teaching) relate to learning approaches, strategies for coping with stress, and self-regulated learning (process variables of learning) and, finally, how they relate to performance and satisfaction with the learning process (product variables). The objective was to clarify the associative and predictive relations between these variables, as contextualized in two different models that use the presage-process-product paradigm (the Biggs and DEDEPRO models). A total of 1101 university students participated in the study. The design was cross-sectional and retrospective with attributional (or selection) variables, using correlations and structural analysis. The results provide consistent and significant empirical evidence for the relationships hypothesized, incorporating variables that are part of and influence the teaching-learning process in Higher Education. Findings confirm the importance of interactive relationships within the teaching-learning process, where personal self-regulation is assumed to take place in connection with regulatory teaching. Variables that are involved in the relationships validated here reinforce the idea that both personal factors and teaching and learning factors should be taken into consideration when dealing with a formal teaching-learning context at university. PMID:25964764

  5. The role of personal self-regulation and regulatory teaching to predict motivational-affective variables, achievement, and satisfaction: a structural model

    PubMed Central

    De la Fuente, Jesus; Zapata, Lucía; Martínez-Vicente, Jose M.; Sander, Paul; Cardelle-Elawar, María

    2014-01-01

    The present investigation examines how personal self-regulation (presage variable) and regulatory teaching (process variable of teaching) relate to learning approaches, strategies for coping with stress, and self-regulated learning (process variables of learning) and, finally, how they relate to performance and satisfaction with the learning process (product variables). The objective was to clarify the associative and predictive relations between these variables, as contextualized in two different models that use the presage-process-product paradigm (the Biggs and DEDEPRO models). A total of 1101 university students participated in the study. The design was cross-sectional and retrospective with attributional (or selection) variables, using correlations and structural analysis. The results provide consistent and significant empirical evidence for the relationships hypothesized, incorporating variables that are part of and influence the teaching–learning process in Higher Education. Findings confirm the importance of interactive relationships within the teaching–learning process, where personal self-regulation is assumed to take place in connection with regulatory teaching. Variables that are involved in the relationships validated here reinforce the idea that both personal factors and teaching and learning factors should be taken into consideration when dealing with a formal teaching–learning context at university. PMID:25964764

  6. REACTIN: Regulatory activity inference of transcription factors underlying human diseases with application to breast cancer

    PubMed Central

    2013-01-01

    Background Genetic alterations of transcription factors (TFs) have been implicated in the tumorigenesis of cancers. In many cancers, alteration of TFs results in aberrant activity of them without changing their gene expression level. Gene expression data from microarray or RNA-seq experiments can capture the expression change of genes, however, it is still challenge to reveal the activity change of TFs. Results Here we propose a method, called REACTIN (REgulatory ACTivity INference), which integrates TF binding data with gene expression data to identify TFs with significantly differential activity between disease and normal samples. REACTIN successfully detect differential activity of estrogen receptor (ER) between ER+ and ER- samples in 10 breast cancer datasets. When applied to compare tumor and normal breast samples, it reveals TFs that are critical for carcinogenesis of breast cancer. Moreover, Reaction can be utilized to identify transcriptional programs that are predictive to patient survival time of breast cancer patients. Conclusions REACTIN provides a useful tool to investigate regulatory programs underlying a biological process providing the related case and control gene expression data. Considering the enormous amount of cancer gene expression data and the increasingly accumulating ChIP-seq data, we expect wide application of REACTIN for revealing the regulatory mechanisms of various diseases. PMID:23885756

  7. Regulation of oncogenic KRAS signaling via a novel KRAS-integrin-linked kinase-hnRNPA1 regulatory loop in human pancreatic cancer cells.

    PubMed

    Chu, P-C; Yang, M-C; Kulp, S K; Salunke, S B; Himmel, L E; Fang, C-S; Jadhav, A M; Shan, Y-S; Lee, C-T; Lai, M-D; Shirley, L A; Bekaii-Saab, T; Chen, C-S

    2016-07-28

    Integrin-linked kinase (ILK) is a mediator of aggressive phenotype in pancreatic cancer. On the basis of our finding that knockdown of either KRAS or ILK has a reciprocal effect on the other's expression, we hypothesized the presence of an ILK-KRAS regulatory loop that enables pancreatic cancer cells to regulate KRAS expression. This study aimed to elucidate the mechanism by which this regulatory circuitry is regulated and to investigate the translational potential of targeting ILK to suppress oncogenic KRAS signaling in pancreatic cancer. Interplay between KRAS and ILK and the roles of E2F1, c-Myc and heterogeneous nuclear ribonucleoprotein as intermediary effectors in this feedback loop was interrogated by genetic manipulations through small interfering RNA/short hairpin RNA knockdown and ectopic expression, western blotting, PCR, promoter-luciferase reporter assays, chromatin immunoprecipitation and pull-down analyses. In vivo efficacy of ILK inhibition was evaluated in two murine xenograft models. Our data show that KRAS regulated the expression of ILK through E2F1-mediated transcriptional activation, which, in turn, controlled KRAS gene expression via hnRNPA1-mediated destabilization of the G-quadruplex on the KRAS promoter. Moreover, ILK inhibition blocked KRAS-driven epithelial-mesenchymal transition and growth factor-stimulated KRAS expression. The knockdown or pharmacological inhibition of ILK suppressed pancreatic tumor growth, in part, by suppressing KRAS signaling. These studies suggest that this KRAS-E2F1-ILK-hnRNPA1 regulatory loop enables pancreatic cancer cells to promote oncogenic KRAS signaling and to interact with the tumor microenvironment to promote aggressive phenotypes. This regulatory loop provides a mechanistic rationale for targeting ILK to suppress oncogenic KRAS signaling, which might foster new therapeutic strategies for pancreatic cancer. PMID:26616862

  8. Selection of terrestrial transfer factors for radioecological assessment models and regulatory guides

    SciTech Connect

    Ng, Y.C.; Hoffman, F.O.

    1983-01-01

    A parameter value for a radioecological assessment model is not a single value but a distribution of values about a central value. The sources that contribute to the variability of transfer factors to predict foodchain transport of radionuclides are enumerated. Knowledge of these sources, judgement in interpreting the available data, consideration of collateral information, and established criteria that specify the desired level of conservatism in the resulting predictions are essential elements when selecting appropriate parameter values for radioecological assessment models and regulatory guides. 39 references, 4 figures, 5 tables.

  9. Direct lineage reprogramming via pioneer factors; a detour through developmental gene regulatory networks.

    PubMed

    Morris, Samantha A

    2016-08-01

    Although many approaches have been employed to generate defined fate in vitro, the resultant cells often appear developmentally immature or incompletely specified, limiting their utility. Growing evidence suggests that current methods of direct lineage conversion may rely on the transition through a developmental intermediate. Here, I hypothesize that complete conversion between cell fates is more probable and feasible via reversion to a developmentally immature state. I posit that this is due to the role of pioneer transcription factors in engaging silent, unmarked chromatin and activating hierarchical gene regulatory networks responsible for embryonic patterning. Understanding these developmental contexts will be essential for the precise engineering of cell identity. PMID:27486230

  10. The transcription factor Net regulates the angiogenic switch.

    PubMed

    Zheng, Hong; Wasylyk, Christine; Ayadi, Abdelkader; Abecassis, Joseph; Schalken, Jack A; Rogatsch, Hermann; Wernert, Nicolas; Maira, Sauveur-Michel; Multon, Marie-Christine; Wasylyk, Bohdan

    2003-09-15

    Angiogenesis is fundamental to physiological and pathological processes. Despite intensive efforts, little is known about the intracellular circuits that regulate angiogenesis. The transcription factor Net is activated by phosphorylation induced by Ras, an indirect regulator of angiogenesis. Net is expressed at sites of vasculogenesis and angiogenesis during early mouse development, suggesting that it could have a role in blood vessel formation. We show here that down-regulation of Net inhibits angiogenesis and vascular endothelial growth factor (VEGF) expression in vivo, ex vivo, and in vitro. Ras-activated phosphorylated Net (P-Net) stimulates the mouse VEGF promoter through the -80 to -53 region that principally binds Sp1. P-Net and VEGF are coexpressed in angiogenic processes in wild-type mouse tissues and in human tumors. We conclude that Net is a regulator of angiogenesis that can switch to an activator following induction by pro-angiogenic molecules. PMID:12975317

  11. Identification of High-Impact cis-Regulatory Mutations Using Transcription Factor Specific Random Forest Models

    PubMed Central

    Svetlichnyy, Dmitry; Imrichova, Hana; Fiers, Mark; Kalender Atak, Zeynep; Aerts, Stein

    2015-01-01

    Cancer genomes contain vast amounts of somatic mutations, many of which are passenger mutations not involved in oncogenesis. Whereas driver mutations in protein-coding genes can be distinguished from passenger mutations based on their recurrence, non-coding mutations are usually not recurrent at the same position. Therefore, it is still unclear how to identify cis-regulatory driver mutations, particularly when chromatin data from the same patient is not available, thus relying only on sequence and expression information. Here we use machine-learning methods to predict functional regulatory regions using sequence information alone, and compare the predicted activity of the mutated region with the reference sequence. This way we define the Predicted Regulatory Impact of a Mutation in an Enhancer (PRIME). We find that the recently identified driver mutation in the TAL1 enhancer has a high PRIME score, representing a “gain-of-target” for MYB, whereas the highly recurrent TERT promoter mutation has a surprisingly low PRIME score. We trained Random Forest models for 45 cancer-related transcription factors, and used these to score variations in the HeLa genome and somatic mutations across more than five hundred cancer genomes. Each model predicts only a small fraction of non-coding mutations with a potential impact on the function of the encompassing regulatory region. Nevertheless, as these few candidate driver mutations are often linked to gains in chromatin activity and gene expression, they may contribute to the oncogenic program by altering the expression levels of specific oncogenes and tumor suppressor genes. PMID:26562774

  12. Identification of High-Impact cis-Regulatory Mutations Using Transcription Factor Specific Random Forest Models.

    PubMed

    Svetlichnyy, Dmitry; Imrichova, Hana; Fiers, Mark; Kalender Atak, Zeynep; Aerts, Stein

    2015-11-01

    Cancer genomes contain vast amounts of somatic mutations, many of which are passenger mutations not involved in oncogenesis. Whereas driver mutations in protein-coding genes can be distinguished from passenger mutations based on their recurrence, non-coding mutations are usually not recurrent at the same position. Therefore, it is still unclear how to identify cis-regulatory driver mutations, particularly when chromatin data from the same patient is not available, thus relying only on sequence and expression information. Here we use machine-learning methods to predict functional regulatory regions using sequence information alone, and compare the predicted activity of the mutated region with the reference sequence. This way we define the Predicted Regulatory Impact of a Mutation in an Enhancer (PRIME). We find that the recently identified driver mutation in the TAL1 enhancer has a high PRIME score, representing a "gain-of-target" for MYB, whereas the highly recurrent TERT promoter mutation has a surprisingly low PRIME score. We trained Random Forest models for 45 cancer-related transcription factors, and used these to score variations in the HeLa genome and somatic mutations across more than five hundred cancer genomes. Each model predicts only a small fraction of non-coding mutations with a potential impact on the function of the encompassing regulatory region. Nevertheless, as these few candidate driver mutations are often linked to gains in chromatin activity and gene expression, they may contribute to the oncogenic program by altering the expression levels of specific oncogenes and tumor suppressor genes. PMID:26562774

  13. Increments and Duplication Events of Enzymes and Transcription Factors Influence Metabolic and Regulatory Diversity in Prokaryotes

    PubMed Central

    Martínez-Núñez, Mario Alberto; Poot-Hernandez, Augusto Cesar; Rodríguez-Vázquez, Katya; Perez-Rueda, Ernesto

    2013-01-01

    In this work, the content of enzymes and DNA-binding transcription factors (TFs) in 794 non-redundant prokaryotic genomes was evaluated. The identification of enzymes was based on annotations deposited in the KEGG database as well as in databases of functional domains (COG and PFAM) and structural domains (Superfamily). For identifications of the TFs, hidden Markov profiles were constructed based on well-known transcriptional regulatory families. From these analyses, we obtained diverse and interesting results, such as the negative rate of incremental changes in the number of detected enzymes with respect to the genome size. On the contrary, for TFs the rate incremented as the complexity of genome increased. This inverse related performance shapes the diversity of metabolic and regulatory networks and impacts the availability of enzymes and TFs. Furthermore, the intersection of the derivatives between enzymes and TFs was identified at 9,659 genes, after this point, the regulatory complexity grows faster than metabolic complexity. In addition, TFs have a low number of duplications, in contrast to the apparent high number of duplications associated with enzymes. Despite the greater number of duplicated enzymes versus TFs, the increment by which duplicates appear is higher in TFs. A lower proportion of enzymes among archaeal genomes (22%) than in the bacterial ones (27%) was also found. This low proportion might be compensated by the interconnection between the metabolic pathways in Archaea. A similar proportion was also found for the archaeal TFs, for which the formation of regulatory complexes has been proposed. Finally, an enrichment of multifunctional enzymes in Bacteria, as a mechanism of ecological adaptation, was detected. PMID:23922780

  14. Evidence for regulatory diversity and auto-regulation at the TAC1 locus in sensory neurones

    PubMed Central

    2011-01-01

    The neuropeptide substance-P (SP) is expressed from the TAC1 gene in sensory neurones where it acts as a key modulator of neurogenic inflammation. The promoter of TAC1 (TAC1prom) plays a central role in the regulation of the TAC1 gene but requires the presence of a second regulatory element; ECR2, to support TAC1 expression in sensory neurones and to respond appropriately to signalling pathways such as MAPkinases and noxious induction by capsaicin. We examined whether the effect of capsaicin on ECR2-TAC1prom activity in larger diameter neurones was cell autonomous or non- cell autonomous. We demonstrate that TRPV1 is not expressed in all the same cells as SP following capsaicin induction suggesting the presence of a non-cell autonomous mechanism for TAC1 up-regulation following capsaicin induction. In addition, we demonstrate that induction of SP and ECR1-TAC1prom activity in these larger diameter neurones can be induced by potassium depolarisation suggesting that, in addition to capsaicin induction, transgene activity may be modulated by voltage gated calcium channels. Furthermore, we show that NK1 is expressed in all SP- expressing cells after capsaicin induction and that an agonist of NK1 can activate both SP and the transgene in larger diameter neurones. These observations suggest the presence of an autocrine loop that controls the expression of the TAC1 promoter in sensory neurones. In contrast, induction of the TAC1 promoter by LPS was not dependent on ECR2 and did not occur in large diameter neurones. These studies demonstrate the diversity of mechanisms modulating the activity of the TAC1 promoter and provide novel directions for the development of new anti-inflammatory therapies. PMID:21294877

  15. Retinoid regulated macrophage cholesterol efflux involves the steroidogenic acute regulatory protein

    PubMed Central

    Manna, Pulak R.

    2016-01-01

    Elimination of excess cholesteryl esters from macrophage-derived foam cells is known to be a key process in limiting plaque stability and progression of atherosclerotic lesions. We have recently demonstrated that regulation of retinoid mediated cholesterol efflux is influenced by liver X receptor (LXR) signaling in mouse macrophages (Manna, P.R. et al., 2015, Biochem. Biophys. Res. Commun., 464:312-317). The data presented in this article evaluate the importance of the steroidogenic acute regulatory protein (StAR) in retinoid mediated macrophage cholesterol efflux. Overexpression of StAR in mouse RAW 264.7 macrophages increased the effects of both all-trans retinoic acid (atRA) and 9-cis RA on cholesterol efflux, suggesting StAR enhances the efficacy of retinoic acid receptor (RAR) and/or retinoid X receptor (RXR) ligands. Additional data revealed that atRA enhances (Bu)2cAMP induced StAR and ATP-binding cassette transporter A1 protein levels. Treatment of macrophages transfected with an LXRE reporter plasmid (pLXREx3-Luc) was found to induce the effects of RAR and RXR analogs on LXR activity. PMID:27081671

  16. Retinoid regulated macrophage cholesterol efflux involves the steroidogenic acute regulatory protein.

    PubMed

    Manna, Pulak R

    2016-06-01

    Elimination of excess cholesteryl esters from macrophage-derived foam cells is known to be a key process in limiting plaque stability and progression of atherosclerotic lesions. We have recently demonstrated that regulation of retinoid mediated cholesterol efflux is influenced by liver X receptor (LXR) signaling in mouse macrophages (Manna, P.R. et al., 2015, Biochem. Biophys. Res. Commun., 464:312-317). The data presented in this article evaluate the importance of the steroidogenic acute regulatory protein (StAR) in retinoid mediated macrophage cholesterol efflux. Overexpression of StAR in mouse RAW 264.7 macrophages increased the effects of both all-trans retinoic acid (atRA) and 9-cis RA on cholesterol efflux, suggesting StAR enhances the efficacy of retinoic acid receptor (RAR) and/or retinoid X receptor (RXR) ligands. Additional data revealed that atRA enhances (Bu)2cAMP induced StAR and ATP-binding cassette transporter A1 protein levels. Treatment of macrophages transfected with an LXRE reporter plasmid (pLXREx3-Luc) was found to induce the effects of RAR and RXR analogs on LXR activity. PMID:27081671

  17. Two classes of regulatory subunits coassemble in the same BK channel and independently regulate gating

    NASA Astrophysics Data System (ADS)

    Gonzalez-Perez, Vivian; Xia, Xiao-Ming; Lingle, Christopher J.

    2015-09-01

    High resolution proteomics increasingly reveals that most native ion channels are assembled in macromolecular complexes. However, whether different partners have additive or cooperative functional effects, or whether some combinations of proteins may preclude assembly of others are largely unexplored topics. The large conductance Ca2+-and-voltage activated potassium channel (BK) is well-suited to discern nuanced differences in regulation arising from combinations of subunits. Here we examine whether assembly of two different classes of regulatory proteins, β and γ, in BK channels is exclusive or independent. Our results show that both γ1 and up to four β2-subunits can coexist in the same functional BK complex, with the gating shift caused by β2-subunits largely additive with that produced by the γ1-subunit(s). The multiplicity of β:γ combinations that can participate in a BK complex therefore allow a range of BK channels with distinct functional properties tuned by the specific stoichiometry of the contributing subunits.

  18. Suppression of preoptic sleep-regulatory neuronal activity during corticotropin-releasing factor-induced sleep disturbance.

    PubMed

    Gvilia, Irma; Suntsova, Natalia; Kumar, Sunil; McGinty, Dennis; Szymusiak, Ronald

    2015-11-01

    Corticotropin releasing factor (CRF) is implicated in sleep and arousal regulation. Exogenous CRF causes sleep suppression that is associated with activation of at least two important arousal systems: pontine noradrenergic and hypothalamic orexin/hypocretin neurons. It is not known whether CRF also impacts sleep-promoting neuronal systems. We hypothesized that CRF-mediated changes in wake and sleep involve decreased activity of hypothalamic sleep-regulatory neurons localized in the preoptic area. To test this hypothesis, we examined the effects of intracerebroventricular administration of CRF on sleep-wake measures and c-Fos expression in GABAergic neurons in the median preoptic nucleus (MnPN) and ventrolateral preoptic area (VLPO) in different experimental conditions. Administration of CRF (0.1 nmol) during baseline rest phase led to delayed sleep onset and decreases in total amount and mean duration of non-rapid eye movement (NREM) sleep. Administration of CRF during acute sleep deprivation (SD) resulted in suppression of recovery sleep and decreased c-Fos expression in MnPN/VLPO GABAergic neurons. Compared with vehicle controls, intracerebroventricular CRF potentiated disturbances of both NREM and REM sleep in rats exposed to a species-specific psychological stressor, the dirty cage of a male conspecific. The number of MnPN/VLPO GABAergic neurons expressing c-Fos was reduced in the CRF-treated group of dirty cage-exposed rats. These findings confirm the involvement of CRF in wake-sleep cycle regulation and suggest that increased CRF signaling in the brain 1) negatively affects homeostatic responses to sleep loss, 2) exacerbates stress-induced disturbances of sleep, and 3) suppresses the activity of sleep-regulatory neurons of the MnPN and VLPO. PMID:26333784

  19. Diversity and distribution of transcription factors: their partner domains play an important role in regulatory plasticity in bacteria.

    PubMed

    Rivera-Gómez, Nancy; Segovia, Lorenzo; Pérez-Rueda, Ernesto

    2011-08-01

    The ability of bacteria to deal with diverse environmental changes depends on their repertoire of genes and their ability to regulate their expression. In this process, DNA-binding transcription factors (TFs) have a fundamental role because they affect gene expression positively and/or negatively depending on operator context and ligand-binding status. Here, we show an exhaustive analysis of winged helix-turn-helix domains (wHTHs), a class of DNA-binding TFs. These proteins were identified in high proportions and widely distributed in bacteria, representing around half of the total TFs identified so far. In addition, we evaluated the repertoire of wHTHs in terms of their partner domains (PaDos), identifying a similar trend, as with TFs, i.e. they are abundant and widely distributed in bacteria. Based on the PaDos, we defined three main groups of families: (i) monolithic, those families with little PaDo diversity, such as LysR; (ii) promiscuous, those families with a high PaDo diversity; and (iii) monodomain, with families of small sizes, such as MarR. These findings suggest that PaDos have a very important role in the diversification of regulatory responses in bacteria, probably contributing to their regulatory complexity. Thus, the TFs discriminate over longer regions on the DNA through their diverse DNA-binding domains. On the other hand, the PaDos would allow a great flexibility for transcriptional regulation due to their ability to sense diverse stimuli through a variety of ligand-binding compounds. PMID:21636649

  20. MicroRNA-7/NF-κB signaling regulatory feedback circuit regulates gastric carcinogenesis

    PubMed Central

    Zhao, Xiao-Di; Lu, Yuan-Yuan; Guo, Hao; Xie, Hua-Hong; He, Li-Jie; Shen, Gao-Fei; Zhou, Jin-Feng; Li, Ting; Hu, Si-Jun; Zhou, Lin; Han, Ya-Nan; Liang, Shu-Li; Wang, Xin; Wu, Kai-Chun; Shi, Yong-Quan; Nie, Yong-Zhan

    2015-01-01

    MicroRNAs play essential roles in gene expression regulation during carcinogenesis. Here, we investigated the role of miR-7 and the mechanism by which it is dysregulated in gastric cancer (GC). We used genome-wide screenings and identified RELA and FOS as novel targets of miR-7. Overexpression of miR-7 repressed RELA and FOS expression and prevented GC cell proliferation and tumorigenesis. These effects were clinically relevant, as low miR-7 expression was correlated with high RELA and FOS expression and poor survival in GC patients. Intriguingly, we found that miR-7 indirectly regulated RELA activation by targeting the IκB kinase IKKε. Furthermore, IKKε and RELA can repress miR-7 transcription, which forms a feedback circuit between miR-7 and nuclear factor κB (NF-κB) signaling. Additionally, we demonstrate that down-regulation of miR-7 may occur as a result of the aberrant activation of NF-κB signaling by Helicobacter pylori infection. These findings suggest that miR-7 may serve as an important regulator in GC development and progression. PMID:26261179

  1. [New insights in regulation factors of lipoprotein lipase].

    PubMed

    Jiang, Yan-Zhi; Xing, Shu-Hua; Cen, Wang-Min; Chen, Jian-Ning; Li, Xue-Wei

    2013-07-01

    Lipoprotein lipase (LPL) is an essential enzyme in the lipid metabolism, and proper regulation of LPL is important for controlling the delivery of lipid nutrients to tissues. Recent studies have identified glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1(GPIHBP1) as the important regulation factor of LPL that serves as a binding platform for lipolysis on the vascular lumen and an endothelial cell transporter transporting LPL from the interstitial spaces to the capillary lumen. In addition, several other regulation factors of LPL have also been identified including microRNAs, SorLA (Sortilin-related receptor with A-type repeats), and apolipoproteins that are potentially important for regulating LPL activity. These discoveries provide new directions for understanding basic mechanisms of lipolysis and hyperlipidemia. In this update, we focused on summarizing recent progresses on GPIHBP1, the endothelial cell LPL transporter. We also highlighted the recent progresses on several other regulation factors of LPL that are relevant to the regulation of LPLactivity. PMID:23853353

  2. Beclin 1 regulates growth factor receptor signaling in breast cancer.

    PubMed

    Rohatgi, R A; Janusis, J; Leonard, D; Bellvé, K D; Fogarty, K E; Baehrecke, E H; Corvera, S; Shaw, L M

    2015-10-16

    Beclin 1 is a haploinsufficient tumor suppressor that is decreased in many human tumors. The function of beclin 1 in cancer has been attributed primarily to its role in the degradative process of macroautophagy. However, beclin 1 is a core component of the vacuolar protein sorting 34 (Vps34)/class III phosphatidylinositoI-3 kinase (PI3KC3) and Vps15/p150 complex that regulates multiple membrane-trafficking events. In the current study, we describe an alternative mechanism of action for beclin 1 in breast cancer involving its control of growth factor receptor signaling. We identify a specific stage of early endosome maturation that is regulated by beclin 1, the transition of APPL1-containing phosphatidyIinositol 3-phosphate-negative (PI3P(-)) endosomes to PI3P(+) endosomes. Beclin 1 regulates PI3P production in response to growth factor stimulation to control the residency time of growth factor receptors in the PI3P(-)/APPL(+)-signaling-competent compartment. As a result, suppression of BECN1 sustains growth factor-stimulated AKT and ERK activation resulting in increased breast carcinoma cell invasion. In human breast tumors, beclin 1 expression is inversely correlated with AKT and ERK phosphorylation. Our data identify a novel role for beclin 1 in regulating growth factor signaling and reveal a mechanism by which loss of beclin 1 expression would enhance breast cancer progression. PMID:25639875

  3. Regulation of cyclic adenosine 3',5'-monophosphate-dependent protein kinase activity and regulatory subunit RII beta content by basic fibroblast growth factor (bFGF) during granulosa cell differentiation: possible implication of protein kinase C in bFGF action.

    PubMed

    Oury, F; Faucher, C; Rives, I; Bensaïd, M; Bouche, G; Darbon, J M

    1992-08-01

    We have previously shown that basic fibroblast growth factor (bFGF) inhibits the FSH-induced differentiation of cultured rat granulosa cells, as manifested by prominent reduction of the LH receptor expression. We now investigate the possible sites and mechanism of action of bFGF. Whereas bFGF decreased the cAMP formation induced by FSH, it enhanced the cAMP production caused by cholera toxin and forskolin, suggesting that bFGF exerted its inhibitory action on cell differentiation at a step to cAMP production. Photoaffinity labeling with 8-azido-[32P]cAMP revealed that bFGF markedly reduced the FSH-induced increase in the level of regulatory subunit RII beta of the cAMP-dependent protein kinase (PKA) type II. In contrast to its striking effect on RII beta expression (70-80% inhibition), bFGF decreased PKA enzymatic activity by only 30%. On the other hand, transforming growth factor-beta (TGF beta) slightly amplified the stimulatory action of FSH and antagonized the bFGF inhibitory effect on both LH receptor expression and RII beta synthesis. We report that the protein kinase C (PKC) activator 12-O-tetradecanoylphorbol-13-acetate (TPA), which impaired granulosa cell differentiation, also abolished the RII beta synthesis induced by FSH. The activation of PKC by bFGF in granulosa cells was supported by the following findings: (i) bFGF markedly enhanced the production of diacylglycerol (2.3-fold stimulation at 5 min), the intracellular activator of PKC; (ii) bFGF promoted tight association of PKC to cellular membranes, a process that is believed to correlate with the enzyme activation; (iii) bFGF induced the phosphorylation of an endogenous M(r) 78,000/pI 4.7 protein that appears as a specific PKC substrate; (iv) bFGF mimicked the TPA-induced transmodulation of the epidermal growth factor (EGF) receptor, reducing by 36% the 125I-EGF binding on granulosa cells. We conclude that bFGF may exert its repressive action on RII beta synthesis, PKA activity, and granulosa cell

  4. The ensembl regulatory build.

    PubMed

    Zerbino, Daniel R; Wilder, Steven P; Johnson, Nathan; Juettemann, Thomas; Flicek, Paul R

    2015-01-01

    Most genomic variants associated with phenotypic traits or disease do not fall within gene coding regions, but in regulatory regions, rendering their interpretation difficult. We collected public data on epigenetic marks and transcription factor binding in human cell types and used it to construct an intuitive summary of regulatory regions in the human genome. We verified it against independent assays for sensitivity. The Ensembl Regulatory Build will be progressively enriched when more data is made available. It is freely available on the Ensembl browser, from the Ensembl Regulation MySQL database server and in a dedicated track hub. PMID:25887522

  5. Cell-penetrable mouse forkhead box protein 3 alleviates experimental arthritis in mice by up-regulating regulatory T cells.

    PubMed

    Liu, Xia; Ji, Baoju; Sun, Mengyi; Wu, Weijiang; Huang, Lili; Sun, Aihua; Zong, Yangyong; Xia, Sheng; Shi, Liyun; Qian, Hui; Xu, Wenrong; Shao, Qixiang

    2015-07-01

    Regulatory T cells (T(regs)) have potential applications in clinical disease therapy, such as autoimmune diseases and transplant rejection. However, their numbers are limited. Forkhead box protein 3 (FoxP3) is a key transcription factor that controls T(reg) development and function. Here, we generated a cell-permeable fusion protein, protein transduction domain (PTD)-conjugated mouse FoxP3 protein (PTD-mFoxP3), and evaluated whether PTD-mFoxp3 can alleviate rheumatoid arthritis (RA) in the collagen-induced arthritis (CIA) mouse model. As expected, PTD-mFoxP3 was transduced into cells effectively, and inhibited T cell activation and attenuated the cell proliferation. It decreased interleukin (IL) 2 and interferon (IFN)-γ expression, and increased IL-10 expression in activated CD4(+)CD25(-) T cells. PTD-mFoxP3-transduced CD4(+)CD25(-) T cells attenuated proliferation of activated CD4(+)CD25(-) T cells. In addition, PTD-mFoxP3 blocked the Th17 differentiation programme in vitro and down-regulated IL-17 production from T cells by modulating induction and levels of retinoid-related orphan receptor gamma t (RORγt). Intra-articular delivery of PTD-mFoxP3 delayed disease incidence remarkably and alleviated autoimmune symptoms of CIA mice. Moreover, protective effects of PTD-mFoxP3 were associated with regulating the balance of T helper type 17 (Th17) and T(regs). These results suggest that PTD-mFoxP3 may be a candidate for RA therapy. PMID:25809415

  6. The role of gene regulatory factors in the evolutionary history of humans.

    PubMed

    Perdomo-Sabogal, Alvaro; Kanton, Sabina; Walter, Maria Beatriz C; Nowick, Katja

    2014-12-01

    Deciphering the molecular basis of how modern human phenotypes have evolved is one of the most fascinating challenges in biology. Here, we will focus on the roles of gene regulatory factors (GRFs), in particular transcription factors (TFs) and long non-coding RNAs (lncRNAs) during human evolution. We will present examples of TFs and lncRNAs that have changed or show signs of positive selection in humans compared to chimpanzees, in modern humans compared to archaic humans, or within modern human populations. On the basis of current knowledge about the functions of these GRF genes, we speculate that they have been involved in speciation as well as in shaping phenotypes such as brain functions, skeletal morphology, and metabolic processes. PMID:25215414

  7. Molecular identification and functional characterisation of the interferon regulatory factor 1 in the blunt snout bream (Megalobrama amblycephala).

    PubMed

    Zhan, Fan-Bin; Liu, Han; Lai, Rui-Fang; Jakovlić, Ivan; Wang, Wen-Bin; Wang, Wei-Min

    2016-07-01

    Interferon regulatory factors (IRFs) play a key role in mediating the host response against pathogen infection and other important biological processes. This is the first report of an IRF family member in blunt snout bream Megalobrama amblycephala. The complete cDNA of M. amblycephala (Ma) IRF1 gene has 1422 nucleotides (nt.), with an open reading frame of 858 nt, encoding a polypeptide of 285 amino acids. The putative MaIRF1 polypeptide shared significant structural homology with known IRF1 homologs: a conserved IRF domain was found at the N-terminal and an IRF association domain 2 at the C-terminal. Phylogenetic analysis showed that MaIRF1 amino acid sequence clustered with other teleost IRF1s, with a grass carp ortholog exhibiting the highest similarity. MaIRF1 mRNA expression patterns were studied using quantitative real-time PCR in healthy fish tissues and after a challenge with Aeromonas hydrophila bacterium. It was constitutively expressed in all examined tissues: the highest in blood, the lowest in muscle. The expression after A. hydrophila challenge was up-regulated in liver, spleen and kidney, but down-regulated in intestine and gills. At the protein level, similar expression patterns were observed in liver and gills. Patterns differed in intestine (up-regulation), spleen (down-regulation) and kidney (expression mostly unchanged). This study indicates that MaIRF1 gene plays an important role in the blunt snout bream immune system, hence providing an important base for further studies. PMID:27150048

  8. Interferon Regulatory Factor 3 and CREB-Binding Protein/p300 Are Subunits of Double-Stranded RNA-Activated Transcription Factor DRAF1

    PubMed Central

    Weaver, Brian K.; Kumar, K. Prasanna; Reich, Nancy C.

    1998-01-01

    Cells respond to viral infection or double-stranded RNA with the transcriptional induction of a subset of alpha/beta interferon-stimulated genes by a pathway distinct from the interferon signal pathway. The transcriptional induction is mediated through a DNA sequence containing the alpha/beta interferon-stimulated response element (ISRE). We previously identified a novel transcription factor, designated double-stranded RNA-activated factor 1 (DRAF1), that recognizes this response element. The DNA-binding specificity of DRAF1 correlates with transcriptional induction, thereby distinguishing it as a positive regulator of alpha/beta interferon-stimulated genes. Two of the components of DRAF1 have now been identified as interferon regulatory factor 3 (IRF-3) and the transcriptional coactivator CREB-binding protein (CBP)/p300. We demonstrate that IRF-3 preexists in the cytoplasm of uninfected cells and translocates to the nucleus following viral infection. Translocation of IRF-3 is accompanied by an increase in serine and threonine phosphorylation. Coimmunoprecipitation analyses of endogenous proteins demonstrate an association of IRF-3 with the transcriptional coactivators CBP and p300 only subsequent to infection. In addition, antibodies to the IRF-3, CBP, and p300 molecules react with DRAF1 bound to the ISRE target site of induced genes. The cellular response that leads to DRAF1 activation and specific gene expression may serve to increase host survival during viral infection. PMID:9488451

  9. Role of conserved cis-regulatory elements in the post-transcriptional regulation of the human MECP2 gene involved in autism

    PubMed Central

    2013-01-01

    Background The MECP2 gene codes for methyl CpG binding protein 2 which regulates activities of other genes in the early development of the brain. Mutations in this gene have been associated with Rett syndrome, a form of autism. The purpose of this study was to investigate the role of evolutionarily conserved cis-elements in regulating the post-transcriptional expression of the MECP2 gene and to explore their possible correlations with a mutation that is known to cause mental retardation. Results A bioinformatics approach was used to map evolutionarily conserved cis-regulatory elements in the transcribed regions of the human MECP2 gene and its mammalian orthologs. Cis-regulatory motifs including G-quadruplexes, microRNA target sites, and AU-rich elements have gained significant importance because of their role in key biological processes and as therapeutic targets. We discovered in the 5′-UTR (untranslated region) of MECP2 mRNA a highly conserved G-quadruplex which overlapped a known deletion in Rett syndrome patients with decreased levels of MeCP2 protein. We believe that this 5′-UTR G-quadruplex could be involved in regulating MECP2 translation. We mapped additional evolutionarily conserved G-quadruplexes, microRNA target sites, and AU-rich elements in the key sections of both untranslated regions. Our studies suggest the regulation of translation, mRNA turnover, and development-related alternative MECP2 polyadenylation, putatively involving interactions of conserved cis-regulatory elements with their respective trans factors and complex interactions among the trans factors themselves. We discovered highly conserved G-quadruplex motifs that were more prevalent near alternative splice sites as compared to the constitutive sites of the MECP2 gene. We also identified a pair of overlapping G-quadruplexes at an alternative 5′ splice site that could potentially regulate alternative splicing in a negative as well as a positive way in the MECP2 pre

  10. Uncertainty analysis in regulatory programs: Application factors versus probabilistic methods in ecological risk assessments of chemicals

    SciTech Connect

    Moore, D.R.J.; Elliot, B.

    1995-12-31

    In assessments of toxic chemicals, sources of uncertainty may be dealt with by two basic approaches: application factors and probabilistic methods. In regulatory programs, the most common approach is to calculate a quotient by dividing the predicted environmental concentration (PEC) by the predicted no effects concentration (PNEC). PNECs are usually derived from laboratory bioassays, thus requiring the use of application factors to account for uncertainty introduced by the extrapolation from the laboratory to the field, and from measurement to assessment endpoints. Using this approach, often with worst-case assumptions about exposure and species sensitivities, the hope is that chemicals with a quotient of less than one will have a very low probability of causing adverse ecological effects. This approach has received widespread criticism recently, particularly because it tends to be overly conservative and does not adequately estimate the magnitude and probability of causing adverse effects. On the plus side, application factors are simple to use, accepted worldwide, and may be used with limited effects data in a quotient calculation. The alternative approach is to use probabilistic methods such as Monte Carlo simulation, Baye`s theorem or other techniques to estimate risk. Such methods often have rigorous statistical assumptions and may have large data requirements. Stating an effect in probabilistic terms, however, forces the identification of sources of uncertainty and quantification of their impact on risk estimation. In this presentation the authors discuss the advantages and disadvantages of using application factors and probabilistic methods in dealing with uncertainty in ecological risk assessments of chemicals. Based on this analysis, recommendations are presented to assist in choosing the appropriate approach for different types of regulatory programs dealing with toxic chemicals.

  11. Superoxide dismutase 1 acts as a nuclear transcription factor to regulate oxidative stress resistance

    PubMed Central

    Tsang, Chi Kwan; Liu, Yuan; Thomas, Janice; Zhang, Yanjie; Zheng, X. F. Steven

    2015-01-01

    Summary Superoxide dismutase 1 (Sod1) has been known for nearly half a century for catalysis of superoxide to hydrogen peroxide. Here we report a new Sod1 function in oxidative signaling: in response to elevated endogenous and exogenous reactive oxygen species (ROS), Sod1 rapidly relocates into the nucleus, which is important for maintaining genomic stability. Interestingly, H2O2 is sufficient to promote Sod1 nuclear localization, indicating that it is responding to general ROS rather than Sod1 substrate superoxide. ROS signaling is mediated by Mec1/ATM and its effector Dun1/Cds1 kinase, through Dun1 interaction with Sod1 and regulation of Sod1 by phosphorylation at S60, 99. In the nucleus, Sod1 binds to the promoters and regulates the expression of oxidative resistance and repair genes. Altogether, our study unravels an unorthodox function of Sod1 as a transcription factor and elucidates the regulatory mechanism for its localization. PMID:24647101

  12. A synopsis of factors regulating beta cell development and beta cell mass.

    PubMed

    Prasadan, Krishna; Shiota, Chiyo; Xiangwei, Xiao; Ricks, David; Fusco, Joseph; Gittes, George

    2016-10-01

    The insulin-secreting beta cells in the endocrine pancreas regulate blood glucose levels, and loss of functional beta cells leads to insulin deficiency, hyperglycemia (high blood glucose) and diabetes mellitus. Current treatment strategies for type-1 (autoimmune) diabetes are islet transplantation, which has significant risks and limitations, or normalization of blood glucose with insulin injections, which is clearly not ideal. The type-1 patients can lack insulin counter-regulatory mechanism; therefore, hypoglycemia is a potential risk. Hence, a cell-based therapy offers a better alternative for the treatment of diabetes. Past research was focused on attempting to generate replacement beta cells from stem cells; however, recently there has been an increasing interest in identifying mechanisms that will lead to the conversion of pre-existing differentiated endocrine cells into beta cells. The goal of this review is to provide an overview of several of the key factors that regulate new beta cell formation (neogenesis) and beta cell proliferation. PMID:27105622

  13. CYLD negatively regulates transforming growth factor-β-signalling via deubiquitinating Akt

    PubMed Central

    Lim, Jae Hyang; Jono, Hirofumi; Komatsu, Kensei; Woo, Chang-Hoon; Lee, Jiyun; Miyata, Masanori; Matsuno, Takashi; Xu, Xiangbin; Huang, Yuxian; Zhang, Wenhong; Park, Soo Hyun; Kim, Yu-Il; Choi, Yoo-Duk; Shen, Huahao; Heo, Kyung-Sun; Xu, Haodong; Bourne, Patricia; Koga, Tomoaki; Xu, Haidong; Yan, Chen; Wang, Binghe; Chen, Lin-Feng; Feng, Xin-Hua; Li, Jian-Dong

    2012-01-01

    Lung injury, whether induced by infection or caustic chemicals, initiates a series of complex wound-healing responses. If uncontrolled, these responses may lead to fibrotic lung diseases and loss of function. Thus, resolution of lung injury must be tightly regulated. The key regulatory proteins required for tightly controlling the resolution of lung injury have yet to be identified. Here we show that loss of deubiquitinase CYLD led to the development of lung fibrosis in mice after infection with Streptococcus pneumoniae. CYLD inhibited transforming growth factor-β-signalling and prevented lung fibrosis by decreasing the stability of Smad3 in an E3 ligase carboxy terminus of Hsc70-interacting protein-dependent manner. Moreover, CYLD decreases Smad3 stability by deubiquitinating K63-polyubiquitinated Akt. Together, our results unveil a role for CYLD in tightly regulating the resolution of lung injury and preventing fibrosis by deubiquitinating Akt. These studies may help develop new therapeutic strategies for preventing lung fibrosis. PMID:22491319

  14. Reprint of "Nuclear transport factors: global regulation of mitosis".

    PubMed

    Forbes, Douglass J; Travesa, Anna; Nord, Matthew S; Bernis, Cyril

    2015-06-01

    The unexpected repurposing of nuclear transport proteins from their function in interphase to an equally vital and very different set of functions in mitosis was very surprising. The multi-talented cast when first revealed included the import receptors, importin alpha and beta, the small regulatory GTPase RanGTP, and a subset of nuclear pore proteins. In this review, we report that recent years have revealed new discoveries in each area of this expanding story in vertebrates: (a) The cast of nuclear import receptors playing a role in mitotic spindle regulation has expanded: both transportin, a nuclear import receptor, and Crm1/Xpo1, an export receptor, are involved in different aspects of spindle assembly. Importin beta and transportin also regulate nuclear envelope and pore assembly. (b) The role of nucleoporins has grown to include recruiting the key microtubule nucleator – the γ-TuRC complex – and the exportin Crm1 to the mitotic kinetochores of humans. Together they nucleate microtubule formation from the kinetochores toward the centrosomes. (c) New research finds that the original importin beta/RanGTP team have been further co-opted by evolution to help regulate other cellular and organismal activities, ranging from the actual positioning of the spindle within the cell perimeter, to regulation of a newly discovered spindle microtubule branching activity, to regulation of the interaction of microtubule structures with specific actin structures. (d) Lastly, because of the multitudinous roles of karyopherins throughout the cell cycle, a recent large push toward testing their potential as chemotherapeutic targets has begun to yield burgeoning progress in the clinic. PMID:26196321

  15. Comparative analysis of transcription factor gene families from Papaver somniferum: identification of regulatory factors involved in benzylisoquinoline alkaloid biosynthesis.

    PubMed

    Agarwal, Parul; Pathak, Sumya; Lakhwani, Deepika; Gupta, Parul; Asif, Mehar Hasan; Trivedi, Prabodh Kumar

    2016-05-01

    Opium poppy (Papaver somniferum L.), known for biosynthesis of several therapeutically important benzylisoquinoline alkaloids (BIAs), has emerged as the premier organism to study plant alkaloid metabolism. The most prominent molecules produced in opium poppy include narcotic analgesic morphine, the cough suppressant codeine, the muscle relaxant papaverine and the anti-microbial agent sanguinarine and berberine. Despite several health benefits, biosynthesis of some of these molecules is very low due to tight temporal and spatial regulation of the genes committed to their biosynthesis. Transcription factors, one of the prime regulators of secondary plant product biosynthesis, might be involved in controlled biosynthesis of BIAs in P. somniferum. In this study, identification of members of different transcription factor gene families using transcriptome datasets of 10 cultivars of P. somniferum with distinct chemoprofile has been carried out. Analysis suggests that most represented transcription factor gene family in all the poppy cultivars is WRKY. Comparative transcriptome analysis revealed differential expression pattern of the members of a set of transcription factor gene families among 10 cultivars. Through analysis, two members of WRKY and one member of C3H gene family were identified as potential candidates which might regulate thebaine and papaverine biosynthesis, respectively, in poppy. PMID:26108744

  16. An Ectopic Network of Transcription Factors Regulated by Hippo Signaling Drives Growth and Invasion of a Malignant Tumor Model.

    PubMed

    Atkins, Mardelle; Potier, Delphine; Romanelli, Lucia; Jacobs, Jelle; Mach, Jana; Hamaratoglu, Fisun; Aerts, Stein; Halder, Georg

    2016-08-22

    Cancer cells have abnormal gene expression profiles; however, to what degree these are chaotic or driven by structured gene regulatory networks is often not known. Here we studied a model of Ras-driven invasive tumorigenesis in Drosophila epithelial tissues and combined in vivo genetics with next-generation sequencing and computational modeling to decipher the regulatory logic of tumor cells. Surprisingly, we discovered that the bulk of the tumor-specific gene expression is controlled by an ectopic network of a few transcription factors that are overexpressed and/or hyperactivated in tumor cells. These factors are Stat, AP-1, the bHLH proteins Myc and AP-4, the nuclear hormone receptor Ftz-f1, the nuclear receptor coactivator Taiman/SRC3, and Mef2. Notably, many of these transcription factors also are hyperactivated in human tumors. Bioinformatic analysis predicted that these factors directly regulate the majority of the tumor-specific gene expression, that they are interconnected by extensive cross-regulation, and that they show a high degree of co-regulation of target genes. Indeed, the factors of this network were required in multiple epithelia for tumor growth and invasiveness, and knockdown of several factors caused a reversion of the tumor-specific expression profile but had no observable effect on normal tissues. We further found that the Hippo pathway effector Yorkie was strongly activated in tumor cells and initiated cellular reprogramming by activating several transcription factors of this network. Thus, modeling regulatory networks identified an ectopic and ordered network of master regulators that control a large part of tumor cell-specific gene expression. PMID:27476594

  17. Impact of Environmental Factors on the Regulation of Cyanotoxin Production

    PubMed Central

    Boopathi, Thangavelu; Ki, Jang-Seu

    2014-01-01

    Cyanobacteria are capable of thriving in almost all environments. Recent changes in climatic conditions due to increased human activities favor the occurrence and severity of harmful cyanobacterial bloom all over the world. Knowledge of the regulation of cyanotoxins by the various environmental factors is essential for effective management of toxic cyanobacterial bloom. In recent years, progress in the field of molecular mechanisms involved in cyanotoxin production has paved the way for assessing the role of various factors on the cyanotoxin production. In this review, we present an overview of the influence of various environmental factors on the production of major group of cyanotoxins, including microcystins, nodularin, cylindrospermopsin, anatoxins and saxitoxins. PMID:24967641

  18. Redox-dependent regulation of epidermal growth factor receptor signaling.

    PubMed

    Heppner, David E; van der Vliet, Albert

    2016-08-01

    Tyrosine phosphorylation-dependent cell signaling represents a unique feature of multicellular organisms, and is important in regulation of cell differentiation and specialized cell functions. Multicellular organisms also contain a diverse family of NADPH oxidases (NOXs) that have been closely linked with tyrosine kinase-based cell signaling and regulate tyrosine phosphorylation via reversible oxidation of cysteine residues that are highly conserved within many proteins involved in this signaling pathway. An example of redox-regulated tyrosine kinase signaling involves the epidermal growth factor receptor (EGFR), a widely studied receptor system with diverse functions in normal cell biology as well as pathologies associated with oxidative stress such as cancer. The purpose of this Graphical Redox Review is to highlight recently emerged concepts with respect to NOX-dependent regulation of this important signaling pathway. PMID:26722841

  19. Redox-dependent regulation of epidermal growth factor receptor signaling

    PubMed Central

    Heppner, David E.; van der Vliet, Albert

    2015-01-01

    Tyrosine phosphorylation-dependent cell signaling represents a unique feature of multicellular organisms, and is important in regulation of cell differentiation and specialized cell functions. Multicellular organisms also contain a diverse family of NADPH oxidases (NOXs) that have been closely linked with tyrosine kinase-based cell signaling and regulate tyrosine phosphorylation via reversible oxidation of cysteine residues that are highly conserved within many proteins involved in this signaling pathway. An example of redox-regulated tyrosine kinase signaling involves the epidermal growth factor receptor (EGFR), a widely studied receptor system with diverse functions in normal cell biology as well as pathologies associated with oxidative stress such as cancer. The purpose of this Graphical Redox Review is to highlight recently emerged concepts with respect to NOX-dependent regulation of this important signaling pathway. PMID:26722841

  20. Analysis of the Salmonella regulatory network suggests involvement of SsrB and H-NS in σE-regulated SPI-2 gene expression

    SciTech Connect

    Li, Jie; Overall, Christopher C.; Nakayasu, Ernesto S.; Kidwai, Afshan S.; Jones, Marcus B.; Johnson, Rudd; Nguyen, Nhu T.; McDermott, Jason E.; Ansong, Charles; Heffron, Fred; Cambronne, Eric; Adkins, Joshua N.

    2015-02-10

    The extracytoplasmic functioning sigma factor σE is known to play an essential role for Salmonella enterica serovar Typhimurium to survive and proliferate in macrophages and mice. However, its regulatory network is not well characterized, especially during infection. Here we used microarray to identify genes regulated by σE in Salmonella grown in three conditions: a nutrient-rich condition and two others that mimic early and late intracellular infection. We found that in each condition σE regulated different sets of genes, and notably, several global regulators. When comparing nutrient-rich and infection-like conditions, large changes were observed in the expression of genes involved in Salmonella pathogenesis island (SPI)-1 type-three secretion system (TTSS), SPI-2 TTSS, protein synthesis, and stress responses. In total, the expression of 58% of Salmonella genes was affected by σE in at least one of the three conditions. An important finding is that σE up-regulates SPI-2 genes, which are essential for Salmonella intracellular survival, by up-regulating SPI-2 activator ssrB expression at the early stage of infection and down-regulating SPI-2 repressor hns expression at a later stage. Moreover, σE is capable of countering the silencing of H-NS, releasing the expression of SPI-2 genes. This connection between σE and SPI-2 genes, combined with the global regulatory effect of σE, may account for the lethality of rpoE-deficient Salmonella in murine infection.

  1. Analysis of the Salmonella regulatory network suggests involvement of SsrB and H-NS in σ(E)-regulated SPI-2 gene expression.

    PubMed

    Li, Jie; Overall, Christopher C; Nakayasu, Ernesto S; Kidwai, Afshan S; Jones, Marcus B; Johnson, Rudd C; Nguyen, Nhu T; McDermott, Jason E; Ansong, Charles; Heffron, Fred; Cambronne, Eric D; Adkins, Joshua N

    2015-01-01

    The extracytoplasmic functioning sigma factor σ(E) is known to play an essential role for Salmonella enterica serovar Typhimurium to survive and proliferate in macrophages and mice. However, its regulatory network is not well-characterized, especially during infection. Here we used microarray to identify genes regulated by σ(E) in Salmonella grown in three conditions: a nutrient-rich condition and two others that mimic early and late intracellular infection. We found that in each condition σ(E) regulated different sets of genes, and notably, several global regulators. When comparing nutrient-rich and infection-like conditions, large changes were observed in the expression of genes involved in Salmonella pathogenesis island (SPI)-1 type-three secretion system (TTSS), SPI-2 TTSS, protein synthesis, and stress responses. In total, the expression of 58% of Salmonella genes was affected by σ(E) in at least one of the three conditions. An important finding is that σ(E) up-regulates SPI-2 genes, which are essential for Salmonella intracellular survival, by up-regulating SPI-2 activator ssrB expression at the early stage of infection and down-regulating SPI-2 repressor hns expression at a later stage. Moreover, σ(E) is capable of countering the silencing of H-NS, releasing the expression of SPI-2 genes. This connection between σ(E) and SPI-2 genes, combined with the global regulatory effect of σ(E), may account for the lethality of rpoE-deficient Salmonella in murine infection. PMID:25713562

  2. Analysis of the Salmonella regulatory network suggests involvement of SsrB and H-NS in σE-regulated SPI-2 gene expression

    PubMed Central

    Li, Jie; Overall, Christopher C.; Nakayasu, Ernesto S.; Kidwai, Afshan S.; Jones, Marcus B.; Johnson, Rudd C.; Nguyen, Nhu T.; McDermott, Jason E.; Ansong, Charles; Heffron, Fred; Cambronne, Eric D.; Adkins, Joshua N.

    2015-01-01

    The extracytoplasmic functioning sigma factor σE is known to play an essential role for Salmonella enterica serovar Typhimurium to survive and proliferate in macrophages and mice. However, its regulatory network is not well-characterized, especially during infection. Here we used microarray to identify genes regulated by σE in Salmonella grown in three conditions: a nutrient-rich condition and two others that mimic early and late intracellular infection. We found that in each condition σE regulated different sets of genes, and notably, several global regulators. When comparing nutrient-rich and infection-like conditions, large changes were observed in the expression of genes involved in Salmonella pathogenesis island (SPI)-1 type-three secretion system (TTSS), SPI-2 TTSS, protein synthesis, and stress responses. In total, the expression of 58% of Salmonella genes was affected by σE in at least one of the three conditions. An important finding is that σE up-regulates SPI-2 genes, which are essential for Salmonella intracellular survival, by up-regulating SPI-2 activator ssrB expression at the early stage of infection and down-regulating SPI-2 repressor hns expression at a later stage. Moreover, σE is capable of countering the silencing of H-NS, releasing the expression of SPI-2 genes. This connection between σE and SPI-2 genes, combined with the global regulatory effect of σE, may account for the lethality of rpoE-deficient Salmonella in murine infection. PMID:25713562

  3. Analysis of the Salmonella regulatory network suggests involvement of SsrB and H-NS in σE-regulated SPI-2 gene expression

    DOE PAGESBeta

    Li, Jie; Overall, Christopher C.; Nakayasu, Ernesto S.; Kidwai, Afshan S.; Jones, Marcus B.; Johnson, Rudd; Nguyen, Nhu T.; McDermott, Jason E.; Ansong, Charles; Heffron, Fred; et al

    2015-02-10

    The extracytoplasmic functioning sigma factor σE is known to play an essential role for Salmonella enterica serovar Typhimurium to survive and proliferate in macrophages and mice. However, its regulatory network is not well characterized, especially during infection. Here we used microarray to identify genes regulated by σE in Salmonella grown in three conditions: a nutrient-rich condition and two others that mimic early and late intracellular infection. We found that in each condition σE regulated different sets of genes, and notably, several global regulators. When comparing nutrient-rich and infection-like conditions, large changes were observed in the expression of genes involved inmore » Salmonella pathogenesis island (SPI)-1 type-three secretion system (TTSS), SPI-2 TTSS, protein synthesis, and stress responses. In total, the expression of 58% of Salmonella genes was affected by σE in at least one of the three conditions. An important finding is that σE up-regulates SPI-2 genes, which are essential for Salmonella intracellular survival, by up-regulating SPI-2 activator ssrB expression at the early stage of infection and down-regulating SPI-2 repressor hns expression at a later stage. Moreover, σE is capable of countering the silencing of H-NS, releasing the expression of SPI-2 genes. This connection between σE and SPI-2 genes, combined with the global regulatory effect of σE, may account for the lethality of rpoE-deficient Salmonella in murine infection.« less

  4. Role of alkaline serine protease, asp, in vibrio alginolyticus virulence and regulation of its expression by luxO-luxR regulatory system.

    PubMed

    Rui, Haopeng; Liu, Qin; Wang, Qiyao; Ma, Yue; Liu, Huan; Shi, Cunbin; Zhang, Yuanxing

    2009-05-01

    The alkaline serine protease asp, which was shown to be a virulence factor of Vibrio alginolyticus as a purified protein, was cloned from V. alginolyticus EPGS, a strain recently isolated from moribund Epinephelus coioides in an outbreak of vibriosis in a mariculture farm of Shenzhen. The asp null mutant was constructed by homologous recombination with suicide plasmid pNQ705-1. Compared with the wild-type strain, the asp null mutant exhibited a significant decrease of total extracellular protease activity, and caused a 15-fold decrease in virulence of V. alginolyticus. In our previous study, the luxO and luxR(val) genes from V. alginolyticus MVP01 were cloned and identified, and the luxO-luxR(val) regulatory couple was shown to regulate various genes expression, suggesting that it played a central role in the quorum sensing system of V. alginolyticus. In this study, the regulation of the asp gene was analyzed by using RT-PCR and quantitative real-time PCR methods; we proved that its transcription was greatly induced at the late large stage of growth and was regulated by luxO-luxR(val) regulatory system. PMID:19494689

  5. Branching of the PIF3 regulatory network in Arabidopsis: roles of PIF3-regulated MIDAs in seedling development in the dark and in response to light.

    PubMed

    Sentandreu, Maria; Leivar, Pablo; Martín, Guiomar; Monte, Elena

    2012-04-01

    Plants need to accurately adjust their development after germination in the underground darkness to ensure survival of the seedling, both in the dark and in the light upon reaching the soil surface. Recent studies have established that the photoreceptors phytochromes and the bHLH phytochrome interacting factors PIFs regulate seedling development to adjust it to the prevailing light environment during post-germinative growth. However, complete understanding of the downstream regulatory network implementing these developmental responses is still lacking. In a recent work, published in The Plant Cell, we report a subset of PIF3-regulated genes in dark-grown seedlings that we have named MIDAs (MISREGULATED IN DARK). Analysis of their functional relevance using mutants showed that four of them present phenotypic alterations in the dark, and that each affected a particular facet of seedling development, suggesting organ-specific branching in the signal that PIF3 relays downstream. Furthermore, our results also showed an altered response to light in seedlings with an impaired PIF3/MIDA regulatory network, indicating that these factors might also be essential to initiate and optimize the developmental adjustment of the seedling to the light environment. PMID:22499182

  6. A Consensus Network of Gene Regulatory Factors in the Human Frontal Lobe.

    PubMed

    Berto, Stefano; Perdomo-Sabogal, Alvaro; Gerighausen, Daniel; Qin, Jing; Nowick, Katja

    2016-01-01

    Cognitive abilities, such as memory, learning, language, problem solving, and planning, involve the frontal lobe and other brain areas. Not much is known yet about the molecular basis of cognitive abilities, but it seems clear that cognitive abilities are determined by the interplay of many genes. One approach for analyzing the genetic networks involved in cognitive functions is to study the coexpression networks of genes with known importance for proper cognitive functions, such as genes that have been associated with cognitive disorders like intellectual disability (ID) or autism spectrum disorders (ASD). Because many of these genes are gene regulatory factors (GRFs) we aimed to provide insights into the gene regulatory networks active in the human frontal lobe. Using genome wide human frontal lobe expression data from 10 independent data sets, we first derived 10 individual coexpression networks for all GRFs including their potential target genes. We observed a high level of variability among these 10 independently derived networks, pointing out that relying on results from a single study can only provide limited biological insights. To instead focus on the most confident information from these 10 networks we developed a method for integrating such independently derived networks into a consensus network. This consensus network revealed robust GRF interactions that are conserved across the frontal lobes of different healthy human individuals. Within this network, we detected a strong central module that is enriched for 166 GRFs known to be involved in brain development and/or cognitive disorders. Interestingly, several hubs of the consensus network encode for GRFs that have not yet been associated with brain functions. Their central role in the network suggests them as excellent new candidates for playing an essential role in the regulatory network of the human frontal lobe, which should be investigated in future studies. PMID:27014338

  7. A Consensus Network of Gene Regulatory Factors in the Human Frontal Lobe

    PubMed Central

    Berto, Stefano; Perdomo-Sabogal, Alvaro; Gerighausen, Daniel; Qin, Jing; Nowick, Katja

    2016-01-01

    Cognitive abilities, such as memory, learning, language, problem solving, and planning, involve the frontal lobe and other brain areas. Not much is known yet about the molecular basis of cognitive abilities, but it seems clear that cognitive abilities are determined by the interplay of many genes. One approach for analyzing the genetic networks involved in cognitive functions is to study the coexpression networks of genes with known importance for proper cognitive functions, such as genes that have been associated with cognitive disorders like intellectual disability (ID) or autism spectrum disorders (ASD). Because many of these genes are gene regulatory factors (GRFs) we aimed to provide insights into the gene regulatory networks active in the human frontal lobe. Using genome wide human frontal lobe expression data from 10 independent data sets, we first derived 10 individual coexpression networks for all GRFs including their potential target genes. We observed a high level of variability among these 10 independently derived networks, pointing out that relying on results from a single study can only provide limited biological insights. To instead focus on the most confident information from these 10 networks we developed a method for integrating such independently derived networks into a consensus network. This consensus network revealed robust GRF interactions that are conserved across the frontal lobes of different healthy human individuals. Within this network, we detected a strong central module that is enriched for 166 GRFs known to be involved in brain development and/or cognitive disorders. Interestingly, several hubs of the consensus network encode for GRFs that have not yet been associated with brain functions. Their central role in the network suggests them as excellent new candidates for playing an essential role in the regulatory network of the human frontal lobe, which should be investigated in future studies. PMID:27014338

  8. Zinc Finger Transcription Factors Displaced SREBP Proteins as the Major Sterol Regulators during Saccharomycotina Evolution

    PubMed Central

    Maguire, Sarah L.; Wang, Can; Holland, Linda M.; Brunel, François; Neuvéglise, Cécile; Nicaud, Jean-Marc; Zavrel, Martin; White, Theodore C.; Wolfe, Kenneth H.; Butler, Geraldine

    2014-01-01

    In most eukaryotes, including the majority of fungi, expression of sterol biosynthesis genes is regulated by Sterol-Regulatory Element Binding Proteins (SREBPs), which are basic helix-loop-helix transcription activators. However, in yeasts such as Saccharomyces cerevisiae and Candida albicans sterol synthesis is instead regulated by Upc2, an unrelated transcription factor with a Gal4-type zinc finger. The SREBPs in S. cerevisiae (Hms1) and C. albicans (Cph2) have lost a domain, are not major regulators of sterol synthesis, and instead regulate filamentous growth. We report here that rewiring of the sterol regulon, with Upc2 taking over from SREBP, likely occurred in the common ancestor of all Saccharomycotina. Yarrowia lipolytica, a deep-branching species, is the only genome known to contain intact and full-length orthologs of both SREBP (Sre1) and Upc2. Deleting YlUPC2, but not YlSRE1, confers susceptibility to azole drugs. Sterol levels are significantly reduced in the YlUPC2 deletion. RNA-seq analysis shows that hypoxic regulation of sterol synthesis genes in Y. lipolytica is predominantly mediated by Upc2. However, YlSre1 still retains a role in hypoxic regulation; growth of Y. lipolytica in hypoxic conditions is reduced in a Ylupc2 deletion and is abolished in a Ylsre1/Ylupc2 double deletion, and YlSre1 regulates sterol gene expression during hypoxia adaptation. We show that YlSRE1, and to a lesser extent YlUPC2, are required for switching from yeast to filamentous growth in hypoxia. Sre1 appears to have an ancestral role in the regulation of filamentation, which became decoupled from its role in sterol gene regulation by the arrival of Upc2 in the Saccharomycotina. PMID:24453983

  9. Rice ASR1 and ASR5 are complementary transcription factors regulating aluminium responsive genes.

    PubMed

    Arenhart, Rafael Augusto; Schunemann, Mariana; Bucker Neto, Lauro; Margis, Rogerio; Wang, Zhi-Yong; Margis-Pinheiro, Marcia

    2016-03-01

    Rice is the most tolerant staple crop to aluminium (Al) toxicity, which is a limiting stress for grain production worldwide. This Al tolerance is the result of combined mechanisms that are triggered in part by the transcription factor ASR5. ASRs are dual target proteins that participate as chaperones in the cytoplasm and as transcription factors in the nucleus. Moreover, these proteins respond to biotic and abiotic stresses, including salt, drought and Al. Rice plants with silenced ASR genes are highly sensitive to Al. ASR5, a well-characterized protein, binds to specific cis elements in Al responsive genes and regulates their expression. Because the Al sensitive phenotype found in silenced rice plants could be due to the mutual silencing of ASR1 and ASR5, we investigated the effect of the specific silencing of ASR5. Plants with artificial microRNA silencing of ASR5 present a non-transformed phenotype in response to Al because of the induction of ASR1. ASR1 has the same subcellular localization as ASR5, binds to ASR5 cis-regulatory elements, regulates ASR5 regulated genes in a non-preferential manner and might replace ASR5 under certain conditions. Our results indicate that ASR1 and ASR5 act in concert and complementarily to regulate gene expression in response to Al. PMID:26476017

  10. RivR is a negative regulator of virulence factor expression in group A Streptococcus.

    PubMed

    Treviño, Jeanette; Liu, Zhuyun; Cao, Tram N; Ramirez-Peña, Esmeralda; Sumby, Paul

    2013-01-01

    The bacterial pathogen group A Streptococcus (GAS) causes human diseases ranging from self-limiting pharyngitis (also known as strep throat) to severely invasive necrotizing fasciitis (also known as the flesh-eating syndrome). To control virulence factor expression, GAS utilizes both protein- and RNA-based mechanisms of regulation. Here we report that the transcription factor RivR (RofA-like protein IV) negatively regulates the abundance of mRNAs encoding the hyaluronic acid capsule biosynthesis proteins (hasABC; ∼7-fold) and the protein G-related α(2)-macroglobulin-binding protein (grab; ∼29-fold). Our data differ significantly from those of a previous study of the RivR regulon. Given that grab and hasABC are also negatively regulated by the two-component system CovR/S (control of virulence), we tested whether RivR functions through CovR/S. A comparison of riv and cov single and double mutant strains showed that RivR requires CovR activity for grab and hasABC regulation. Analysis of the upstream region of rivR identified a novel promoter the deletion of which reduced rivR mRNA abundance by 70%. A rivR mutant strain had a reduced ability to adhere to human keratinocytes relative to that of the parental and complemented strains, a phenotype that was abolished upon GAS pretreatment with hyaluronidase, highlighting the importance of capsule regulation by RivR during colonization. The rivR mutant strain was also attenuated for virulence in a murine model of bacteremia infection. Thus, we identify RivR as an important regulator of GAS virulence and provide new insight into the regulatory networks controlling virulence factor production in this pathogen. PMID:23147037

  11. RivR Is a Negative Regulator of Virulence Factor Expression in Group A Streptococcus

    PubMed Central

    Treviño, Jeanette; Liu, Zhuyun; Cao, Tram N.; Ramirez-Peña, Esmeralda

    2013-01-01

    The bacterial pathogen group A Streptococcus (GAS) causes human diseases ranging from self-limiting pharyngitis (also known as strep throat) to severely invasive necrotizing fasciitis (also known as the flesh-eating syndrome). To control virulence factor expression, GAS utilizes both protein- and RNA-based mechanisms of regulation. Here we report that the transcription factor RivR (RofA-like protein IV) negatively regulates the abundance of mRNAs encoding the hyaluronic acid capsule biosynthesis proteins (hasABC; ∼7-fold) and the protein G-related α2-macroglobulin-binding protein (grab; ∼29-fold). Our data differ significantly from those of a previous study of the RivR regulon. Given that grab and hasABC are also negatively regulated by the two-component system CovR/S (control of virulence), we tested whether RivR functions through CovR/S. A comparison of riv and cov single and double mutant strains showed that RivR requires CovR activity for grab and hasABC regulation. Analysis of the upstream region of rivR identified a novel promoter the deletion of which reduced rivR mRNA abundance by 70%. A rivR mutant strain had a reduced ability to adhere to human keratinocytes relative to that of the parental and complemented strains, a phenotype that was abolished upon GAS pretreatment with hyaluronidase, highlighting the importance of capsule regulation by RivR during colonization. The rivR mutant strain was also attenuated for virulence in a murine model of bacteremia infection. Thus, we identify RivR as an important regulator of GAS virulence and provide new insight into the regulatory networks controlling virulence factor production in this pathogen. PMID:23147037

  12. Interferon Regulatory Factor 6 promotes differentiation of the periderm by activating expression of Grainyhead-like 3

    PubMed Central

    de la Garza, Gabriel; Schleiffarth, Jack Robert; Dunnwald, Martine; Mankad, Anuj; Weirather, Jason L.; Bonde, Gregory; Butcher, Stephen; Mansour, Tamer A.; Kousa, Youssef A.; Fukazawa, Cindy F.; Houston, Douglas W.; Manak, J. Robert; Schutte, Brian C.; Wagner, Daniel; Cornell, Robert A.

    2012-01-01

    Interferon Regulatory Factor 6 (IRF6) is a transcription factor that, in mammals, is required for the differentiation of skin, breast epithelium, and oral epithelium. However, the transcriptional targets that mediate these effects are currently unknown. In zebrafish and frog embryos Irf6 is necessary for differentiation of the embryonic superficial epithelium, or periderm. Here we use microarrays to identify genes that are expressed in the zebrafish periderm and whose expression is inhibited by a dominant-negative variant of Irf6 (dnIrf6). These methods identify Grhl3, an ancient regulator of the epidermal permeability barrier, as acting downstream of Irf6. In human keratinocytes, IRF6 binds conserved elements near the GHRL3 promoter. We show that one of these elements has enhancer activity in human keratinocytes and zebrafish periderm, suggesting that Irf6 directly stimulates Grhl3 expression in these tissues. Simultaneous inhibition of grhl1 and grhl3 disrupts periderm differentiation in zebrafish, and, intriguingly, forced grhl3 expression restores periderm markers in both zebrafish injected with dnIrf6 and frog embryos depleted of Irf6. Finally, in Irf6 deficient mouse embryos, Grhl3 expression in the periderm and oral epithelium is virtually absent. These results indicate that Grhl3 is a key effector of Irf6 in periderm differentiation. PMID:22931925

  13. Polymorphisms in the Tyrosine Kinase 2 and Interferon Regulatory Factor 5 Genes Are Associated with Systemic Lupus Erythematosus

    PubMed Central

    Sigurdsson, Snaevar; Nordmark, Gunnel; Göring, Harald H. H.; Lindroos, Katarina; Wiman, Ann-Christin; Sturfelt, Gunnar; Jönsen, Andreas; Rantapää-Dahlqvist, Solbritt; Möller, Bozena; Kere, Juha; Koskenmies, Sari; Widén, Elisabeth; Eloranta, Maija-Leena; Julkunen, Heikki; Kristjansdottir, Helga; Steinsson, Kristjan; Alm, Gunnar; Rönnblom, Lars; Syvänen, Ann-Christine

    2005-01-01

    Systemic lupus erythematosus (SLE) is a complex systemic autoimmune disease caused by both genetic and environmental factors. Genome scans in families with SLE point to multiple potential chromosomal regions that harbor SLE susceptibility genes, and association studies in different populations have suggested several susceptibility alleles for SLE. Increased production of type I interferon (IFN) and expression of IFN-inducible genes is commonly observed in SLE and may be pivotal in the molecular pathogenesis of the disease. We analyzed 44 single-nucleotide polymorphisms (SNPs) in 13 genes from the type I IFN pathway in 679 Swedish, Finnish, and Icelandic patients with SLE, in 798 unaffected family members, and in 438 unrelated control individuals for joint linkage and association with SLE. In two of the genes—the tyrosine kinase 2 (TYK2) and IFN regulatory factor 5 (IRF5) genes—we identified SNPs that displayed strong signals in joint analysis of linkage and association (unadjusted P<10-7) with SLE. TYK2 binds to the type I IFN receptor complex and IRF5 is a regulator of type I IFN gene expression. Thus, our results support a disease mechanism in SLE that involves key components of the type I IFN system. PMID:15657875

  14. Global Identification of SMAD2 Target Genes Reveals a Role for Multiple Co-regulatory Factors in Zebrafish Early Gastrulas*

    PubMed Central

    Liu, Zhaoting; Lin, Xiwen; Cai, Zhaoping; Zhang, Zhuqiang; Han, Chunsheng; Jia, Shunji; Meng, Anming; Wang, Qiang

    2011-01-01

    Nodal and Smad2/3 signals play pivotal roles in mesendoderm induction and axis determination during late blastulation and early gastrulation in vertebrate embryos. However, Smad2/3 direct target genes during those critical developmental stages have not been systematically identified. Here, through ChIP-chip assay, we show that the promoter/enhancer regions of 679 genes are bound by Smad2 in the zebrafish early gastrulas. Expression analyses confirm that a significant proportion of Smad2 targets are indeed subjected to Nodal/Smad2 regulation at the onset of gastrulation. The co-existence of DNA-binding sites of other transcription factors in the Smad2-bound regions allows the identification of well known Smad2-binding partners, such as FoxH1 and Lef1/β-catenin, as well as many previously unknown Smad2 partners, including Oct1 and Gata6, during embryogenesis. We demonstrate that Oct1 physically associates with and enhances the transcription and mesendodermal induction activity of Smad2, whereas Gata6 exerts an inhibitory role in Smad2 signaling and mesendodermal induction. Thus, our study systemically uncovers a large number of Smad2 targets in early gastrulas and suggests cooperative roles of Smad2 and other transcription factors in controlling target gene transcription, which will be valuable for studying regulatory cascades during germ layer formation and patterning of vertebrate embryos. PMID:21669877

  15. Tumour necrosis factor-alpha and interferon-gamma synergistically activate the RANTES promoter through nuclear factor kappaB and interferon regulatory factor 1 (IRF-1) transcription factors.

    PubMed

    Lee, A H; Hong, J H; Seo, Y S

    2000-08-15

    Inflammatory cytokines such as tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) synergistically activate expression of the RANTES (regulated upon activation, normal T-cell expressed and secreted) gene, which plays a crucial role in the chemoattraction of leukocytes during the inflammatory response. To understand at the molecular level the mechanism by which the two cytokines activate RANTES gene expression, we determined the requirement of cis-acting elements in the RANTES promoter and trans-acting factors. The murine RANTES promoter contained one putative interferon regulatory factor, IRF, and three putative nuclear factor kappaB (NF-kappaB) binding sites. Specific destruction of the IRF binding site and one of the three NF-kappaB binding sites abolished the inducibility of promoter activity by IFN-gamma and TNF-alpha, respectively. In contrast, mutation of the other two putative NF-kappaB binding sites did not affect RANTES promoter activity significantly. In addition, the RANTES promoter was stimulated by co-transfection of plasmids that expressed either p65, an NF-kappaB family protein, or the IRF-1 transcription factor. RANTES promoters with mutations in the NF-kappaB or IRF binding sites were not stimulated by p65 or IRF-1 expression, respectively. In electrophoretic mobility-shift and immunologic assays, we showed that IRF-1 was induced after cells were treated with IFN-gamma and that NF-kappaB was activated by TNF-alpha treatment. These results demonstrate that both NF-kappaB and IRF-1 transcription factors mediate the induction of RANTES expression via their cognate cis-acting elements when cells are stimulated by TNF-alpha and IFN-gamma. PMID:10926836

  16. Apoptosis in mammalian preimplantation embryos: regulation by survival factors.

    PubMed

    Brison, Daniel R.

    2000-01-01

    The formation of a developmentally competent mammalian blastocyst requires the transition from a unicellular state, the fertilized zygote, to a differentiated multicellular structure. In common with other developing organisms, generation of the required cell population involves the processes of cell division, differentiation and cell death, all of which can be regulated by peptide growth factors. Cell death in the preimplantation embryo occurs by apoptosis and, by analogy with other systems, may serve to eliminate unwanted cells during the critical developmental transitions that take place during this period. Cells may be eliminated because they are abnormal or possess defects, including damaged DNA or chromosomal abnormalities. At the early cleavage stages, apoptosis may be associated with activation of the embryonic genome and may contribute to the blastomere fragmentation commonly observed in human IVF embryos. The major wave of apoptosis occurs in a number of species in the inner cell mass of the blastocyst, as identified using nuclear labelling including terminal transferase-mediated dUTP nick end labelling (TUNEL) and fluorescence and confocal microscopy. Apoptosis may protect the integrity and cellular composition of the inner cell mass, by eliminating damaged cells or possibly those with an inappropriate phenotype. Preimplantation embryos express genes involved in the regulation and execution of apoptosis and their cells can undergo this default pathway in the absence of exogenous survival signals. Evidence is now accumulating from several species that apoptosis in the embryo is regulated by soluble peptide growth factors acting as survival factors in an autocrine or paracrine manner. To date, these include transforming growth factor alpha and members of the insulin-like growth factor family. Apoptosis may also be affected by environmental factors, including culture conditions and the composition of media. The regulation of apoptosis in the preimplantation

  17. Discrimination between thermodynamic models of cis-regulation using transcription factor occupancy data.

    PubMed

    Zeigler, Robert D; Cohen, Barak A

    2014-02-01

    Many studies have identified binding preferences for transcription factors (TFs), but few have yielded predictive models of how combinations of transcription factor binding sites generate specific levels of gene expression. Synthetic promoters have emerged as powerful tools for generating quantitative data to parameterize models of combinatorial cis-regulation. We sought to improve the accuracy of such models by quantifying the occupancy of TFs on synthetic promoters in vivo and incorporating these data into statistical thermodynamic models of cis-regulation. Using chromatin immunoprecipitation-seq, we measured the occupancy of Gcn4 and Cbf1 in synthetic promoter libraries composed of binding sites for Gcn4, Cbf1, Met31/Met32 and Nrg1. We measured the occupancy of these two TFs and the expression levels of all promoters in two growth conditions. Models parameterized using only expression data predicted expression but failed to identify several interactions between TFs. In contrast, models parameterized with occupancy and expression data predicted expression data, and also revealed Gcn4 self-cooperativity and a negative interaction between Gcn4 and Nrg1. Occupancy data also allowed us to distinguish between competing regulatory mechanisms for the factor Gcn4. Our framework for combining occupancy and expression data produces predictive models that better reflect the mechanisms underlying combinatorial cis-regulation of gene expression. PMID:24288374

  18. Mga2 Transcription Factor Regulates an Oxygen-responsive Lipid Homeostasis Pathway in Fission Yeast.

    PubMed

    Burr, Risa; Stewart, Emerson V; Shao, Wei; Zhao, Shan; Hannibal-Bach, Hans Kristian; Ejsing, Christer S; Espenshade, Peter J

    2016-06-01

    Eukaryotic lipid synthesis is oxygen-dependent with cholesterol synthesis requiring 11 oxygen molecules and fatty acid desaturation requiring 1 oxygen molecule per double bond. Accordingly, organisms evaluate oxygen availability to control lipid homeostasis. The sterol regulatory element-binding protein (SREBP) transcription factors regulate lipid homeostasis. In mammals, SREBP-2 controls cholesterol biosynthesis, whereas SREBP-1 controls triacylglycerol and glycerophospholipid biosynthesis. In the fission yeast Schizosaccharomyces pombe, the SREBP-2 homolog Sre1 regulates sterol homeostasis in response to changing sterol and oxygen levels. However, notably missing is an SREBP-1 analog that regulates triacylglycerol and glycerophospholipid homeostasis in response to low oxygen. Consistent with this, studies have shown that the Sre1 transcription factor regulates only a fraction of all genes up-regulated under low oxygen. To identify new regulators of low oxygen adaptation, we screened the S. pombe nonessential haploid deletion collection and identified 27 gene deletions sensitive to both low oxygen and cobalt chloride, a hypoxia mimetic. One of these genes, mga2, is a putative transcriptional activator. In the absence of mga2, fission yeast exhibited growth defects under both normoxia and low oxygen conditions. Mga2 transcriptional targets were enriched for lipid metabolism genes, and mga2Δ cells showed disrupted triacylglycerol and glycerophospholipid homeostasis, most notably with an increase in fatty acid saturation. Indeed, addition of exogenous oleic acid to mga2Δ cells rescued the observed growth defects. Together, these results establish Mga2 as a transcriptional regulator of triacylglycerol and glycerophospholipid homeostasis in S. pombe, analogous to mammalian SREBP-1. PMID:27053105

  19. Fasting-Induced Protein Phosphatase 1 Regulatory Subunit Contributes to Postprandial Blood Glucose Homeostasis via Regulation of Hepatic Glycogenesis

    PubMed Central

    Luo, Xiaolin; Zhang, Yongxian; Ruan, Xiangbo; Jiang, Xiaomeng; Zhu, Lu; Wang, Xiao; Ding, Qiurong; Liu, Weizhong; Pan, Yi; Wang, Zhenzhen; Chen, Yan

    2011-01-01

    OBJECTIVE Most animals experience fasting–feeding cycles throughout their lives. It is well known that the liver plays a central role in regulating glycogen metabolism. However, how hepatic glycogenesis is coordinated with the fasting–feeding cycle to control postprandial glucose homeostasis remains largely unknown. This study determines the molecular mechanism underlying the coupling of hepatic glycogenesis with the fasting–feeding cycle. RESEARCH DESIGN AND METHODS Through a series of molecular, cellular, and animal studies, we investigated how PPP1R3G, a glycogen-targeting regulatory subunit of protein phosphatase 1 (PP1), is implicated in regulating hepatic glycogenesis and glucose homeostasis in a manner tightly orchestrated with the fasting–feeding cycle. RESULTS PPP1R3G in the liver is upregulated during fasting and downregulated after feeding. PPP1R3G associates with glycogen pellet, interacts with the catalytic subunit of PP1, and regulates glycogen synthase (GS) activity. Fasting glucose level is reduced when PPP1R3G is overexpressed in the liver. Hepatic knockdown of PPP1R3G reduces postprandial elevation of GS activity, decreases postprandial accumulation of liver glycogen, and decelerates postprandial clearance of blood glucose. Other glycogen-targeting regulatory subunits of PP1, such as PPP1R3B, PPP1R3C, and PPP1R3D, are downregulated by fasting and increased by feeding in the liver. CONCLUSIONS We propose that the opposite expression pattern of PPP1R3G versus other PP1 regulatory subunits comprise an intricate regulatory machinery to control hepatic glycogenesis during the fasting–feeding cycle. Because of its unique expression pattern, PPP1R3G plays a major role to control postprandial glucose homeostasis during the fasting–feeding transition via its regulation on liver glycogenesis. PMID:21471512

  20. The Transcription Factor Interferon Regulatory Factor 1 Is Expressed after Cerebral Ischemia and Contributes to Ischemic Brain Injury

    PubMed Central

    Iadecola, Costantino; Salkowski, Cindy A.; Zhang, Fangyi; Aber, Tracy; Nagayama, Masao; Vogel, Stefanie N.; Elizabeth Ross, M.

    1999-01-01

    The transcription factor interferon regulatory factor 1 (IRF-1) is involved in the molecular mechanisms of inflammation and apoptosis, processes that contribute to ischemic brain injury. In this study, the induction of IRF-1 in response to cerebral ischemia and its role in ischemic brain injury were investigated. IRF-1 gene expression was markedly upregulated within 12 h of occlusion of the middle cerebral artery in C57BL/6 mice. The expression reached a peak 4 d after ischemia (6.0 ± 1.8-fold; P < 0.001) and was restricted to the ischemic regions of the brain. The volume of ischemic injury was reduced by 23 ± 3% in IRF-1+/− and by 46 ± 9% in IRF-1−/− mice (P < 0.05). The reduction in infarct volume was paralleled by a substantial attenuation in neurological deficits. Thus, IRF-1 is the first nuclear transacting factor demonstrated to contribute directly to cerebral ischemic damage and may be a novel therapeutic target in ischemic stroke. PMID:9989987

  1. Adenovirus Induction of an Interferon-Regulatory Factor during Entry into the Late Phase of Infection

    PubMed Central

    Feigenblum, David; Walker, Robert; Schneider, Robert J.

    1998-01-01

    Virus infection of animal cells can induce intracellular antiviral responses mediated by the induction of interferon-regulatory transcription factors (IRFs), which bind to and control genes directed by the interferon-stimulated response element (ISRE). The purpose of this study was to determine whether adenovirus (Ad) induces IRFs during infection, because they might play a role in promoting viral pathogenesis. Here we show that after the late phase of infection, Ad induces a transcription factor related to the IRF family of factors. The IRF is induced shortly after Ad entry into late phase and is shown to stimulate ISRE-directed transcription, to require activation by protein tyrosine kinase signalling, and to be induced several hours prior to the inhibition of cell protein synthesis. Inhibition of tyrosine kinase activity blocks Ad induction and activation of the IRF. Attempts to identify the Ad-induced factor immunologically and by photo-UV cross-linking indicate that it is likely a novel member of the IRF family. Finally, several independent lines of evidence also suggest that Ad induction of the IRF might correlate with the ability of the virus to block host cell protein synthesis later during infection. PMID:9765473

  2. Regulation of endogenous human gene expression by ligand-inducible TALE transcription factors.

    PubMed

    Mercer, Andrew C; Gaj, Thomas; Sirk, Shannon J; Lamb, Brian M; Barbas, Carlos F

    2014-10-17

    The construction of increasingly sophisticated synthetic biological circuits is dependent on the development of extensible tools capable of providing specific control of gene expression in eukaryotic cells. Here, we describe a new class of synthetic transcription factors that activate gene expression in response to extracellular chemical stimuli. These inducible activators consist of customizable transcription activator-like effector (TALE) proteins combined with steroid hormone receptor ligand-binding domains. We demonstrate that these ligand-responsive TALE transcription factors allow for tunable and conditional control of gene activation and can be used to regulate the expression of endogenous genes in human cells. Since TALEs can be designed to recognize any contiguous DNA sequence, the conditional gene regulatory system described herein will enable the design of advanced synthetic gene networks. PMID:24251925

  3. Transcription factor AP-2 regulates human immunodeficiency virus type 1 gene expression.

    PubMed Central

    Perkins, N D; Agranoff, A B; Duckett, C S; Nabel, G J

    1994-01-01

    Human immunodeficiency virus type 1 (HIV-1) gene expression is regulated by an enhancer region composed of multiple potential cis-acting regulatory sites. Here, we describe binding sites for the transcription factor AP-2 in the HIV-1 long terminal repeat which modulate HIV enhancer function. One site is embedded within the two previously described kappa B elements, and a second site is detected further downstream. DNase I footprinting and electrophoretic mobility shift assay experiments demonstrated that AP-2 binds to the site between the kappa B elements. Interestingly, AP-2 and NF-kappa B bind to this region in a mutually exclusive manner. Mutations which disrupt this AP-2-binding site lower basal levels of transcription but do not affect NF-kappa B-mediated induction by tumor necrosis factor alpha in Jurkat T leukemia cells. Images PMID:8084021

  4. The microRNA regulatory network: a far-reaching approach to the regulate the Wnt signaling pathway in number of diseases.

    PubMed

    Mahmood, Shahid; Bhatti, Attya; Syed, Nida Ali; John, Peter

    2016-06-01

    Wnt signaling pathway plays an important role in cell renewal, tumorigenesis, organogenesis, bone formation and bone resorption. Wnt signaling pathway is divided into two outlets: Wnt-β-catenin pathway (canonical pathway) and Wnt-calcium pathway (non-canonical pathway). miRNAs play a key role in the regulation of Wnt signaling pathway. In this review, we highlight the basic indulgent of miRNAs-mediated regulation of Wnt signaling pathway. We focus on the role of miRNAs at different levels of Wnt signaling: signaling molecules, their associated signaling proteins, regulatory proteins, transcription factors and related cytokines. Finally, we concluded that these multiple levels of targeting may have diagnostic potential as well as therapeutic prospective in future treatment. PMID:26523375

  5. Regulatory elements responsible for inducible expression of the granulocyte colony-stimulating factor gene in macrophages.

    PubMed Central

    Nishizawa, M; Nagata, S

    1990-01-01

    Granulocyte colony-stimulating factor (G-CSF) plays an essential role in granulopoiesis during bacterial infection. Macrophages produce G-CSF in response to bacterial endotoxins such as lipopolysaccharide (LPS). To elucidate the mechanism of the induction of G-CSF gene in macrophages or macrophage-monocytes, we have examined regulatory cis elements in the promoter of mouse G-CSF gene. Analyses of linker-scanning and internal deletion mutants of the G-CSF promoter by the chloramphenicol acetyltransferase assay have indicated that at least three regulatory elements are indispensable for the LPS-induced expression of the G-CSF gene in macrophages. When one of the three elements was reiterated and placed upstream of the TATA box of the G-CSF promoter, it mediated inducibility as a tissue-specific and orientation-independent enhancer. Although this element contains a conserved NF-kappa B-like binding site, the gel retardation assay and DNA footprint analysis with nuclear extracts from macrophage cell lines demonstrated that nuclear proteins bind to the DNA sequence downstream of the NF-kappa B-like element, but not to the conserved element itself. The DNA sequence of the binding site was found to have some similarities to the LPS-responsive element which was recently identified in the promoter of the mouse class II major histocompatibility gene. Images PMID:1691438

  6. Brain-derived neurotrophic factor, food intake regulation, and obesity.

    PubMed

    Rosas-Vargas, Haydeé; Martínez-Ezquerro, José Darío; Bienvenu, Thierry

    2011-08-01

    Brain-derived neurotrophic factor (BDNF) is a neurotrophin that plays a fundamental role in development and plasticity of the central nervous system (CNS). It is currently recognized as a major participant in the regulation of food intake. Multiple studies have shown that different regulators of appetite such as leptin, insulin and pancreatic polypeptide (PP) potentially exert anorexigenic effects through BDNF. Low circulating levels of BDNF are associated with a higher risk of eating disorders such as anorexia nervosa (AN) and bulimia nervosa (BN). Strict food restriction reduces BDNF and may trigger binge-eating episodes and weight gain. The existence of mutations that cause haploinsufficiency of BDNF as well as some genetic variants, notably the BDNF p.Val66Met polymorphism, are also associated with the development of obese phenotypes and hyperphagia. However, association of the Met allele with AN and BN, which have different phenotypic characteristics, shows clearly the existence of other relevant factors that regulate eating behavior. This may, in part, be explained by the epigenetic regulation of BDNF through mechanisms like DNA methylation and histone acetylation. Environmental factors, primarily during early development, are crucial to the establishment of these stable but reversible changes that alter the transcriptional expression and are transgenerationally heritable, with potential concomitant effects on the development of eating disorders and body weight control. PMID:21945389

  7. Regulation of Drosophila Eye Development by the Transcription Factor Sine oculis

    PubMed Central

    Kwak, Su-Jin; Wang, Feng; Wang, Hui; Chen, Rui; Mardon, Graeme

    2014-01-01

    Homeodomain transcription factors of the Sine oculis (SIX) family direct multiple regulatory processes throughout the metazoans. Sine oculis (So) was first characterized in the fruit fly Drosophila melanogaster, where it is both necessary and sufficient for eye development, regulating cell survival, proliferation, and differentiation. Despite its key role in development, only a few direct targets of So have been described previously. In the current study, we aim to expand our knowledge of So-mediated transcriptional regulation in the developing Drosophila eye using ChIP-seq to map So binding regions throughout the genome. We find 7,566 So enriched regions (peaks), estimated to map to 5,952 genes. Using overlap between the So ChIP-seq peak set and genes that are differentially regulated in response to loss or gain of so, we identify putative direct targets of So. We find So binding enrichment in genes not previously known to be regulated by So, including genes that encode cell junction proteins and signaling pathway components. In addition, we analyze a subset of So-bound novel genes in the eye, and find eight genes that have previously uncharacterized eye phenotypes and may be novel direct targets of So. Our study presents a greatly expanded list of candidate So targets and serves as basis for future studies of So-mediated gene regulation in the eye. PMID:24586968

  8. Unraveling the regulatory network in Streptococcus pyogenes: the global response regulator CovR represses rivR directly.

    PubMed

    Roberts, Samantha A; Churchward, Gordon G; Scott, June R

    2007-02-01

    The response regulator CovR acts as a master regulator of virulence in Streptococcus pyogenes by repressing transcription of approximately 15% of the group A streptococcus genome directly or indirectly. We demonstrate that phosphorylated CovR represses transcription of rivR directly by binding to conserved sequences located downstream from the promoter to block procession of RNA polymerase. This establishes the first link in a regulatory network where CovR interacts directly with other proteins that modulate gene expression. PMID:16963575

  9. Understanding the molecular mechanism of transcriptional regulation of banana Sucrose phosphate synthase (SPS) gene during fruit ripening: an insight into the functions of various cis-acting regulatory elements.

    PubMed

    Choudhury, Swarup Roy; Roy, Sujit; Singh, Sanjay Kumar; Sengupta, Dibyendu N

    2010-05-01

    Recently, we have reported the characterization of promoter region of Sucrose phosphate synthase (SPS) gene in banana and investigated the role of some cis-elements/motifs, present in the promoter of SPS, in the transcriptional regulation of the gene. DNA-protein interaction studies have demonstrated the presence of specific trans-acting factors which showed specific interactions with ethylene, auxin, low temperature and light responsive elements in regulating SPS transcription. Transient expression analyses have demonstrated the functional significance of the various cis-acting regulatory elements present in banana SPS promoter in regulating SPS expression during ripening. (1) Here, we have further discussed the possible role of these regulatory sequences in the regulation of transcriptional network and comment on their function in relation to sucrose metabolism during banana fruit ripening. PMID:20139735

  10. Identification of the bases in the ompF regulatory region, which interact with the transcription factor OmpR.

    PubMed

    Huang, K J; Igo, M M

    1996-10-11

    Expression of the outer membrane protein OmpF of Escherichia coli K-12 is influenced by a variety of environmental signals. Most of the signals are thought to regulate OmpF expression at the level of transcription initiation. A key element of this regulation is the interaction between the transcriptional factor OmpR and the cis-acting regulatory region of ompF. In this study, we used a combination of DNase I, dimethyl sulfate and hydroxyl radical footprinting analysis and DNA migration retardation assays to identify the bases within the ompF regulatory region that are in contact with OmpR. Our results indicate that the -107 to -39 region of ompF contains three individual binding sites and that a single OmpR-binding site is capable of interacting with two OmpR molecules. We also establish that a single OmpR-binding site is composed of two half-sites and that both half-sites are required for the formation of stable OmpR/DNA complexes. Comparisons of the sequences protected by OmpR indicate that an OmpR-binding site spans approximately 18 bp and has two highly conserved G/C base-pairs that are separated by three nucleotides. Although the three OmpR-binding sites we identified exhibit limited sequence similarity, this may reflect the fact that two of the sites are incapable of binding OmpR independently and can bind OmpR only if adjacent to another OmpR-binding site. Finally, our DNA migration retardation assays suggest that phosphorylation stimulates the cooperative interactions between OmpR molecules bound at neighboring sites. Therefore, this study provides a detailed understanding of how OmpR interacts with its binding sites immediately upstream of ompF and serves as a foundation for studying how phosphorylation of OmpR results in the regulation of ompF expression in response to environmental signals. PMID:8876642

  11. Crystal Structure of the Pseudomonas aeruginosa Virulence Factor Regulator

    SciTech Connect

    Cordes, Timothy J.; Worzalla, Gregory A.; Ginster, Aaron M.; Forest, Katrina T.

    2012-09-07

    Virulence factor regulator (Vfr) enhances Pseudomonas aeruginosa pathogenicity through its role as a global transcriptional regulator. The crystal structure of Vfr shows that it is a winged-helix DNA-binding protein like its homologue cyclic AMP receptor protein (CRP). In addition to an expected primary cyclic AMP-binding site, a second ligand-binding site is nestled between the N-terminal domain and the C-terminal helix-turn-helix domain. Unlike CRP, Vfr is a symmetric dimer in the absence of DNA. Removal of seven disordered N-terminal residues of Vfr prvents the growth of P. aeruginosa.

  12. Overview of Variable Renewable Energy Regulatory Issues: A Clean Energy Regulators Initiative Report

    SciTech Connect

    Miller, M.; Cox, S.

    2014-05-01

    This CERI report aims to provide an introductory overview of key regulatory issues associated with the deployment of renewable energy -- particularly variable renewable energy (VRE) sources such wind and solar power. The report draws upon the research and experiences from various international contexts, and identifies key ideas that have emerged from the growing body of VRE deployment experience and regulatory knowledge. The report assumes basic familiarity with regulatory concepts, and although it is not written for a technical audience, directs the reader to further reading when available. VRE deployment generates various regulatory issues: substantive, procedural, and public interest issues, and the report aims to provide an empirical and technical grounding for all three types of questions as appropriate.

  13. Coordinated regulation of biosynthetic and regulatory genes coincides with anthocyanin accumulation in developing eggplant fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Violet to black pigmentation of eggplant (Solanum melongena) fruit is attributed to anthocyanin accumulation. Model systems support the interaction of biosynthetic and regulatory genes for anthocyanin biosynthesis. Anthocyanin structural gene transcription requires the expression of at least one m...

  14. Regulatory domains of the A-Myb transcription factor and its interaction with the CBP/p300 adaptor molecules.

    PubMed Central

    Facchinetti, V; Loffarelli, L; Schreek, S; Oelgeschläger, M; Lüscher, B; Introna, M; Golay, J

    1997-01-01

    The A-Myb transcription factor belongs to the Myb family of oncoproteins and is likely to be involved in the regulation of proliferation and/or differentiation of normal B cells and Burkitt's lymphoma cells. To characterize in detail the domains of A-Myb that regulate its function, we have generated a series of deletion mutants and have investigated their trans-activation potential as well as their DNA-binding activity. Our results have allowed us to delineate the trans-activation domain as well as two separate regulatory regions. The boundaries of the trans-activation domain (amino acid residues 218-319) are centred on a sequence rich in charged amino acids (residues 259-281). A region (residues 320-482) localized immediately downstream of the trans-activation domain and containing a newly identified conserved stretch of 48 residues markedly inhibits specific DNA binding. Finally the last 110 residues of A-Myb (residues 643-752), which include a sequence conserved in all mammalian myb genes (region III), negatively regulate the maximal trans-activation potential of A-Myb. We have also investigated the functional interaction between A-Myb and the nuclear adaptor molecule CBP [cAMP response element-binding protein (CREB)-binding protein]. We demonstrate that CBP synergizes with A-Myb in a dose-dependent fashion, and that this co-operative effect can be inhibited by E1A and can also be observed with the CBP homologue p300. We show that this functional synergism requires the presence of the A-Myb charged sequence and that it involves physical interaction between A-Myb and the CREB-binding domain of CBP. PMID:9210395

  15. Keratinocyte sensitization to tumour necrosis factor-induced nuclear factor kappa B activation by the E2 regulatory protein of human papillomaviruses.

    PubMed

    Boulabiar, Manel; Boubaker, Samir; Favre, Michel; Demeret, Caroline

    2011-10-01

    Human papillomavirus (HPV) life cycle requires extensive manipulation of cell signalling to provide conditions adequate for viral replication within the stratified epithelia. In this regard, we show that the E2 regulatory protein of α, β and μ-HPV genotypes enhances tumour necrosis factor (TNF)-induced activation of nuclear factor kappa B (NF-κB). This activation is mediated by the N-terminal domain of E2, but does not rely on its transcriptional properties. It is independent of the NF-κB regulator Tax1BP1, which nevertheless interacts with all the E2 proteins. E2 specifically activates NF-κB pathways induced by TNF, while interleukin-1-induced pathways are not affected. E2 stimulates the activating K63-linked ubiquitination of TRAF5, and interacts with both TRAF5 and TRAF6. Our data suggest that E2 potentiates TNF-induced NF-κB signalling mediated by TRAF5 activation through direct binding. Since NF-κB controls epithelial differentiation, this activity may be involved in the commitment of infected keratinocytes to proliferation arrest and differentiation, both required for the implementation of the productive viral cycle. PMID:21715600

  16. REGULATORY STRATEGIES TO MINIMIZE GENERATION OF REGULATED WASTES FROM CLEANUP, CONTINUED USE OR DECOMMISSIONING OF NUCLEAR FACILITIES CONTAMINATED WITH POLYCHLORINATED BIPHENYLS (PCBS) - 11198

    SciTech Connect

    Lowry, N.

    2010-11-05

    Disposal costs for liquid PCB radioactive waste are among the highest of any category of regulated waste. The high cost is driven by the fact that disposal options are extremely limited. Toxic Substances Control Act (TSCA) regulations require most liquids with PCBs at concentration of {ge} 50 parts-per-million to be disposed by incineration or equivalent destructive treatment. Disposal fees can be as high as $200 per gallon. This figure does not include packaging and the cost to transport the waste to the disposal facility, or the waste generator's labor costs for managing the waste prior to shipment. Minimizing the generation of liquid radioactive PCB waste is therefore a significant waste management challenge. PCB spill cleanups often generate large volumes of waste. That is because the removal of PCBs typically requires the liberal use of industrial solvents followed by a thorough rinsing process. In a nuclear facility, the cleanup process may be complicated by the presence of radiation and other occupational hazards. Building design and construction features, e.g., the presence of open grating or trenches, may also complicate cleanup. In addition to the technical challenges associated with spill cleanup, selection of the appropriate regulatory requirements and approach may be challenging. The TSCA regulations include three different sections relating to the cleanup of PCB contamination or spills. EPA has also promulgated a separate guidance policy for fresh PCB spills that is published as Subpart G of 40 CFR 761 although it is not an actual regulation. Applicability is based on the circumstances of each contamination event or situation. Other laws or regulations may also apply. Identification of the allowable regulatory options is important. Effective communication with stakeholders, particularly regulators, is just as important. Depending on the regulatory path that is taken, cleanup may necessitate the generation of large quantities of regulated waste

  17. Interleukin-2 transcription is regulated in vivo at the level of coordinated binding of both constitutive and regulated factors.

    PubMed Central

    Garrity, P A; Chen, D; Rothenberg, E V; Wold, B J

    1994-01-01

    Interleukin-2 (IL-2) transcription is developmentally restricted to T cells and physiologically dependent on specific stimuli such as antigen recognition. Prior studies have shown that this stringent two-tiered regulation is mediated through a transcriptional promoter/enhancer DNA segment which is composed of diverse recognition elements. Factors binding to some of these elements are present constitutively in many cell types, while others are signal dependent, T cell specific, or both. This raises several questions about the molecular mechanism by which IL-2 expression is regulated. Is the developmental commitment of T cells reflected molecularly by stable interaction between available factors and the IL-2 enhancer prior to signal-dependent induction? At which level, factor binding to DNA or factor activity once bound, are individual regulatory elements within the native enhancer regulated? By what mechanism is developmental and physiological specificity enforced, given the participation of many relatively nonspecific elements? To answer these questions, we have used in vivo footprinting to determine and compare patterns of protein-DNA interactions at the native IL-2 locus in cell environments, including EL4 T-lymphoma cells and 32D clone 5 premast cells, which express differing subsets of IL-2 DNA-binding factors. We also used the immunosuppressant cyclosporin A as a pharmacological agent to further dissect the roles played by cyclosporin A-sensitive factors in the assembly and maintenance of protein-DNA complexes. Occupancy of all site types was observed exclusively in T cells and then only upon excitation of signal transduction pathways. This was true even though partially overlapping subsets of IL-2-binding activities were shown to be present in 32D clone 5 premast cells. This observation was especially striking in 32D cells because, upon signal stimulation, they mobilized a substantial set of IL-2 DNA-binding activities, as measured by in vitro assays using

  18. Mangiferin inhibits macrophage classical activation via downregulating interferon regulatory factor 5 expression.

    PubMed

    Wei, Zhiquan; Yan, Li; Chen, Yixin; Bao, Chuanhong; Deng, Jing; Deng, Jiagang

    2016-08-01

    Mangiferin is a natural polyphenol and the predominant effective component of Mangifera indica Linn. leaves. For hundreds of years, Mangifera indica Linn. leaf has been used as an ingredient in numerous traditional Chinese medicine preparations for the treatment of bronchitis. However, the pharmacological mechanism of mangiferin in the treatment of bronchitis remains to be elucidated. Macrophage classical activation is important role in the process of bronchial airway inflammation, and interferon regulatory factor 5 (IRF5) has been identified as a key regulatory factor for macrophage classical activation. The present study used the THP‑1 human monocyte cell line to investigate whether mangiferin inhibits macrophage classical activation via suppressing IRF5 expression in vitro. THP‑1 cells were differentiated to macrophages by phorbol 12‑myristate 13‑acetate. Macrophages were polarized to M1 macrophages following stimulation with lipopolysaccharide (LPS)/interferon‑γ (IFN‑γ). Flow cytometric analysis was conducted to detect the M1 macrophages. Reverse transcription‑quantitative polymerase chain reaction was used to investigate cellular IRF5 gene expression. Levels of proinflammatory cytokines and IRF5 were assessed following cell culture and cellular homogenization using enzyme‑linked immunosorbent assay. IRF5 protein and nuclei co‑localization was performed in macrophages with laser scanning confocal microscope immunofluorescence analysis. The results of the present study demonstrated that mangiferin significantly inhibits LPS/IFN‑γ stimulation‑induced classical activation of macrophages in vitro and markedly decreases proinflammatory cytokine release. In addition, cellular IRF5 expression was markedly downregulated. These results suggest that the inhibitory effect of mangiferin on classical activation of macrophages may be exerted via downregulation of cellular IRF5 expression levels. PMID:27277156

  19. Mangiferin inhibits macrophage classical activation via downregulating interferon regulatory factor 5 expression

    PubMed Central

    Wei, Zhiquan; Yan, Li; Chen, Yixin; Bao, Chuanhong; Deng, Jing; Deng, Jiagang

    2016-01-01

    Mangiferin is a natural polyphenol and the predominant effective component of Mangifera indica Linn. leaves. For hundreds of years, Mangifera indica Linn. leaf has been used as an ingredient in numerous traditional Chinese medicine preparations for the treatment of bronchitis. However, the pharmacological mechanism of mangiferin in the treatment of bronchitis remains to be elucidated. Macrophage classical activation is important role in the process of bronchial airway inflammation, and interferon regulatory factor 5 (IRF5) has been identified as a key regulatory factor for macrophage classical activation. The present study used the THP-1 human monocyte cell line to investigate whether mangiferin inhibits macrophage classical activation via suppressing IRF5 expression in vitro. THP-1 cells were differentiated to macrophages by phorbol 12-myristate 13-acetate. Macrophages were polarized to M1 macrophages following stimulation with lipopolysaccharide (LPS)/interferon-γ (IFN-γ). Flow cytometric analysis was conducted to detect the M1 macrophages. Reverse transcription-quantitative polymerase chain reaction was used to investigate cellular IRF5 gene expression. Levels of proinflammatory cytokines and IRF5 were assessed following cell culture and cellular homogenization using enzyme-linked immunosorbent assay. IRF5 protein and nuclei co-localization was performed in macrophages with laser scanning confocal microscope immunofluorescence analysis. The results of the present study demonstrated that mangiferin significantly inhibits LPS/IFN-γ stimulation-induced classical activation of macrophages in vitro and markedly decreases proinflammatory cytokine release. In addition, cellular IRF5 expression was markedly downregulated. These results suggest that the inhibitory effect of mangiferin on classical activation of macrophages may be exerted via downregulation of cellular IRF5 expression levels. PMID:27277156

  20. RpoS Regulates Essential Virulence Factors Remaining to Be Identified in Borrelia burgdorferi

    PubMed Central

    Xu, Qilong; Shi, Yanlin; Dadhwal, Poonam; Liang, Fang Ting

    2012-01-01

    Background Since the RpoN-RpoS regulatory network was revealed in the Lyme disease spirochete Borrelia burgdorferi a decade ago, both upstream and downstream of the pathway have been intensively investigated. While significant progress has been made into understanding of how the network is regulated, most notably, discovering a relationship of the network with Rrp2 and BosR, only three crucial virulence factors, including outer surface protein C (OspC) and decorin-binding proteins (Dbps) A and B, are associated with the pathway. Moreover, for more than 10 years no single RpoS-controlled gene has been found to be critical for infection, raising a question about whether additional RpoS-dependent virulence factors remain to be identified. Methodology/Principal Findings The rpoS gene was deleted in B. burgdorferi; resulting mutants were modified to constitutively express all the known virulence factors, OspC, DbpA and DbpB. This genetic modification was unable to restore the rpoS mutant with infectivity. Conclusions/Significance The inability to restore the rpoS mutant with infectivity by simultaneously over-expressing all the three virulence factors allows us to conclude RpoS also regulates essential genes that remain to be identified in B. burgdorferi. PMID:23300893

  1. Hormonal regulatory role of eyestalk factors on growth of heart in mud crab, Scylla serrata

    PubMed Central

    Allayie, Sartaj Ahmad; Ravichandran, S.; Bhat, Bilal Ahmad

    2011-01-01

    The present study was attempted to know the growth regulation of eyestalk factors on the growth of heart in Scylla serrata using eyestalk extractions and bilateral eyestalk ablations. The bilateral eyestalk ablation led to the maximum growth indices of the heart ((H) indices) to 0.162 and 0.158 in ablated male and female, respectively, in comparison to 0.153 and 0.167 in the control male and female and 0.147 and 0.157 in injected male and female, respectively. The data have shown that the heart of male crabs grows faster than female crabs. The study has also shown that bilateral eyestalk ablation resulted in a significant increase in the heart indices in males and has least effect on the growth of the female heart. The results presented strongly support a potential role of the eyestalk factors and molting hormone regulating the growth of the heart in S. serrata. PMID:23961136

  2. Regulation of platelet activating factor receptor coupled phosphoinositide-specific phospholipase C activity

    SciTech Connect

    Morrison, W.J.

    1988-01-01

    The major objectives of this study were two-fold. The first was to establish whether binding of platelet activating factor (PAF) to its receptor was integral to the stimulation of polyphosphoinositide-specific phospholipase C (PLC) in rabbit platelets. The second was to determine regulatory features of this receptor-coupled mechanism. ({sup 3}H)PAF binding demonstrated two binding sites, a high affinity site with a inhibitory constant (Ki) of 2.65 nM and a low affinity site with a Ki of 0.80 {mu}M. PAF receptor coupled activation of phosphoinositide-specific PLC was studied in platelets which were made refractory, by short term pretreatments, to either PAF or thrombin. Saponin-permeabilized rabbit platelets continue to regulate the mechanism(s) coupling PAF receptors to PLC stimulation. However, TRP{gamma}S and GDP{beta}S, which affect guanine nucleotide regulatory protein functions, were unable to modulate the PLC activity to any appreciable extent as compared to PAF. The possible involvement of protein kinase C (PKC) activation in regulating PAF-stimulated PLC activity was studied in rabbit platelets pretreated with staurosporine followed by pretreatments with PAF or phorbol 12-myristate 13-acetate (PMA).

  3. Genetic effects of polymorphisms in myogenic regulatory factors on chicken muscle fiber traits.

    PubMed

    Yang, Zhi-Qin; Qing, Ying; Zhu, Qing; Zhao, Xiao-Ling; Wang, Yan; Li, Di-Yan; Liu, Yi-Ping; Yin, Hua-Dong

    2015-06-01

    The myogenic regulatory factors is a family of transcription factors that play a key role in the development of skeletal muscle fibers, which are the main factors to affect the meat taste and texture. In the present study, we performed candidate gene analysis to identify single-nucleotide polymorphisms in the MyoD, Myf5, MyoG, and Mrf4 genes using polymerase chain reaction-single strand conformation polymorphism in 360 Erlang Mountain Chickens from three different housing systems (cage, pen, and free-range). The general linear model procedure was used to estimate the statistical significance of association between combined genotypes and muscle fiber traits of chickens. Two polymorphisms (g.39928301T>G and g.11579368C>T) were detected in the Mrf4 and MyoD gene, respectively. The diameters of thigh and pectoralis muscle fibers were higher in birds with the combined genotypes of GG-TT and TT-CT (p<0.05). Moreover, the interaction between housing system and combined genotypes has no significant effect on the traits of muscle fiber (p>0.05). Our findings suggest that the combined genotypes of TT-CT and GG-TT might be advantageous for muscle fiber traits, and could be the potential genetic markers for breeding program in Erlang Mountain Chickens. PMID:25925055

  4. Genetic Effects of Polymorphisms in Myogenic Regulatory Factors on Chicken Muscle Fiber Traits

    PubMed Central

    Yang, Zhi-Qin; Qing, Ying; Zhu, Qing; Zhao, Xiao-Ling; Wang, Yan; Li, Di-Yan; Liu, Yi-Ping; Yin, Hua-Dong

    2015-01-01

    The myogenic regulatory factors is a family of transcription factors that play a key role in the development of skeletal muscle fibers, which are the main factors to affect the meat taste and texture. In the present study, we performed candidate gene analysis to identify single-nucleotide polymorphisms in the MyoD, Myf5, MyoG, and Mrf4 genes using polymerase chain reaction-single strand conformation polymorphism in 360 Erlang Mountain Chickens from three different housing systems (cage, pen, and free-range). The general linear model procedure was used to estimate the statistical significance of association between combined genotypes and muscle fiber traits of chickens. Two polymorphisms (g.39928301T>G and g.11579368C>T) were detected in the Mrf4 and MyoD gene, respectively. The diameters of thigh and pectoralis muscle fibers were higher in birds with the combined genotypes of GG-TT and TT-CT (p<0.05). Moreover, the interaction between housing system and combined genotypes has no significant effect on the traits of muscle fiber (p>0.05). Our findings suggest that the combined genotypes of TT-CT and GG-TT might be advantageous for muscle fiber traits, and could be the potential genetic markers for breeding program in Erlang Mountain Chickens. PMID:25925055

  5. Behavioral and regulatory abnormalities in mice deficient in the NPAS1 and NPAS3 transcription factors.

    PubMed

    Erbel-Sieler, Claudia; Dudley, Carol; Zhou, Yudong; Wu, Xinle; Estill, Sandi Jo; Han, Tina; Diaz-Arrastia, Ramon; Brunskill, Eric W; Potter, S Steven; McKnight, Steven L

    2004-09-14

    Laboratory mice bearing inactivating mutations in the genes encoding the NPAS1 and NPAS3 transcription factors have been shown to exhibit a spectrum of behavioral and neurochemical abnormalities. Behavioral abnormalities included diminished startle response, as measured by prepulse inhibition, and impaired social recognition. NPAS1/NPAS3-deficient mice also exhibited stereotypic darting behavior at weaning and increased locomotor activity. Immunohistochemical staining assays showed that the NPAS1 and NPAS3 proteins are expressed in inhibitory interneurons and that the viability and anatomical distribution of these neurons are unaffected by the absence of either transcription factor. Adult brain tissues from NPAS3- and NPAS1/NPAS3-deficient mice exhibited a distinct reduction in reelin, a large, secreted protein whose expression has been reported to be attenuated in the postmortem brain tissue of patients with schizophrenia. These observations raise the possibility that a regulatory program controlled in inhibitory interneurons by the NPAS1 and NPAS3 transcription factors may be either substantively or tangentially relevant to psychosis. PMID:15347806

  6. Novel mechanism and factor for regulation by HIV-1 Tat.

    PubMed Central

    Zhou, Q; Sharp, P A

    1995-01-01

    Tat regulation of human immunodeficiency virus (HIV) transcription is unique because of its specificity for an RNA target, TAR, and its ability to increase the efficiency of elongation by polymerase. A reconstituted reaction that is Tat-specific and TAR-dependent for activation of HIV transcription has been used to identify and partially purify a cellular activity that is required for trans-activation by Tat, but not by other activators. In the reaction, Tat stimulates the efficiency of elongation by polymerase, whereas Sp1 and other DNA sequence-specific transcription factors activate the rate of initiation. Furthermore, while TATA binding protein (TBP)-associated factors (TAFs) in the TFIID complex are required for activation by transcription factors, they are dispensable for Tat function. Thus, Tat acts through a novel mechanism, which is mediated by a specific host cellular factor, to stimulate HIV-1 gene expression. Images PMID:7835343

  7. Regulation of brain-derived neurotrophic factor expression in neurons

    PubMed Central

    Zheng, Fei; Zhou, Xianju; Moon, Changjong; Wang, Hongbing

    2012-01-01

    Brain-derived neurotrophic factor (BDNF) plays critical roles in many aspects of brain functions, including cell survival, differentiation, development, learning and memory. Aberrant BDNF expression has also been implicated in numerous neurological disorders. Thus, significant effort has been made to understand how BDNF transcription as well as translation is regulated. Interestingly, the BDNF gene structure suggests that multiple promoters control its transcription, leading to the existence of distinct mRNA species. Further, the long- and short-tail of the 3’un-translated region may dictate different sub-cellular BDNF mRNA targeting and translational responses following neuronal stimulation. This review aims to summarize the main findings that demonstrate how neuronal activities specifically up-regulate the transcription and translation of unique BDNF transcripts. We also discuss some of the recent reports that emphasize the epigenetic regulation of BDNF transcription. PMID:23320132

  8. Growth factors in critical illness: regulation and therapeutic aspects.

    PubMed

    Frost, R A; Lang, C H

    1998-03-01

    The erosion of lean body mass observed during catabolic illness is still a major cause of morbidity and mortality. The known anabolic actions of growth hormone and insulin-like growth factor-I have stimulated interest in the use of these agents to mitigate the loss of muscle protein after injury. This review summarizes advances in our understanding of how nutrition, hormones and proinflammatory cytokines regulate the somatotropic axis in health and disease, and recent studies involving the use of growth hormone or insulin-like growth factor-I in the treatment of critically ill patients. PMID:10565348

  9. Regulation of the ndh gene of Escherichia coli by integration host factor and a novel regulator, Arr.

    PubMed

    Green, J; Anjum, M F; Guest, J R

    1997-09-01

    The ndh gene of Escherichia coli encodes the non-proton-translocating NADH dehydrogenase II. Expression of the ndh gene is subject to a complex network of regulatory controls at the transcriptional level. Under anaerobic conditions ndh is repressed by the regulator of fumarate and nitrate reduction (FNR). However, in the absence of FNR, ndh expression is activated by the amino acid response regulator (Arr) during anaerobic growth in rich medium. Expression of the ndh gene varies during the growth cycle in response to the intracellular concentration of the heat-stable DNA-binding protein, Fis. In this work two additional heat-stable proteins, integration host factor (IHF) and the histone-like protein HU were found to interact with the ndh promoter. IHF was shown to bind at three sites centred at +26, -17 and -58 in the ndh promoter (Kd = 10(-8) M), to prevent open-complex formation and to repress ndh transcription in vitro. Studies with an ndh-lacZ fusion confirmed that IHF represses ndh expression in vivo. Two putative binding sites for Arr, which overlap the two FNR boxes in the ndh promoter, were identified. Studies with the FNR-activated and amino-acid-inducible asparaginase II gene (ansB) showed that IHF and a component of the Arr-containing fraction (but not HU) interact with the corresponding ansB promoter. PMID:9308170

  10. Structure and regulatory targets of SCO3201, a highly promiscuous TetR-like regulator of Streptomyces coelicolor M145.

    PubMed

    Xu, Delin; Waack, Paul; Zhang, Qizhong; Werten, Sebastiaan; Hinrichs, Winfried; Virolle, Marie-Joelle

    2014-07-18

    SCO3201, a regulator of the TetR family, is a strong repressor of both morphological differentiation and antibiotic production when overexpressed in Streptomyces coelicolor. Here, we report the identification of 14 novel putative regulatory targets of this regulator using in vitro formaldehyde cross-linking. Direct binding of purified His6-SCO3201 was demonstrated for the promoter regions of 5 regulators (SCO1716, SCO1950, SCO3367, SCO4009 and SCO5046), a putative histidine phosphatase (SCO1809), an acetyltransferase (SCO0988) and the polyketide synthase RedX (SCO5878), using EMSA. Reverse transcriptional analysis demonstrated that the expression of the transcriptional regulators SCO1950, SCO4009, SCO5046, as well as of SCO0988 and RedX was down regulated, upon SCO3201 overexpression, whereas the expression of SCO1809 and SCO3367 was up regulated. A consensus binding motif was derived via alignment of the promoter regions of the genes negatively regulated. The positions of the predicted operator sites were consistent with a direct repressive effect of SCO3201 on 5 out of 7 of these promoters. Furthermore, the 2.1Å crystal structure of SCO3201 was solved, which provides a possible explanation for the high promiscuity of this regulator that might account for its dramatic effect on the differentiation process of S. coelicolor. PMID:24928397

  11. Identification of novel transcription factors regulating secondary cell wall formation in Arabidopsis

    PubMed Central

    Cassan-Wang, Hua; Goué, Nadia; Saidi, Mohammed N.; Legay, Sylvain; Sivadon, Pierre; Goffner, Deborah; Grima-Pettenati, Jacqueline

    2013-01-01

    The presence of lignin in secondary cell walls (SCW) is a major factor preventing hydrolytic enzymes from gaining access to cellulose, thereby limiting the saccharification potential of plant biomass. To understand how lignification is regulated is a prerequisite for selecting plant biomass better adapted to bioethanol production. Because transcriptional regulation is a major mechanism controlling the expression of genes involved in lignin biosynthesis, our aim was to identify novel transcription factors (TFs) dictating lignin profiles in the model plant Arabidopsis. To this end, we have developed a post-genomic approach by combining four independent in-house SCW-related transcriptome datasets obtained from (1) the fiber cell wall-deficient wat1 Arabidopsis mutant, (2) Arabidopsis lines over-expressing either the master regulatory activator EgMYB2 or (3) the repressor EgMYB1 and finally (4) Arabidopsis orthologs of Eucalyptus xylem-expressed genes. This allowed us to identify 502 up- or down-regulated TFs. We preferentially selected those present in more than one dataset and further analyzed their in silico expression patterns as an additional selection criteria. This selection process led to 80 candidates. Notably, 16 of them were already proven to regulate SCW formation, thereby validating the overall strategy. Then, we phenotyped 43 corresponding mutant lines focusing on histological observations of xylem and interfascicular fibers. This phenotypic screen revealed six mutant lines exhibiting altered lignification patterns. Two of them [Bel-like HomeoBox6 (blh6) and a zinc finger TF] presented hypolignified SCW. Three others (myb52, myb-like TF, hb5) showed hyperlignified SCW whereas the last one (hb15) showed ectopic lignification. In addition, our meta-analyses highlighted a reservoir of new potential regulators adding to the gene network regulating SCW but also opening new avenues to ultimately improve SCW composition for biofuel production. PMID:23781226

  12. Distinct roles for the complement regulators factor H and Crry in protection of the kidney from injury.

    PubMed

    Laskowski, Jennifer; Renner, Brandon; Le Quintrec, Moglie; Panzer, Sarah; Hannan, Jonathan P; Ljubanovic, Danica; Ruseva, Marieta M; Borza, Dorin-Bogdan; Antonioli, Alexandra H; Pickering, Matthew C; Holers, V Michael; Thurman, Joshua M

    2016-07-01

    Mutations in the complement regulatory proteins are associated with several different diseases. Although these mutations cause dysregulated alternative pathway activation throughout the body, the kidneys are the most common site of injury. The susceptibility of the kidney to alternative pathway-mediated injury may be due to limited expression of complement regulatory proteins on several tissue surfaces within the kidney. To examine the roles of the complement regulatory proteins factor H and Crry in protecting distinct renal surfaces from alternative pathway mediated injury, we generated mice with targeted deletions of the genes for both proteins. Surprisingly, mice with combined genetic deletions of factor H and Crry developed significantly milder renal injury than mice deficient in only factor H. Deficiency of both factor H and Crry was associated with C3 deposition at multiple locations within the kidney, but glomerular C3 deposition was lower than that in factor H alone deficient mice. Thus, factor H and Crry are critical for regulating complement activation at distinct anatomic sites within the kidney. However, widespread activation of the alternative pathway reduces injury by depleting the pool of C3 available at any 1 location. PMID:27165610

  13. Interferon-Regulatory Factor 5-Dependent Signaling Restricts Orthobunyavirus Dissemination to the Central Nervous System

    PubMed Central

    Proenca-Modena, Jose Luiz; Hyde, Jennifer L.; Sesti-Costa, Renata; Lucas, Tiffany; Pinto, Amelia K.; Richner, Justin M.; Gorman, Matthew J.; Lazear, Helen M.

    2015-01-01

    ABSTRACT Interferon (IFN)-regulatory factor 5 (IRF-5) is a transcription factor that induces inflammatory responses after engagement and signaling by pattern recognition receptors. To define the role of IRF-5 during bunyavirus infection, we evaluated Oropouche virus (OROV) and La Crosse virus (LACV) pathogenesis and immune responses in primary cells and in mice with gene deletions in Irf3, Irf5, and Irf7 or in Irf5 alone. Deletion of Irf3, Irf5, and Irf7 together resulted in uncontrolled viral replication in the liver and spleen, hypercytokinemia, extensive liver injury, and an early-death phenotype. Remarkably, deletion of Irf5 alone resulted in meningoencephalitis and death on a more protracted timeline, 1 to 2 weeks after initial OROV or LACV infection. The clinical signs in OROV-infected Irf5−/− mice were associated with abundant viral antigen and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL)-positive cells in several regions of the brain. Circulating dendritic cell (DC) subsets in Irf5−/− mice had higher levels of OROV RNA in vivo yet produced lower levels of type I IFN than wild-type (WT) cells. This result was supported by data obtained in vitro, since a deficiency of IRF-5 resulted in enhanced OROV infection and diminished type I IFN production in bone marrow-derived DCs. Collectively, these results indicate a key role for IRF-5 in modulating the host antiviral response in peripheral organs that controls bunyavirus neuroinvasion in mice. IMPORTANCE Oropouche virus (OROV) and La Crosse virus (LACV) are orthobunyaviruses that are transmitted by insects and cause meningitis and encephalitis in subsets of individuals in the Americas. Recently, we demonstrated that components of the type I interferon (IFN) induction pathway, particularly the regulatory transcription factors IRF-3 and IRF-7, have key protective roles during OROV infection. However, the lethality in Irf3−/− Irf7−/− (DKO) mice infected with OROV

  14. Transcription factors of Lotus: regulation of isoflavonoid biosynthesis requires coordinated changes in transcription factor activity.

    PubMed

    Shelton, Dale; Stranne, Maria; Mikkelsen, Lisbeth; Pakseresht, Nima; Welham, Tracey; Hiraka, Hideki; Tabata, Satoshi; Sato, Shusei; Paquette, Suzanne; Wang, Trevor L; Martin, Cathie; Bailey, Paul

    2012-06-01

    Isoflavonoids are a class of phenylpropanoids made by legumes, and consumption of dietary isoflavonoids confers benefits to human health. Our aim is to understand the regulation of isoflavonoid biosynthesis. Many studies have shown the importance of transcription factors in regulating the transcription of one or more genes encoding enzymes in phenylpropanoid metabolism. In this study, we coupled bioinformatics and coexpression analysis to identify candidate genes encoding transcription factors involved in regulating isoflavonoid biosynthesis in Lotus (Lotus japonicus). Genes encoding proteins belonging to 39 of the main transcription factor families were examined by microarray analysis of RNA from leaf tissue that had been elicited with glutathione. Phylogenetic analyses of each transcription factor family were used to identify subgroups of proteins that were specific to L. japonicus or closely related to known regulators of the phenylpropanoid pathway in other species. R2R3MYB subgroup 2 genes showed increased expression after treatment with glutathione. One member of this subgroup, LjMYB14, was constitutively overexpressed in L. japonicus and induced the expression of at least 12 genes that encoded enzymes in the general phenylpropanoid and isoflavonoid pathways. A distinct set of six R2R3MYB subgroup 2-like genes was identified. We suggest that these subgroup 2 sister group proteins and those belonging to the main subgroup 2 have roles in inducing isoflavonoid biosynthesis. The induction of isoflavonoid production in L. japonicus also involves the coordinated down-regulation of competing biosynthetic pathways by changing the expression of other transcription factors. PMID:22529285

  15. Regulation of the yeast metabolic cycle by transcription factors with periodic activities

    PubMed Central

    2011-01-01

    Background When growing budding yeast under continuous, nutrient-limited conditions, over half of yeast genes exhibit periodic expression patterns. Periodicity can also be observed in respiration, in the timing of cell division, as well as in various metabolite levels. Knowing the transcription factors involved in the yeast metabolic cycle is helpful for determining the cascade of regulatory events that cause these patterns. Results Transcription factor activities were estimated by linear regression using time series and genome-wide transcription factor binding data. Time-translation matrices were estimated using least squares and were used to model the interactions between the most significant transcription factors. The top transcription factors have functions involving respiration, cell cycle events, amino acid metabolism and glycolysis. Key regulators of transitions between phases of the yeast metabolic cycle appear to be Hap1, Hap4, Gcn4, Msn4, Swi6 and Adr1. Conclusions Analysis of the phases at which transcription factor activities peak supports previous findings suggesting that the various cellular functions occur during specific phases of the yeast metabolic cycle. PMID:21992532

  16. A Rhesus Rhadinovirus Viral Interferon (IFN) Regulatory Factor Is Virion Associated and Inhibits the Early IFN Antiviral Response

    PubMed Central

    Morin, Gabriela; Robinson, Bridget A.; Rogers, Kelsey S.

    2015-01-01

    ABSTRACT The interferon (IFN) response is the earliest host immune response dedicated to combating viral infection. As such, viruses have evolved strategies to subvert this potent antiviral response. Two closely related gammaherpesviruses, Kaposi's sarcoma-associated herpesvirus (KSHV) and rhesus macaque rhadinovirus (RRV), are unique in that they express viral homologues to cellular interferon regulatory factors (IRFs), termed viral IRFs (vIRFs). Cellular IRFs are a family of transcription factors that are particularly important for the transcription of type I IFNs. Here, we demonstrate a strategy employed by RRV to ensure rapid inhibition of virus-induced type I IFN induction. We found that RRV vIRF R6, when expressed ectopically, interacts with a transcriptional coactivator, CREB-binding protein (CBP), in the nucleus. As a result, phosphorylated IRF3, an important transcriptional regulator in beta interferon (IFN-β) transcription, fails to effectively bind to the IFN-β promoter, thus inhibiting the activation of IFN-β genes. In addition, we found R6 within RRV virion particles via immunoelectron microscopy and, furthermore, that virion-associated R6 is capable of inhibiting the type I IFN response by preventing efficient binding of IRF3/CBP complexes to the IFN-β promoter in the context of infection. The work shown here is the first example of a vIRF being associated with either the KSHV or RRV virion. The presence of this immunomodulatory protein in the RRV virion provides the virus with an immediate mechanism to evade the host IFN response, thus enabling the virus to effectively establish an infection within the host. IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) and the closely related rhesus macaque rhadinovirus (RRV) are the only viruses known to encode viral homologues to cellular interferon regulatory factors (IRFs), known as vIRFs. In KSHV, these proteins have been shown to play major roles in a variety of cellular processes and are

  17. 76 FR 10527 - Regulatory Flexibility Act: Section 610 Review of National Organic Program Regulations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-25

    ... regulations implementing the National Organic Program (NOP) were published December 21, 2000 (65 FR 80548... FR 14827), its schedule to review certain regulations, including the NOP regulations, under criteria... Organic Program Regulations AGENCY: Agricultural Marketing Service, USDA. ACTION: Review and request...

  18. WRKY Transcription Factors: Molecular Regulation and Stress Responses in Plants

    PubMed Central

    Phukan, Ujjal J.; Jeena, Gajendra S.; Shukla, Rakesh K.

    2016-01-01

    Plants in their natural habitat have to face multiple stresses simultaneously. Evolutionary adaptation of developmental, physiological, and biochemical parameters give advantage over a single window of stress but not multiple. On the other hand transcription factors like WRKY can regulate diverse responses through a complicated network of genes. So molecular orchestration of WRKYs in plant may provide the most anticipated outcome of simultaneous multiple responses. Activation or repression through W-box and W-box like sequences is regulated at transcriptional, translational, and domain level. Because of the tight regulation involved in specific recognition and binding of WRKYs to downstream promoters, they have become promising candidate for crop improvement. Epigenetic, retrograde and proteasome mediated regulation enable WRKYs to attain the dynamic cellular homeostatic reprograming. Overexpression of several WRKYs face the paradox of having several beneficial affects but with some unwanted traits. These overexpression-associated undesirable phenotypes need to be identified and removed for proper growth, development and yeild. Taken together, we have highlighted the diverse regulation and multiple stress response of WRKYs in plants along with the future prospects in this field of research. PMID:27375634

  19. The GATA transcription factor GtaC regulates early developmental gene expression dynamics in Dictyostelium.

    PubMed

    Santhanam, Balaji; Cai, Huaqing; Devreotes, Peter N; Shaulsky, Gad; Katoh-Kurasawa, Mariko

    2015-01-01

    In many systems, including the social amoeba Dictyostelium discoideum, development is often marked by dynamic morphological and transcriptional changes orchestrated by key transcription factors. However, efforts to examine sequential genome-wide changes of gene regulation in developmental processes have been fairly limited. Here we report the developmental regulatory dynamics of GtaC, a GATA-type zinc-finger transcription factor, through the analyses of serial ChIP- and RNA-sequencing data. GtaC is essential for developmental progression, decoding extracellular cAMP pulses during early development and may play a role in mediating cell-type differentiation at later stages. We find that GtaC exhibits temporally distinctive DNA-binding patterns concordant with each developmental stage. We identify direct GtaC targets and observe cotemporaneous GtaC-binding and developmental expression regulation. Our results suggest that GtaC regulates multiple physiological processes as Dictyostelium transitions from a group of unicellular amoebae to an integrated multicellular organism. PMID:26144553

  20. Transcription Factor Foxo1 Is a Negative Regulator of NK Cell Maturation and Function

    PubMed Central

    Deng, Youcai; Kerdiles, Yann; Chu, Jianhong; Yuan, Shunzong; Wang, Youwei; Chen, Xilin; Mao, Hsiaoyin; Zhang, Lingling; Zhang, Jianying; Hughes, Tiffany; Deng, Yafei; Zhang, Qi; Wang, Fangjie; Zou, Xianghong; Liu, Chang-Gong; Freud, Aharon G.; Li, Xiaohui; Caligiuri, Michael A; Vivier, Eric; Yu, Jianhua

    2015-01-01

    SUMMARY Little is known about the role of negative regulators in controlling natural killer (NK) cell development and effector functions. Foxo1 is a multifunctional transcription factor of the forkhead family. Using a mouse model of conditional deletion in NK cells, we found that Foxo1 negatively controlled NK cell differentiation and function. Immature NK cells expressed abundant Foxo1 and little Tbx21 relative to mature NK cells, but these two transcription factors reversed their expression as NK cells proceeded through development. Foxo1 promoted NK cell homing to lymph nodes through upregulating CD62L expression, and impaired late-stage maturation and effector functions by repressing Tbx21 expression. Loss of Foxo1 rescued the defect in late-stage NK cell maturation in heterozygous Tbx21+/− mice. Collectively, our data reveal a regulatory pathway by which the negative regulator Foxo1 and the positive regulator Tbx21 play opposing roles in controlling NK cell development and effector functions. PMID:25769609

  1. Thyroid Hormone Regulates Hepatic Expression of Fibroblast Growth Factor 21 in a PPARα-dependent Manner*

    PubMed Central

    Adams, Andrew C.; Astapova, Inna; Fisher, ffolliott M.; Badman, Michael K.; Kurgansky, Katherine E.; Flier, Jeffrey S.; Hollenberg, Anthony N.; Maratos-Flier, Eleftheria

    2010-01-01

    Thyroid hormone has profound and diverse effects on liver metabolism. Here we show that tri-iodothyronine (T3) treatment in mice acutely and specifically induces hepatic expression of the metabolic regulator fibroblast growth factor 21 (FGF21). Mice treated with T3 showed a dose-dependent increase in hepatic FGF21 expression with significant induction at doses as low as 100 μg/kg. Time course studies determined that induction is seen as early as 4 h after treatment with a further increase in expression at 6 h after injection. As FGF21 expression is downstream of the nuclear receptor peroxisome proliferator-activated receptor α (PPARα), we treated PPARα knock-out mice with T3 and found no increase in expression, indicating that hepatic regulation of FGF21 by T3 in liver is via a PPARα-dependent mechanism. In contrast, in white adipose tissue, FGF21 expression was suppressed by T3 treatment, with other T3 targets unaffected. In cell culture studies with an FGF21 reporter construct, we determined that three transcription factors are required for induction of FGF21 expression: thyroid hormone receptor β (TRβ), retinoid X receptor (RXR), and PPARα. These findings indicate a novel regulatory pathway whereby T3 positively regulates hepatic FGF21 expression, presenting a novel therapeutic target for diseases such as non-alcoholic fatty liver disease. PMID:20236931

  2. The GATA transcription factor GtaC regulates early developmental gene expression dynamics in Dictyostelium

    PubMed Central

    Santhanam, Balaji; Cai, Huaqing; Devreotes, Peter N.; Shaulsky, Gad; Katoh-Kurasawa, Mariko

    2015-01-01

    In many systems, including the social amoeba Dictyostelium discoideum, development is often marked by dynamic morphological and transcriptional changes orchestrated by key transcription factors. However, efforts to examine sequential genome-wide changes of gene regulation in developmental processes have been fairly limited. Here we report the developmental regulatory dynamics of GtaC, a GATA-type zinc-finger transcription factor, through the analyses of serial ChIP- and RNA-sequencing data. GtaC is essential for developmental progression, decoding extracellular cAMP pulses during early development and may play a role in mediating cell-type differentiation at later stages. We find that GtaC exhibits temporally distinctive DNA-binding patterns concordant with each developmental stage. We identify direct GtaC targets and observe cotemporaneous GtaC-binding and developmental expression regulation. Our results suggest that GtaC regulates multiple physiological processes as Dictyostelium transitions from a group of unicellular amoebae to an integrated multicellular organism. PMID:26144553

  3. A response regulator promotes Francisella tularensis intramacrophage growth by repressing an anti-virulence factor.

    PubMed

    Ramsey, Kathryn M; Dove, Simon L

    2016-08-01

    The orphan response regulator PmrA is essential for the intramacrophage growth and survival of Francisella tularensis. PmrA was thought to promote intramacrophage growth by binding directly to promoters on the Francisella Pathogenicity Island (FPI) and positively regulating the expression of FPI genes, which encode a Type VI secretion system required for intramacrophage growth. Using both ChIP-Seq and RNA-Seq we identify those regions of the F. tularensis chromosome occupied by PmrA and those genes that are regulated by PmrA. We find that PmrA associates with 252 distinct regions of the F. tularensis chromosome, but exerts regulatory effects at only a few of these locations. Rather than by functioning directly as an activator of FPI gene expression we present evidence that PmrA promotes intramacrophage growth by repressing the expression of a single target gene we refer to as priM (PmrA-repressed inhibitor of intramacrophage growth). Our findings thus indicate that the role of PmrA in facilitating intracellular growth is to repress a previously unknown anti-virulence factor. PriM is the first bacterially encoded factor to be described that can interfere with the intramacrophage growth and survival of F. tularensis. PMID:27169554

  4. Class IA PI3Kinase Regulatory Subunit, p85α, Mediates Mast Cell Development through Regulation of Growth and Survival Related Genes

    PubMed Central

    Krishnan, Subha; Mali, Raghuveer Singh; Koehler, Karl R.; Vemula, Sasidhar; Chatterjee, Anindya; Ghosh, Joydeep; Ramdas, Baskar; Ma, Peilin; Hashino, Eri; Kapur, Reuben

    2012-01-01

    Stem cell factor (SCF) mediated KIT receptor activation plays a pivotal role in mast cell growth, maturation and survival. However, the signaling events downstream from KIT are poorly understood. Mast cells express multiple regulatory subunits of class 1A PI3Kinase (PI3K) including p85α, p85β, p50α, and p55α. While it is known that PI3K plays an essential role in mast cells; the precise mechanism by which these regulatory subunits impact specific mast cell functions including growth, survival and cycling are not known. We show that loss of p85α impairs the growth, survival and cycling of mast cell progenitors (MCp). To delineate the molecular mechanism (s) by which p85α regulates mast cell growth, survival and cycling, we performed microarray analyses to compare the gene expression profile of MCps derived from WT and p85α-deficient mice in response to SCF stimulation. We identified 151 unique genes exhibiting altered expression in p85α-deficient cells in response to SCF stimulation compared to WT cells. Functional categorization based on DAVID bioinformatics tool and Ingenuity Pathway Analysis (IPA) software relates the altered genes due to lack of p85α to transcription, cell cycle, cell survival, cell adhesion, cell differentiation, and signal transduction. Our results suggest that p85α is involved in mast cell development through regulation of expression of growth, survival and cell cycle related genes. PMID:22238586

  5. Asynchronous combinatorial action of four regulatory factors activates Bcl11b for T cell commitment.

    PubMed

    Kueh, Hao Yuan; Yui, Mary A; Ng, Kenneth K H; Pease, Shirley S; Zhang, Jingli A; Damle, Sagar S; Freedman, George; Siu, Sharmayne; Bernstein, Irwin D; Elowitz, Michael B; Rothenberg, Ellen V

    2016-08-01

    During T cell development, multipotent progenitors relinquish competence for other fates and commit to the T cell lineage by turning on Bcl11b, which encodes a transcription factor. To clarify lineage commitment mechanisms, we followed developing T cells at the single-cell level using Bcl11b knock-in fluorescent reporter mice. Notch signaling and Notch-activated transcription factors collaborate to activate Bcl11b expression irrespectively of Notch-dependent proliferation. These inputs work via three distinct, asynchronous mechanisms: an early locus 'poising' function dependent on TCF-1 and GATA-3, a stochastic-permissivity function dependent on Notch signaling, and a separate amplitude-control function dependent on Runx1, a factor already present in multipotent progenitors. Despite their necessity for Bcl11b expression, these inputs act in a stage-specific manner, providing a multitiered mechanism for developmental gene regulation. PMID:27376470

  6. Extreme Diversity in the Regulation of Ndt80-Like Transcription Factors in Fungi

    PubMed Central

    Katz, Margaret E.; Cooper, Sarah

    2015-01-01

    The Saccharomyces cerevisiae Ndt80 protein is the founding member of a class of p53-like transcription factors that is known as the NDT80/PhoG-like DNA-binding family. The number of NDT80-like genes in different fungi is highly variable and their roles, which have been examined in only a few species, include regulation of meiosis, sexual development, biofilm formation, drug resistance, virulence, the response to nutrient stress and programmed cell death. The protein kinase Ime2 regulates the single NDT80 gene present in S. cerevisiae. In this study we used a genetic approach to investigate whether the Aspergillus nidulans Ime2 homolog, ImeB, and/or protein kinases MpkC, PhoA and PhoB regulate the two NDT80-like genes (xprG and ndtA) in A. nidulans. Disruption of imeB, but not mpkC, phoA or phoB, led to increased extracellular protease activity and a defect in mycotoxin production similar to the xprG1 gain-of-function mutation. Quantitative RT-PCR showed that ImeB is a negative regulator of xprG expression and XprG is a negative regulator of xprG and ndtA expression. Thus, in contrast to Ime2, which is a positive regulator of NDT80 in S. cerevisiae, ImeB is a negative regulator as in Neurospora crassa. However, the ability of Ndt80 to autoregulate NDT80 is conserved in A. nidulans though the autoregulatory effect is negative rather than positive. Unlike N. crassa, a null mutation in imeB does not circumvent the requirement for XprG or NdtA. These results show that the regulatory activities of Ime2 and Ndt80-like proteins display an extraordinarily level of evolutionary flexibility. PMID:26497142

  7. Characterization of the Methylation Status of Pax7 and Myogenic Regulator Factors in Cell Myogenic Differentiation

    PubMed Central

    Chao, Zhe; Zheng, Xin-Li; Sun, Rui-Ping; Liu, Hai-Long; Huang, Li-Li; Cao, Zong-Xi; Deng, Chang-Yan; Wang, Feng

    2016-01-01

    Epigenetic processes in the development of skeletal muscle have been appreciated for over a decade. DNA methylation is a major epigenetic modification important for regulating gene expression and suppressing spurious transcription. Up to now, the importance of epigenetic marks in the regulation of Pax7 and myogenic regulatory factors (MRFs) expression is far less explored. In the present study, semi-quantitative the real-time polymerase chain reaction (RT-PCR) analyses showed MyoD and Myf5 were expressed in activated and quiescent C2C12 cells. MyoG was expressed in a later stage of myogenesis. Pax7 was weakly expressed in differentiated C2C12 cells. To further understand the regulation of expression of these genes, the DNA methylation status of Pax7, MyoD, and Myf5 was determined by bisulfite sequencing PCR. During the C2C12 myoblasts fusion process, the changes of promoter and exon 1 methylation of Pax7, MyoD, and Myf5 genes were observed. In addition, an inverse relationship of low methylation and high expression was found. These results suggest that DNA methylation may be an important mechanism regulating Pax7 and MRFs transcription in cell myogenic differentiation. PMID:26954143

  8. Characterization of the Methylation Status of Pax7 and Myogenic Regulator Factors in Cell Myogenic Differentiation.

    PubMed

    Chao, Zhe; Zheng, Xin-Li; Sun, Rui-Ping; Liu, Hai-Long; Huang, Li-Li; Cao, Zong-Xi; Deng, Chang-Yan; Wang, Feng

    2016-07-01

    Epigenetic processes in the development of skeletal muscle have been appreciated for over a decade. DNA methylation is a major epigenetic modification important for regulating gene expression and suppressing spurious transcription. Up to now, the importance of epigenetic marks in the regulation of Pax7 and myogenic regulatory factors (MRFs) expression is far less explored. In the present study, semi-quantitative the real-time polymerase chain reaction (RT-PCR) analyses showed MyoD and Myf5 were expressed in activated and quiescent C2C12 cells. MyoG was expressed in a later stage of myogenesis. Pax7 was weakly expressed in differentiated C2C12 cells. To further understand the regulation of expression of these genes, the DNA methylation status of Pax7, MyoD, and Myf5 was determined by bisulfite sequencing PCR. During the C2C12 myoblasts fusion process, the changes of promoter and exon 1 methylation of Pax7, MyoD, and Myf5 genes were observed. In addition, an inverse relationship of low methylation and high expression was found. These results suggest that DNA methylation may be an important mechanism regulating Pax7 and MRFs transcription in cell myogenic differentiation. PMID:26954143

  9. A Genome-wide Regulatory Network Identifies Key Transcription Factors for Memory CD8+ T Cell Development

    PubMed Central

    Hu, Guangan; Chen, Jianzhu

    2014-01-01

    Memory CD8+ T cell development is defined by the expression of a specific set of memory signature genes (MSGs). Despite recent progress, many components of the transcriptional control of memory CD8+ T cell development are still unknown. To identify transcription factors (TFs) and their interactions in memory CD8+ T cell development, we construct a genome-wide regulatory network and apply it to identify key TFs that regulate MSGs. Most of the known TFs in memory CD8+ T cell development are rediscovered and about a dozen new TFs are also identified. Sox4, Bhlhe40, Bach2 and Runx2 are experimentally verified and Bach2 is further shown to promote both development and recall proliferation of memory CD8+ T cells through Prdm1 and Id3. Gene perturbation study identifies the mode of interactions among the TFs with Sox4 as a hub. The identified TFs and insights into their interactions should facilitate further dissection of molecular mechanisms underlying memory CD8+ T cell development. PMID:24335726

  10. Interferon Regulatory Factor-1 Mediates Alveolar Macrophage Pyroptosis During LPS-Induced Acute Lung Injury in Mice.

    PubMed

    Wu, Dongdong; Pan, Pinhua; Su, Xiaoli; Zhang, Lemeng; Qin, Qingwu; Tan, Hongyi; Huang, Li; Li, Yuanyuan

    2016-09-01

    Previously, we demonstrated that pyroptosis in alveolar macrophages (AMs) plays an essential role in lipopolysaccharide (LPS)-induced acute lung injury. However, the underlying mechanism remains largely unclear. Here, we show that the absence of interferon regulatory factor 1 (IRF-1) in genetic knock-out mice strongly abrogates pyroptosis in AMs and alleviates the LPS-induced lung injury and systemic inflammation. Our study demonstrates that IRF-1 contributes to caspase-1 activation and apoptosis-associated speck-like protein containing a caspase activation and recruitment domain pyroptosome formation in AMs and leads to downstream inflammatory cytokine release, including that of IL-1β, IL-18, and HMGB1. The nuclear translocation of IRF-1 is linked to the presence of toll-like receptor 4 (TLR4). Our findings suggest that pyroptosis and the downstream inflammatory response in AMs induced by LPS is a process that is dependent on TLR4-mediated up-regulation of IRF-1. In summary, IRF-1 plays a key role in controlling caspase-1-dependent pyroptosis and inflammation. PMID:26939040

  11. Nuclear factor 45 (NF45) is a regulatory subunit of complexes with NF90/110 involved in mitotic control.

    PubMed

    Guan, Deyu; Altan-Bonnet, Nihal; Parrott, Andrew M; Arrigo, Cindy J; Li, Quan; Khaleduzzaman, Mohammed; Li, Hong; Lee, Chee-Gun; Pe'ery, Tsafi; Mathews, Michael B

    2008-07-01

    Nuclear factor 90 (NF90) and its C-terminally extended isoform, NF110, have been isolated as DNA- and RNA-binding proteins together with the less-studied protein NF45. These complexes have been implicated in gene regulation, but little is known about their cellular roles and whether they are redundant or functionally distinct. We show that heterodimeric core complexes, NF90-NF45 and NF110-NF45, exist within larger complexes that are more labile and contain multiple NF90/110 isoforms and additional proteins. Depletion of the NF45 subunit by RNA interference is accompanied by a dramatic decrease in the levels of NF90 and NF110. Reciprocally, depletion of NF90 but not of NF110 greatly reduces the level of NF45. Coregulation of NF90 and NF45 is a posttranscriptional phenomenon, resulting from protein destabilization in the absence of partners. Depletion of NF90-NF45 complexes retards cell growth by inhibition of DNA synthesis. Giant multinucleated cells containing nuclei attached by constrictions accumulate when either NF45 or NF90, but not NF110, is depleted. This study identified NF45 as an unstable regulatory subunit of NF90-NF45 complexes and uncovered their critical role in normal cell division. Furthermore, the study revealed that NF90 is functionally distinct from NF110 and is more important for cell growth. PMID:18458058

  12. Decoding the trans-histone crosstalk: methods to analyze H2B ubiquitination, H3 methylation and their regulatory factors

    PubMed Central

    Chandrasekharan, Mahesh B.; Huang, Fu; Sun, Zu-Wen

    2011-01-01

    Regulation of histone H3 lysine 4 and 79 methylation by histone H2B lysine 123 monoubiquitination is an evolutionarily conserved trans-histone crosstalk mechanism, which demonstrates a functional role for histone ubiquitination within the cell. The regulatory enzymes, factors and processes involved in the establishment and dynamic modulation of these modifications and their genome-wide distribution patterns have been determined in many model systems. Rapid progress in understanding this trans-histone crosstalk has been made using the standard experimental tools of chromatin biology in budding yeast (Saccharomyces cerevisiae), a highly tractable model organism. Here, we provide a set of modified and refined experimental procedures that can be used to gain further insights into the underlying mechanisms that govern this crosstalk in budding yeast. Importantly, the improved procedures and their underlying principles can also be applied to other model organisms. Methods presented here provide a rapid