77 FR 3380 - Airworthiness Directives; Eurocopter France (ECF) Model AS350B, B1, B2, B3, BA, and D; and AS355E...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-24

... Airworthiness Directives; Eurocopter France (ECF) Model AS350B, B1, B2, B3, BA, and D; and AS355E, F, F1, F2... Register as of February 8, 2012. We must receive comments on this AD by March 26, 2012. ADDRESSES: You may..., 2009, specifying MOD 073330 for the Model SA350B, B1, B2, B3, BA, BB, D, and L1 helicopters. ECF has...

F-22 Increment 3.2B Modernization (F-22 Inc 3.2B Mod)

DTIC Science & Technology

2013-12-01

MAR 2016 SEP 2016 SEP 2016 (Ch-1) Full Rate Production JAN 2018 JAN 2018 JUL 2018 JUL 2018 (Ch-1) Required Assets Available ( RAA ) MAR 2019 MAR 2019 SEP...2019 SEP 2019 (Ch-1) Change Explanations (Ch-1) The Milestone C, Full Rate Production, and Required Assets Available ( RAA ) current estimates changed...successful. Memo RAA is defined as six aircraft and associated support equipment. F-22 Inc 3.2B Mod December 2013 SAR April 16, 2014 17:04:43

The B(E2;4^+1->2^+1) / B(E2;2^+1->0^+1) Ratio in Even-Even Nuclei

NASA Astrophysics Data System (ADS)

Loelius, C.; Sharon, Y. Y.; Zamick, L.; G"Urdal, G.

2009-10-01

We considered 207 even-even nuclei throughout the chart of nuclides for which the NNDC Tables had data on the energies and lifetimes of the 2^+1 and 4^+1 states. Using these data we calculated for each nucleus the electric quadrupole transition strengths B(E2;4^+1->2^+1) and B(E2;2^+1->0^+1), as well as their ratio. The internal conversion coefficients were obtained by using the NNDC HSICC calculator. For each nucleus we plotted the B(E2) ratio against A, N, and Z. We found that for close to 90% of the nuclei considered the ratio had values between 0.5 and 2.5. Most of the outliers had magic numbers of protons or neutrons. Our ratio results were compared with the theoretical predictions for this ratio by different models--10/7 in the rotational model and 2 in the simplest vibrational model. In the rotational regions (for 150 < A < 180 and A > 220) the ratios were indeed close to 10/7. For the few nuclei thought to be vibrational the ratios were usually less than 2. Otherwise, we got a wide scatter of ratio values. Hence other models, including the NpNn scheme, must be considered in interpreting these results.

E2F1/TS Immunophenotype and Survival of Patients with Colorectal Cancer Treated with 5FU-Based Adjuvant Therapy.

PubMed

Sulzyc-Bielicka, Violetta; Domagala, Pawel; Bielicki, Dariusz; Safranow, Krzysztof; Rogowski, Wojciech; Domagala, Wenancjusz

2016-07-01

The predictive value of thymidylate synthase (TS) expression alone for 5FU-based treatment of colorectal cancer (CRC) has not been clinically confirmed. Little is known on the association of expression of E2F1, which controls the transcription of genes encoding proteins engaged in DNA synthesis including TS, and survival of patients with CRC. The purpose of this study is to assess the correlation between expression of both E2F1 and TS in CRCs and survival of patients administered adjuvant 5FU-based chemotherapy, in order to find a better predictor of treatment outcome than expression of TS or E2F1 alone. Nuclear TS and E2F1 were detected by immunohistochemistry in tissue microarrays from 190 CRCs (Astler-Coller stage B2 or C). Multivariate analysis identified significant association of the combined E2F1+TS+ immunophenotype with worse OS (HR = 3,78, P = 0,009) and DFS (HR = 2,30, P = 0,03) of patients with colon cancer. There were significant differences between E2F1+TS+ and E2F1-TS- Kaplan-Meier survival curves in relation to DFS (P = 0.008) and OS (P = 0.01). About 37 and 31 % difference in 3-year DFS and OS respectively were seen between patients with E2F1+TS+ vs. E2F1-TS- colon cancer immunophenotype. The E2F1+TS+ immunophenotype may be a marker of poor prognosis (the worst DFS and OS) of patients with colon cancer treated with 5FU-based adjuvant therapy. A subgroup of patients with this immunophenotype may require different and perhaps more aggressive treatment than 5FU-based chemotherapy. Thus, the combined E2F1/TS immunophenotype could be a potential indicator of colon cancer sensitivity to 5FU.

75 FR 34062 - Airworthiness Directives; Eurocopter France Model AS 350 B, BA, B1, B2, B3, and D, and Model...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-16

... Airworthiness Directives; Eurocopter France Model AS 350 B, BA, B1, B2, B3, and D, and Model AS355 E, F, F1, F2... AS 350 B, BA, B1, B2, B3, and D, and Model AS355 E, F, F1, F2, and N helicopters, with certain main... an unsafe condition for certain Eurocopter France Model AS 350 B, BA, BB, B1, B2, B3, and D, and...

26 CFR 1.503(e)-2 - Requirements.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 7 2014-04-01 2013-04-01 true Requirements. 1.503(e)-2 Section 1.503(e)-2...) INCOME TAXES (CONTINUED) Exempt Organizations § 1.503(e)-2 Requirements. (a) In general. The requirements... price may not be a valid price for 1,000 bonds and the purchase may therefore not meet the requirements...

26 CFR 1.503(e)-2 - Requirements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 26 Internal Revenue 7 2011-04-01 2009-04-01 true Requirements. 1.503(e)-2 Section 1.503(e)-2...) INCOME TAXES (CONTINUED) Exempt Organizations § 1.503(e)-2 Requirements. (a) In general. The requirements... price may not be a valid price for 1,000 bonds and the purchase may therefore not meet the requirements...

26 CFR 1.503(e)-2 - Requirements.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 26 Internal Revenue 7 2013-04-01 2013-04-01 false Requirements. 1.503(e)-2 Section 1.503(e)-2...) INCOME TAXES (CONTINUED) Exempt Organizations § 1.503(e)-2 Requirements. (a) In general. The requirements... price may not be a valid price for 1,000 bonds and the purchase may therefore not meet the requirements...

E2F1 interactions with hHR23A inhibit its degradation and promote DNA repair.

PubMed

Singh, Randeep K; Dagnino, Lina

2016-05-03

Nucleotide excision repair (NER) is a major mechanism for removal of DNA lesions induced by exposure to UV radiation in the epidermis. Recognition of damaged DNA sites is the initial step in their repair, and requires multiprotein complexes that contain XPC and hHR23 proteins, or their orthologues. A variety of transcription factors are also involved in NER, including E2F1. In epidermal keratinocytes, UV exposure induces E2F1 phosphorylation, which allows it to recruit various NER factors to sites of DNA damage. However, the relationship between E2F1 and hHR23 proteins vis-à-vis NER has remained unexplored. We now show that E2F1 and hHR23 proteins can interact, and this interaction stabilizes E2F1, inhibiting its proteasomal degradation. Reciprocally, E2F1 regulates hHR23A subcellular localization, recruiting it to sites of DNA photodamage. As a result, E2F1 and hHR23A enhance DNA repair following exposure to UV radiation, contributing to genomic stability in the epidermis.

E2F1 interactions with hHR23A inhibit its degradation and promote DNA repair

PubMed Central

Singh, Randeep K.; Dagnino, Lina

2016-01-01

Nucleotide excision repair (NER) is a major mechanism for removal of DNA lesions induced by exposure to UV radiation in the epidermis. Recognition of damaged DNA sites is the initial step in their repair, and requires multiprotein complexes that contain XPC and hHR23 proteins, or their orthologues. A variety of transcription factors are also involved in NER, including E2F1. In epidermal keratinocytes, UV exposure induces E2F1 phosphorylation, which allows it to recruit various NER factors to sites of DNA damage. However, the relationship between E2F1 and hHR23 proteins vis-à-vis NER has remained unexplored. We now show that E2F1 and hHR23 proteins can interact, and this interaction stabilizes E2F1, inhibiting its proteasomal degradation. Reciprocally, E2F1 regulates hHR23A subcellular localization, recruiting it to sites of DNA photodamage. As a result, E2F1 and hHR23A enhance DNA repair following exposure to UV radiation, contributing to genomic stability in the epidermis. PMID:27028861

Dynamic NF-κB and E2F interactions control the priority and timing of inflammatory signalling and cell proliferation

PubMed Central

Ankers, John M; Awais, Raheela; Jones, Nicholas A; Boyd, James; Ryan, Sheila; Adamson, Antony D; Harper, Claire V; Bridge, Lloyd; Spiller, David G; Jackson, Dean A; Paszek, Pawel; Sée, Violaine; White, Michael RH

2016-01-01

Dynamic cellular systems reprogram gene expression to ensure appropriate cellular fate responses to specific extracellular cues. Here we demonstrate that the dynamics of Nuclear Factor kappa B (NF-κB) signalling and the cell cycle are prioritised differently depending on the timing of an inflammatory signal. Using iterative experimental and computational analyses, we show physical and functional interactions between NF-κB and the E2 Factor 1 (E2F-1) and E2 Factor 4 (E2F-4) cell cycle regulators. These interactions modulate the NF-κB response. In S-phase, the NF-κB response was delayed or repressed, while cell cycle progression was unimpeded. By contrast, activation of NF-κB at the G1/S boundary resulted in a longer cell cycle and more synchronous initial NF-κB responses between cells. These data identify new mechanisms by which the cellular response to stress is differentially controlled at different stages of the cell cycle. DOI: http://dx.doi.org/10.7554/eLife.10473.001 PMID:27185527

EBP1 is a novel E2F target gene regulated by transforming growth factor-β.

PubMed

Judah, David; Chang, Wing Y; Dagnino, Lina

2010-11-10

Regulation of gene expression requires transcription factor binding to specific DNA elements, and a large body of work has focused on the identification of such sequences. However, it is becoming increasingly clear that eukaryotic transcription factors can exhibit widespread, nonfunctional binding to genomic DNA sites. Conversely, some of these proteins, such as E2F, can also modulate gene expression by binding to non-consensus elements. E2F comprises a family of transcription factors that play key roles in a wide variety of cellular functions, including survival, differentiation, activation during tissue regeneration, metabolism, and proliferation. E2F factors bind to the Erb3-binding protein 1 (EBP1) promoter in live cells. We now show that E2F binding to the EBP1 promoter occurs through two tandem DNA elements that do not conform to typical consensus E2F motifs. Exogenously expressed E2F1 activates EBP1 reporters lacking one, but not both sites, suggesting a degree of redundancy under certain conditions. E2F1 increases the levels of endogenous EBP1 mRNA in breast carcinoma and other transformed cell lines. In contrast, in non-transformed primary epidermal keratinocytes, E2F, together with the retinoblastoma family of proteins, appears to be involved in decreasing EBP1 mRNA abundance in response to growth inhibition by transforming growth factor-β1. Thus, E2F is likely a central coordinator of multiple responses that culminate in regulation of EBP1 gene expression, and which may vary depending on cell type and context.

Secretion and translocation signals and DspB/F-binding domains in the type III effector DspA/E of Erwinia amylovora.

PubMed

Oh, Chang-Sik; Carpenter, Sara C D; Hayes, Marshall L; Beer, Steven V

2010-04-01

DspA/E is a type III effector of Erwinia amylovora, the bacterial pathogen that causes fire blight disease in roseaceous plants. This effector is indispensable for disease development, and it is translocated into plant cells. A DspA/E-specific chaperone, DspB/F, is necessary for DspA/E secretion and possibly for its translocation. In this work, DspB/F-binding sites and secretion and translocation signals in the DspA/E protein were determined. Based on yeast two-hybrid assays, DspB/F was found to bind DspA/E within the first 210 amino acids of the protein. Surprisingly, both DspB/F and OrfA, the putative chaperone of Eop1, also interacted with the C-terminal 1059 amino acids of DspA/E; this suggests another chaperone-binding site. Secretion and translocation assays using serial N-terminal lengths of DspA/E fused with the active form of AvrRpt2 revealed that at least the first 109 amino acids, including the first N-terminal chaperone-binding motif and DspB/F, were required for efficient translocation of DspA/E, although the first 35 amino acids were sufficient for its secretion and the presence of DspB/F was not required. These results indicate that secretion and translocation signals are present in the N terminus of DspA/E, and that at least one DspB/F-binding motif is required for efficient translocation into plant cells.

Magnetoelectric effect in antiferromagnetic multiferroic Pb (F e1 /2N b1 /2)O3 and its solid solutions with PbTi O3

NASA Astrophysics Data System (ADS)

Laguta, V. V.; Stephanovich, V. A.; Raevski, I. P.; Raevskaya, S. I.; Titov, V. V.; Smotrakov, V. G.; Eremkin, V. V.

2017-01-01

Antiferromagnets (AFMs) are presently considered as promising materials for applications in spintronics and random access memories due to the robustness of information stored in the AFM state against perturbing magnetic fields. In this respect, AFM multiferroics may be attractive alternatives for conventional AFMs as the coupling of magnetism with ferroelectricity (magnetoelectric effect) offers an elegant possibility of electric-field control and switching of AFM domains. Here we report the results of comprehensive experimental and theoretical investigations of the quadratic magnetoelectric (ME) effect in single crystals and highly resistive ceramics of Pb (F e1 /2N b1 /2)O3 (PFN) and (1 -x ) Pb (F e1 /2N b1 /2) O3-x PbTi O3(PFN -x PT ) . We are interested primarily in the temperature range of the multiferroic phase, T <150 K , where the ME coupling coefficient is extremely large (as compared to the well-known multiferroic BiFe O3 ) and shows sign reversal at the paramagnetic-to-antiferromagnetic phase transition. Moreover, we observe strong ME response nonlinearity in the AFM phase in the magnetic fields of only a few kOe. To describe the temperature and magnetic field dependencies of the above unusual features of the ME effect in PFN and PFN-x PT , we use a simple phenomenological Landau approach which explains experimental data surprisingly well. Our ME measurements demonstrate that the electric field of only 20-25 kV/cm is able to switch the AFM domains and align them with ferroelectric ones even in PFN ceramic samples.

B1 Cell IgE Impedes Mast Cell-Mediated Enhancement of Parasite Expulsion through B2 IgE Blockade.

PubMed

Martin, Rebecca K; Damle, Sheela R; Valentine, Yolander A; Zellner, Matthew P; James, Briana N; Lownik, Joseph C; Luker, Andrea J; Davis, Elijah H; DeMeules, Martha M; Khandjian, Laura M; Finkelman, Fred D; Urban, Joseph F; Conrad, Daniel H

2018-02-13

Helminth infection is known for generating large amounts of poly-specific IgE. Here we demonstrate that innate-like B1 cells are responsible for this IgE production during infection with the nematode parasites Nippostrongylus brasiliensis and Heligmosomoides polygyrus bakeri. In vitro analysis of B1 cell immunoglobulin class switch recombination to IgE demonstrated a requirement for anti-CD40 and IL-4 that was further enhanced when IL-5 was added or when the B1 source was helminth infected mice. An IL-25-induced upregulation of IgE in B1 cells was also demonstrated. In T cell-reconstituted RAG1 -/- mice, N. brasiliensis clearance was enhanced with the addition of B2 cells in an IgE-dependent manner. This enhanced clearance was impeded by reconstitution with IgE sufficient B1 cells. Mucosal mast cells mediated the B2 cell enhancement of clearance in the absence of B1 cells. The data support B1 cell IgE secretion as a regulatory response exploited by the helminth. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Elevated autophagy gene expression in adipose tissue of obese humans: A potential non-cell-cycle-dependent function of E2F1

PubMed Central

Haim, Yulia; Blüher, Matthias; Slutsky, Noa; Goldstein, Nir; Klöting, Nora; Harman-Boehm, Ilana; Kirshtein, Boris; Ginsberg, Doron; Gericke, Martin; Guiu Jurado, Esther; Kovsan, Julia; Tarnovscki, Tanya; Kachko, Leonid; Bashan, Nava; Gepner, Yiftach; Shai, Iris; Rudich, Assaf

2015-01-01

Autophagy genes' expression is upregulated in visceral fat in human obesity, associating with obesity-related cardio-metabolic risk. E2F1 (E2F transcription factor 1) was shown in cancer cells to transcriptionally regulate autophagy. We hypothesize that E2F1 regulates adipocyte autophagy in obesity, associating with endocrine/metabolic dysfunction, thereby, representing non-cell-cycle function of this transcription factor. E2F1 protein (N=69) and mRNA (N=437) were elevated in visceral fat of obese humans, correlating with increased expression of ATG5 (autophagy-related 5), MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β), but not with proliferation/cell-cycle markers. Elevated E2F1 mainly characterized the adipocyte fraction, whereas MKI67 (marker of proliferation Ki-67) was elevated in the stromal-vascular fraction of adipose tissue. In human visceral fat explants, chromatin-immunoprecipitation revealed body mass index (BMI)-correlated increase in E2F1 binding to the promoter of MAP1LC3B, but not to the classical cell cycle E2F1 target, CCND1 (cyclin D1). Clinically, omental fat E2F1 expression correlated with insulin resistance, circulating free-fatty-acids (FFA), and with decreased circulating ADIPOQ/adiponectin, associations attenuated by adjustment for autophagy genes. Overexpression of E2F1 in HEK293 cells enhanced promoter activity of several autophagy genes and autophagic flux, and sensitized to further activation of autophagy by TNF. Conversely, mouse embryonic fibroblast (MEF)-derived adipocytes from e2f1 knockout mice (e2f1−/−) exhibited lower autophagy gene expression and flux, were more insulin sensitive, and secreted more ADIPOQ. Furthermore, e2f1−/− MEF-derived adipocytes, and autophagy-deficient (by Atg7 siRNA) adipocytes were resistant to cytokines-induced decrease in ADIPOQ secretion. Jointly, upregulated E2F1 sensitizes adipose tissue autophagy to inflammatory stimuli, linking visceral obesity to adipose and systemic

E2F4 is required for early eye patterning.

PubMed

Ruzhynsky, Vladimir A; Furimsky, Marosh; Park, David S; Wallace, Valerie A; Slack, Ruth S

2009-01-01

Increasingly, studies reveal novel functions for cell cycle proteins during development. Here, we investigated the role of E2F4 in eye development. E2F4-deficient mouse embryos exhibit severe early eye patterning defects, which are evident from embryonic day 11.5 and characterized by aberrant shape of the optic cup, coloboma as well as abnormal eye pigmentation. Loss of E2F4 is associated with proximal-distal patterning defects in the optic vesicle. These defects are characterized by the expansion of optic stalk marker gene expression to the optic cup and reduced expression of ventral optic cup markers. These defects are associated with a split of Shh expression domain at the ventral midline of the forebrain and expansion of the Shh activity into the ventral optic cup. Despite these patterning defects, early neuronal differentiation and Shh expression in the retina are not affected by E2F4 deletion. Overall, the results of our studies show a novel role of E2F4 in the early eye development. 2009 S. Karger AG, Basel.

Bioactive constituents from Chinese natural medicines. XXII. Absolute structures of new megastigmane glycosides, sedumosides E1, E2, E3, F1, F2, and G, from Sedum sarmentosum (Crassulaceae).

PubMed

Morikawa, Toshio; Zhang, Yi; Nakamura, Seikou; Matsuda, Hisashi; Muraoka, Osamu; Yoshikawa, Masayuki

2007-03-01

Six new megastigmane glycosides, sedumosides E1, E2, E3, F1, F2, and G, were isolated from the whole plant of Sedum sarmentosum (Crassulaceae). The structures of new constituents including the absolute configuration were elucidated on the basis of chemical and physicochemical evidence.

E2F1 transcription is induced by genotoxic stress through ATM/ATR activation.

PubMed

Carcagno, Abel L; Ogara, María F; Sonzogni, Silvina V; Marazita, Mariela C; Sirkin, Pablo F; Ceruti, Julieta M; Cánepa, Eduardo T

2009-05-01

E2F1, a member of the E2F family of transcription factors, plays a critical role in controlling both cell cycle progression and apoptotic cell death in response to DNA damage and oncogene activation. Following genotoxic stresses, E2F1 protein is stabilized by phosphorylation and acetylation driven to its accumulation. The aim of the present work was to examine whether the increase in E2F1 protein levels observed after DNA damage is only a reflection of an increase in E2F1 protein stability or is also the consequence of enhanced transcription of the E2F1 gene. The data presented here demonstrates that UV light and other genotoxics induce the transcription of E2F1 gene in an ATM/ATR dependent manner, which results in increasing E2F1 mRNA and protein levels. After genotoxic stress, transcription of cyclin E, an E2F1 target gene, was significantly induced. This induction was the result of two well-differentiated effects, one of them dependent on de novo protein synthesis and the other on the protein stabilization. Our results strongly support a transcriptional effect of DNA damaging agents on E2F1 expression. The results presented herein uncover a new mechanism involving E2F1 in response to genotoxic stress.

HP-41CV Flight Performance Advisory System (FPAS) for the E-2C, E-2B, and C-2A Aircraft

DTIC Science & Technology

1982-06-01

NPS67-82- 003 NAVAL POSTGRADUATE SCHOOL Monterey, California DTIC HP-41CV FLIGHT PERFORMANCE ADVISORY SYSTEM (FPAS) FOR THE E-2C, E-2B, AND C-2A...A’P-𔃻"’f .00 ____________ 4. TITLE9 (and Subtil) SL TYPE OF REPORT & PERIOD COVERED H1P-41CV FLIGHT PERFORMANCE ADVISORY SYSTEM (FPAS) TECHNICAL REPORT...complement the original design of a Flight Performance Advisory System (FPAS) for the E-2C aircraft. The original design fulfilled the requirements of AE 3001

Arginine methylation-dependent reader-writer interplay governs growth control by E2F-1

PubMed Central

Zheng, Shunsheng; Moehlenbrink, Jutta; Lu, Yi-Chien; Zalmas, Lykourgos-Panagiotis; Sagum, Cari A.; Carr, Simon; McGouran, Joanna F.; Alexander, Leila; Fedorov, Oleg; Munro, Shonagh; Kessler, Benedikt; Bedford, Mark T.; Yu, Qiang; La Thangue, Nicholas B.

2014-01-01

Summary The mechanisms that underlie and dictate the different biological outcomes of E2F-1 activity have yet to be elucidated. We describe the residue-specific methylation of E2F-1 by the asymmetric dimethylating protein arginine methyltransferase (PRMT) 1 and symmetric dimethylating PRMT5, and relate the marks to different functional consequences of E2F-1 activity. Methylation by PRMT1 hinders methylation by PRMT5, which augments E2F-1-dependent apoptosis, whereas PRMT5-dependent methylation favours proliferation by antagonising methylation by PRMT1. The ability of E2F-1 to prompt apoptosis in DNA damaged cells coincides with enhanced PRMT1 methylation. In contrast, cyclin A binding to E2F-1 impedes PRMT1 methylation and augments PRMT5 methylation, thus ensuring that E2F-1 is locked into its cell cycle progression mode. The Tudor domain protein p100-TSN reads the symmetric methylation mark, and binding of p100-TSN down-regulates E2F-1 apoptotic activity. Our results define an exquisite level of precision in the reader-writer interplay that governs the biological outcome of E2F-1 activity. PMID:24076217

Doping evolution of the second magnetization peak and magnetic relaxation in (B a1 -xKx ) F e2A s2 single crystals

NASA Astrophysics Data System (ADS)

Liu, Yong; Zhou, Lin; Sun, Kewei; Straszheim, Warren E.; Tanatar, Makariy A.; Prozorov, Ruslan; Lograsso, Thomas A.

2018-02-01

We present a thorough study of doping dependent magnetic hysteresis and relaxation characteristics in single crystals of (B a1 -xKx ) F e2A s2 (0.18 ≤x ≤1 ). The critical current density Jc reaches maximum in the underdoped sample x =0.26 and then decreases in the optimally doped and overdoped samples. Meanwhile, the magnetic relaxation rate S rapidly increases and the flux creep activation barrier U0 sharply decreases in the overdoped sample x =0.70 . These results suggest that vortex pinning is very strong in the underdoped regime, but it is greatly reduced in the optimally doped and overdoped regime. Transmission electron microscope (TEM) measurements reveal the existence of dislocations and inclusions in all three studied samples x =0.38 , 0.46, and 0.65. An investigation of the paramagnetic Meissner effect (PME) suggests that spatial variations in Tc become small in the samples x =0.43 and 0.46, slightly above the optimal doping levels. Our results support that two types of pinning sources dominate the (B a1 -xKx ) F e2A s2 crystals: (i) strong δl pinning, which results from the fluctuations in the mean free path l and δ Tc pinning from the spatial variations in Tc in the underdoped regime, and (ii) weak δ Tc pinning in the optimally doped and overdoped regime.

75 FR 65222 - Airworthiness Directives; Eurocopter France Model AS 350 B, BA, B1, B2, B3, and D, and Model...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-22

... Airworthiness Directives; Eurocopter France Model AS 350 B, BA, B1, B2, B3, and D, and Model AS355 E, F, F1, F2... adopting a new airworthiness directive (AD) for the Eurocopter France Model AS 350 B, BA, B1, B2, B3, and D... 14 CFR part 39 to include an AD that would apply to the Eurocopter France Model AS 350 B, BA, B1, B2...

E2F1-mediated human POMC expression in ectopic Cushing's syndrome.

PubMed

Araki, Takako; Liu, Ning-Ai; Tone, Yukiko; Cuevas-Ramos, Daniel; Heltsley, Roy; Tone, Masahide; Melmed, Shlomo

2016-11-01

Cushing's syndrome is caused by excessive adrenocorticotropic hormone (ACTH) secretion derived from pituitary corticotroph tumors (Cushing disease) or from non-pituitary tumors (ectopic Cushing's syndrome). Hypercortisolemic features of ectopic Cushing's syndrome are severe, and no definitive treatment for paraneoplastic ACTH excess is available. We aimed to identify subcellular therapeutic targets by elucidating transcriptional regulation of the human ACTH precursor POMC (proopiomelanocortin) and ACTH production in non-pituitary tumor cells and in cell lines derived from patients with ectopic Cushing's syndrome. We show that ectopic hPOMC transcription proceeds independently of pituitary-specific Tpit/Pitx1 and demonstrate a novel E2F1-mediated transcriptional mechanism regulating hPOMC We identify an E2F1 cluster binding to the proximal hPOMC promoter region (-42 to +68), with DNA-binding activity determined by the phosphorylation at Ser-337. hPOMC mRNA expression in cancer cells was upregulated (up to 40-fold) by the co-expression of E2F1 and its heterodimer partner DP1. Direct and indirect inhibitors of E2F1 activity suppressed hPOMC gene expression and ACTH by modifying E2F1 DNA-binding activity in ectopic Cushing's cell lines and primary tumor cells, and also suppressed paraneoplastic ACTH and cortisol levels in xenografted mice. E2F1-mediated hPOMC transcription is a potential target for suppressing ACTH production in ectopic Cushing's syndrome. © 2016 Society for Endocrinology.

A novel mechanism of E2F1 regulation via nucleocytoplasmic shuttling: determinants of nuclear import and export.

PubMed

Ivanova, Iordanka A; Vespa, Alisa; Dagnino, Lina

2007-09-01

E2F1 is a transcription factor central for cell survival, proliferation, and repair following genomic insult. Depending on the cell type and conditions, E2F1 can induce apoptosis in transformed cells, behaving as a tumour suppressor, or impart growth advantages favouring tumour formation. The pleiotropic functions of E2F1 are a likely consequence of its ability to transcriptionally control a wide variety of target genes, and require tight regulation of its activity at multiple levels. Although sequestration of proteins to particular cellular compartments is a well-established regulatory mechanism, virtually nothing is known about its contribution to modulation of E2F1 target gene expression. We have examined the subcellular trafficking of E2F1 and, contrary to the widely held notion that this factor is constitutively nuclear, we now demonstrate that it is subjected to continuous nucleocytoplasmic shuttling. We have also defined two nuclear localization domains and a nuclear export region, which mediates CRM1-dependent transit out of the nucleus. The predominant subcellular location of E2F1 is likely determined by the balance between the activity of nuclear import and export domains, and can be modulated by differentiation stimuli in epidermal cells. Thus, we have identified a hitherto unrecognized mechanism to control E2F1 function through modulation of its subcellular localization.

E2F1 transcription factor and its impact on growth factor and cytokine signaling.

PubMed

Ertosun, Mustafa Gokhan; Hapil, Fatma Zehra; Osman Nidai, Ozes

2016-10-01

E2F1 is a transcription factor involved in cell cycle regulation and apoptosis. The transactivation capacity of E2F1 is regulated by pRb. In its hypophosphorylated form, pRb binds and inactivates DNA binding and transactivating functions of E2F1. The growth factor stimulation of cells leads to activation of CDKs (cyclin dependent kinases), which in turn phosphorylate Rb and hyperphosphorylated Rb is released from E2F1 or E2F1/DP complex, and free E2F1 can induce transcription of several genes involved in cell cycle entry, induction or inhibition of apoptosis. Thus, growth factors and cytokines generally utilize E2F1 to direct cells to either fate. Furthermore, E2F1 regulates expressions of various cytokines and growth factor receptors, establishing positive or negative feedback mechanisms. This review focuses on the relationship between E2F1 transcription factor and cytokines (IL-1, IL-2, IL-3, IL-6, TGF-beta, G-CSF, LIF), growth factors (EGF, KGF, VEGF, IGF, FGF, PDGF, HGF, NGF), and interferons (IFN-α, IFN-β and IFN-γ). Copyright © 2016 Elsevier Ltd. All rights reserved.

E2F8 is essential for polyploidization in mammalian cells.

PubMed

Pandit, Shusil K; Westendorp, Bart; Nantasanti, Sathidpak; van Liere, Elsbeth; Tooten, Peter C J; Cornelissen, Peter W A; Toussaint, Mathilda J M; Lamers, Wouter H; de Bruin, Alain

2012-11-01

Polyploidization is observed in all mammalian species and is a characteristic feature of hepatocytes, but its molecular mechanism and biological significance are unknown. Hepatocyte polyploidization in rodents occurs through incomplete cytokinesis, starts after weaning and increases with age. Here, we show in mice that atypical E2F8 is induced after weaning and required for hepatocyte binucleation and polyploidization. A deficiency in E2f8 led to an increase in the expression level of E2F target genes promoting cytokinesis and thereby preventing polyploidization. In contrast, loss of E2f1 enhanced polyploidization and suppressed the polyploidization defect of hepatocytes deficient for atypical E2Fs. In addition, E2F8 and E2F1 were found on the same subset of target promoters. Contrary to the long-standing hypothesis that polyploidization indicates terminal differentiation and senescence, we show that prevention of polyploidization through inactivation of atypical E2Fs has, surprisingly, no impact on liver differentiation, zonation, metabolism and regeneration. Together, these results identify E2F8 as a repressor and E2F1 as an activator of a transcriptional network controlling polyploidization in mammalian cells.

Charmless hadronic B →(f1(1285 ),f1(1420 ))P decays in the perturbative QCD approach

NASA Astrophysics Data System (ADS)

Liu, Xin; Xiao, Zhen-Jun; Li, Jing-Wu; Zou, Zhi-Tian

2015-01-01

We study 20 charmless hadronic B →f1P decays in the perturbative QCD (pQCD) formalism with B denoting Bu, Bd, and Bs mesons; P standing for the light pseudoscalar mesons; and f1 representing axial-vector mesons f1(1285 ) and f1(1420 ) that result from a mixing of quark-flavor f1 q[u/u ¯ +d d ¯ √{2 } ] and f1 s[s s ¯ ] states with the angle ϕf1.The estimations of C P -averaged branching ratios and C P asymmetries of the considered B →f1P decays, in which the Bs→f1P modes are investigated for the first time, are presented in the pQCD approach with ϕf 1˜24 ° from recently measured Bd /s→J /ψ f1(1285 ) decays. It is found that (a) the tree (penguin) dominant B+→f1π+(K+) decays with large branching ratios [O (10-6) ] and large direct C P violations (around 14%-28% in magnitude) simultaneously are believed to be clearly measurable at the LHCb and Belle II experiments; (b) the Bd→f1KS0 and Bs→f1(η ,η') decays with nearly pure penguin contributions and safely negligible tree pollution also have large decay rates in the order of 10-6- 10-5 , which can be confronted with the experimental measurements in the near future; (c) as the alternative channels, the B+→f1(π+,K+) and Bd→f1KS0 decays have the supplementary power in providing more effective constraints on the Cabibbo-Kobayashi-Maskawa weak phases α , γ , and β , correspondingly, which are explicitly analyzed through the large decay rates and the direct and mixing-induced C P asymmetries in the pQCD approach and are expected to be stringently examined by the measurements with high precision; (d) the weak annihilation amplitudes play important roles in the B+→f1(1420 )K+ , Bd→f1(1420 )KS0 , Bs→f1(1420 )η' decays, and so on, which would offer more evidence, once they are confirmed by the experiments, to identify the soft-collinear effective theory and the pQCD approach on the evaluations of annihilation diagrams and to help further understand the annihilation mechanism in the heavy

F-22 Increment 3.2B Modernization (F-22 Inc 3.2B Mod)

DTIC Science & Technology

2015-12-01

Production Jan 2018 Jan 2018 Jul 2018 Jul 2018 Required Assets Available ( RAA ) Mar 2019 Mar 2019 Sep 2019 Sep 2019 Change Explanations None Notes... RAA is defined as six aircraft and associated support equipment. F-22 Inc 3.2B Mod December 2015 SAR March 23, 2016 16:11:54 UNCLASSIFIED 9...Mar 2016 N/A Jun 2016 RAA N/A Mar 2019 N/A Sep 2019 Total Cost (TY $M) N/A 1584.1 N/A 1542.6 Total Quantity N/A 152 N/A 152 PAUC N/A 10.422 N/A 10.149

E2F8 as a Novel Therapeutic Target for Lung Cancer

PubMed Central

Park, Sin-Aye; Platt, James; Lee, Jong Woo; López-Giráldez, Francesc; Herbst, Roy S.

2015-01-01

Background: The E2F members have been divided into transcription activators (E2F1-E2F3) and repressors (E2F4-E2F8). E2F8 with E2F7 has been known to play an important physiologic role in embryonic development and cell cycle regulation by repressing E2F1. However, the function of E2F8 in cancer cells is unknown. Methods: E2F8 expression was assessed by immunoblotting or immunofluorescence staining in human lung cancer (LC) cells and tissues from LC patients (n = 45). Cell proliferation, colony formation, and invasion analysis were performed to evaluate the role of E2F8 in LC. Microarray analysis was used to determine the target genes of E2F8. The regulation of E2F8 on the expression of ubiquitin-like PHD and RING domain-containing 1 (UHRF1), one of E2F8 target genes, was determined using chromatin immunoprecipitation and promoter activity assays. Human LC xenograft models were used to determine the effects of inhibiting E2F8 by siRNAs (n = 7 per group) or antisense morpholino (n = 8 per group) on tumor growth. Survival was analyzed using the Kaplan-Meier method and group differences by the Student’s t test. All statistical tests were two-sided. Results: LC tumors overexpressed E2F8 compared with normal lung tissues. Depletion of E2F8 inhibited cell proliferation and tumor growth. E2F8 knockdown statistically significantly reduced the expression of UHRF1 (~60%-70%, P < .001), and the direct binding of E2F8 on the promoter of UHRF1 was identified. Kaplan-Meier analysis with a public database showed prognostic significance of aberrant E2F8 expression in LC (HR = 1.91 95% CI = 1.21 to 3.01 in chemo-naïve patients, P = .0047). Conclusions: We demonstrated that E2F8 is overexpressed in LC and is required for the growth of LC cells. These findings implicate E2F8 as a novel therapeutic target for LC treatment. PMID:26089541

75 FR 80293 - Airworthiness Directives; Eurocopter France Model AS 350 B, BA, B1, B2, B3, and D, and Model...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-22

... Airworthiness Directives; Eurocopter France Model AS 350 B, BA, B1, B2, B3, and D, and Model AS355 E, F, F1, F2... identified in the Applicability section, Table 1, of the AD. As published, two part numbers shown in Table 1... corrected to read as follows: Table 1 Component Part No. (P/N) Serial No. (S/N) Main rotor servo-control...

HTLV-1 bZIP factor protein targets the Rb/E2F-1 pathway to promote proliferation and apoptosis of primary CD4+ T cells

PubMed Central

Kawatsuki, A; Yasunaga, J-i; Mitobe, Y; Green, PL; Matsuoka, M

2016-01-01

Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus that induces a fatal T-cell malignancy, adult T-cell leukemia (ATL). Among several regulatory/accessory genes in HTLV-1, HTLV-1 bZIP factor (HBZ) is the only viral gene constitutively expressed in infected cells. Our previous study showed that HBZ functions in two different molecular forms, HBZ protein and HBZ RNA. In this study, we show that HBZ protein targets retinoblastoma protein (Rb), which is a critical tumor suppressor in many types of cancers. HBZ protein interacts with the Rb/E2F-1 complex and activates the transcription of E2F-target genes associated with cell cycle progression and apoptosis. Mouse primary CD4+ T cells transduced with HBZ show accelerated G1/S transition and apoptosis, and importantly, T cells from HBZ transgenic (HBZ-Tg) mice also demonstrate enhanced cell proliferation and apoptosis. To evaluate the functions of HBZ protein alone in vivo, we generated a new transgenic mouse strain that expresses HBZ mRNA altered by silent mutations but encoding intact protein. In these mice, the numbers of effector/memory and Foxp3+ T cells were increased, and genes associated with proliferation and apoptosis were upregulated. This study shows that HBZ protein promotes cell proliferation and apoptosis in primary CD4+ T cells through activation of the Rb/E2F pathway, and that HBZ protein also confers onto CD4+ T-cell immunophenotype similar to those of ATL cells, suggesting that HBZ protein has important roles in dysregulation of CD4+ T cells infected with HTLV-1. PMID:26804169

The Role of a Novel Nucleolar Protein in Regulation of E2F1 in Breast Cancer

DTIC Science & Technology

2009-09-01

publication and successful defense of a PhD. 8 References 1. Paik JC, Wang B, Liu K, Lue J , Lin WC. Regulation of E2F1-induced apoptosis by...the nucleolar protein RRP1B. J Biol Chem. 2009 Dec 29. [E-pub ahead of print] 2. Hsieh SM, Look MP, Sieuwerts AM, Foekens JA, Hunter KW. Distinct...factor. J Biol Chem. 2009 Oct 16;284(42):28660-73. 4. Crawford NP, Walker RC, Lukes L, Officewala JS, Williams RW, Hunter KW. The Diasporin Pathway: a

HBV core promoter mutations promote cellular proliferation through E2F1-mediated upregulation of S-phase kinase-associated protein 2 transcription.

PubMed

Huang, Yuehua; Tai, Andrew W; Tong, Shuping; Lok, Anna S F

2013-06-01

Hepatitis B virus (HBV) core promoter (CP) mutations have been associated with an increased risk of hepatocellular carcinoma (HCC) in clinical studies. We previously reported that a combination of CP mutations seen in HCC patients, expressed in HBx gene, increased SKP2 (S-phase kinase-associated protein 2) expression, thereby promoting cellular proliferation. Here, we investigate the possible mechanisms by which CP mutations upregulate SKP2. We used immunoblotting and ATPlite assay to validate the effect of CP mutations in full-length HBV genome on cell cycle regulator levels and cell proliferation. Activation of SKP2 mRNA was assessed by quantitative real-time PCR in primary human hepatocytes (PHH) and HCC cell lines. Effect of CP mutations on SKP2 promoter activity was determined by luciferase assay. Target regulation of E2F1 on SKP2 was analyzed by siRNAs. CP mutations in full-length HBV genome upregulated SKP2 expression, thereby downregulating cell cycle inhibitors and accelerating cellular proliferation. CP mutations enhanced SKP2 promoter activity but had no effect on SKP2 protein stability. Mapping of the SKP2 promoter identified a region necessary for activation by CP mutations that contains an E2F1 response element. Knocking down E2F1 reduced the effects of CP mutations on SKP2 and cellular proliferation. The effect of CP mutations on E2F1 might be mediated through hyperphosphorylation of RB. HBV CP mutations enhance SKP2 transcription by activating the E2F1 transcription factor and in turn downregulate cell cycle inhibitors, thus providing a potential mechanism for an association between CP mutations and HCC. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

8-Substituted 1,3-dimethyltetrahydropyrazino[2,1-f]purinediones: Water-soluble adenosine receptor antagonists and monoamine oxidase B inhibitors.

PubMed

Brunschweiger, Andreas; Koch, Pierre; Schlenk, Miriam; Rafehi, Muhammad; Radjainia, Hamid; Küppers, Petra; Hinz, Sonja; Pineda, Felipe; Wiese, Michael; Hockemeyer, Jörg; Heer, Jag; Denonne, Frédéric; Müller, Christa E

2016-11-01

Multitarget approaches, i.e., addressing two or more targets simultaneously with a therapeutic agent, are hypothesized to offer additive therapeutic benefit for the treatment of neurodegenerative diseases. Validated targets for the treatment of Parkinson's disease are, among others, the A 2A adenosine receptor (AR) and the enzyme monoamine oxidase B (MAO-B). Additional blockade of brain A 1 ARs may also be beneficial. We recently described 8-benzyl-substituted tetrahydropyrazino[2,1-f]purinediones as a new lead structure for the development of such multi-target drugs. We have now designed a new series of tetrahydropyrazino[2,1-f]purinediones to extensively explore their structure-activity-relationships. Several compounds blocked human and rat A 1 and A 2A ARs at similar concentrations representing dual A 1 /A 2A antagonists with high selectivity versus the other AR subtypes. Among the best dual A 1 /A 2A AR antagonists were 8-(3-(4-chlorophenyl)propyl)-1,3-dimethyl-6,7,8,9-tetrahydropyrazino[2,1-f]purine-2,4(1H,3H)-dione (41, K i human A 1 : 65.5nM, A 2A : 230nM; K i rat A 1 : 352nM, A 2A : 316nM) and 1,3-dimethyl-8-((2-(thiophen-2-yl)thiazol-4-yl)methyl)-6,7,8,9-tetrahydropyrazino[2,1-f]purine-2,4(1H,3H)-dione (57, K i human A 1 : 642nM, A 2A : 203nM; K i rat A 1 : 166nM, A 2A : 121nM). Compound 57 was found to be well water-soluble (0.7mg/mL) at a physiological pH value of 7.4. One of the new compounds showed triple-target inhibition: (R)-1,3-dimethyl-8-(2,1,3,4-tetrahydronaphthalen-1-yl)-6,7,8,9-tetrahydropyrazino[2,1-f]purine-2,4(1H,3H)-dione (49) was about equipotent at A 1 and A 2A ARs and at MAO-B (K i human A 1 : 393nM, human A 2A : 595nM, IC 50 human MAO-B: 210nM) thus allowing future in vivo explorations of the intended multi-target approach. Copyright © 2016 Elsevier Ltd. All rights reserved.

48 CFR 47.305-2 - Solicitations f.o.b. origin and f.o.b. destination-lowest overall cost.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Solicitations f.o.b. origin and f.o.b. destination-lowest overall cost. 47.305-2 Section 47.305-2 Federal Acquisition... Contracts 47.305-2 Solicitations f.o.b. origin and f.o.b. destination—lowest overall cost. (a) Solicitations...

Nonleptonic decays of B →(f1(1285 ),f1(1420 ))V in the perturbative QCD approach

NASA Astrophysics Data System (ADS)

Liu, Xin; Xiao, Zhen-Jun; Zou, Zhi-Tian

2016-12-01

We investigate the branching ratios, the polarization fractions, the direct C P -violating asymmetries, and the relative phases in 20 nonleptonic decay modes of B →f1V within the framework of the perturbative QCD approach at leading order with f1 including two 3P1-axial-vector states f1(1285 ) and f1(1420 ) . Here, B denotes B+, B0, and Bs0 mesons and V stands for the lightest vector mesons ρ , K*, ω , and ϕ , respectively. The Bs0→f1V decays are studied theoretically for the first time in the literature. Together with the angle ϕf1≈(24-2.7+3.2)∘ extracted from the measurement through Bd /s→J /ψ f1(1285 ) modes for the f1(1285 )-f1(1420 ) mixing system, it is of great interest to find phenomenologically some modes such as the tree-dominated B+→f1ρ+ and the penguin-dominated B+,0→f1K*+,0 , Bs0→f1ϕ with large branching ratios around O (10-6) or even O (10-5), which are expected to be measurable at the LHCb and/or the Belle-II experiments in the near future. The good agreement (sharp contrast) of branching ratios and decay pattern for B+→f1ρ+ , B+,0→f1(1285 )K*+,0[B+,0→f1(1420 )K*+,0] decays between QCD factorization and perturbative QCD factorization predictions can help us to distinguish these two rather different factorization approaches via precision measurements, which would also be helpful for us in exploring the annihilation decay mechanism through its important roles for the considered B →f1V decays.

E2F8 as a Novel Therapeutic Target for Lung Cancer.

PubMed

Park, Sin-Aye; Platt, James; Lee, Jong Woo; López-Giráldez, Francesc; Herbst, Roy S; Koo, Ja Seok

2015-09-01

The E2F members have been divided into transcription activators (E2F1-E2F3) and repressors (E2F4-E2F8). E2F8 with E2F7 has been known to play an important physiologic role in embryonic development and cell cycle regulation by repressing E2F1. However, the function of E2F8 in cancer cells is unknown. E2F8 expression was assessed by immunoblotting or immunofluorescence staining in human lung cancer (LC) cells and tissues from LC patients (n = 45). Cell proliferation, colony formation, and invasion analysis were performed to evaluate the role of E2F8 in LC. Microarray analysis was used to determine the target genes of E2F8. The regulation of E2F8 on the expression of ubiquitin-like PHD and RING domain-containing 1 (UHRF1), one of E2F8 target genes, was determined using chromatin immunoprecipitation and promoter activity assays. Human LC xenograft models were used to determine the effects of inhibiting E2F8 by siRNAs (n = 7 per group) or antisense morpholino (n = 8 per group) on tumor growth. Survival was analyzed using the Kaplan-Meier method and group differences by the Student's t test. All statistical tests were two-sided. LC tumors overexpressed E2F8 compared with normal lung tissues. Depletion of E2F8 inhibited cell proliferation and tumor growth. E2F8 knockdown statistically significantly reduced the expression of UHRF1 (~60%-70%, P < .001), and the direct binding of E2F8 on the promoter of UHRF1 was identified. Kaplan-Meier analysis with a public database showed prognostic significance of aberrant E2F8 expression in LC (HR = 1.91 95% CI = 1.21 to 3.01 in chemo-naïve patients, P = .0047). We demonstrated that E2F8 is overexpressed in LC and is required for the growth of LC cells. These findings implicate E2F8 as a novel therapeutic target for LC treatment. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

YB-1, the E2F Pathway, and Regulation of Tumor Cell Growth

PubMed Central

Samuel, Weini; Cao, Helen; Patel, Rachna; Mehta, Reena; Stern, J. Lewis; Reid, Glen; Woolley, Adele G.; Miller, Lance D.; Black, Michael A; Shelling, Andrew N.; Print, Cristin G.; Braithwaite, Antony W.

2012-01-01

Background Y-box binding factor 1 (YB-1) has been associated with prognosis in many tumor types. Reduced YB-1 expression inhibits tumor cell growth, but the mechanism is unclear. Methods YB-1 mRNA levels were compared with tumor grade and histology using microarray data from 771 breast cancer patients and with disease-free survival and distant metastasis–free survival using data from 375 of those patients who did not receive adjuvant therapy. Microarrays were further searched for genes that had correlated expression with YB-1 mRNA. Small interfering RNA (siRNA) was used to study the effects of reduced YB-1 expression on growth of three tumor cell lines (MCF-7 breast, HCT116 colon, and A549 lung cancer cells), on tumorigenesis by A549 cells in nude mice, and on global transcription in the three cancer cell lines. Reporter gene assays were used to determine whether YB-1 siRNAs affected the expression of E2F1, and chromatin immunoprecipitation was used to determine whether YB-1 bound to various E2F promoters as well as E2F1-regulated promoters. All P values were from two-sided tests. Results YB-1 levels were elevated in more aggressive tumors and were strongly associated with poor disease-free survival and distant metastasis–free survival. YB-1 expression was often associated with the expression of genes with E2F sites in their promoters. Cells expressing YB-1 siRNA grew substantially more slowly than control cells and formed tumors less readily in nude mice. Transcripts that were altered in cancer cell lines with YB-1 siRNA included 32 genes that are components of prognostic gene expression signatures. YB-1 regulated expression of an E2F1 promoter–reporter construct in A549 cells (eg, relative E2F1 promoter activity with control siRNA = 4.04; with YB-1 siRNA = 1.40, difference= −2.64, 95% confidence interval = −3.57 to −1.71, P < .001) and bound to the promoters of several well-defined E2F1 target genes. Conclusion YB-1 expression is associated with the

E2F1 promote the aggressiveness of human colorectal cancer by activating the ribonucleotide reductase small subunit M2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Zejun; Gong, Chaoju; Liu, Hong

2015-08-21

As the ribonucleotide reductase small subunit, the high expression of ribonucleotide reductase small subunit M2 (RRM2) induces cancer and contributes to tumor growth and invasion. In several colorectal cancer (CRC) cell lines, we found that the expression levels of RRM2 were closely related to the transcription factor E2F1. Mechanistic studies were conducted to determine the molecular basis. Ectopic overexpression of E2F1 promoted RRM2 transactivation while knockdown of E2F1 reduced the levels of RRM2 mRNA and protein. To further investigate the roles of RRM2 which was activated by E2F1 in CRC, CCK-8 assay and EdU incorporation assay were performed. Overexpression ofmore » E2F1 promoted cell proliferation in CRC cells, which was blocked by RRM2 knockdown attenuation. In the migration and invasion tests, overexpression of E2F1 enhanced the migration and invasion of CRC cells which was abrogated by silencing RRM2. Besides, overexpression of RRM2 reversed the effects of E2F1 knockdown partially in CRC cells. Examination of clinical CRC specimens demonstrated that both RRM2 and E2F1 were elevated in most cancer tissues compared to the paired normal tissues. Further analysis showed that the protein expression levels of E2F1 and RRM2 were parallel with each other and positively correlated with lymph node metastasis (LNM), TNM stage and distant metastasis. Consistently, the patients with low E2F1 and RRM2 levels have a better prognosis than those with high levels. Therefore, we suggest that E2F1 can promote CRC proliferation, migration, invasion and metastasis by regulating RRM2 transactivation. Understanding the role of E2F1 in activating RRM2 transcription will help to explain the relationship between E2F1 and RRM2 in CRC and provide a novel predictive marker for diagnosis and prognosis of the disease. - Highlights: • E2F1 promotes RRM2 transactivation in CRC cells. • E2F1 promotes the proliferation of CRC cells by activating RRM2. • E2F1 promotes the migration

Synergistic cooperation of MDM2 and E2F1 contributes to TAp73 transcriptional activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kasim, Vivi, E-mail: vivikasim78@gmail.com; Huang, Can; Zhang, Jing

2014-07-04

Highlights: • MDM2 is a novel positive regulator of TAp73 transcriptional activity. • MDM2 colocalizes together and physically interacts with E2F1. • Synergistic cooperation of MDM2 and E2F1 is crucial for TAp73 transcription. • MDM2 regulates TAp73 transcriptional activity in a p53-independent manner. - Abstract: TAp73, a structural homologue of p53, plays an important role in tumorigenesis. E2F1 had been reported as a transcriptional regulator of TAp73, however, the detailed mechanism remains to be elucidated. Here we reported that MDM2-silencing reduced the activities of the TAp73 promoters and the endogenous TAp73 expression level significantly; while MDM2 overexpression upregulated them. Wemore » further revealed that the regulation of TAp73 transcriptional activity occurs as a synergistic effect of MDM2 and E2F1, most probably through their physical interaction in the nuclei. Furthermore, we also suggested that MDM2 might be involved in DNA damage-induced TAp73 transcriptional activity. Finally, we elucidated that MDM2-silencing reduced the proliferation rate of colon carcinoma cells regardless of the p53 status. Our data show a synergistic effect of MDM2 and E2F1 on TAp73 transcriptional activity, suggesting a novel regulation pathway of TAp73.« less

Nicotine, IFN-γ and retinoic acid mediated induction of MUC4 in pancreatic cancer requires E2F1 and STAT-1 transcription factors and utilize different signaling cascades.

PubMed

Kunigal, Sateesh; Ponnusamy, Moorthy P; Momi, Navneet; Batra, Surinder K; Chellappan, Srikumar P

2012-04-26

The membrane-bound mucins are thought to play an important biological role in cell-cell and cell-matrix interactions, in cell signaling and in modulating biological properties of cancer cell. MUC4, a transmembrane mucin is overexpressed in pancreatic tumors, while remaining undetectable in the normal pancreas, thus indicating a potential role in pancreatic cancer pathogenesis. The molecular mechanisms involved in the regulation of MUC4 gene are not yet fully understood. Smoking is strongly correlated with pancreatic cancer and in the present study; we elucidate the molecular mechanisms by which nicotine as well as agents like retinoic acid (RA) and interferon-γ (IFN-γ) induce the expression of MUC4 in pancreatic cancer cell lines CD18, CAPAN2, AsPC1 and BxPC3. Chromatin immunoprecipitation assays and real-time PCR showed that transcription factors E2F1 and STAT1 can positively regulate MUC4 expression at the transcriptional level. IFN-γ and RA could collaborate with nicotine in elevating the expression of MUC4, utilizing E2F1 and STAT1 transcription factors. Depletion of STAT1 or E2F1 abrogated the induction of MUC4; nicotine-mediated induction of MUC4 appeared to require α7-nicotinic acetylcholine receptor subunit. Further, Src and ERK family kinases also mediated the induction of MUC4, since inhibiting these signaling molecules prevented the induction of MUC4. MUC4 was also found to be necessary for the nicotine-mediated invasion of pancreatic cancer cells, suggesting that induction of MUC4 by nicotine and other agents might contribute to the genesis and progression of pancreatic cancer. Our studies show that agents that can promote the growth and invasion of pancreatic cancer cells induce the MUC4 gene through multiple pathways and this induction requires the transcriptional activity of E2F1 and STAT1. Further, the Src as well as ERK signaling pathways appear to be involved in the induction of this gene. It appears that targeting these signaling pathways

Nicotine, IFN-γ and retinoic acid mediated induction of MUC4 in pancreatic cancer requires E2F1 and STAT-1 transcription factors and utilize different signaling cascades

PubMed Central

2012-01-01

Background The membrane-bound mucins are thought to play an important biological role in cell–cell and cell–matrix interactions, in cell signaling and in modulating biological properties of cancer cell. MUC4, a transmembrane mucin is overexpressed in pancreatic tumors, while remaining undetectable in the normal pancreas, thus indicating a potential role in pancreatic cancer pathogenesis. The molecular mechanisms involved in the regulation of MUC4 gene are not yet fully understood. Smoking is strongly correlated with pancreatic cancer and in the present study; we elucidate the molecular mechanisms by which nicotine as well as agents like retinoic acid (RA) and interferon-γ (IFN-γ) induce the expression of MUC4 in pancreatic cancer cell lines CD18, CAPAN2, AsPC1 and BxPC3. Results Chromatin immunoprecipitation assays and real-time PCR showed that transcription factors E2F1 and STAT1 can positively regulate MUC4 expression at the transcriptional level. IFN-γ and RA could collaborate with nicotine in elevating the expression of MUC4, utilizing E2F1 and STAT1 transcription factors. Depletion of STAT1 or E2F1 abrogated the induction of MUC4; nicotine-mediated induction of MUC4 appeared to require α7-nicotinic acetylcholine receptor subunit. Further, Src and ERK family kinases also mediated the induction of MUC4, since inhibiting these signaling molecules prevented the induction of MUC4. MUC4 was also found to be necessary for the nicotine-mediated invasion of pancreatic cancer cells, suggesting that induction of MUC4 by nicotine and other agents might contribute to the genesis and progression of pancreatic cancer. Conclusions Our studies show that agents that can promote the growth and invasion of pancreatic cancer cells induce the MUC4 gene through multiple pathways and this induction requires the transcriptional activity of E2F1 and STAT1. Further, the Src as well as ERK signaling pathways appear to be involved in the induction of this gene. It appears that

LAPTM4b recruits the LAT1-4F2hc Leu transporter to lysosomes and promotes mTORC1 activation.

PubMed

Milkereit, Ruth; Persaud, Avinash; Vanoaica, Liviu; Guetg, Adriano; Verrey, Francois; Rotin, Daniela

2015-05-22

Mammalian target of rapamycin 1 (mTORC1), a master regulator of cellular growth, is activated downstream of growth factors, energy signalling and intracellular essential amino acids (EAAs) such as Leu. mTORC1 activation occurs at the lysosomal membrane, and involves V-ATPase stimulation by intra-lysosomal EAA (inside-out activation), leading to activation of the Ragulator, RagA/B-GTP and mTORC1 via Rheb-GTP. How Leu enters the lysosomes is unknown. Here we identified the lysosomal protein LAPTM4b as a binding partner for the Leu transporter, LAT1-4F2hc (SLC7A5-SLAC3A2). We show that LAPTM4b recruits LAT1-4F2hc to lysosomes, leading to uptake of Leu into lysosomes, and is required for mTORC1 activation via V-ATPase following EAA or Leu stimulation. These results demonstrate a functional Leu transporter at the lysosome, and help explain the inside-out lysosomal activation of mTORC1 by Leu/EAA.

E2F function in muscle growth is necessary and sufficient for viability in Drosophila

PubMed Central

Zappia, Maria Paula; Frolov, Maxim V.

2016-01-01

The E2F transcription factor is a key cell cycle regulator. However, the inactivation of the entire E2F family in Drosophila is permissive throughout most of animal development until pupation when lethality occurs. Here we show that E2F function in the adult skeletal muscle is essential for animal viability since providing E2F function in muscles rescues the lethality of the whole-body E2F-deficient animals. Muscle-specific loss of E2F results in a significant reduction in muscle mass and thinner myofibrils. We demonstrate that E2F is dispensable for proliferation of muscle progenitor cells, but is required during late myogenesis to directly control the expression of a set of muscle-specific genes. Interestingly, E2f1 provides a major contribution to the regulation of myogenic function, while E2f2 appears to be less important. These findings identify a key function of E2F in skeletal muscle required for animal viability, and illustrate how the cell cycle regulator is repurposed in post-mitotic cells. PMID:26823289

Epigenetic involvement of Alien/ESET complex in thyroid hormone-mediated repression of E2F1 gene expression and cell proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hong, Wei, E-mail: hongwei@tijmu.edu.cn; College of Basic Medicine, Tianjin Medical University, 300070 Tianjin; Li, Jinru

Highlights: Black-Right-Pointing-Pointer Corepressor Alien interacts with histone methyltransferase ESET in vivo. Black-Right-Pointing-Pointer Alien/ESET complex is recruited to nTRE of T3-responsive gene by liganded TR{beta}1. Black-Right-Pointing-Pointer ESET-mediated H3K9 methylation is required for liganded TR{beta}1-repressed transcription. Black-Right-Pointing-Pointer ESET is involved in T3-repressed G1/S phase transition and proliferation. -- Abstract: The ligand-bound thyroid hormone receptor (TR) is known to repress via a negative TRE (nTRE) the expression of E2F1, a key transcription factor that controls the G1/S phase transition. Alien has been identified as a novel interacting factor of E2F1 and acts as a corepressor of E2F1. The detailed molecular mechanism by whichmore » Alien inhibits E2F1 gene expression remains unclear. Here, we report that the histone H3 lysine 9 (H3K9) methyltransferase (HMT) ESET is an integral component of the corepressor Alien complex and the Alien/ESET complex is recruited to both sites, the E2F1 and the nTRE site of the E2F1 gene while the recruitment to the negative thyroid hormone response element (nTRE) is induced by the ligand-bound TR{beta}1 within the E2F1 gene promoter. We show that, overexpression of ESET promotes, whereas knockdown of ESET releases, the inhibition of TR{beta}1-regulated gene transcription upon T3 stimulation; and H3K9 methylation is required for TR{beta}1-repressed transcription. Furthermore, depletion of ESET impairs thyroid hormone-repressed proliferation as well as the G1/S transition of the cell cycle. Taken together, our data indicate that ESET is involved in TR{beta}1-mediated transcription repression and provide a molecular basis of thyroid hormone-induced repression of proliferation.« less

Pressure-induced magnetic collapse and metallization of TlF e1.6S e2

NASA Astrophysics Data System (ADS)

Naumov, P. G.; Filsinger, K.; Shylin, S. I.; Barkalov, O. I.; Ksenofontov, V.; Qi, Y.; Palasyuk, T.; Schnelle, W.; Medvedev, S. A.; Greenblatt, M.; Felser, C.

2017-08-01

The crystal structure, magnetic ordering, and electrical resistivity of TlF e1.6S e2 were studied at high pressures. Below ˜7 GPa , TlF e1.6S e2 is an antiferromagnetically ordered semiconductor with a ThC r2S i2 -type structure. The insulator-to-metal transformation observed at a pressure of ˜7 GPa is accompanied by a loss of magnetic ordering and an isostructural phase transition. In the pressure range ˜7.5 -11 GPa a remarkable downturn in resistivity, which resembles a superconducting transition, is observed below 15 K. We discuss this feature as the possible onset of superconductivity originating from a phase separation in a small fraction of the sample in the vicinity of the magnetic transition.

mTORC1 and CK2 coordinate ternary and eIF4F complex assembly

PubMed Central

Gandin, Valentina; Masvidal, Laia; Cargnello, Marie; Gyenis, Laszlo; McLaughlan, Shannon; Cai, Yutian; Tenkerian, Clara; Morita, Masahiro; Balanathan, Preetika; Jean-Jean, Olivier; Stambolic, Vuk; Trost, Matthias; Furic, Luc; Larose, Louise; Koromilas, Antonis E.; Asano, Katsura; Litchfield, David; Larsson, Ola; Topisirovic, Ivan

2016-01-01

Ternary complex (TC) and eIF4F complex assembly are the two major rate-limiting steps in translation initiation regulated by eIF2α phosphorylation and the mTOR/4E-BP pathway, respectively. How TC and eIF4F assembly are coordinated, however, remains largely unknown. We show that mTOR suppresses translation of mRNAs activated under short-term stress wherein TC recycling is attenuated by eIF2α phosphorylation. During acute nutrient or growth factor stimulation, mTORC1 induces eIF2β phosphorylation and recruitment of NCK1 to eIF2, decreases eIF2α phosphorylation and bolsters TC recycling. Accordingly, eIF2β mediates the effect of mTORC1 on protein synthesis and proliferation. In addition, we demonstrate a formerly undocumented role for CK2 in regulation of translation initiation, whereby CK2 stimulates phosphorylation of eIF2β and simultaneously bolsters eIF4F complex assembly via the mTORC1/4E-BP pathway. These findings imply a previously unrecognized mode of translation regulation, whereby mTORC1 and CK2 coordinate TC and eIF4F complex assembly to stimulate cell proliferation. PMID:27040916

26 CFR 1.475(b)-2 - Exemptions-identification requirements.

Code of Federal Regulations, 2010 CFR

2010-04-01

... requirements. (a) Identification of the basis for exemption. An identification of a security as exempt from mark to market does not satisfy section 475(b)(2) if it fails to state whether the security is described in— (1) Either of the first two subparagraphs of section 475(b)(1) (identifying a security as held...

Dock/Nck facilitates PTP61F/PTP1B regulation of insulin signalling.

PubMed

Wu, Chia-Lun; Buszard, Bree; Teng, Chun-Hung; Chen, Wei-Lin; Warr, Coral G; Tiganis, Tony; Meng, Tzu-Ching

2011-10-01

PTP1B (protein tyrosine phosphatase 1B) is a negative regulator of IR (insulin receptor) activation and glucose homoeostasis, but the precise molecular mechanisms governing PTP1B substrate selectivity and the regulation of insulin signalling remain unclear. In the present study we have taken advantage of Drosophila as a model organism to establish the role of the SH3 (Src homology 3)/SH2 adaptor protein Dock (Dreadlocks) and its mammalian counterpart Nck in IR regulation by PTPs. We demonstrate that the PTP1B orthologue PTP61F dephosphorylates the Drosophila IR in S2 cells in vitro and attenuates IR-induced eye overgrowth in vivo. Our studies indicate that Dock forms a stable complex with PTP61F and that Dock/PTP61F associate with the IR in response to insulin. We report that Dock is required for effective IR dephosphorylation and inactivation by PTP61F in vitro and in vivo. Furthermore, we demonstrate that Nck interacts with PTP1B and that the Nck/PTP1B complex inducibly associates with the IR for the attenuation of IR activation in mammalian cells. Our studies reveal for the first time that the adaptor protein Dock/Nck attenuates insulin signalling by recruiting PTP61F/PTP1B to its substrate, the IR.

Copy number variations of E2F1: a new genetic risk factor for testicular cancer.

PubMed

Rocca, Maria Santa; Di Nisio, Andrea; Marchiori, Arianna; Ghezzi, Marco; Opocher, Giuseppe; Foresta, Carlo; Ferlin, Alberto

2017-03-01

Testicular germ cell tumor (TGCT) is one of the most heritable forms of cancer. In last years, many evidence suggested that constitutional genetic factors, mainly single nucleotide polymorphisms, can increase its risk. However, the possible contribution of copy number variations (CNVs) in TGCT susceptibility has not been substantially addressed. Indeed, an increasing number of studies have focused on the effect of CNVs on gene expression and on the role of these structural genetic variations as risk factors for different forms of cancer. E2F1 is a transcription factor that plays an important role in regulating cell growth, differentiation, apoptosis and response to DNA damage. Therefore, deficiency or overexpression of this protein might significantly influence fundamental biological processes involved in cancer development and progression, including TGCT. We analyzed E2F1 CNVs in 261 cases with TGCT and 165 controls. We found no CNVs in controls, but 17/261 (6.5%) cases showed duplications in E2F1 Blot analysis demonstrated higher E2F1 expression in testicular samples of TGCT cases with three copies of the gene. Furthermore, we observed higher phosphorylation of Akt and mTOR in samples with E2F1 duplication. Interestingly, normal, non-tumoral testicular tissue in patient with E2F1 duplication showed lower expression of E2F1 and lower AKT/mTOR phosphorylation with respect to adjacent tumor tissue. Furthermore, increased expression of E2F1 obtained in vitro in NTERA-2 testicular cell line induced increased AKT/mTOR phosphorylation. This study suggests for the first time an involvement of E2F1 CNVs in TGCT susceptibility and supports previous preliminary data on the importance of AKT/mTOR signaling pathway in this cancer. © 2017 Society for Endocrinology.

Major antigenic determinants of F and ColB2 pili.

PubMed Central

Finlay, B B; Frost, L S; Paranchych, W; Parker, J M; Hodges, R S

1985-01-01

F-like conjugative pili are expressed by plasmids with closely related transfer systems. They are tubular filaments that are composed of repeating pilin subunits arranged in a helical array. Both F and ColB2 pilin have nearly identical protein sequences, and both contain an acetylated amino-terminal alanine residue. However, they differ by a few amino acid residues at their amino termini. Rabbit antisera raised against purified F and ColB2 pili are immunologically cross-reactive by only 25%, as measured by a competition enzyme-linked immunosorbent assay (ELISA). A tryptic peptide corresponding to the first 15 amino acid residues of ColB2 pilin was isolated and found to remove nearly 80% of ColB2 pilus-directed rabbit antibodies. The corresponding tryptic peptide from F pilin, which reacted with anti-F pilus antibodies to remove 80%, was less than 20% reactive with anti-ColB2 pilus antiserum. Cleavage of these peptides with cyanogen bromide (at a methionine residue approximately in the middle of the peptide) did not affect the antigenicity of these peptides. Synthetic N alpha-acetylated peptides corresponding to the first eight amino acids of F pilin (Ac-Ala-Gly-Ser-Ser-Gly-Gln-Asp-Leu-COOH) and the first six amino acids of ColB2 pilin (Ac-Ala-Gln-Gly-Gln-Asp-Leu-COOH) were prepared and tested by competition ELISA with homologous and heterologous anti-pilus antisera. The F peptide F(1-8) inhibited the interaction of F pili and anti-F pilus antiserum to 80%, while the ColB2 peptide ColB2(1-6) inhibited anti-ColB2 pilus antiserum reacting with ColB2 pili by greater than 60%. The two peptides F(1-8) and ColB2(1-6) were inactive by competition ELISAs with heterologous antisera. These results suggest that the major antigenic determinant of both F and ColB2 pili is at the amino terminus of the pilin subunit and that 80% of antibodies raised against these pili are specific for this region of the pilin molecule. PMID:2409073

Inheritance of steroid-independent male sexual behavior in male offspring of B6D2F1 mice.

PubMed

McInnis, Christine M; Bonthuis, Paul J; Rissman, Emilie F; Park, Jin Ho

2016-04-01

The importance of gonadal steroids in modulating male sexual behavior is well established. Individual differences in male sexual behavior, independent of gonadal steroids, are prevalent across a wide range of species, including man. However, the genetic mechanisms underlying steroid-independent male sexual behavior are poorly understood. A high proportion of B6D2F1 hybrid male mice demonstrates steroid-independent male sexual behavior (identified as "maters"), providing a mouse model that opens up avenues of investigation into the mechanisms regulating male sexual behavior in the absence of gonadal hormones. Recent studies have revealed several proteins that play a significant factor in regulating steroid-independent male sexual behavior in B6D2F1 male mice, including amyloid precursor protein (APP), tau, and synaptophysin. The specific goals of our study were to determine whether steroid-independent male sexual behavior was a heritable trait by determining if it was dependent upon the behavioral phenotype of the B6D2F1 sire, and whether the differential expression of APP, tau, and synaptophysin in the medial preoptic area found in the B6D2F1 sires that did and did not mate after gonadectomy was similar to those found in their male offspring. After adult B6D2F1 male mice were bred with C57BL/6J female mice, they and their male offspring (BXB1) were orchidectomized and identified as either maters or "non-maters". A significant proportion of the BXB1 maters was sired only from B6D2F1 maters, indicating that the steroid-independent male sexual behavior behavioral phenotype of the B6D2F1 hybrid males, when crossed with C57BL/6J female mice, is inherited by their male offspring. Additionally, APP, tau, and synaptophysin were elevated in in the medial preoptic area in both the B6D2F1 and BXB1 maters relative to the B6D2F1 and BXB1 non-maters, respectively, suggesting a potential genetic mechanism for the inheritance of steroid-independent male sexual behavior. Copyright

Inheritance of steroid-independent male sexual behavior in male offspring of B6D2F1 mice

PubMed Central

McInnis, Christine M.; Bonthuis, Paul J.; Rissman, Emilie F.; Park, Jin Ho

2016-01-01

The importance of gonadal steroids in modulating male sexual behavior is well established. Individual differences in male sexual behavior, independent of gonadal steroids, are prevalent across a wide range of species, including man. However, the genetic mechanisms underlying steroid-independent male sexual behavior are poorly understood. A high proportion of B6D2F1 hybrid male mice demonstrate steroid-independent male sexual behavior (identified as “maters”), providing a mouse model that opens up avenues of investigation into the mechanisms regulating male sexual behavior in the absence of gonadal hormones. Recent studies have revealed several proteins that play a significant factor in regulating steroid-independent male sexual behavior in B6D2F1 male mice, including amyloid precursor protein (APP), tau, and synaptophysin. The specific goals of our study were to determine whether steroid-independent male sexual behavior was a heritable trait by determining if it was dependent upon the behavioral phenotype of the B6D2F1 sire, and whether the differential expression of APP, tau, and synaptophysin in the medial preoptic area found in the B6D2F1 sires that did and did not mate after gonadectomy was similar to those found in their male offspring. After adult B6D2F1 male mice were bred with C57BL/6J female mice, they and their male offspring (BXB1) were orchidectomized and identified as either maters or “non-maters.” A significant proportion of the BXB1 maters were sired only from B6D2F1 maters, indicating that the steroid-independent male sexual behavior behavioral phenotype of the B6D2F1 hybrid males, when crossed with C57BL/6J female mice, is inherited by their male offspring. Additionally, APP, tau, and synaptophysin were elevated in in the medial preoptic area in both the B6D2F1 and BXB1 maters relative to the B6D2F1 and BXB1 non-maters, respectively, suggesting a potential genetic mechanism for the inheritance of steroid-independent male sexual behavior

26 CFR 1.6031(b)-2T - REMIC reporting requirements (temporary). [Reserved

Code of Federal Regulations, 2010 CFR

2010-04-01

... requirements (temporary). [Reserved] ... 26 Internal Revenue 13 2010-04-01 2010-04-01 false REMIC reporting requirements (temporary). [Reserved] 1.6031(b)-2T Section 1.6031(b)-2T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE...

Zebrafish Lmx1b.1 and Lmx1b.2 are required for maintenance of the isthmic organizer.

PubMed

O'Hara, F Patrick; Beck, Ernestine; Barr, Lauren K; Wong, Lily L; Kessler, Daniel S; Riddle, Robert D

2005-07-01

The mesencephalic and metencephalic region (MMR) of the vertebrate central nervous system develops in response to signals produced by the isthmic organizer (IsO). We have previously reported that the LIM homeobox transcription factor Lmx1b is expressed within the chick IsO, where it is sufficient to maintain expression of the secreted factor wnt1. In this paper, we show that zebrafish express two Lmx1b orthologs, lmx1b.1 and lmx1b.2, in the rostral IsO, and demonstrate that these genes are necessary for key aspects of MMR development. Simultaneous knockdown of Lmx1b.1 and Lmx1b.2 using morpholino antisense oligos results in a loss of wnt1, wnt3a, wnt10b, pax8 and fgf8 expression at the IsO, leading ultimately to programmed cell death and the loss of the isthmic constriction and cerebellum. Single morpholino knockdown of either Lmx1b.1 or Lmx1b.2 has no discernible effect on MMR development. Maintenance of lmx1b.1 and lmx1b.2 expression at the isthmus requires the function of no isthmus/pax2.1, as well as Fgf signaling. Transient misexpression of Lmx1b.1 or Lmx1b.2 during early MMR development induces ectopic wnt1 and fgf8 expression in the MMR, as well as throughout much of the embryo. We propose that Lmx1b.1- and Lmx1b.2-mediated regulation of wnt1, wnt3a, wnt10b, pax8 and fgf8 maintains cell survival in the isthmocerebellar region.

Investigation of the 2f1-f2 and 2f2-f1 distortion product otoacoustic emissions using a computational model of the gerbil ear.

PubMed

Wen, Haiqi; Bowling, Thomas; Meaud, Julien

2018-05-19

In this work, a three-dimensional computational model of the gerbil ear is used to investigate the generation of the 2f 1 -f 2 and 2f 2 -f 1 distortion product otoacoustic emissions (DPOAEs). In order to predict both the distortion and reflection sources, cochlear roughness is modeled by introducing random inhomogeneities in the outer hair cell properties. The model was used to simulate the generation of DPOAEs in response to a two-tone stimulus for various primary stimulus levels and frequency ratios. As in published experiments, the 2f 1 -f 2 DPOAEs are mostly dominated by the distortion component while the 2f 2 -f 1 DPOAEs are dominated by the reflection component; furthermore, the influence of the levels and frequency ratio of the primaries are consistent with measurements. Analysis of the intracochlear response shows that the distortion component has the highest magnitude at all longitudinal locations for the 2f 1 -f 2 distortion product (DP) while the distortion component only dominates close to the DP best place in the case of the 2f 2 -f 1 DP. Decomposition of the intracochlear DPs into forward and reverse waves demonstrates that the 2f 1 -f 2 DP generates reverse waves for both the distortion and reflection components; however, a reverse wave is only generated for the reflection component in the case of the 2f 2 -f 1 DP. As in experiments in the gerbil, the group delay of the reflection component of the DPOAE is between 1× and 2× the forward group delay, which is consistent with the propagation of DP towards the stapes as slow reverse waves. Copyright © 2018 Elsevier B.V. All rights reserved.

Enhanced expression of rat hepatic CYP2B1/2B2 and 2E1 by pyridine: differential induction kinetics and molecular basis of expression.

PubMed

Kim, H; Putt, D; Reddy, S; Hollenberg, P F; Novak, R F

1993-11-01

Expression of the cytochrome P450 (CYP) 2B subfamily in rat and rabbit hepatic tissues after pyridine (PY) treatment has been examined, and the molecular basis for enhanced 2B1/2B2 expression has been determined. P450 expression was monitored using metabolic activity, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analyses, and the identity of the proteins was confirmed through N-terminus microsequence analysis. PY caused a dose-dependent elevation of hepatic CYP2B1/B2B levels in rats, which ranged from 4- to 22-fold over the dosing regimen of 100 to 400 mg PY/kg/day, for 3 days, respectively. PY at low dose failed to induce CYP2B in rabbit hepatic tissue, suggesting a species-dependent response in 2B expression. Anti-2B1 IgG addition to PY-induced microsomes inhibited benzphetamine N-demethylase activity by only approximately 15%, in sharp contrast to the approximately 73% inhibition observed for phenobarbital-induced microsomes, suggesting the induction of other form(s) of P450 having benzphetamine N-demethylase activity. Northern blot analysis revealed that PY treatment increased 2B1 and 2B2 poly(A)+ RNA levels approximately 69- and approximately 34-fold, respectively, whereas the 2E1 poly(A)+ RNA levels failed to increase. The results of this study show that PY induces CYP2B1/2B2 and that induction is species-dependent and kinetically distinguishable from 2E1 induction. Moreover, 2B1/2B2 induction occurs as a result of elevated mRNA levels associated with either transcriptional activation or mRNA stabilization, and it differs from the mechanism of hepatic 2E1 induction by PY.

The E2F3—Oncomir 1 axis is activated in Wilms Tumor

PubMed Central

Kort, Eric J.; Farber, Leslie; Tretiakova, Maria; Petillo, David; Furge, Kyle A.; Yang, Ximing J.; Cornelius, Albert; Teh, Bin T.

2008-01-01

Oncomir-1 is an oncogenic cluster of microRNAs located on chromosome 13. Previous in vitro studies demonstrated that it is transcriptionally regulated by the transcription factor E2F3. In this report we combine expression profiling of both messenger RNA (mRNA) and micro RNAs (miRNA) in Wilms tumor (WT) samples to provide the first evidence that the E2F3—Oncomir 1 axis, previously identified in cell culture, is deregulated in primary human tumors. Analysis of RNA expression signatures demonstrated that an E2F3 gene signature was activated in all Wilms tumor samples analyzed, in contrast to other kidney tumors. This finding was validated by immunohistochemistry (IHC) on the protein level. Expression of E2F3 was lowest in early stage tumors, and highest in metastatic tissue. Expression profiling of miRNAs in WT showed that expression of each measured member of the Oncomir-1 family was highest in WT relative to other kidney tumor subtypes. Quantitative polymerase chain reaction (PCR) confirmed that these microRNAs were overexpressed in Wilms tumor relative to normal kidney tissue. These results suggest that the E2F3—Oncomir-1 axis is activated in Wilms tumor. Our study also demonstrates the utility of integrated genomics combining gene signature analysis with miRNA expression profiling to identify protein-miRNA interactions that are perturbed in disease states. PMID:18519660

Inhibition of ERK1/2 or AKT Activity Equally Enhances Radiation Sensitization in B16F10 Cells

PubMed Central

Kalal, Bhuvanesh Sukhlal; Fathima, Faraz; Pai, Vinitha Ramanath; Sanjeev, Ganesh; Krishna, Chilakapati Murali; Upadhya, Dinesh

2018-01-01

Background The aim of the study was to evaluate the radiation sensitizing ability of ERK1/2, PI3K-AKT and JNK inhibitors in highly radiation resistant and metastatic B16F10 cells which carry wild-type Ras and Braf. Methods Mouse melanoma cell line B16F10 was exposed to 1.0, 2.0 and 3.0 Gy of electron beam radiation. Phosphorylated ERK1/2, AKT and JNK levels were estimated by ELISA. Cells were exposed to 2.0 and 3.0 Gy of radiation with or without prior pharmacological inhibition of ERK1/2, AKT as well as JNK pathways. Cell death induced by radiation as well as upon inhibition of these pathways was measured by TUNEL assay using flow cytometry. Results Exposure of B16F10 cells to 1.0, 2.0 and 3.0 Gy of electron beam irradiation triggered an increase in all the three phosphorylated proteins compared to sham-treated and control groups. B16F10 cells pre-treated with either ERK1/2 or AKT inhibitors equally enhanced radiation-induced cell death at 2.0 as well as 3.0 Gy (P < 0.001), while inhibition of JNK pathway increased radiation-induced cell death to a lesser extent. Interestingly combined inhibition of ERK1/2 or AKT pathways did not show additional cell death compared to individual ERK1/2 or AKT inhibition. This indicates that ERK1/2 or AKT mediates radiation resistance through common downstream molecules in B16F10 cells. Conclusions Even without activating mutations in Ras or Braf genes, ERK1/2 and AKT play a critical role in B16F10 cell survival upon radiation exposure and possibly act through common downstream effector/s. PMID:29581812

Inhibition of ERK1/2 or AKT Activity Equally Enhances Radiation Sensitization in B16F10 Cells.

PubMed

Kalal, Bhuvanesh Sukhlal; Fathima, Faraz; Pai, Vinitha Ramanath; Sanjeev, Ganesh; Krishna, Chilakapati Murali; Upadhya, Dinesh

2018-02-01

The aim of the study was to evaluate the radiation sensitizing ability of ERK1/2, PI3K-AKT and JNK inhibitors in highly radiation resistant and metastatic B16F10 cells which carry wild-type Ras and Braf . Mouse melanoma cell line B16F10 was exposed to 1.0, 2.0 and 3.0 Gy of electron beam radiation. Phosphorylated ERK1/2, AKT and JNK levels were estimated by ELISA. Cells were exposed to 2.0 and 3.0 Gy of radiation with or without prior pharmacological inhibition of ERK1/2, AKT as well as JNK pathways. Cell death induced by radiation as well as upon inhibition of these pathways was measured by TUNEL assay using flow cytometry. Exposure of B16F10 cells to 1.0, 2.0 and 3.0 Gy of electron beam irradiation triggered an increase in all the three phosphorylated proteins compared to sham-treated and control groups. B16F10 cells pre-treated with either ERK1/2 or AKT inhibitors equally enhanced radiation-induced cell death at 2.0 as well as 3.0 Gy (P < 0.001), while inhibition of JNK pathway increased radiation-induced cell death to a lesser extent. Interestingly combined inhibition of ERK1/2 or AKT pathways did not show additional cell death compared to individual ERK1/2 or AKT inhibition. This indicates that ERK1/2 or AKT mediates radiation resistance through common downstream molecules in B16F10 cells. Even without activating mutations in Ras or Braf genes, ERK1/2 and AKT play a critical role in B16F10 cell survival upon radiation exposure and possibly act through common downstream effector/s.

ERBB2 Deficiency Alters an E2F-1-Dependent Adaptive Stress Response and Leads to Cardiac Dysfunction

PubMed Central

Perry, Marie-Claude; Dufour, Catherine R.; Eichner, Lillian J.; Tsang, David W. K.; Deblois, Geneviève; Muller, William J.

2014-01-01

The tyrosine kinase receptor ERBB2 is required for normal development of the heart and is a potent oncogene in breast epithelium. Trastuzumab, a monoclonal antibody targeting ERBB2, improves the survival of breast cancer patients, but cardiac dysfunction is a major side effect of the drug. The molecular mechanisms underlying how ERBB2 regulates cardiac function and why trastuzumab is cardiotoxic remain poorly understood. We show here that ERBB2 hypomorphic mice develop cardiac dysfunction that mimics the side effects observed in patients treated with trastuzumab. We demonstrate that this phenotype is related to the critical role played by ERBB2 in cardiac homeostasis and physiological hypertrophy. Importantly, genetic and therapeutic reduction of ERBB2 activity in mice, as well as ablation of ERBB2 signaling by trastuzumab or siRNAs in human cardiomyocytes, led to the identification of an impaired E2F-1-dependent genetic program critical for the cardiac adaptive stress response. These findings demonstrate the existence of a previously unknown mechanistic link between ERBB2 and E2F-1 transcriptional activity in heart physiology and trastuzumab-induced cardiac dysfunction. PMID:25246633

HER2 signaling drives DNA anabolism and proliferation through SRC-3 phosphorylation and E2F1-regulated genes

PubMed Central

Nikolai, Bryan C.; Lanz, Rainer B.; York, Brian; Dasgupta, Subhamoy; Mitsiades, Nicholas; Creighton, Chad J.; Tsimelzon, Anna; Hilsenbeck, Susan G.; Lonard, David M.; Smith, Carolyn L.; O’Malley, Bert W.

2016-01-01

Approximately 20% of early-stage breast cancers display amplification or overexpression of the ErbB2/HER2 oncogene, conferring poor prognosis and resistance to endocrine therapy. Targeting HER2+ tumors with trastuzumab or the receptor tyrosine kinase (RTK) inhibitor lapatinib significantly improves survival, yet tumor resistance and progression of metastatic disease still develop over time. While the mechanisms of cytosolic HER2 signaling are well studied, nuclear signaling components and gene regulatory networks that bestow therapeutic resistance and limitless proliferative potential are incompletely understood. Here, we use biochemical and bioinformatic approaches to identify effectors and targets of HER2 transcriptional signaling in human breast cancer. Phosphorylation and activity of the Steroid Receptor Coactivator-3 (SRC-3) is reduced upon HER2 inhibition, and recruitment of SRC-3 to regulatory elements of endogenous genes is impaired. Transcripts regulated by HER2 signaling are highly enriched with E2F1 binding sites and define a gene signature associated with proliferative breast tumor subtypes, cell cycle progression, and DNA replication. We show that HER2 signaling promotes breast cancer cell proliferation through regulation of E2F1-driven DNA metabolism and replication genes together with phosphorylation and activity of the transcriptional coactivator SRC-3. Furthermore, our analyses identified a cyclin dependent kinase (CDK) signaling node that, when targeted using the CDK4/6 inhibitor Palbociclib, defines overlap and divergence of adjuvant pharmacological targeting. Importantly, lapatinib and palbociclib strictly block de novo synthesis of DNA, mostly through disruption of E2F1 and its target genes. These results have implications for rational discovery of pharmacological combinations in pre-clinical models of adjuvant treatment and therapeutic resistance. PMID:26833126

Competing E2 and SN2 Mechanisms for the F- + CH3CH2I Reaction.

PubMed

Yang, Li; Zhang, Jiaxu; Xie, Jing; Ma, Xinyou; Zhang, Linyao; Zhao, Chenyang; Hase, William L

2017-02-09

Anti-E2, syn-E2, inv-, and ret-S N 2 reaction channels for the gas-phase reaction of F - + CH 3 CH 2 I were characterized with a variety of electronic structure calculations. Geometrical analysis confirmed synchronous E2-type transition states for the elimination of the current reaction, instead of nonconcerted processes through E1cb-like and E1-like mechanisms. Importantly, the controversy concerning the reactant complex for anti-E2 and inv-S N 2 paths has been clarified in the present work. A positive barrier of +19.2 kcal/mol for ret-S N 2 shows the least feasibility to occur at room temperature. Negative activation energies (-16.9, -16.0, and -4.9 kcal/mol, respectively) for inv-S N 2, anti-E2, and syn-E2 indicate that inv-S N 2 and anti-E2 mechanisms significantly prevail over the eclipsed elimination. Varying the leaving group for a series of reactions F - + CH 3 CH 2 Y (Y = F, Cl, Br, and I) leads to monotonically decreasing barriers, which relates to the gradually looser TS structures following the order F > Cl > Br > I. The reactivity of each channel nearly holds unchanged except for the perturbation between anti-E2 and inv-S N 2. RRKM calculation reveals that the reaction of the fluorine ion with ethyl iodide occurs predominately via anti-E2 elimination, and the inv-S N 2 pathway is suppressed, although it is energetically favored. This phenomenon indicates that, in evaluating the competition between E2 and S N 2 processes, the kinetic or dynamical factors may play a significant role. By comparison with benchmark CCSD(T) energies, MP2, CAM-B3LYP, and M06 methods are recommended to perform dynamics simulations of the title reaction.

The over expression of long non-coding RNA ANRIL promotes epithelial-mesenchymal transition by activating the ATM-E2F1 signaling pathway in pancreatic cancer: An in vivo and in vitro study.

PubMed

Chen, Shi; Zhang, Jia-Qiang; Chen, Jiang-Zhi; Chen, Hui-Xing; Qiu, Fu-Nan; Yan, Mao-Lin; Chen, Yan-Ling; Peng, Cheng-Hong; Tian, Yi-Feng; Wang, Yao-Dong

2017-09-01

This study aims to investigate the roles of lncRNA ANRIL in epithelial-mesenchymal transition (EMT) by regulating the ATM-E2F1 signaling pathway in pancreatic cancer (PC). PC rat models were established and ANRIL overexpression and interference plasmids were transfected. The expression of ANRIL, EMT markers (E-cadherin, N-cadherin and Vimentin) and ATM-E2F1 signaling pathway-related proteins (ATM, E2F1, INK4A, INK4B and ARF) were detected. Small molecule drugs were applied to activate and inhibit the ATM-E2F1 signaling pathway. Transwell assay and the scratch test were adopted to detect cell invasion and migration abilities. ANRIL expression in the PC cells was higher than in normal pancreatic duct epithelial cells. In the PC rat models and PC cells, ANRIL interference promoted the expressions of INK4B, INK4A, ARF and E-cadherin, while reduced N-cadherin and Vimentin expression. Over-expressed ANRIL decreased the expression of INK4B, INK4A, ARF and E-cadherin, but raised N-cadherin and Vimentin expressions. By inhibiting the ATM-E2F1 signaling pathway in PC cells, E-cadherin expression increased but N-cadherin and Vimentin expressions decreased. After ANRIL was silenced or the ATM-E2F1 signaling pathway inhibited, PC cell migration and invasion abilities were decreased. In conclusion, over-expression of lncRNA ANRIL can promote EMT of PC cells by activating the ATM-E2F1 signaling pathway. Copyright © 2017 Elsevier B.V. All rights reserved.

ROS Production Is Essential for the Apoptotic Function of E2F1 in Pheochromocytoma and Neuroblastoma Cell Lines

PubMed Central

Espada, Lilia; Meo-Evoli, Nathalie; Sancho, Patricia; Real, Sebastian; Fabregat, Isabel; Ambrosio, Santiago; Tauler, Albert

2012-01-01

In this study we demonstrate that accumulation of reactive oxygen species (ROS) is essential for E2F1 mediated apoptosis in ER-E2F1 PC12 pheochromocytoma, and SH-SY5Y and SK-N-JD neuroblastoma stable cell lines. In these cells, the ER-E2F1 fusion protein is expressed in the cytosol; the addition of 4-hydroxytamoxifen (OHT) induces its translocation to the nucleus and activation of E2F1target genes. Previously we demonstrated that, in ER-E2F1 PC12 cells, OHT treatment induced apoptosis through activation of caspase-3. Here we show that caspase-8 activity did not change upon treatment with OHT. Moreover, over-expression of Bcl-xL arrested OHT-induced apoptosis; by contrast, over-expression of c-FLIP, did not have any effect on OHT-induced apoptosis. OHT addition induces BimL expression, its translocation to mitochondria and activation of Bax, which is paralleled by diminished mitochondrial enrichment of Bcl-xL. Treatment with a Bax-inhibitory peptide reduced OHT-induced apoptosis. These results point out the essential role of mitochondria on the apoptotic process driven by E2F1. ROS accumulation followed E2F1 induction and treatment with the antioxidant N-acetylcysteine, inhibited E2F1-induced Bax translocation to mitochondria and subsequent apoptosis. The role of ROS in mediating OHT-induced apoptosis was also studied in two neuroblastoma cell lines, SH-SY5Y and SK-N-JD. In SH-SY5Y cells, activation of E2F1 by the addition of OHT induced ROS production and apoptosis, whereas over-expression of E2F1 in SK-N-JD cells failed to induce either response. Transcriptional profiling revealed that many of the genes responsible for scavenging ROS were down-regulated following E2F1-induction in SH-SY5Y, but not in SK-N-JD cells. Finally, inhibition of GSK3β blocked ROS production, Bax activation and the down regulation of ROS scavenging genes. These findings provide an explanation for the apparent contradictory role of E2F1 as an apoptotic agent versus a cell cycle activator

E6/E7-P53-POU2F1-CTHRC1 axis promotes cervical cancer metastasis and activates Wnt/PCP pathway

PubMed Central

Zhang, Rong; Lu, Huan; Lyu, Yuan-yuan; Yang, Xiao-mei; Zhu, Lin-yan; Yang, Guang-dong; Jiang, Peng-cheng; Re, Yuan; Song, Wei-wei; Wang, Jin-hao; Zhang, Can-can; Gu, Fei; Luo, Tian-jiao; Wu, Zhi-yong; Xu, Cong-jian

2017-01-01

Cervical cancer is an infectious cancer and the most common gynecologic cancer worldwide. E6/E7, the early genes of the high-risk mucosal human papillomavirus type, play key roles in the carcinogenic process of cervical cancer. However, little was known about its roles in modulating tumor microenvironment, particular extracellular matrix (ECM). In this study, we found that E6/E7 could regulate multiple ECM proteins, especially collagen triple helix repeat containing 1 (CTHRC1). CTHRC1 is highly expressed in cervical cancer tissue and serum and closely correlated with clinicopathological parameters. CTHRC1 promotes cervical cancer cell migration and invasion in vitro and metastasis in vivo. E6/E7 regulates the expression of CTHRC1 in cervical cancer by E6/E7-p53-POU2F1 (POU class 2 homeobox 1) axis. Futhermore, CTHRC1 activates Wnt/PCP signaling pathway. Take together, E6/E7-p53-POU2F1-CTHRC1 axis promotes cervical cancer cell invasion and metastasis and may act as a potential therapeutic target for interventions against cervical cancer invasion and metastasis. PMID:28303973

Inhibition of E2F1 activity and cell cycle progression by arsenic via retinoblastoma protein.

PubMed

Sheldon, Lynn A

2017-01-01

The regulation of cell cycle progression by steroid hormones and growth factors is important for maintaining normal cellular processes including development and cell proliferation. Deregulated progression through the G1/S and G2/M cell cycle transitions can lead to uncontrolled cell proliferation and cancer. The transcription factor E2F1, a key cell cycle regulator, targets genes encoding proteins that regulate cell cycle progression through the G1/S transition as well as proteins important in DNA repair and apoptosis. E2F1 expression and activity is inhibited by inorganic arsenic (iAs) that has a dual role as a cancer therapeutic and as a toxin that leads to diseases including cancer. An understanding of what underlies this dichotomy will contribute to understanding how to use iAs as a more effective therapeutic and also how to treat cancers that iAs promotes. Here, we show that quiescent breast adenocarcinoma MCF-7 cells treated with 17-β estradiol (E2) progress through the cell cycle, but few cells treated with E2 + iAs progress from G1 into S-phase due to a block in cell cycle progression. Our data support a model in which iAs inhibits the dissociation of E2F1 from the tumor suppressor, retinoblastoma protein (pRB) due to changes in pRB phosphorylation which leads to decreased E2F1 transcriptional activity. These findings present an explanation for how iAs can disrupt cell cycle progression through E2F1-pRB and has implications for how iAs acts as a cancer therapeutic as well as how it may promote tumorigenesis through decreased DNA repair.

[Morphologic changes in cultures of different tissues exposed to the toxins of C1. perfringens types B, C, E and F].

PubMed

Ermakova, M P; Zemlianitskaia, E P

1975-11-01

There were revealed morphological peculiarities of the action of C1. perfringens toxins, types B, C, D, E and F on the cultures of fibroblasts of chick embryo, amniotic cells and intestinal tissue. The toxin type B was characterized by a marked vocuolization of the cell cytoplasm; the action of the toxin of type C was expressed in the swelling of the nuclei and the lysis of the chromatine substance, the toxin of type E casued kariorhexis, and the toxin of type F--hyperchromatosis of the nuclei. All the cultures proved to be insensitive to the toxin of type D. Peculiarity of the morphological affection of the cells permitted to differentiate toxin of type B in the cultures of the fibroblasts of chick embryo, whereas the toxins of types C, E and F--in the cultures of the amniotic cells under control of the reaction of neutralization with the homologous antitoxic sera.

16Oxygen irradiation enhances cued fear memory in B6D2F1 mice

NASA Astrophysics Data System (ADS)

Raber, Jacob; Marzulla, Tessa; Kronenberg, Amy; Turker, Mitchell S.

2015-11-01

The space radiation environment includes energetic charged particles that may impact cognitive performance. We assessed the effects of 16O ion irradiation on cognitive performance of C57BL/6J × DBA/2J F1 (B6D2F1) mice at OHSU (Portland, OR) one month following irradiation at Brookhaven National Laboratory (BNL, Upton, NY). Hippocampus-dependent contextual fear memory and hippocampus-independent cued fear memory of B6D2F1 mice were tested. 16O ion exposure enhanced cued fear memory. This effect showed a bell-shaped dose response curve. Cued fear memory was significantly stronger in mice irradiated with 16O ions at a dose of 0.4 or 0.8 Gy than in sham-irradiated mice or following irradiation at 1.6 Gy. In contrast to cued fear memory, contextual fear memory was not affected following 16O ion irradiation at the doses used in this study. These data indicate that the amygdala might be particularly susceptible to effects of 16O ion exposure.

The association of GSK3 beta with E2F1 facilitates nerve growth factor-induced neural cell differentiation.

PubMed

Zhou, Fangfang; Zhang, Long; Wang, Aijun; Song, Bo; Gong, Kai; Zhang, Lihai; Hu, Min; Zhang, Xiufang; Zhao, Nanming; Gong, Yandao

2008-05-23

It is widely acknowledged that E2F1 and GSK3beta are both involved in the process of cell differentiation. However, the relationship between E2F1 and GSK3beta in cell differentiation has yet to be discovered. Here, we provide evidence that in the differentiation of PC12 cells induced by nerve growth factor (NGF), GSK3beta was increased at both the mRNA and protein levels, whereas E2F1 at these two levels was decreased. Both wild-type GSK3beta and its kinase-defective mutant GSK3beta KM can inhibit E2F1 by promoting its ubiquitination through physical interaction. In addition, the colocalization of GSK3beta and E2F1 and their subcellular distribution, regulated by NGF, were observed in the process of PC12 differentiation. At the tissue level, GSK3beta colocalized and interacted with E2F1 in mouse hippocampus. Furthermore, GSK3beta facilitated neurite outgrowth by rescuing the promoter activities of Cdk inhibitors p21 and p15 from the inhibition caused by E2F1. To summarize, our findings suggest that GSK3beta can promote the ubiquitination of E2F1 via physical interaction and thus inhibit its transcription activity in a kinase activity independent manner, which plays an important role in the NGF-induced PC12 differentiation.

Carcinogenicity of acrylamide in B6C3F(1) mice and F344/N rats from a 2-year drinking water exposure.

PubMed

Beland, Frederick A; Mellick, Paul W; Olson, Greg R; Mendoza, Maria C B; Marques, M Matilde; Doerge, Daniel R

2013-01-01

Acrylamide is a component of roasted coffee and certain baked and fried carbohydrate-rich foods prepared at high temperatures. We have assessed the carcinogenicity of acrylamide in male and female B6C3F(1) mice and F344/N rats administered 0, 0.0875, 0.175, 0.35, or 0.70mM acrylamide in the drinking water ad libitum for 2 years. Acrylamide caused significant dose-related decreasing trends in the body weights of F344/N rats. Acrylamide administration resulted in significant dose-related decreasing trends in survival in both sexes of B6C3F(1) mice and in female F344/N rats. Histopathological analyses indicated significant dose-related increases in Harderian gland and lung tumors in male and female B6C3F(1) mice. Male B6C3F(1) mice also had a significantly increased incidence of forestomach tumors, while female B6C3F(1) mice had significant dose-related increases in mammary gland, ovary, and skin tumors. In male and female F344/N rats, there were significant increases in thyroid tumors. Male F344/N rats also had significant dose-related increases in testes, heart, and pancreas tumors, while female F344 rats demonstrated significant increases in clitoral gland, mammary gland, oral cavity, and skin tumors. These results, combined with previous mechanistic studies, provide strong support for the concept that acrylamide is activated to a carcinogen through metabolism to glycidamide. Published by Elsevier Ltd.

48 CFR 47.303-2 - F.o.b. origin, contractor's facility.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false F.o.b. origin, contractor... REGULATION CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 47.303-2 F.o.b. origin, contractor's facility. (a) Explanation of delivery term. F.o.b. origin, contractor's facility means free of...

Human Parvovirus B19 NS1 Protein Aggravates Liver Injury in NZB/W F1 Mice

PubMed Central

Tsai, Chun-Chou; Chiu, Chun-Ching; Hsu, Jeng-Dong; Hsu, Huai-Sheng; Tzang, Bor-Show; Hsu, Tsai-Ching

2013-01-01

Human parvovirus B19 (B19) has been associated with a variety of diseases. However, the influence of B19 viral proteins on hepatic injury in SLE is still obscure. To elucidate the effects of B19 viral proteins on livers in SLE, recombinant B19 NS1, VP1u or VP2 proteins were injected subcutaneously into NZB/W F1 mice, respectively. Significant expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were detected in NZB/W F1 mice receiving B19 NS1 as compared to those mice receiving PBS. Markedly hepatocyte disarray and lymphocyte infiltration were observed in livers from NZB/WF 1 mice receiving B19 NS1 as compared to those mice receiving PBS. Additionally, significant increases of Tumor Necrosis Factor –α (TNF-α), TNF-α receptor, IκB kinase –α (IKK-α), nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor (IκB) and nuclear factor-kappa B (NF-κB) were detected in livers from NZB/W F1 mice receiving B19 NS1 as compared to those mice receiving PBS. Accordingly, significant increases of matrix metalloproteinase-9 (MMP9) and U-plasminogen activator (uPA) were also detected in livers from NZB/W F1 mice receiving B19 NS1 as compared to those mice receiving PBS. Contrarily, no significant variation on livers from NZB/W F1 mice receiving B19 VP1u or VP2 was observed as compared to those mice receiving PBS. These findings firstly demonstrated the aggravated effects of B19 NS1 but not VP1u or VP2 protein on hepatic injury and provide a clue in understanding the role of B19 NS1 on hepatic injury in SLE. PMID:23555760

Painful Charcot-Marie-Tooth neuropathy type 2E/1F due to a novel NEFL mutation.

PubMed

Doppler, Kathrin; Kunstmann, Erdmute; Krüger, Stefan; Sommer, Claudia

2017-05-01

Charcot-Marie-Tooth neuropathy (CMT) 2E/1F is caused by mutations in the neurofilament light-chain polypeptide (NEFL) gene. Giant axons are a histological hallmark frequently seen in nerves of patients with CMT2E. We describe the case of a 43-year-old patient with a painful, predominantly sensory neuropathy. The patient's sural nerve biopsy showed multiple giant axons. Genetic sequencing of the NEFL gene revealed that the patient was heterozygous for an altered sequence of the gene, c.816C>G, p.Asn272Lys, which has not yet been described in CMT2E/1F. In contrast to other cases of CMT2E/1F, where motor symptoms are predominant, pain was the most disabling symptom in this patient. Muscle Nerve 55: 752-755, 2017. © 2016 Wiley Periodicals, Inc.

DPL-1 DP, LIN-35 Rb and EFL-1 E2F act with the MCD-1 zinc-finger protein to promote programmed cell death in Caenorhabditis elegans.

PubMed

Reddien, Peter W; Andersen, Erik C; Huang, Michael C; Horvitz, H Robert

2007-04-01

The genes egl-1, ced-9, ced-4, and ced-3 play major roles in programmed cell death in Caenorhabditis elegans. To identify genes that have more subtle activities, we sought mutations that confer strong cell-death defects in a genetically sensitized mutant background. Specifically, we screened for mutations that enhance the cell-death defects caused by a partial loss-of-function allele of the ced-3 caspase gene. We identified mutations in two genes not previously known to affect cell death, dpl-1 and mcd-1 (modifier of cell death). dpl-1 encodes the C. elegans homolog of DP, the human E2F-heterodimerization partner. By testing genes known to interact with dpl-1, we identified roles in cell death for four additional genes: efl-1 E2F, lin-35 Rb, lin-37 Mip40, and lin-52 dLin52. mcd-1 encodes a novel protein that contains one zinc finger and that is synthetically required with lin-35 Rb for animal viability. dpl-1 and mcd-1 act with efl-1 E2F and lin-35 Rb to promote programmed cell death and do so by regulating the killing process rather than by affecting the decision between survival and death. We propose that the DPL-1 DP, MCD-1 zinc finger, EFL-1 E2F, LIN-35 Rb, LIN-37 Mip40, and LIN-52 dLin52 proteins act together in transcriptional regulation to promote programmed cell death.

Escherichia coli F1Fo-ATP synthase with a b/δ fusion protein allows analysis of the function of the individual b subunits.

PubMed

Gajadeera, Chathurada S; Weber, Joachim

2013-09-13

The "stator stalk" of F1Fo-ATP synthase is essential for rotational catalysis as it connects the nonrotating portions of the enzyme. In Escherichia coli, the stator stalk consists of two (identical) b subunits and the δ subunit. In mycobacteria, one of the b subunits and the δ subunit are replaced by a b/δ fusion protein; the remaining b subunit is of the shorter b' type. In the present study, it is shown that it is possible to generate a functional E. coli ATP synthase containing a b/δ fusion protein. This construct allowed the analysis of the roles of the individual b subunits. The full-length b subunit (which in this case is covalently linked to δ in the fusion protein) is responsible for connecting the stalk to the catalytic F1 subcomplex. It is not required for interaction with the membrane-embedded Fo subcomplex, as its transmembrane helix can be removed. Attachment to Fo is the function of the other b subunit which in turn has only a minor (if any at all) role in binding to δ. Also in E. coli the second b subunit can be shortened to a b' type.

M2-F1 lifting body and Paresev 1B on ramp

NASA Technical Reports Server (NTRS)

1963-01-01

In this photo of the M2-F1 lifting body and the Paresev 1B on the ramp, the viewer sees two vehicles representing different approaches to building a research craft to simulate a spacecraft able to land on the ground instead of splashing down in the ocean as the Mercury capsules did. The M2-F1 was a lifting body, a shape able to re-enter from orbit and land. The Paresev (Paraglider Research Vehicle) used a Rogallo wing that could be (but never was) used to replace a conventional parachute for landing a capsule-type spacecraft, allowing it to make a controlled landing on the ground. The wingless, lifting body aircraft design was initially conceived as a means of landing an aircraft horizontally after atmospheric reentry. The absence of wings would make the extreme heat of re-entry less damaging to the vehicle. In 1962, Dryden management approved a program to build a lightweight, unpowered lifting body as a prototype to flight test the wingless concept. It would look like a 'flying bathtub,' and was designated the M2-F1, the 'M' referring to 'manned' and 'F' referring to 'flight' version. It featured a plywood shell placed over a tubular steel frame crafted at Dryden. Construction was completed in 1963. The first flight tests of the M2-F1 were over Rogers Dry Lake at the end of a tow rope attached to a hopped-up Pontiac convertible driven at speeds up to about 120 mph. This vehicle needed to be able to tow the M2-F1 on the Rogers Dry Lakebed adjacent to NASA's Flight Research Center (FRC) at a minimum speed of 100 miles per hour. To do that, it had to handle the 400-pound pull of the M2-F1. Walter 'Whitey' Whiteside, who was a retired Air Force maintenance officer working in the FRC's Flight Operations Division, was a dirt-bike rider and hot-rodder. Together with Boyden 'Bud' Bearce in the Procurement and Supply Branch of the FRC, Whitey acquired a Pontiac Catalina convertible with the largest engine available. He took the car to Bill Straup's renowned hot-rod shop

Functional interaction of CCAAT/enhancer-binding-protein-α basic region mutants with E2F transcription factors and DNA.

PubMed

Kowenz-Leutz, Elisabeth; Schuetz, Anja; Liu, Qingbin; Knoblich, Maria; Heinemann, Udo; Leutz, Achim

2016-07-01

The transcription factor CCAAT/enhancer-binding protein α (C/EBPα) regulates cell cycle arrest and terminal differentiation of neutrophils and adipocytes. Mutations in the basic leucine zipper domain (bZip) of C/EBPα are associated with acute myeloid leukemia. A widely used murine transforming C/EBPα basic region mutant (BRM2) entails two bZip point mutations (I294A/R297A). BRM2 has been discordantly described as defective for DNA binding or defective for interaction with E2F. We have separated the two BRM2 mutations to shed light on the intertwined reciprocity between C/EBPα-E2F-DNA interactions. Both, C/EBPα I294A and R297A retain transactivation capacity and interaction with E2F-DP. The C/EBPα R297A mutation destabilized DNA binding, whereas the C/EBPα I294A mutation enhanced binding to DNA. The C/EBPα R297A mutant, like BRM2, displayed enhanced interaction with E2F-DP but failed to repress E2F-dependent transactivation although both mutants were readily suppressed by E2F1 for transcription through C/EBP cis-regulatory sites. In contrast, the DNA binding enhanced C/EBPα I294A mutant displayed increased repression of E2F-DP mediated transactivation and resisted E2F-DP mediated repression. Thus, the efficient repression of E2F dependent S-phase genes and the activation of differentiation genes reside in the balanced DNA binding capacity of C/EBPα. Copyright © 2016 Elsevier B.V. All rights reserved.

Identification of novel posttranscriptional targets of the BCR/ABL oncoprotein by ribonomics: requirement of E2F3 for BCR/ABL leukemogenesis

PubMed Central

Eiring, Anna M.; Neviani, Paolo; Santhanam, Ramasamy; Oaks, Joshua J.; Chang, Ji Suk; Notari, Mario; Willis, William; Gambacorti-Passerini, Carlo; Volinia, Stefano; Marcucci, Guido; Caligiuri, Michael A.; Leone, Gustavo W.

2008-01-01

Several RNA binding proteins (RBPs) have been implicated in the progression of chronic myelogenous leukemia (CML) from the indolent chronic phase to the aggressively fatal blast crisis. In the latter phase, expression and function of specific RBPs are aberrantly regulated at transcriptional or posttranslational levels by the constitutive kinase activity of the BCR/ABL oncoprotein. As a result, altered expression/function of RBPs leads to increased resistance to apoptotic stimuli, enhanced survival, growth advantage, and differentiation arrest of CD34+ progenitors from patients in CML blast crisis. Here, we identify the mRNAs bound to the hnRNP-A1, hnRNP-E2, hnRNP-K, and La/SSB RBPs in BCR/ABLtransformed myeloid cells. Interestingly, we found that the mRNA encoding the transcription factor E2F3 associates to hnRNP-A1 through a conserved binding site located in the E2F3 3′ untranslated region (UTR). E2F3 levels were up-regulated in CML-BCCD34+ in a BCR/ABL kinase– and hnRNP-A1 shuttling–dependent manner. Moreover, by using shRNA-mediated E2F3 knock-down and BCR/ABL-transduced lineage-negative bone marrow cells from E2F3+/+ and E2F3−/− mice, we show that E2F3 expression is important for BCR/ABL clonogenic activity and in vivo leukemogenic potential. Thus, the complexity of the mRNA/RBP network, together with the discovery of E2F3 as an hnRNP-A1–regulated factor, outlines the relevant role played by RBPs in posttranscriptional regulation of CML development and progression. PMID:17925491

AML1 is overexpressed in patients with myeloproliferative neoplasms and mediates JAK2V617F-independent overexpression of NF-E2

PubMed Central

Wang, Wei; Schwemmers, Sven; Hexner, Elizabeth O.

2010-01-01

The transcription factor NF-E2 is overexpressed in the majority of patients with polycythemia vera (PV). Concomitantly, 95% of these patients carry the JAK2V617F mutation. Although NF-E2 levels correlate with JAK2V671F allele burden in some PV cohorts, the molecular mechanism causing aberrant NF-E2 expression has not been described. Here we show that NF-E2 expression is also increased in patients with essential thrombocythemia and primary myelofibrosis independent of the presence of the JAK2V617F mutation. Characterization of the NF-E2 promoter revealed multiple functional binding sites for AML1/RUNX-1. Chromatin immunoprecipitation demonstrated AML1 binding to the NF-E2 promoter in vivo. Moreover, AML1 binding to the NF-E2 promoter was significantly increased in granulocytes from PV patients compared with healthy controls. AML1 mRNA expression was elevated in patients with PV, essential thrombocythemia, and primary myelofibrosis both in the presence and absence of JAK2V617F. In addition, AML1 and NF-E2 expression were highly correlated. RNAi-mediated suppression of either AML1 or of its binding partner CBF-β significantly decreased NF-E2 expression. Moreover, expression of the leukemic fusion protein AML/ETO drastically decreased NF-E2 protein levels. Our data identify NF-E2 as a novel AML1 target gene and delineate a role for aberrant AML1 expression in mediating elevated NF-E2 expression in MPN patients. PMID:20339092

40 CFR Table 2b to Subpart E of... - Reactivity Factors for Aliphatic Hydrocarbon Solvent Mixtures

Code of Federal Regulations, 2010 CFR

2010-07-01

... Hydrocarbon Solvent Mixtures 2B Table 2B to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Averageboiling point * (degrees F) Criteria Reactivityfactor 1 80-205 Alkanes... + Dry Point) / 2 (b) Aromatic Hydrocarbon Solvents ...

40 CFR Table 2b to Subpart E of... - Reactivity Factors for Aliphatic Hydrocarbon Solvent Mixtures

Code of Federal Regulations, 2011 CFR

2011-07-01

... Hydrocarbon Solvent Mixtures 2B Table 2B to Subpart E of Part 59 Protection of Environment ENVIRONMENTAL... Hydrocarbon Solvent Mixtures Bin Averageboiling point * (degrees F) Criteria Reactivityfactor 1 80-205 Alkanes... + Dry Point) / 2 (b) Aromatic Hydrocarbon Solvents ...

THE ROLE OF THE RETINOBLASTOMA/E2F1 TUMOR SUPPRESSOR PATHWAY IN THE LESION RECOGNITION STEP OF NUCLEOTIDE EXCISION REPAIR

PubMed Central

Lin, Patrick S.; McPherson, Lisa A.; Chen, Aubrey Y.; Sage, Julien; Ford, James M.

2009-01-01

The retinoblastoma Rb/E2F tumor suppressor pathway plays a major role in the regulation of mammalian cell cycle progression. The pRb protein, along with closely related proteins p107 and p130, exerts its anti-proliferative effects by binding to the E2F family of transcription factors known to regulate essential genes throughout the cell cycle. We sought to investigate the role of the Rb/E2F1 pathway in the lesion recognition step of nucleotide excision repair (NER) in mouse embryonic fibroblasts (MEFs). Rb−/−;p107−/−;p130−/− MEFs repaired both cyclobutane pyrimidine dimers (CPD) and 6-4 photoproducts (6-4PPs) at higher efficiency than did wildtype cells following UV-C irradiation. The expression of damaged DNA binding gene DDB2 involved in the DNA lesion recognition step was elevated in the Rb family-deficient MEFs. To determine if the enhanced DNA repair in the absence of the Rb gene family is due to the derepression of E2F1, we assayed the ability of E2F1-deficient cells to repair damaged DNA and demonstrated that E2F1−/− MEFs are impaired for the removal of both CPDs and 6-4PPs. Furthermore, wildtype cells induced a higher expression of DDB2 and xeroderma pigmentosum gene XPC transcript levels than did E2F1−/− cells following UV-C irradiation. Using an E2F SiteScan algorithm, we uncovered a putative E2F-responsive element in the XPC promoter upstream of the transcription start site. We showed with chromatin immunoprecipitation assays the binding of E2F1 to the XPC promoter in a UV-dependent manner, suggesting that E2F1 is a transcriptional regulator of XPC. Our study identifies a novel E2F1 gene target and further supports the growing body of evidence that the Rb/E2F1 tumor suppressor pathway is involved in the regulation of the DNA lesion recognition step of nucleotide excision repair. PMID:19376752

(2E,5E)-2,5-Bis(3-hydroxy-4-methoxybenzylidene) cyclopentanone Exerts Anti-Melanogenesis and Anti-Wrinkle Activities in B16F10 Melanoma and Hs27 Fibroblast Cells.

PubMed

Jung, Hee Jin; Lee, A Kyoung; Park, Yeo Jin; Lee, Sanggwon; Kang, Dongwan; Jung, Young Suk; Chung, Hae Young; Moon, Hyung Ryong

2018-06-11

Ultraviolet (UV) radiation exposure is the primary cause of extrinsic skin aging, which results in skin hyperpigmentation and wrinkling. In this study, we investigated the whitening effect of (2 E ,5 E )-2,5-bis(3-hydroxy-4-methoxybenzylidene)cyclopentanone (BHCP) on B16F10 melanoma and its anti-wrinkle activity on Hs27 fibroblasts cells. BHCP was found to potently inhibit tyrosinase, with 50% inhibition concentration (IC 50 ) values of 1.10 µM and 8.18 µM for monophenolase (l-tyrosine) and diphenolase (l-DOPA), and the enzyme kinetics study revealed that BHCP is a competitive-type tyrosinase inhibitor. Furthermore, BHCP significantly inhibited melanin content and cellular tyrosinase activity, and downregulated the levels of microphthalmia-associated transcription factor (MITF), phosphorylated levels of cAMP response element-binding (CREB) protein, and tyrosinase in α-melanocyte stimulating hormone (α-MSH)-induced B16F10 melanoma cells. Moreover, BHCP inhibited the phosphorylation of p65 and expression of matrix metalloproteinases (MMP-1, MMP-9, MMP-12, and MMP-13) in Hs27 fibroblasts stimulated with UV radiation. Therefore, our results demonstrate that BHCP may be a good candidate for the development of therapeutic agents for diseases associated with hyperpigmentation and wrinkling.

E2F1 somatic mutation within miRNA target site impairs gene regulation in colorectal cancer.

PubMed

Lopes-Ramos, Camila M; Barros, Bruna P; Koyama, Fernanda C; Carpinetti, Paola A; Pezuk, Julia; Doimo, Nayara T S; Habr-Gama, Angelita; Perez, Rodrigo O; Parmigiani, Raphael B

2017-01-01

Genetic studies have largely concentrated on the impact of somatic mutations found in coding regions, and have neglected mutations outside of these. However, 3' untranslated regions (3' UTR) mutations can also disrupt or create miRNA target sites, and trigger oncogene activation or tumor suppressor inactivation. We used next-generation sequencing to widely screen for genetic alterations within predicted miRNA target sites of oncogenes associated with colorectal cancer, and evaluated the functional impact of a new somatic mutation. Target sequencing of 47 genes was performed for 29 primary colorectal tumor samples. For 71 independent samples, Sanger methodology was used to screen for E2F1 mutations in miRNA predicted target sites, and the functional impact of these mutations was evaluated by luciferase reporter assays. We identified germline and somatic alterations in E2F1. Of the 100 samples evaluated, 3 had germline alterations at the MIR205-5p target site, while one had a somatic mutation at MIR136-5p target site. E2F1 gene expression was similar between normal and tumor tissues bearing the germline alteration; however, expression was increased 4-fold in tumor tissue that harbored a somatic mutation compared to that in normal tissue. Luciferase reporter assays revealed both germline and somatic alterations increased E2F1 activity relative to wild-type E2F1. We demonstrated that somatic mutation within E2F1:MIR136-5p target site impairs miRNA-mediated regulation and leads to increased gene activity. We conclude that somatic mutations that disrupt miRNA target sites have the potential to impact gene regulation, highlighting an important mechanism of oncogene activation.

B-2 Extremely High Frequency SATCOM and Computer Increment 1 (B-2 EHF Inc 1)

DTIC Science & Technology

2013-12-01

2012 FEB 2012 FEB 2012 FEB 2012 Final DIOT&E flight JUL 2012 JUL 2012 JUL 2012 JUL 2012 RAA MAR 2015 MAR 2015 MAR 2016 MAR 2015 Change Explanations...None Memo RAA is defined as eight assigned aircraft modified, sufficient aircrews and maintenance personnel trained, sufficient aircrew and...incremental upgrade. Acronyms and Abbreviations DIOT&E - Dedicated Initial Operational Test and Evaluation RAA - Required Assets Available B-2 EHF Inc 1

E2F transcription factor-1 deficiency reduces pathophysiology in the mouse model of Duchenne muscular dystrophy through increased muscle oxidative metabolism.

PubMed

Blanchet, Emilie; Annicotte, Jean-Sébastien; Pradelli, Ludivine A; Hugon, Gérald; Matecki, Stéfan; Mornet, Dominique; Rivier, François; Fajas, Lluis

2012-09-01

E2F1 deletion leads to increased mitochondrial number and function, increased body temperature in response to cold and increased resistance to fatigue with exercise. Since E2f1-/- mice show increased muscle performance, we examined the effect of E2f1 genetic inactivation in the mdx background, a mouse model of Duchenne muscular dystrophy (DMD). E2f1-/-;mdx mice demonstrated a strong reduction of physiopathological signs of DMD, including preservation of muscle structure, decreased inflammatory profile, increased utrophin expression, resulting in better endurance and muscle contractile parameters, comparable to normal mdx mice. E2f1 deficiency in the mdx genetic background increased the oxidative metabolic gene program, mitochondrial activity and improved muscle functions. Interestingly, we observed increased E2F1 protein levels in DMD patients, suggesting that E2F1 might represent a promising target for the treatment of DMD.

Dibenzo[b,f][1,4]oxazepines and dibenzo[b,e]oxepines: Influence of the chlorine substitution pattern on the pharmacology at the H1R, H4R, 5-HT2AR and other selected GPCRs.

PubMed

Naporra, Franziska; Gobleder, Susanne; Wittmann, Hans-Joachim; Spindler, Julia; Bodensteiner, Michael; Bernhardt, Günther; Hübner, Harald; Gmeiner, Peter; Elz, Sigurd; Strasser, Andrea

2016-11-01

Inspired by VUF6884 (7-Chloro-11-(4-methylpiperazin-1-yl)dibenzo[b,f][1,4]oxazepine), reported as a dual H 1 /H 4 receptor ligand (pK i : 8.11 (human H 1 R (hH 1 R)), 7.55 (human H 4 R (hH 4 R))), four known and 28 new oxazepine and related oxepine derivatives were synthesised and pharmacologically characterized at histamine receptors and selected aminergic GPCRs. In contrast to the oxazepine series, within the oxepine series, the new compounds showed high affinity to the hH 1 R (pK i : 6.8-8.7), but no or moderate affinity to the hH 4 R (pK i :≤5.3). For one oxepine derivative (1-(2-Chloro-6,11-dihydrodibenzo[b,e]oxepin-11-yl)-4-methylpiperazine), the enantiomers were separated and the R-enantiomer was identified as the eutomer at the hH 1 R (pK i : 8.83 (R), 7.63 (S)) and the guinea-pig H 1 R (gpH 1 R) (pK i : 8.82 (R), 7.41 (S)). Molecular dynamic studies suggest that the tricyclic core of the compounds is bound in a similar mode into the binding pocket, as described for doxepine in the hH 1 R crystal structure. Moreover, docking studies of all oxepine derivatives at the hH 1 R indicate that the oxygen and the position of the chlorine in the tricyclic core determines, if the R- or the S-enantiomer is the eutomer. For some of the oxazepines and oxepines the affinity to other aminergic GPCRs is in the same range as to hH 1 R or hH 4 R, thus, those compounds have to be classified as dirty drugs. However, one oxazepine derivative (3,7-Dichloro-11-(4-methylpiperazin-1-yl)dibenzo[b,f][1,4]oxazepine was identified as dual hH 1 /h5-HT 2A receptor ligand (pK i : 9.23 (hH 1 R), 8.74 (h5-HT 2A R), ≤7 at other analysed GPCRs), whereas one oxepine derivative (1-(3,8-Dichloro-6,11-dihydrodibenzo[b,e]oxepin-11-yl)-4-methylpiperazine) was identified as selective hH 1 R antagonist (pK i : 8.44 (hH 1 R), ≤6.7 at other analyzed GPCRs). Thus, the pharmacological results suggest that the oxazepine/oxepine moiety and additionally the chlorine substitution pattern toggles

E2F1-mediated upregulation of p19INK4d determines its periodic expression during cell cycle and regulates cellular proliferation.

PubMed

Carcagno, Abel L; Marazita, Mariela C; Ogara, María F; Ceruti, Julieta M; Sonzogni, Silvina V; Scassa, María E; Giono, Luciana E; Cánepa, Eduardo T

2011-01-01

A central aspect of development and disease is the control of cell proliferation through regulation of the mitotic cycle. Cell cycle progression and directionality requires an appropriate balance of positive and negative regulators whose expression must fluctuate in a coordinated manner. p19INK4d, a member of the INK4 family of CDK inhibitors, has a unique feature that distinguishes it from the remaining INK4 and makes it a likely candidate for contributing to the directionality of the cell cycle. p19INK4d mRNA and protein levels accumulate periodically during the cell cycle under normal conditions, a feature reminiscent of cyclins. In this paper, we demonstrate that p19INK4d is transcriptionally regulated by E2F1 through two response elements present in the p19INK4d promoter. Ablation of this regulation reduced p19 levels and restricted its expression during the cell cycle, reflecting the contribution of a transcriptional effect of E2F1 on p19 periodicity. The induction of p19INK4d is delayed during the cell cycle compared to that of cyclin E, temporally separating the induction of these proliferative and antiproliferative target genes. Specific inhibition of the E2F1-p19INK4d pathway using triplex-forming oligonucleotides that block E2F1 binding on p19 promoter, stimulated cell proliferation and increased the fraction of cells in S phase. The results described here support a model of normal cell cycle progression in which, following phosphorylation of pRb, free E2F induces cyclin E, among other target genes. Once cyclinE/CDK2 takes over as the cell cycle driving kinase activity, the induction of p19 mediated by E2F1 leads to inhibition of the CDK4,6-containing complexes, bringing the G1 phase to an end. This regulatory mechanism constitutes a new negative feedback loop that terminates the G1 phase proliferative signal, contributing to the proper coordination of the cell cycle and provides an additional mechanism to limit E2F activity.

E2F1-Mediated Upregulation of p19INK4d Determines Its Periodic Expression during Cell Cycle and Regulates Cellular Proliferation

PubMed Central

Carcagno, Abel L.; Marazita, Mariela C.; Ogara, María F.; Ceruti, Julieta M.; Sonzogni, Silvina V.; Scassa, María E.; Giono, Luciana E.; Cánepa, Eduardo T.

2011-01-01

Background A central aspect of development and disease is the control of cell proliferation through regulation of the mitotic cycle. Cell cycle progression and directionality requires an appropriate balance of positive and negative regulators whose expression must fluctuate in a coordinated manner. p19INK4d, a member of the INK4 family of CDK inhibitors, has a unique feature that distinguishes it from the remaining INK4 and makes it a likely candidate for contributing to the directionality of the cell cycle. p19INK4d mRNA and protein levels accumulate periodically during the cell cycle under normal conditions, a feature reminiscent of cyclins. Methodology/Principal Findings In this paper, we demonstrate that p19INK4d is transcriptionally regulated by E2F1 through two response elements present in the p19INK4d promoter. Ablation of this regulation reduced p19 levels and restricted its expression during the cell cycle, reflecting the contribution of a transcriptional effect of E2F1 on p19 periodicity. The induction of p19INK4d is delayed during the cell cycle compared to that of cyclin E, temporally separating the induction of these proliferative and antiproliferative target genes. Specific inhibition of the E2F1-p19INK4d pathway using triplex-forming oligonucleotides that block E2F1 binding on p19 promoter, stimulated cell proliferation and increased the fraction of cells in S phase. Conclusions/Significance The results described here support a model of normal cell cycle progression in which, following phosphorylation of pRb, free E2F induces cyclin E, among other target genes. Once cyclinE/CDK2 takes over as the cell cycle driving kinase activity, the induction of p19 mediated by E2F1 leads to inhibition of the CDK4,6-containing complexes, bringing the G1 phase to an end. This regulatory mechanism constitutes a new negative feedback loop that terminates the G1 phase proliferative signal, contributing to the proper coordination of the cell cycle and provides an

20 CFR 655.700 - What statutory provisions govern the employment of H-1B, H-1B1, and E-3 nonimmigrants and how do...

Code of Federal Regulations, 2012 CFR

2012-04-01

... employment of H-1B, H-1B1, and E-3 nonimmigrants and how do employers apply for H-1B, H-1B1, and E-3 visas... Requirements for Employers Seeking To Employ Nonimmigrants on H-1b Visas in Specialty Occupations and as Fashion Models, and Requirements for Employers Seeking To Employ Nonimmigrants on H-1b1 and E-3 Visas in...

20 CFR 655.700 - What statutory provisions govern the employment of H-1B, H-1B1, and E-3 nonimmigrants and how do...

Code of Federal Regulations, 2013 CFR

2013-04-01

... employment of H-1B, H-1B1, and E-3 nonimmigrants and how do employers apply for H-1B, H-1B1, and E-3 visas... Requirements for Employers Seeking To Employ Nonimmigrants on H-1b Visas in Specialty Occupations and as Fashion Models, and Requirements for Employers Seeking To Employ Nonimmigrants on H-1b1 and E-3 Visas in...

20 CFR 655.700 - What statutory provisions govern the employment of H-1B, H-1B1, and E-3 nonimmigrants and how do...

Code of Federal Regulations, 2014 CFR

2014-04-01

... employment of H-1B, H-1B1, and E-3 nonimmigrants and how do employers apply for H-1B, H-1B1, and E-3 visas... Requirements for Employers Seeking To Employ Nonimmigrants on H-1b Visas in Specialty Occupations and as Fashion Models, and Requirements for Employers Seeking To Employ Nonimmigrants on H-1b1 and E-3 Visas in...

20 CFR 655.700 - What statutory provisions govern the employment of H-1B, H-1B1, and E-3 nonimmigrants and how do...

Code of Federal Regulations, 2011 CFR

2011-04-01

... employment of H-1B, H-1B1, and E-3 nonimmigrants and how do employers apply for H-1B, H-1B1, and E-3 visas... Requirements for Employers Seeking To Employ Nonimmigrants on H-1b Visas in Specialty Occupations and as Fashion Models, and Requirements for Employers Seeking To Employ Nonimmigrants on H-1b1 and E-3 Visas in...

20 CFR 655.700 - What statutory provisions govern the employment of H-1B, H-1B1, and E-3 nonimmigrants and how do...

Code of Federal Regulations, 2010 CFR

2010-04-01

... employment of H-1B, H-1B1, and E-3 nonimmigrants and how do employers apply for H-1B, H-1B1, and E-3 visas... Requirements for Employers Seeking To Employ Nonimmigrants on H-1b Visas in Specialty Occupations and as Fashion Models, and Requirements for Employers Seeking To Employ Nonimmigrants on H-1b1 and E-3 Visas in...

The NAMPT/E2F2/SIRT1 axis promotes proliferation and inhibits p53-dependent apoptosis in human melanoma cells.

PubMed

Zhao, Hailong; Tang, Weiwei; Chen, Xiaowen; Wang, Siyu; Wang, Xianyan; Xu, Haiyan; Li, Lijuan

2017-11-04

Melanoma is the most common primary malignant neoplasm in adults, causing more deaths than any other skin cancer, necessitating the development of new target-based approaches. Current evidence suggests SIRT1, the mammalian nicotinamide adenine dinucleotide (NAD + )-dependent protein deacetylase, and nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting NAD + biosynthetic enzyme, together comprise a novel systemic regulatory network to play a pivotal role in cell proliferation and apoptosis. Nevertheless, how the regulation of this cofactor interfaces with signal transduction network remains poorly understood in melanoma. Here, we report NAMPT is highly expressed in melanomaassociated with poor overall survival in patients. Pharmacological and genetic inhibition of NAMPT decreased NAD + levels and melanoma cell proliferation capacity, and NAMPT knockdown induced apoptosis through the activity of the tumor suppressor p53. Next, we demonstrate NAMPT regulates the transcription factor E2F family member 2 (E2F2) in the apoptosis process. Downstream, E2F2 control the mRNA and protein levels of SIRT1. Finally, we find NAMPT mediates the apoptosis resistance of melanoma cells through NAMPT-E2F2-SIRT1 axis, more than NAD + -driven transcriptional program. Accordingly, our results demonstrated that NAMPT is a prognostic marker in melanoma, and the identificationofNAMPT-E2F2-SIRT1 pathway establishes another link between NAMPT and apoptosis events in melanoma, with therapeutic implications for this deadly cancer. Copyright © 2017 Elsevier Inc. All rights reserved.

Exacerbating Effects of Human Parvovirus B19 NS1 on Liver Fibrosis in NZB/W F1 Mice

PubMed Central

Hsu, Tsai-Ching; Tsai, Chun-Chou; Chiu, Chun-Ching; Hsu, Jeng-Dong; Tzang, Bor-Show

2013-01-01

Systemic lupus erythematosus (SLE) is an autoimmune disorder with unknown etiology that impacts various organs including liver. Recently, human parvovirus B19 (B19) is recognized to exacerbate SLE. However, the effects of B19 on liver in SLE are still unclear. Herein we aimed to investigate the effects of B19 on liver in NZB/W F1 mice by injecting subcutaneously with PBS, recombinant B19 NS1, VP1u or VP2, respectively. Our experimental results revealed that B19 NS1 protein significantly enhanced the TGF-β/Smad fibrotic signaling by increasing the expressions of TGF-β, Smad2/3, phosphorylated Smad2/3, Smad4 and Sp1. The consequent fibrosis-related proteins, PAI-1 and α-SMA, were also significantly induced in livers of NZB/W F1 mice receiving B19 NS1 protein. Accordingly, markedly increased collagen deposition was also observed in livers of NZB/W F1 mice receiving B19 NS1 protein. However, no significant difference was observed in livers of NZB/W F1 mice receiving B19 VP1u or VP2 as compared to the controls. These findings indicate that B19 NS1 plays a crucial role in exacerbating liver fibrosis in NZB/W F1 mice through enhancing the TGF-â/Smad fibrotic signaling. PMID:23840852

ATM-dependent E2F1 accumulation in the nucleolus is an indicator of ribosomal stress in early response to DNA damage

PubMed Central

Jin, Ya-Qiong; An, Guo-Shun; Ni, Ju-Hua; Li, Shu-Yan; Jia, Hong-Ti

2014-01-01

The nucleolus plays a major role in ribosome biogenesis. Most genotoxic agents disrupt nucleolar structure and function, which results in the stabilization/activation of p53, inducing cell cycle arrest or apoptosis. Likewise, transcription factor E2F1 as a DNA damage responsive protein also plays roles in cell cycle arrest, DNA repair, or apoptosis in response to DNA damage through transcriptional response and protein–protein interaction. Furthermore, E2F1 is known to be involved in regulating rRNA transcription. However, how E2F1 displays in coordinating DNA damage and nucleolar stress is unclear. In this study, we demonstrate that ATM-dependent E2F1 accumulation in the nucleolus is a characteristic feature of nucleolar stress in early response to DNA damage. We found that at the early stage of DNA damage, E2F1 accumulation in the nucleolus was an ATM-dependent and a common event in p53-suficient and -deficient cells. Increased nucleolar E2F1 was sequestered by the nucleolar protein p14ARF, which repressed E2F1-dependent rRNA transcription initiation, and was coupled with S phase. Our data indicate that early accumulation of E2F1 in the nucleolus is an indicator for nucleolar stress and a component of ATM pathway, which presumably buffers elevation of E2F1 in the nucleoplasm and coordinates the diversifying mechanisms of E2F1 acts in cell cycle progression and apoptosis in early response to DNA damage. PMID:24675884

ATM-dependent E2F1 accumulation in the nucleolus is an indicator of ribosomal stress in early response to DNA damage.

PubMed

Jin, Ya-Qiong; An, Guo-Shun; Ni, Ju-Hua; Li, Shu-Yan; Jia, Hong-Ti

2014-01-01

The nucleolus plays a major role in ribosome biogenesis. Most genotoxic agents disrupt nucleolar structure and function, which results in the stabilization/activation of p53, inducing cell cycle arrest or apoptosis. Likewise, transcription factor E2F1 as a DNA damage responsive protein also plays roles in cell cycle arrest, DNA repair, or apoptosis in response to DNA damage through transcriptional response and protein-protein interaction. Furthermore, E2F1 is known to be involved in regulating rRNA transcription. However, how E2F1 displays in coordinating DNA damage and nucleolar stress is unclear. In this study, we demonstrate that ATM-dependent E2F1 accumulation in the nucleolus is a characteristic feature of nucleolar stress in early response to DNA damage. We found that at the early stage of DNA damage, E2F1 accumulation in the nucleolus was an ATM-dependent and a common event in p53-suficient and -deficient cells. Increased nucleolar E2F1 was sequestered by the nucleolar protein p14ARF, which repressed E2F1-dependent rRNA transcription initiation, and was coupled with S phase. Our data indicate that early accumulation of E2F1 in the nucleolus is an indicator for nucleolar stress and a component of ATM pathway, which presumably buffers elevation of E2F1 in the nucleoplasm and coordinates the diversifying mechanisms of E2F1 acts in cell cycle progression and apoptosis in early response to DNA damage.

Word Frequency Analysis. MOS: 91E. Skill Levels 1 & 2.

DTIC Science & Technology

1981-05-01

QUALITY 2 QUART I QUIET..AIR I READY 2 RECORD-DENfAC 2 REDUCE 2 REMOVAL 2 REPLACE 2 REPORTED 2 REPRODUCTION I REQUIRES 2 RESERVOIR 2 RESIDUE 2...IVE 14 (- IVF ; I GLASS * Gk 1 - S r,?AVxAL~v GkA46 3 GREASE I.~~1 I. .U6F3tRi~E GFIEV INC I~. ot tit I11 rl (1w: 1FEE Aj~P~ S-.AV IAG F PI Hll tUSI

Detection of Hearing Loss Using 2f2-f1 and 2f1-f2 Distortion-Product Otoacoustic Emissions

ERIC Educational Resources Information Center

Fitzgerald, Tracy S.; Prieve, Beth A.

2005-01-01

Although many distortion-product otoacoustic emissions (DPOAEs) may be measured in the ear canal in response to 2 pure tone stimuli, the majority of clinical studies have focused exclusively on the DPOAE at the frequency 2f1-f2. This study investigated another DPOAE, 2f2-f1, in an attempt to determine the following: (a) the optimal stimulus…

Transcription factors ETF, E2F, and SP-1 are involved in cytokine-independent proliferation of murine hepatocytes.

PubMed

Zellmer, Sebastian; Schmidt-Heck, Wolfgang; Godoy, Patricio; Weng, Honglei; Meyer, Christoph; Lehmann, Thomas; Sparna, Titus; Schormann, Wiebke; Hammad, Seddik; Kreutz, Clemens; Timmer, Jens; von Weizsäcker, Fritz; Thürmann, Petra A; Merfort, Irmgard; Guthke, Reinhard; Dooley, Steven; Hengstler, Jan G; Gebhardt, Rolf

2010-12-01

The cellular basis of liver regeneration has been intensely investigated for many years. However, the mechanisms initiating hepatocyte "plasticity" and priming for proliferation are not yet fully clear. We investigated alterations in gene expression patterns during the first 72 hours of C57BL/6N mouse hepatocyte culture on collagen monolayers (CM), which display a high basal frequency of proliferation in the absence of cytokines. Although many metabolic genes were down-regulated, genes related to mitogen-activated protein kinase (MAPK) signaling and cell cycle were up-regulated. The latter genes showed an overrepresentation of transcription factor binding sites (TFBS) for ETF (TEA domain family member 2), E2F1 (E2F transcription factor 1), and SP-1 (Sp1 transcription factor) (P < 0.001), all depending on MAPK signaling. Time-dependent increase of ERK1/2 phosphorylation occurred during the first 48 hours (and beyond) in the absence of cytokines, accompanied by an enhanced bromodeoxyuridine labeling index of 20%. The MEK inhibitor PD98059 blunted these effects indicating MAPK signaling as major trigger for this cytokine-independent proliferative response. In line with these in vitro findings, liver tissue of mice challenged with CCl(4) displayed hepatocytes with intense p-ERK1/2 staining and nuclear SP-1 and E2F1 expression. Furthermore, differentially expressed genes in mice after partial hepatectomy contained overrepresented TFBS for ETF, E2F1, and SP-1 and displayed increased expression of E2F1. Cultivation of murine hepatocytes on CM primes cells for proliferation through cytokine-independent activation of MAPK signaling. The transcription factors ETF, E2F1, and SP-1 seem to play a pronounced role in mediating proliferation-dependent differential gene expression. Similar events, but on a shorter time-scale, occur very early after liver damage in vivo. Copyright © 2010 American Association for the Study of Liver Diseases.

Essential role for Stat5a/b in myeloproliferative neoplasms induced by BCR-ABL1 and JAK2V617F in mice

PubMed Central

Walz, Christoph; Ahmed, Wesam; Lazarides, Katherine; Betancur, Monica; Patel, Nihal; Hennighausen, Lothar; Zaleskas, Virginia M.

2012-01-01

STAT5 proteins are constitutively activated in malignant cells from many patients with leukemia, including the myeloproliferative neoplasms (MPNs) chronic myeloid leukemia (CML) and polycythemia vera (PV), but whether STAT5 is essential for the pathogenesis of these diseases is not known. In the present study, we used mice with a conditional null mutation in the Stat5a/b gene locus to determine the requirement for STAT5 in MPNs induced by BCR-ABL1 and JAK2V617F in retroviral transplantation models of CML and PV. Loss of one Stat5a/b allele resulted in a decrease in BCR-ABL1–induced CML-like MPN and the appearance of B-cell acute lymphoblastic leukemia, whereas complete deletion of Stat5a/b prevented the development of leukemia in primary recipients. However, BCR-ABL1 was expressed and active in Stat5-null leukemic stem cells, and Stat5 deletion did not prevent progression to lymphoid blast crisis or abolish established B-cell acute lymphoblastic leukemia. JAK2V617F failed to induce polycythemia in recipients after deletion of Stat5a/b, although the loss of STAT5 did not prevent the development of myelofibrosis. These results demonstrate that STAT5a/b is essential for the induction of CML-like leukemia by BCR-ABL1 and of polycythemia by JAK2V617F, and validate STAT5a/b and the genes they regulate as targets for therapy in these MPNs. PMID:22234689

fMRI orientation decoding in V1 does not require global maps or globally coherent orientation stimuli.

PubMed

Alink, Arjen; Krugliak, Alexandra; Walther, Alexander; Kriegeskorte, Nikolaus

2013-01-01

The orientation of a large grating can be decoded from V1 functional magnetic resonance imaging (fMRI) data, even at low resolution (3-mm isotropic voxels). This finding has suggested that columnar-level neuronal information might be accessible to fMRI at 3T. However, orientation decodability might alternatively arise from global orientation-preference maps. Such global maps across V1 could result from bottom-up processing, if the preferences of V1 neurons were biased toward particular orientations (e.g., radial from fixation, or cardinal, i.e., vertical or horizontal). Global maps could also arise from local recurrent or top-down processing, reflecting pre-attentive perceptual grouping, attention spreading, or predictive coding of global form. Here we investigate whether fMRI orientation decoding with 2-mm voxels requires (a) globally coherent orientation stimuli and/or (b) global-scale patterns of V1 activity. We used opposite-orientation gratings (balanced about the cardinal orientations) and spirals (balanced about the radial orientation), along with novel patch-swapped variants of these stimuli. The two stimuli of a patch-swapped pair have opposite orientations everywhere (like their globally coherent parent stimuli). However, the two stimuli appear globally similar, a patchwork of opposite orientations. We find that all stimulus pairs are robustly decodable, demonstrating that fMRI orientation decoding does not require globally coherent orientation stimuli. Furthermore, decoding remained robust after spatial high-pass filtering for all stimuli, showing that fine-grained components of the fMRI patterns reflect visual orientations. Consistent with previous studies, we found evidence for global radial and vertical preference maps in V1. However, these were weak or absent for patch-swapped stimuli, suggesting that global preference maps depend on globally coherent orientations and might arise through recurrent or top-down processes related to the perception of

The Cdk4-E2f1 pathway regulates early pancreas development by targeting Pdx1+ progenitors and Ngn3+ endocrine precursors

PubMed Central

Kim, So Yoon; Rane, Sushil G.

2011-01-01

Cell division and cell differentiation are intricately regulated processes vital to organ development. Cyclin-dependent kinases (Cdks) are master regulators of the cell cycle that orchestrate the cell division and differentiation programs. Cdk1 is essential to drive cell division and is required for the first embryonic divisions, whereas Cdks 2, 4 and 6 are dispensable for organogenesis but vital for tissue-specific cell development. Here, we illustrate an important role for Cdk4 in regulating early pancreas development. Pancreatic development involves extensive morphogenesis, proliferation and differentiation of the epithelium to give rise to the distinct cell lineages of the adult pancreas. The cell cycle molecules that specify lineage commitment within the early pancreas are unknown. We show that Cdk4 and its downstream transcription factor E2f1 regulate mouse pancreas development prior to and during the secondary transition. Cdk4 deficiency reduces embryonic pancreas size owing to impaired mesenchyme development and fewer Pdx1+ pancreatic progenitor cells. Expression of activated Cdk4R24C kinase leads to increased Nkx2.2+ and Nkx6.1+ cells and a rise in the number and proliferation of Ngn3+ endocrine precursors, resulting in expansion of the β cell lineage. We show that E2f1 binds and activates the Ngn3 promoter to modulate Ngn3 expression levels in the embryonic pancreas in a Cdk4-dependent manner. These results suggest that Cdk4 promotes β cell development by directing E2f1-mediated activation of Ngn3 and increasing the pool of endocrine precursors, and identify Cdk4 as an important regulator of early pancreas development that modulates the proliferation potential of pancreatic progenitors and endocrine precursors. PMID:21490060

A Novel P1B-type Mn2+-transporting ATPase Is Required for Secreted Protein Metallation in Mycobacteria*

PubMed Central

Padilla-Benavides, Teresita; Long, Jarukit E.; Raimunda, Daniel; Sassetti, Christopher M.; Argüello, José M.

2013-01-01

Transition metals are central for bacterial virulence and host defense. P1B-ATPases are responsible for cytoplasmic metal efflux and play roles either in limiting cytosolic metal concentrations or in the maturation of secreted metalloproteins. The P1B-ATPase, CtpC, is required for Mycobacterium tuberculosis survival in a mouse model (Sassetti, C. M., and Rubin, E. J. (2003) Genetic requirements for mycobacterial survival during infection. Proc. Natl. Acad. Sci. U.S.A. 100, 12989–12994). CtpC prevents Zn2+ toxicity, suggesting a role in Zn2+ export from the cytosol (Botella, H., Peyron, P., Levillain, F., Poincloux, R., Poquet, Y., Brandli, I., Wang, C., Tailleux, L., Tilleul, S., Charriere, G. M., Waddell, S. J., Foti, M., Lugo-Villarino, G., Gao, Q., Maridonneau-Parini, I., Butcher, P. D., Castagnoli, P. R., Gicquel, B., de Chastellièr, C., and Neyrolles, O. (2011) Mycobacterial P1-type ATPases mediate resistance to zinc poisoning in human macrophages. Cell Host Microbe 10, 248–259). However, key metal-coordinating residues and the overall structure of CtpC are distinct from Zn2+-ATPases. We found that isolated CtpC has metal-dependent ATPase activity with a strong preference for Mn2+ over Zn2+. In vivo, CtpC is unable to complement Escherichia coli lacking a functional Zn2+-ATPase. Deletion of M. tuberculosis or Mycobacterium smegmatis ctpC leads to cytosolic Mn2+ accumulation but no alterations in other metals levels. Whereas ctpC-deficient M. tuberculosis is sensitive to extracellular Zn2+, the M. smegmatis mutant is not. Both ctpC mutants are sensitive to oxidative stress, which might explain the Zn2+-sensitive phenotype of the M. tuberculosis ctpC mutant. CtpC is a high affinity/slow turnover ATPase, suggesting a role in protein metallation. Consistent with this hypothesis, mutation of CtpC leads to a decrease of Mn2+ bound to secreted proteins and of the activity of secreted Fe/Mn-superoxide dismutase, particularly in M. smegmatis. Alterations in the

26 CFR 1.410(b)-1 - Minimum coverage requirements (before 1994).

Code of Federal Regulations, 2013 CFR

2013-04-01

... plan satisfies section 410(b)(1) if it satisfies the requirements of paragraph (b)(1) or (b)(2) of this... this subparagraph if it benefits— (i) Seventy percent or more of all employees, or (ii) Eighty percent... requirements of section 410(b)(1) and this subparagraph if it benefits such employees as qualify under a...

Domain structure and reorientation in CoF e2O4

NASA Astrophysics Data System (ADS)

Abes, M.; Koops, C. T.; Hrkac, S. B.; McCord, J.; Urs, N. O.; Wolff, N.; Kienle, L.; Ren, W. J.; Bouchenoire, L.; Murphy, B. M.; Magnussen, O. M.

2016-05-01

The microscopic processes underlying magnetostriction in ferrites were studied for the case of CoF e2O4 single crystals by high-resolution in situ x-ray diffraction and complementary magnetic microscopy techniques. The data support the reports of Yang and Ren [Phys. Rev. B 77, 014407 (2008), 10.1103/PhysRevB.77.014407] that magnetostriction in these materials originates from the switching of crystallographic domains, similar to ferroelastic or ferroelectric domain switching, and reveals the presence of two coexisting tetragonal spinel structures, corresponding to domains of high and of low strain. The latter alternate in the crystal, separated by 90° domain boundaries, and can be explained by the effect of internal stress emerging during the transition into the ferrimagnetic phase. During magnetization of the sample two structural transitions are observed: a conversion of the transversal into axial domains at 1.95 kOe and a growth of the high-strain domains at the cost of the low-strain axial domains at 2.8 kOe. These microscopic changes are in good agreement with the macroscopic magnetization and magnetostriction behavior of CoF e2O4 .

Touch responsiveness in zebrafish requires voltage-gated calcium channel 2.1b

PubMed Central

Low, Sean E.; Woods, Ian G.; Lachance, Mathieu; Ryan, Joel; Saint-Amant, Louis

2012-01-01

The molecular and physiological basis of the touch-unresponsive zebrafish mutant fakir has remained elusive. Here we report that the fakir phenotype is caused by a missense mutation in the gene encoding voltage-gated calcium channel 2.1b (CACNA1Ab). Injection of RNA encoding wild-type CaV2.1 restores touch responsiveness in fakir mutants, whereas knockdown of CACNA1Ab via morpholino oligonucleotides recapitulates the fakir mutant phenotype. Fakir mutants display normal current-evoked synaptic communication at the neuromuscular junction but have attenuated touch-evoked activation of motor neurons. NMDA-evoked fictive swimming is not affected by the loss of CaV2.1b, suggesting that this channel is not required for motor pattern generation. These results, coupled with the expression of CACNA1Ab by sensory neurons, suggest that CaV2.1b channel activity is necessary for touch-evoked activation of the locomotor network in zebrafish. PMID:22490555

Activation of the Rb/E2F1 pathway by the nonproliferative p38 MAPK during Fas (APO1/CD95)-mediated neuronal apoptosis.

PubMed

Hou, Sheng T; Xie, Xiaoqi; Baggley, Anne; Park, David S; Chen, Gao; Walker, Teena

2002-12-13

Aberrant activation of the Rb/E2F1 pathway in cycling cells, in response to mitogenic or nonmitogenic stress signals, leads to apoptosis through hyperphosphorylation of Rb. To test whether in postmitotic neurons the Rb/E2F1 pathway can be activated by the nonmitogenic stress signaling, we examined the role of the p38 stress-activated protein kinase (SAPK) in regulating Rb phosphorylation in response to Fas (CD95/APO1)-mediated apoptosis of cultured cerebellar granule neurons (CGNs). Anti-Fas antibody induced a dramatic and early activation of p38. Activated p38 was correlated with the induction of hyperphosphorylation of both endogenous and exogenous Rb. The p38-selective inhibitor, SB203580, attenuated such an increase in pRb phosphorylation and significantly protected CGNs from Fas-induced apoptosis. The cyclin-dependent kinase-mediated Rb phosphorylation played a lesser role in this neuronal death paradigm, since cyclin-dependent kinase inhibitors, such as olomoucine, roscovitine, and flavopiridol, did not significantly prevent anti-Fas antibody-evoked neuronal apoptosis. Hyperphosphorylation of Rb by p38 SAPK resulted in the release of Rb-bound E2F1. Increased E2F1 modulated neuronal apoptosis, since E2F1-/- CGNs were significantly less susceptible to Fas-mediated apoptosis in comparison with the wild-type CGNs. Taken together, these studies demonstrate that neuronal Rb/E2F1 is modulated by the nonproliferative p38 SAPK in Fas-mediated neuronal apoptosis.

26 CFR 1.411(b)-1 - Accrued benefit requirements.

Code of Federal Regulations, 2010 CFR

2010-04-01

... account of increasing age or service, see paragraph (d)(3) of this section. (viii) Separate accounting. For rules relating to requirements for separate accounting, see paragraph (e) of this section. (ix... participant in the J Corporation's plan on January 1, 1980. As of December 31, 1990, B's compensation history...

Word Frequency Analysis MOS: 15E. Skill Levels 1 and 2.

DTIC Science & Technology

1982-05-01

AR 34 ARE I I AREA1 L 5 15 ARM 1 .: 𔃻A’FNT 3 AROL D 25 AS 12 ASSEI 3LE 12 ASSEPALED11 iES b8 ASSEMBLY 4 ASSISTA CE27 ASSISTANT13 1’A T . SSISTED 29 ...CABLE31 CA3Lr.P 2, C.ABLES . . 1 L.BLI"IG I CAM C>; 4 CA’"UT 2 CANvA S 29 CAP2 CYPSCRE ,S 4 CAPTIVE A , L I AR o,7 CAREFiULLY .... CARRY IG 2 LA.TELL 1...1 (l. 5 1 jS I E (f r I FR I 5 IP E V PEET ~ (F I 4 3 E X P N A WL S q 6 XPL11S VE E EXPIUSIVS I z~ SE 17 *.!GU I 5 EXTE nrEC 3 WI’S1. lltj 3 29 ~Il

PopF1 and PopF2, Two Proteins Secreted by the Type III Protein Secretion System of Ralstonia solanacearum, Are Translocators Belonging to the HrpF/NopX Family†

PubMed Central

Meyer, Damien; Cunnac, Sébastien; Guéneron, Mareva; Declercq, Céline; Van Gijsegem, Frédérique; Lauber, Emmanuelle; Boucher, Christian; Arlat, Matthieu

2006-01-01

Ralstonia solanacearum GMI1000 is a gram-negative plant pathogen which contains an hrp gene cluster which codes for a type III protein secretion system (TTSS). We identified two novel Hrp-secreted proteins, called PopF1 and PopF2, which display similarity to one another and to putative TTSS translocators, HrpF and NopX, from Xanthomonas spp. and rhizobia, respectively. They also show similarities with TTSS translocators of the YopB family from animal-pathogenic bacteria. Both popF1 and popF2 belong to the HrpB regulon and are required for the interaction with plants, but PopF1 seems to play a more important role in virulence and hypersensitive response (HR) elicitation than PopF2 under our experimental conditions. PopF1 and PopF2 are not necessary for the secretion of effector proteins, but they are required for the translocation of AvrA avirulence protein into tobacco cells. We conclude that PopF1 and PopF2 are type III translocators belonging to the HrpF/NopX family. The hrpF gene of Xanthomonas campestris pv. campestris partially restored HR-inducing ability to popF1 popF2 mutants of R. solanacearum, suggesting that translocators of R. solanacearum and Xanthomonas are functionally conserved. Finally, R. solanacearum strain UW551, which does not belong to the same phylotype as GMI1000, also possesses two putative translocator proteins. However, although one of these proteins is clearly related to PopF1 and PopF2, the other seems to be different and related to NopX proteins, thus showing that translocators might be variable in R. solanacearum. PMID:16788199

Essential but partially redundant roles for POU4F1/Brn-3a and POU4F2/Brn-3b transcription factors in the developing heart

PubMed Central

Maskell, Lauren J; Qamar, Kashif; Babakr, Aram A; Hawkins, Thomas A; Heads, Richard J; Budhram-Mahadeo, Vishwanie S

2017-01-01

Congenital heart defects contribute to embryonic or neonatal lethality but due to the complexity of cardiac development, the molecular changes associated with such defects are not fully understood. Here, we report that transcription factors (TFs) Brn-3a (POU4F1) and Brn-3b (POU4F2) are important for normal cardiac development. Brn-3a directly represses Brn-3b promoter in cardiomyocytes and consequently Brn-3a knockout (KO) mutant hearts express increased Brn-3b mRNA during mid-gestation, which is linked to hyperplastic growth associated with elevated cyclin D1, a known Brn-3b target gene. However, during late gestation, Brn-3b can cooperate with p53 to enhance transcription of pro-apoptotic genes e.g. Bax, thereby increasing apoptosis and contribute to morphological defects such as non-compaction, ventricular wall/septal thinning and increased crypts/fissures, which may cause lethality of Brn-3a KO mutants soon after birth. Despite this, early embryonic lethality in e9.5 double KO (Brn-3a−/− : Brn-3b−/−) mutants indicate essential functions with partial redundancy during early embryogenesis. High conservation between mammals and zebrafish (ZF) Brn-3b (87%) or Brn-3a (76%) facilitated use of ZF embryos to study potential roles in developing heart. Double morphant embryos targeted with morpholino oligonucleotides to both TFs develop significant cardiac defects (looping abnormalities and valve defects) suggesting essential roles for Brn-3a and Brn-3b in developing hearts. PMID:28594399

KDM4A Coactivates E2F1 to Regulate the PDK-Dependent Metabolic Switch between Mitochondrial Oxidation and Glycolysis.

PubMed

Wang, Ling-Yu; Hung, Chiu-Lien; Chen, Yun-Ru; Yang, Joy C; Wang, Junjian; Campbell, Mel; Izumiya, Yoshihiro; Chen, Hong-Wu; Wang, Wen-Ching; Ann, David K; Kung, Hsing-Jien

2016-09-13

The histone lysine demethylase KDM4A/JMJD2A has been implicated in prostate carcinogenesis through its role in transcriptional regulation. Here, we describe KDM4A as a E2F1 coactivator and demonstrate a functional role for the E2F1-KDM4A complex in the control of tumor metabolism. KDM4A associates with E2F1 on target gene promoters and enhances E2F1 chromatin binding and transcriptional activity, thereby modulating the transcriptional profile essential for cancer cell proliferation and survival. The pyruvate dehydrogenase kinases (PDKs) PDK1 and PDK3 are direct targets of KDM4A and E2F1 and modulate the switch between glycolytic metabolism and mitochondrial oxidation. Downregulation of KDM4A leads to elevated activity of pyruvate dehydrogenase and mitochondrial oxidation, resulting in excessive accumulation of reactive oxygen species. The altered metabolic phenotypes can be partially rescued by ectopic expression of PDK1 and PDK3, indicating a KDM4A-dependent tumor metabolic regulation via PDK. Our results suggest that KDM4A is a key regulator of tumor metabolism and a potential therapeutic target for prostate cancer. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

The use of Endopep-MS to detect multiple subtypes of botulinum neurotoxins A, B, E, and F

NASA Astrophysics Data System (ADS)

Kalb, Suzanne R.; Smith, Theresa J.; Moura, Hercules; Hill, Karen; Lou, Jianlong; Geren, Isin N.; Garcia-Rodriguez, Consuelo; Marks, James D.; Smith, Leonard A.; Pirkle, James L.; Barr, John R.

2008-12-01

Botulinum neurotoxins (BoNTs) cause the disease botulism, which can be lethal if untreated. Rapid determination of exposure to BoNT is an important public health goal. Previous work in our laboratory focused on the development of Endopep-MS, a mass spectrometry-based endopeptidase method for detecting and differentiating BoNT A-G in buffer and BoNT A, B, E, and F in clinical samples. We introduce here the use of Endopep-MS to detect non-commercial subtypes of BoNT A, B, E, and F which have been associated with botulism outbreaks. We have now tested and successfully detected 15 of the 17 known subtypes of BoNT A, B, E, and F by Endopep-MS. Extraction of BoNT A and B from a complex mixture prior to analysis is accomplished by using monoclonal antibodies specific for the catalytically inactive heavy chain of the toxin. These antibodies have high-binding affinities and do not interfere with the catalytic activity of the light chain resulting in a lower limit of detection for BoNT A and B than previously reported. We also report for the first time limits of detection for BoNT A2, A3, B2, and bivalent B using Endopep-MS.

NASA's F-15B Research Testbed aircraft flies in the supersonic shock wave of a U.S. Navy F-5E as par

NASA Technical Reports Server (NTRS)

2002-01-01

NASA's F-15B Research Testbed aircraft recently flew in the supersonic shock wave of a U.S. Navy F-5E in support of the F-5 Shaped Sonic Boom Demonstration (SSBD) project, part of the Defense Advanced Research Projects Agency's (DARPA) Quiet Supersonic Platform (QSP) program. The flights originated from the NASA Dryden Flight Research Center at Edwards, California. Four flights were flown in order to measure the F-5E's near-field (close-up) sonic boom signature at Mach 1.4, during which more than 50 shockwave patterns were measured at distances as close as 100 feet below the F-5E.

Repression of transcriptional activity of C/EBPalpha by E2F-dimerization partner complexes.

PubMed

Zaragoza, Katrin; Bégay, Valérie; Schuetz, Anja; Heinemann, Udo; Leutz, Achim

2010-05-01

The transcription factor CCAAT/enhancer-binding protein alpha (C/EBPalpha) coordinates proliferation arrest and the differentiation of myeloid progenitors, adipocytes, hepatocytes, keratinocytes, and cells of the lung and placenta. C/EBPalpha transactivates lineage-specific differentiation genes and inhibits proliferation by repressing E2F-regulated genes. The myeloproliferative C/EBPalpha BRM2 mutant serves as a paradigm for recurrent human C-terminal bZIP C/EBPalpha mutations that are involved in acute myeloid leukemogenesis. BRM2 fails to repress E2F and to induce adipogenesis and granulopoiesis. The data presented here show that, independently of pocket proteins, C/EBPalpha interacts with the dimerization partner (DP) of E2F and that C/EBPalpha-E2F/DP interaction prevents both binding of C/EBPalpha to its cognate sites on DNA and transactivation of C/EBP target genes. The BRM2 mutant, in addition, exhibits enhanced interaction with E2F-DP and reduced affinity toward DNA and yet retains transactivation potential and differentiation competence that becomes exposed when E2F/DP levels are low. Our data suggest a tripartite balance between C/EBPalpha, E2F/DP, and pocket proteins in the control of proliferation, differentiation, and tumorigenesis.

48 CFR 847.303-1 - F.o.b. origin.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false F.o.b. origin. 847.303-1 Section 847.303-1 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS CONTRACT MANAGEMENT TRANSPORTATION Transportation in Supply Contracts 847.303-1 F.o.b. origin. Shipments falling within this category must be shipped on a bill of...

Silencing of E2F3 suppresses tumor growth of Her2+ breast cancer cells by restricting mitosis.

PubMed

Lee, Miyoung; Oprea-Ilies, Gabriela; Saavedra, Harold I

2015-11-10

The E2F transcriptional activators E2F1, E2F2 and E2F3a regulate many important cellular processes, including DNA replication, apoptosis and centrosome duplication. Previously, we demonstrated that silencing E2F1 or E2F3 suppresses centrosome amplification (CA) and chromosome instability (CIN) in Her2+ breast cancer cells without markedly altering proliferation. However, it is unknown whether and how silencing a single E2F activator, E2F3, affects malignancy of human breast cancer cells. Thus, we injected HCC1954 Her2+ breast cancer cells silenced for E2F3 into mammary fat pads of immunodeficient mice and demonstrated that loss of E2F3 retards tumor growth. Surprisingly, silencing of E2F3 led to significant reductions in mitotic indices relative to vector controls, while the percentage of cells undergoing S phase were not affected. Nek2 is a mitotic kinase commonly upregulated in breast cancers and a critical regulator of Cdk4- or E2F-mediated CA. In this report, we found that Nek2 overexpression rescued back the CA caused by silencing of shE2F3. However, the effects of Nek2 overexpression in affecting tumor growth rates of shE2F3 and shE2F3; GFP cells were inconclusive. Taken together, our results indicate that E2F3 silencing decreases mammary tumor growth by reducing percentage of cells undergoing mitosis.

Telomerase Reverse Transcriptase Deficiency Prevents Neointima Formation Through Chromatin Silencing of E2F1 Target Genes.

PubMed

Endorf, Elizabeth B; Qing, Hua; Aono, Jun; Terami, Naoto; Doyon, Geneviève; Hyzny, Eric; Jones, Karrie L; Findeisen, Hannes M; Bruemmer, Dennis

2017-02-01

Aberrant proliferation of smooth muscle cells (SMC) in response to injury induces pathological vascular remodeling during atherosclerosis and neointima formation. Telomerase is rate limiting for tissue renewal and cell replication; however, the physiological role of telomerase in vascular diseases remains to be determined. The goal of the present study was to determine whether telomerase reverse transcriptase (TERT) affects proliferative vascular remodeling and to define the molecular mechanism by which TERT supports SMC proliferation. We first demonstrate high levels of TERT expression in replicating SMC of atherosclerotic and neointimal lesions. Using a model of guidewire-induced arterial injury, we demonstrate decreased neointima formation in TERT-deficient mice. Studies in SMC isolated from TERT-deficient and TERT overexpressing mice with normal telomere length established that TERT is necessary and sufficient for cell proliferation. TERT deficiency did not induce a senescent phenotype but resulted in G1 arrest albeit hyperphosphorylation of the retinoblastoma protein. This proliferative arrest was associated with stable silencing of the E2F1-dependent S-phase gene expression program and not reversed by ectopic overexpression of E2F1. Finally, chromatin immunoprecipitation and accessibility assays revealed that TERT is recruited to E2F1 target sites and promotes chromatin accessibility for E2F1 by facilitating the acquisition of permissive histone modifications. These data indicate a previously unrecognized role for TERT in neointima formation through epigenetic regulation of proliferative gene expression in SMC. © 2016 American Heart Association, Inc.

(2 + 1) resonant enhanced multiphoton ionization of H2 via the E,F 1Sigma(+)g state

NASA Technical Reports Server (NTRS)

Rudolph, H.; Lynch, D. L.; Dixit, S. N.; Mckoy, V.; Huo, Winifred M.

1987-01-01

In this paper, the results of ab initio calculations of photoelectron angular distributions and vibrational branching ratios for the (2 + 1) resonant enhanced multiphoton ionization (REMPI) of H2 via the E,F 1Sigma(+)g state are reported, and these are compared with the experimental data of Anderson et al. (1984). These results show that the observed non-Franck-Condon behavior is predominantly due to the R dependence of the transition matrix elements, and to a lesser degree to the energy dependence. This work presents the first molecular REMPI study employing a correlated wave function to describe the Rydberg-valence mixing in the resonant intermediate state.

Epitaxial growth of lithium fluoride on the (1 1 1) surface of CaF 2

NASA Astrophysics Data System (ADS)

Klumpp, St; Dabringhaus, H.

1999-08-01

Growth of lithium fluoride by molecular beam epitaxy on the (1 1 1) surface of calcium fluoride crystals was studied by TEM and LEED for crystal temperatures from 400 to 773 K and impinging lithium fluoride fluxes from 3×10 11 to 3×10 14 cm -2 s -1. Growth starts, usually, at the <1 1 0> steps on the (1 1 1) surface of CaF 2. For larger step distances and at later growth stages also growth on the terraces between the steps is found. Preferably, longish, roof-like crystallites are formed, which can be interpreted by growth of LiF(2 0 1¯)[0 1 0] parallel to CaF 2(1 1 1)[ 1¯ 0 1]. To a lesser extent square crystallites, i.e. growth with LiF(0 0 1), and, rarely, three-folded pyramidal crystallites, i.e. growth with LiF(1 1 1) parallel to CaF 2(1 1 1), are observed. While the pyramidal crystallites show strict epitaxial orientation with LiF[ 1¯ 0 1]‖CaF 2[ 1¯ 0 1] and LiF[ 1¯ 0 1]‖CaF 2[1 2¯ 1], only about 80% of the square crystallites exhibit an epitaxial alignment, where LiF[1 0 0]‖CaF 2[ 1¯ 0 1] is preferred to LiF[1 1 0]‖CaF 2[ 1¯ 0 1]. The epitaxial relationships are discussed on the basis of theoretically calculated adsorption positions of the lithium fluoride monomer and dimer on the terrace and at the steps of the CaF 2(1 1 1) surface.

A lentiviral vector with expression controlled by E2F-1: A potential tool for the study and treatment of proliferative diseases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strauss, Bryan E.; Patricio, Juliana Rotelli; Program in Biotechnology, University of Sao Paulo

2006-10-06

We have constructed a lentiviral vector with expression limited to cells presenting active E2F-1 protein, a potential advantage for gene therapy of proliferative diseases. For the FE2FLW vector, the promoter region of the human E2F-1 gene was utilized to drive expression of luciferase cDNA, included as a reporter of viral expression. Primary, immortalized, and transformed cells were transduced with the FE2FLW vector and cell cycle alterations were induced with serum starvation/replacement, contact inhibition or drug treatment, revealing cell cycle-dependent changes in reporter activity. Forced E2F-1 expression, but not E2F-2 or E2F-3, increased reporter activity, indicating a major role for thismore » factor in controlling expression from the FE2FLW virus. We show the utility of this vector as a reporter of E2F-1 and proliferation-dependent cellular alterations upon cytotoxic/cytostatic treatment, such as the introduction of tumor suppressor genes. We propose that the FE2FLW vector may be a starting point for the development of gene therapy strategies for proliferative diseases, such as cancer or restinosis.« less

M2-F1 cockpit

NASA Technical Reports Server (NTRS)

1963-01-01

aircraft and released. These initial car-tow tests produced enough flight data about the M2-F1 to proceed with flights behind the C-47 tow plane at greater altitudes. The C-47 took the craft to an altitude of 12,000 where free flights back to Rogers Dry Lake began. Pilot for the first series of flights of the M2-F1 was NASA research pilot Milt Thompson. Typical glide flights with the M2-F1 lasted about two minutes and reached speeds of 110 to l20 mph. A small solid landing rocket, referred to as the 'instant L/D rocket,' was installed in the rear base of the M2-F1. This rocket, which could be ignited by the pilot, provided about 250 pounds of thrust for about 10 seconds. The rocket could be used to extend the flight time near landing if needed. More than 400 ground tows and 77 aircraft tow flights were carried out with the M2-F1. The success of Dryden's M2-F1 program led to NASA's development and construction of two heavyweight lifting bodies based on studies at NASA's Ames and Langley research centers--the M2-F2 and the HL-10, both built by the Northrop Corporation, and the U.S. Air Force's X-24 program, with an X-24A and -B built by Martin. The Lifting Body program also heavily influenced the Space Shuttle program. The M2-F1 program demonstrated the feasibility of the lifting body concept for horizontal landings of atmospheric entry vehicles. It also demonstrated a procurement and management concept for prototype flight test vehicles that produced rapid results at very low cost (approximately $50,000, excluding salaries of government employees assigned to the project).

E2F Activators Signal and Maintain Centrosome Amplification in Breast Cancer Cells

PubMed Central

Lee, Mi-Young; Moreno, Carlos S.

2014-01-01

Centrosomes ensure accurate chromosome segregation by directing spindle bipolarity. Loss of centrosome regulation results in centrosome amplification, multipolar mitosis and aneuploidy. Since centrosome amplification is common in premalignant lesions and breast tumors, it is proposed to play a central role in breast tumorigenesis, a hypothesis that remains to be tested. The coordination between the cell and centrosome cycles is of paramount importance to maintain normal centrosome numbers, and the E2Fs may be responsible for regulating these cycles. However, the role of E2F activators in centrosome amplification is unclear. Because E2Fs are deregulated in Her2+ cells displaying centrosome amplification, we addressed whether they signal this abnormal process. Knockdown of E2F1 or E2F3 in Her2+ cells decreased centrosome amplification without significantly affecting cell cycle progression, whereas the overexpression of E2F1, E2F2, or E2F3 increased centrosome amplification in MCF10A mammary epithelial cells. Our results revealed that E2Fs affect the expression of proteins, including Nek2 and Plk4, known to influence the cell/centrosome cycles and mitosis. Downregulation of E2F3 resulted in cell death and delays/blocks in cytokinesis, which was reversed by Nek2 overexpression. Nek2 overexpression enhanced centrosome amplification in Her2+ breast cancer cells silenced for E2F3, revealing a role for the E2F activators in maintaining centrosome amplification in part through Nek2. PMID:24797070

E2F activators signal and maintain centrosome amplification in breast cancer cells.

PubMed

Lee, Mi-Young; Moreno, Carlos S; Saavedra, Harold I

2014-07-01

Centrosomes ensure accurate chromosome segregation by directing spindle bipolarity. Loss of centrosome regulation results in centrosome amplification, multipolar mitosis and aneuploidy. Since centrosome amplification is common in premalignant lesions and breast tumors, it is proposed to play a central role in breast tumorigenesis, a hypothesis that remains to be tested. The coordination between the cell and centrosome cycles is of paramount importance to maintain normal centrosome numbers, and the E2Fs may be responsible for regulating these cycles. However, the role of E2F activators in centrosome amplification is unclear. Because E2Fs are deregulated in Her2(+) cells displaying centrosome amplification, we addressed whether they signal this abnormal process. Knockdown of E2F1 or E2F3 in Her2(+) cells decreased centrosome amplification without significantly affecting cell cycle progression, whereas the overexpression of E2F1, E2F2, or E2F3 increased centrosome amplification in MCF10A mammary epithelial cells. Our results revealed that E2Fs affect the expression of proteins, including Nek2 and Plk4, known to influence the cell/centrosome cycles and mitosis. Downregulation of E2F3 resulted in cell death and delays/blocks in cytokinesis, which was reversed by Nek2 overexpression. Nek2 overexpression enhanced centrosome amplification in Her2(+) breast cancer cells silenced for E2F3, revealing a role for the E2F activators in maintaining centrosome amplification in part through Nek2.

Oxidation of Methyl and Ethyl Nitrosamines by Cytochromes P450 2E1 and 2B1

PubMed Central

Chowdhury, Goutam; Calcutt, M. Wade; Nagy, Leslie D.; Guengerich, F. Peter

2012-01-01

Cytochrome P450 (P450) 2E1 is the major enzyme that oxidizes N-nitrosodimethylamine (N,N-dimethylnitrosamine, DMN), a carcinogen and also a representative of some nitrosamines formed endogenously. Oxidation of DMN by rat or human P450 2E1 to HCHO showed a high apparent intrinsic kinetic deuterium isotope effect (KIE), ≥ 8. The KIE was not attenuated in non-competitive intermolecular experiments with rat liver microsomes (DV 12.5, D(V/K) 10.9, nomenclature of Northrop, D.B. (1982) Methods Enzymol. 87, 607–625) but was with purified human P450 2E1 (DV 3.3, D(V/K) 3.7), indicating that C-H bond breaking is partially rate-limiting with human P450 2E1. With N-nitrosodiethylamine (N,N-diethylnitrosamine, DEN), the intrinsic KIE was slightly lower and was not expressed (e.g., D(V/K) 1.2) in non-competitive intermolecular experiments. The same general pattern of KIEs was also seen in the D(V/K) results with DMN and DEN for the minor products resulting from the denitrosation reactions (CH3NH2, CH3CH2NH2, and NO2−). Experiments with deuterated N-nitroso-N-methyl,N-ethylamine demonstrated that the lower KIEs associated for ethyl compared to methyl oxidation could be distinguished within a single molecule. P450 2E1 oxidized DMN and DEN to aldehydes and then to the carboxylic acids. No kinetic lags were observed in acid formation; pulse-chase experiments with carrier aldehydes showed only limited equilibration with P450 2E1-bound aldehydes, indicative of processive reactions, as reported for P450 2A6 (Chowdhury, G. et al. (2010) J. Biol. Chem. 285, 8031–8044). These same features (no lag phase for HCO2H formation, lack of equilibration in pulse-chase assays) were also seen with (rat) P450 2B1, which has lower catalytic efficiency for DMN oxidation and a larger active site. Thus, the processivity of dialkylnitrosamine oxidation appears to be shared by a number of P450s. PMID:23186213

Effect of NQO1 and CYP4F2 genotypes on warfarin dose requirements in Hispanic-Americans and African-Americans.

PubMed

Bress, Adam; Patel, Shitalben R; Perera, Minoli A; Campbell, Richard T; Kittles, Rick A; Cavallari, Larisa H

2012-12-01

The objective of this study was to determine the additional contribution of NQO1 and CYP4F2 genotypes to warfarin dose requirements across two racial groups after accounting for known clinical and genetic predictors. The following were assessed in a cohort of 260 African-Americans and 53 Hispanic-Americans: clinical data; NQO1 p.P187S (*1/*2); CYP2C9*2, *3, *5, *6, *8 and *11; CYP4F2 p.V433M; and VKORC1 c.-1639G>A genotypes. Both the CYP4F2 433M (0.23 vs 0.06; p < 0.05) and NQO1*2 (0.27 vs 0.18; p < 0.05) allele frequencies were higher in Hispanic-Americans compared with African-Americans. Multiple regression analysis in the Hispanic-American cohort revealed that each CYP4F2 433M allele was associated with a 22% increase in warfarin maintenance dose (p = 0.019). Possession of the NQO1*2 allele was associated with a 34% increase in warfarin maintenance dose (p = 0.004), while adjusting for associated genetic (CYP2C9, CYP4F2 and VKORC1) and clinical factors. In this population, the inclusion of CYP4F2 and NQO1*2 genotypes improved the dose variability explained by the model from 0.58 to 0.68 (p = 0.001), a 17% relative improvement. By contrast, there was no association between CYP4F2 or NQO1*2 genotype and therapeutic warfarin dose in African-Americans after adjusting for known genetic and clinical predictors. In our cohort of inner-city Hispanic-Americans, the CYP4F2 and NQO1*2 genotypes significantly contributed to warfarin dose requirements. If our findings are confirmed, they would suggest that inclusion of the CYP4F2 and NQO1*2 genotypes in warfarin dose prediction algorithms may improve the predictive ability of such algorithms in Hispanic-Americans.

Effect of NQO1 and CYP4F2 genotypes on warfarin dose requirements in Hispanic–Americans and African–Americans

PubMed Central

Bress, Adam; Patel, Shitalben R; Perera, Minoli A; Campbell, Richard T; Kittles, Rick A; Cavallari, Larisa H

2013-01-01

Aim The objective of this study was to determine the additional contribution of NQO1 and CYP4F2 genotypes to warfarin dose requirements across two racial groups after accounting for known clinical and genetic predictors. Patients & methods The following were assessed in a cohort of 260 African–Americans and 53 Hispanic–Americans: clinical data; NQO1 p.P187S (*1/*2); CYP2C9*2, *3, *5, *6, *8 and *11; CYP4F2 p.V433M; and VKORC1 c.-1639G>A genotypes. Results Both the CYP4F2 433M (0.23 vs 0.06; p < 0.05) and NQO1*2 (0.27 vs. 0.18; p < 0.05) allele frequencies were higher in Hispanic–Americans compared with African–Americans. Multiple regression analysis in the Hispanic–American cohort revealed that each CYP4F2 433M allele was associated with a 22% increase in warfarin maintenance dose (p = 0.019). Possession of the NQO1*2 allele was associated with a 34% increase in warfarin maintenance dose (p = 0.004), while adjusting for associated genetic (CYP2C9, CYP4F2 and VKORC1) and clinical factors. In this population, the inclusion of CYP4F2 and NQO1*2 genotypes improved the dose variability explained by the model from 0.58 to 0.68 (p = 0.001), a 17% relative improvement. By contrast, there was no association between CYP4F2 or NQO1*2 genotype and therapeutic warfarin dose in African–Americans after adjusting for known genetic and clinical predictors. Conclusion In our cohort of inner-city Hispanic–Americans, the CYP4F2 and NQO1*2 genotypes significantly contributed to warfarin dose requirements. If our findings are confirmed, they would suggest that inclusion of the CYP4F2 and NQO1*2 genotypes in warfarin dose prediction algorithms may improve the predictive ability of such algorithms in Hispanic–Americans. PMID:23215885

DEPDC1 promotes cell proliferation and tumor growth via activation of E2F signaling in prostate cancer.

PubMed

Huang, Lin; Chen, Keng; Cai, Zhao-Peng; Chen, Fu-Chao; Shen, Hui-Yong; Zhao, Wei-Hua; Yang, Song-Jie; Chen, Xu-Biao; Tang, Guo-Xue; Lin, Xi

2017-08-26

DEP domain containing 1 (DEPDC1) is recently reported to be overexpressed in several types of human cancer; however the role of DEPDC1 in prostate cancer remains to be investigated. Herein, we identified that the DEPDC1 mRNA and protein expression levels were dramatically increased in prostate cancer tissues and cell lines. Overexpression of DEPDC1 promoted, but depletion of DEPDC1 inhibited cell proliferation by regulating the G1-S phase cell cycle transition. Importantly, we found that DEPDC1 was essential for the tumor growth and formation of bone metastases of prostate cancer cells in vivo. Finally, we demonstrated that DEPDC1 interacted with E2F1 and increased its transcriptional activity, leading to hyper-activation of E2F signaling in prostate cancer cells. Our findings reveal an oncogenic role of DEPDC1 in prostate cancer progression via activation of E2F signaling, and suggest DEPDC1 might be a potential therapeutic target against the disease. Copyright © 2017 Elsevier Inc. All rights reserved.

Mitochondrial ribosomal protein S18-2 is highly expressed in endometrial cancers along with free E2F1

PubMed Central

Iurchenko, Natalia; Kovalevska, Larysa; Stip, Maria C; Budnikova, Daria; Andersson, Sonia; Polischuk, Ludmila; Buchynska, Lubov; Kashuba, Elena

2016-01-01

Endometrial cancer (EC) is one of the most frequent causes of cancer death among women in developed countries. Histopathological diagnosis and imaging techniques for EC are limited, thus new prognostic markers are needed to offer patients the best treatment and follow-up. In the present paper we showed that the level of mitochondrial ribosomal protein MRPS18-2 (S18-2) increased in EC compared with the normal endometrium and hyperplasia, based on a study of 42 patient biopsies. Importantly, high expression of free E2F1 in EC correlates well with high S18-2 expression. The EC cell line HEC-1-A, which overexpresses S18-2 constitutively, showed an increased proliferation capacity in vitro and in vivo (in SCID mice). Moreover, pan-keratin, beta-catenin and E-cadherin signals are diminished in these cells, compared to the parental HEC-1-A line, in contrast to vimentin signal that is increased. This may be associated with epithelial-mesenchymal cell transition (EMT). We conclude that high expression of S18-2 and free E2F1, and low pan-keratin, beta-catenin, and E-cadherin signals might be a good set of prognostic markers for EC. PMID:26959119

Evidence for the η(b)(2S) and observation of h(b)(1P)→η(b)(1S)γ and h(b)(2P)→η(b)(1S)γ.

PubMed

Mizuk, R; Asner, D M; Bondar, A; Pedlar, T K; Adachi, I; Aihara, H; Arinstein, K; Aulchenko, V; Aushev, T; Aziz, T; Bakich, A M; Bay, A; Belous, K; Bhardwaj, V; Bhuyan, B; Bischofberger, M; Bonvicini, G; Bozek, A; Bračko, M; Brodzicka, J; Browder, T E; Chekelian, V; Chen, A; Chen, P; Cheon, B G; Chilikin, K; Chistov, R; Cho, I-S; Cho, K; Choi, S-K; Choi, Y; Dalseno, J; Danilov, M; Doležal, Z; Drásal, Z; Drutskoy, A; Eidelman, S; Epifanov, D; Fast, J E; Gaur, V; Gabyshev, N; Garmash, A; Golob, B; Haba, J; Hara, T; Hayasaka, K; Hayashii, H; Horii, Y; Hoshi, Y; Hou, W-S; Hsiung, Y B; Hyun, H J; Iijima, T; Ishikawa, A; Itoh, R; Iwabuchi, M; Iwasaki, Y; Iwashita, T; Jaegle, I; Julius, T; Kang, J H; Kapusta, P; Kawasaki, T; Kim, H J; Kim, H O; Kim, J H; Kim, K T; Kim, M J; Kim, Y J; Kinoshita, K; Ko, B R; Koblitz, S; Kodyš, P; Korpar, S; Kouzes, R T; Križan, P; Krokovny, P; Kuhr, T; Kumita, T; Kuzmin, A; Kwon, Y-J; Lange, J S; Lee, S-H; Li, J; Libby, J; Liu, C; Liu, Y; Liu, Z Q; Liventsev, D; Louvot, R; Matvienko, D; McOnie, S; Miyabayashi, K; Miyata, H; Mohanty, G B; Mohapatra, D; Moll, A; Muramatsu, N; Mussa, R; Nakao, M; Natkaniec, Z; Ng, C; Nishida, S; Nishimura, K; Nitoh, O; Nozaki, T; Ohshima, T; Okuno, S; Olsen, S L; Onuki, Y; Pakhlov, P; Pakhlova, G; Park, C W; Park, H; Pestotnik, R; Petrič, M; Piilonen, L E; Poluektov, A; Röhrken, M; Sakai, Y; Sandilya, S; Santel, D; Sanuki, T; Sato, Y; Schneider, O; Schwanda, C; Senyo, K; Seon, O; Sevior, M E; Shapkin, M; Shen, C P; Shibata, T-A; Shiu, J-G; Shwartz, B; Sibidanov, A; Simon, F; Smerkol, P; Sohn, Y-S; Sokolov, A; Solovieva, E; Stanič, S; Starič, M; Sumihama, M; Sumiyoshi, T; Tanida, K; Tatishvili, G; Teramoto, Y; Tikhomirov, I; Trabelsi, K; Tsuboyama, T; Uchida, M; Uehara, S; Uglov, T; Unno, Y; Uno, S; Vanhoefer, P; Varner, G; Varvell, K E; Vinokurova, A; Vorobyev, V; Wang, C H; Wang, M-Z; Wang, P; Wang, X L; Watanabe, M; Watanabe, Y; Williams, K M; Won, E; Yabsley, B D; Yamaoka, J; Yamashita, Y; Yuan, C Z; Zhang, Z P; Zhilich, V

2012-12-07

We report the first evidence for the η(b)(2S) using the h(b)(2P)→η(b)(2S)γ transition and the first observation of the h(b)(1P)→η(b)(1S)γ and h(b)(2P)→η(b)(1S)γ transitions. The mass and width of the η(b)(1S) and η(b)(2S) are measured to be m(η(b)(1S))=(9402.4±1.5±1.8) MeV/c(2), m(η(b)(2S))=(9999.0±3.5(-1.9)(+2.8)) MeV/c(2), and Γ(η(b)(1S))=(10.8(-3.7-2.0)(+4.0+4.5)) MeV. We also update the h(b)(1P) and h(b)(2P) mass measurements. We use a 133.4 fb(-1) data sample collected at energies near the Υ(5S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider.

Interrupted E2F1-miR-34c-SCF negative feedback loop by hyper-methylation promotes colorectal cancer cell proliferation

PubMed Central

Yang, Shu; Wu, Bo; Sun, Haimei; Ji, Fengqing; Sun, Tingyi; Zhao, Yan; Zhou, Deshan

2015-01-01

Tumour suppressor miR-34c deficiency resulted from hyper-methylation in its promoter is believed to be one of the main causes of colorectal cancer (CRC). Till date, miR-34c has been validated as a direct target of p53; but previous evidence suggested other transcription factor(s) must be involved in miR-34c transcription. In the present study, we in the first place identified a core promoter region (−1118 to −883 bp) of pre-miR-34c which was embedded within a hyper-methylated CpG island. Secondly, E2F1 promoted miR-34c transcription by physical interaction with the miR-34c promoter at site −897 to −889 bp. The transcriptional activating effect of E2F1 on miR-34c was in a p53 independent manner but profoundly promoted in the presence of p53 with exposure to 5-aza-2′-deoxycytidine (DAC). Thirdly, stem cell factor (SCF), a miR-34c target, was specifically reduced upon an introduction of E2F1 which lead to suppression of CRC cell proliferation. The E2F1-suppressed cell proliferation was partially abrogated by additional miR-34c inhibitor, indicating that the anti-proliferation effect of E2F1 was probably through activating miR-34c-SCF axis. Finally, SCF/KIT signalling increased E2F1 production by reducing its proteosomal degradation dependent on PI3K/Akt-GSK3β pathway. In conclusion, our results suggested the existence of E2F1-miR-34c-SCF negative feedback loop which was interrupted by the hyper-methylation of miR-34c promoter in CRC cells and increased cell proliferation. PMID:26704889

Genetic polymorphisms of genes coding to alcohol-metabolizing enzymes in western Mexicans: association of CYP2E1*c2/CYP2E1*5B allele with cirrhosis and liver function.

PubMed

García-Bañuelos, Jesús; Panduro, Arturo; Gordillo-Bastidas, Daniela; Gordillo-Bastidas, Elizabeth; Muñoz-Valle, José Francisco; Gurrola-Díaz, Carmen M; Sánchez-Enríquez, Sergio; Ruiz-Madrigal, Bertha; Bastidas-Ramírez, Blanca Estela

2012-03-01

Alcoholic cirrhosis constitutes a major public health problem in the world where ADH1B, ALDH2, and CYP2E1 polymorphisms could be playing an important role. We determined ADH1B*2, ALDH2*2, and CYP2E1*c2 allele frequencies in healthy control individuals (C) and patients with alcoholic cirrhosis (AC) from western Mexico. Ninety C and 41 patients with AC were studied. Genotype and allele frequency were determined through polymerase chain reaction-restriction fragment length polymorphisms. Polymorphic allele distribution in AC was 1.6%ADH1B*2, 0.0%ALDH2*2, and 19.5%CYP2E1*c2; in C: 6.1%ADH1B*2, 0%ALDH2*2, and 10.6%CYP2E1*c2. CYP2E1*c2 polymorphic allele and c1/c2 genotype frequency were significantly higher (p < 0.05 and p < 0.01, respectively) in patients with AC when compared to C. Patients with AC, carrying the CYP2E1*c2 allele, exhibited more decompensated liver functioning evaluated by total bilirubin and prothrombin time, than c1 allele carrying patients (p < 0.05). Cirrhosis severity, assessed by Child's Pugh score and mortality, was higher in patients carrying the c2 allele, although not statistically significant. In this study, CYP2E1*c2 allele was associated with susceptibility to AC; meanwhile, ADH1B*2 and ALDH2*2 alleles were not. CYP2E1*c2 allele was associated with AC severity, which could probably be attributed to the oxidative stress promoted by this polymorphic form. Further studies to clearly establish CYP2E1*c2 clinical relevance in the development of alcohol-induced liver damage and its usefulness as a probable prognostic marker, should be performed. Also, increasing the number of patients and including a control group conformed by alcoholic patients free of liver damage may render more conclusive results. These findings contribute to the understanding of the influence of gene variations in AC development among populations, alcohol metabolism, and pharmacogenetics. Copyright © 2011 by the Research Society on Alcoholism.

B1 to B2 structural phase transition in LiF under pressure

NASA Astrophysics Data System (ADS)

Jain, Aayushi; Dixit, R. C.

2018-05-01

In the last few decades the alkali halides emerged as crystals with useful applications and their high-pressure behaviour is the most intensively studied subject in high-pressure physics/chemistry, material science, and geosciences. Most alkali halides follow the B1 (NaCl-type)→B2 (CsCl-type) phase-transition route under pressure. In the present paper, we have investigated the characteristics of structural phase transition that occurred in Lithium Florid compound under high pressure. The transition pressure of B1-B2 was calculated using an effective interionic interaction potential (EIOP). The changes of the characteristics of crystals like, Gibbs free energy, cohesive energy, volume collapse, and lattice constant are calculated for the B1 and B2 structures. These data were compared with the available experimental and theoretical data.

Krüppel-like factor 1 mutations and expression of hemoglobins F and A2 in homozygous hemoglobin E syndrome.

PubMed

Tepakhan, Wanicha; Yamsri, Supawadee; Fucharoen, Goonnapa; Sanchaisuriya, Kanokwan; Fucharoen, Supan

2015-07-01

The basis for variability of hemoglobin (Hb) F in homozygous Hb E disease is not well understood. We have examined multiple mutations of the Krüppel-like factor 1 (KLF1) gene; an erythroid specific transcription factor and determined their associations with Hbs F and A2 expression in homozygous Hb E. Four KLF1 mutations including G176AfsX179, T334R, R238H, and -154 (C-T) were screened using specific PCR assays on 461 subjects with homozygous Hb E and 100 normal controls. None of these four mutations were observed in 100 normal controls. Among 461 subjects with homozygous Hb E, 306 had high (≥5 %) and 155 had low (<5 %) Hb F. DNA analysis identified the KLF1 mutations in 35 cases of the former group with high Hb F, including the G176AfsX179 mutation (17/306 = 5.6 %), T334R mutation (9/306 = 2.9 %), -154 (C-T) mutation (7/306 = 2.3 %), and R328H mutation (2/306 = 0.7 %). Only two subjects in the latter group with low Hb F carried the G176AfsX179 and -154 (C-T) mutations. Significant higher Hb A2 level was observed in those of homozygous Hb E with the G176AfsX179 mutation as compared to those without KLF1 mutations. These results indicate that KLF1 is among the genetic factors associated with increased Hbs F and A2, and in combination with other factors could explain the variabilities of these Hb expression in Hb E syndrome.

Effects of Al content and annealing on the phases formation, lattice parameters, and magnetization of A l x F e 2 B 2 ( x = 1.0 , 1.1 , 1.2 ) alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levin, E. M.; Jensen, B. A.; Barua, R.

AlFe 2B 2 is a ferromagnet with the Curie temperature around 300 K and has the potential to be an outstanding rare-earth free candidate for magnetocaloric applications. However, samples prepared from the melt contain additional phases which affect the functional response of the AlFe 2B 2 phase. Here, we report on the effects of Al content in samples with the initial (nominal) composition of Al xFe 2B 2 where x=1.0, 1.1, and 1.2 prepared by arc-melting followed by suction casting and annealing. The as-cast Al xFe 2B 2 alloys contain AlFe 2B 2 as well as additional phases including themore » primary solidifying FeB and Al 13Fe 4 compounds which are ferromagnetic and paramagnetic, respectively, at 300 K. The presence of these phases makes it difficult to extract the intrinsic magnetic properties of AlFe 2B 2 phase. Annealing of Al xFe 2B 2 alloys at 1040°C for 3 days allows for reaction of the FeB with Al 13Fe 4 to form the AlFe 2B 2 phase, significantly reduces the amount of additional phases, and results in nearly pure AlFe 2B2 phase as confirmed with XRD, magnetization, scanning electron microscopy, and electronic transport. The values of the magnetization, effective magnetic moment per Fe atom, specific heat capacity, electrical resistivity and Seebeck coefficient for the AlFe 2B 2 compound have been established.« less

Effects of Al content and annealing on the phases formation, lattice parameters, and magnetization of A l x F e 2 B 2 ( x = 1.0 , 1.1 , 1.2 ) alloys

DOE PAGES

Levin, E. M.; Jensen, B. A.; Barua, R.; ...

2018-03-26

AlFe 2B 2 is a ferromagnet with the Curie temperature around 300 K and has the potential to be an outstanding rare-earth free candidate for magnetocaloric applications. However, samples prepared from the melt contain additional phases which affect the functional response of the AlFe 2B 2 phase. Here, we report on the effects of Al content in samples with the initial (nominal) composition of Al xFe 2B 2 where x=1.0, 1.1, and 1.2 prepared by arc-melting followed by suction casting and annealing. The as-cast Al xFe 2B 2 alloys contain AlFe 2B 2 as well as additional phases including themore » primary solidifying FeB and Al 13Fe 4 compounds which are ferromagnetic and paramagnetic, respectively, at 300 K. The presence of these phases makes it difficult to extract the intrinsic magnetic properties of AlFe 2B 2 phase. Annealing of Al xFe 2B 2 alloys at 1040°C for 3 days allows for reaction of the FeB with Al 13Fe 4 to form the AlFe 2B 2 phase, significantly reduces the amount of additional phases, and results in nearly pure AlFe 2B2 phase as confirmed with XRD, magnetization, scanning electron microscopy, and electronic transport. The values of the magnetization, effective magnetic moment per Fe atom, specific heat capacity, electrical resistivity and Seebeck coefficient for the AlFe 2B 2 compound have been established.« less

OVA-bound nanoparticles induce OVA-specific IgG1, IgG2a, and IgG2b responses with low IgE synthesis.

PubMed

Yanase, Noriko; Toyota, Hiroko; Hata, Kikumi; Yagyu, Seina; Seki, Takahiro; Harada, Mitsunori; Kato, Yasuki; Mizuguchi, Junichiro

2014-10-14

There is an urgent requirement for a novel vaccine that can stimulate immune responses without unwanted toxicity, including IgE elevation. We examined whether antigen ovalbumin (OVA) conjugated to the surface of nanoparticles (NPs) (OVA-NPs) with average diameter of 110nm would serve as an immune adjuvant. When BALB/c mice were immunized with OVA-NPs, they developed sufficient levels of OVA-specific IgG1 antibody responses with low levels of IgE synthesis, representing helper T (Th)2-mediated humoral immunity. OVA-specific IgG2a and IgG2b responses (i.e., Th1-mediated immunity) were also induced by secondary immunization with OVA-NPs. As expected, immunization with OVA in alum (OVA-alum) stimulated humoral immune responses, including IgG1 and IgE antibodies, with only low levels of IgG2a/IgG2b antibodies. CD4-positive T cells from mice primed with OVA-NPs produced substantial levels of IL-21 and IL-4, comparable to those from OVA-alum group. The irradiated mice receiving OVA-NPs-primed B cells together with OVA-alum-primed T cells exhibited enhanced anti-OVA IgG2b responses relative to OVA-alum-primed B cells and T cells following stimulation with OVA-NPs. Moreover, when OVA-NPs-primed, but not OVA-alum-primed, B cells were cultured in the presence of anti-CD40 monoclonal antibody, IL-4, and IL-21, or LPS plus TGF-β in vitro, OVA-specific IgG1 or IgG2b antibody responses were elicited, suggesting that immunization with OVA-NPs modulates B cells to generate IgG1 and IgG2b responses. Thus, OVA-NPs might exert their adjuvant action on B cells, and they represent a promising potential vaccine for generating both IgG1 and IgG2a/IgG2b antibody responses with low IgE synthesis. Copyright © 2014 Elsevier Ltd. All rights reserved.

New perspective of Grodzins E × B(E2) ↑ product rule

NASA Astrophysics Data System (ADS)

Gupta, J. B.; Katoch, Vikas

In the collective spectra of atomic nuclei, the level energy E(21+) varies with atomic number Z and neutron number N. Also the E2 decay-reduced transition probability B(E2, 01+ → 2 1+) is related to the energy E(21+). The product E(21+) × B(E2) ↑ is constant according to Grodzins product rule, independent of the vibration or rotational status of the nucleus. The product rule is often used for determining B(E2) from the known E(21+). However, the variation of the product with various parameters is also suggested in the literature. Hence, a detailed global study of this rule for (Z = 54‑‑78, 66 < N < 126) region is warranted. We use a novel method of displaying the linear relation of B(E2) ↑ with 1/E(21+) for the isotopes of each element (Xe-Pt), instead of their variation with N,Z or A. Through our work, we firmly establish the global validity of the Grodzins relation of B(E2), being proportional to the moment of inertia, except for the deviation in specific cases. Our B(E2) ↑ versus 1/E plots provide a transparent view of the variation of the low-energy nuclear structure. This gives a new perspective of their nuclear structure. Also the various theoretical interpretations of B(E2)s and the energy E(21+) are reviewed.

8 CFR 343b.2 - Number of applications required.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Number of applications required. 343b.2 Section 343b.2 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY NATIONALITY REGULATIONS SPECIAL CERTIFICATE OF NATURALIZATION FOR RECOGNITION BY A FOREIGN STATE § 343b.2 Number of applications required. A...

8 CFR 343b.2 - Number of applications required.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Number of applications required. 343b.2 Section 343b.2 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY NATIONALITY REGULATIONS SPECIAL CERTIFICATE OF NATURALIZATION FOR RECOGNITION BY A FOREIGN STATE § 343b.2 Number of applications required. A...

KDM2B Recruitment of the Polycomb Group Complex, PRC1.1, Requires Cooperation between PCGF1 and BCORL1.

PubMed

Wong, Sarah J; Gearhart, Micah D; Taylor, Alexander B; Nanyes, David R; Ha, Daniel J; Robinson, Angela K; Artigas, Jason A; Lee, Oliver J; Demeler, Borries; Hart, P John; Bardwell, Vivian J; Kim, Chongwoo A

2016-10-04

KDM2B recruits H2A-ubiquitinating activity of a non-canonical Polycomb Repression Complex 1 (PRC1.1) to CpG islands, facilitating gene repression. We investigated the molecular basis of recruitment using in vitro assembly assays to identify minimal components, subcomplexes, and domains required for recruitment. A minimal four-component PRC1.1 complex can be assembled by combining two separately isolated subcomplexes: the DNA-binding KDM2B/SKP1 heterodimer and the heterodimer of BCORL1 and PCGF1, a core component of PRC1.1. The crystal structure of the KDM2B/SKP1/BCORL1/PCGF1 complex illustrates the crucial role played by the PCGF1/BCORL1 heterodimer. The BCORL1 PUFD domain positions residues preceding the RAWUL domain of PCGF1 to create an extended interface for interaction with KDM2B, which is unique to the PCGF1-containing PRC1.1 complex. The structure also suggests how KDM2B might simultaneously function in PRC1.1 and an SCF ubiquitin ligase complex and the possible molecular consequences of BCOR PUFD internal tandem duplications found in pediatric kidney and brain tumors. Copyright © 2016 Elsevier Ltd. All rights reserved.

40 CFR 52.2355 - Section 110(a)(2) infrastructure requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... of section 110(a)(2): (A), (B), (C) with respect to PSD and minor NSR requirements, (D)(i)(II) with respect to PSD requirements, (E)(i), (E)(iii), (F), (G), (H), (J), (K), (L), and (M). [76 FR 43905, July...

Characterisation of Translation Elongation Factor eEF1B Subunit Expression in Mammalian Cells and Tissues and Co-Localisation with eEF1A2

PubMed Central

Janikiewicz, Justyna; Doig, Jennifer; Abbott, Catherine M.

2014-01-01

Translation elongation is the stage of protein synthesis in which the translation factor eEF1A plays a pivotal role that is dependent on GTP exchange. In vertebrates, eEF1A can exist as two separately encoded tissue-specific isoforms, eEF1A1, which is almost ubiquitously expressed, and eEF1A2, which is confined to neurons and muscle. The GTP exchange factor for eEF1A1 is a complex called eEF1B made up of subunits eEF1Bα, eEF1Bδ and eEF1Bγ. Previous studies have cast doubt on the ability of eEF1B to interact with eEF1A2, suggesting that this isoform might use a different GTP exchange factor. We show that eEF1B subunits are all widely expressed to varying degrees in different cell lines and tissues, and at different stages of development. We show that ablation of any of the subunits in human cell lines has a small but significant impact on cell viability and cycling. Finally, we show that both eEF1A1 and eEF1A2 colocalise with all eEF1B subunits, in such close proximity that they are highly likely to be in a complex. PMID:25436608

Metabolism of styrene to styrene oxide and vinylphenols in cytochrome P450 2F2- and P450 2E1-knockout mouse liver and lung microsomes

PubMed Central

Shen, Shuijie; Li, Lei; Ding, Xinxin; Zheng, Jiang

2014-01-01

Pulmonary toxicity of styrene is initiated by cytochromes P450-dependent metabolic activation. P450 2E1 and P450 2F2 are considered to be two main cytochrome P450 (CYP) enzymes responsible for styrene metabolism in mice. The objective of the current study was to determine the correlation between the formation of styrene metabolites (i.e. styrene oxide and 4-vinylphenol) and pulmonary toxicity of styrene, using Cyp2e1- and Cyp2f2-null mouse models. Dramatic decrease in the formation of styrene glycol and 4-vinylphenol was found in Cyp2f2-null mouse lung microsomes, relative to that in the wild-type mouse lung microsomes. However, no significant difference in the production of the styrene metabolites was observed between lung microsomes obtained from Cyp2e1-null and the wild-type mice. The knock–out and wild-type mice were treated with styrene (6.0 mmol/kg, ip), and cell counts and LDH activity in bronchoalveolar lavage fluids were monitored to evaluate the pulmonary toxicity induced by styrene. Cyp2e1-null mice displayed similar susceptibility to lung toxicity of styrene as the wild-type animals. However, Cyp2f2-null mice were resistant to styrene-induced pulmonary toxicity. In conclusion, both P450 2E1 and P450 2F2 are responsible for the metabolic activation of styrene. The latter enzyme plays an important role in styrene-induced pulmonary toxicity. Both styrene oxide and 4-vinylphenol are suggested to participate in the development of lung injury induced by styrene. PMID:24320693

Metabolism of styrene to styrene oxide and vinylphenols in cytochrome P450 2F2- and P450 2E1-knockout mouse liver and lung microsomes.

PubMed

Shen, Shuijie; Li, Lei; Ding, Xinxin; Zheng, Jiang

2014-01-21

Pulmonary toxicity of styrene is initiated by cytochromes P450-dependent metabolic activation. P450 2E1 and P450 2F2 are considered to be two main cytochrome P450 enzymes responsible for styrene metabolism in mice. The objective of the current study was to determine the correlation between the formation of styrene metabolites (i.e., styrene oxide and 4-vinylphenol) and pulmonary toxicity of styrene, using Cyp2e1- and Cyp2f2-null mouse models. A dramatic decrease in the formation of styrene glycol and 4-vinylphenol was found in Cyp2f2-null mouse lung microsomes relative to that in the wild-type mouse lung microsomes; however, no significant difference in the production of the styrene metabolites was observed between lung microsomes obtained from Cyp2e1-null and the wild-type mice. The knockout and wild-type mice were treated with styrene (6.0 mmol/kg, ip), and cell counts and LDH activity in bronchoalveolar lavage fluids were monitored to evaluate the pulmonary toxicity induced by styrene. Cyp2e1-null mice displayed a susceptibility to lung toxicity of styrene similar to that of the wild-type animals; however, Cyp2f2-null mice were resistant to styrene-induced pulmonary toxicity. In conclusion, both P450 2E1 and P450 2F2 are responsible for the metabolic activation of styrene. The latter enzyme plays an important role in styrene-induced pulmonary toxicity. Both styrene oxide and 4-vinylphenol are suggested to participate in the development of lung injury induced by styrene.

Study of Infrared Emission Spectroscopy for the B1Δg-A1Πu and B'1Σg+-A1Πu Systems of C2

NASA Astrophysics Data System (ADS)

Tang, Jian; Chen, Wang; Kawaguchi, Kentarou; Bernath, Peter F.

2016-06-01

Recently, we carried out the perturbation analysis of C_2 spectra and identified forbidden singlet-triplet intersystem transitions, which aroused further interest in other C_2 spectra for the many low-lying electronic states of this fundamental molecule. In 1988, the B1Δg-A1Πu and B'1Σg+-A1Πu band systems were discovered by Douay et al., who observed eight bands of the B1Δg-A1Πu system with v up to 5 for the B1Δg state and six bands of the B'1Σg+-A1Πu system with v up to 3 for the B'1Σg+ state in the Fourier transform infrared emission spectra of hydrocarbon discharges. In the work presented here, we identified twenty-four bands of the two systems, among which the B'1Σg+ v = 4 and the B1Δg v = 6, 7 and 8 vibrational levels involved in nine bands were studied for the first time. A direct global analysis with Dunham parameters was carried out satisfactorily for the B1Δg-A1Πu system except for a small perturbation in the B1Δg v = 6 level. The calculated rovibrational term energies up to B1Δg v = 12 showed that the level crossing between the B1Δg and d3Πg states is responsible for many of the prominent perturbations in the Swan system observed previously. Nineteen lines of the B1Δg-a3Πu forbidden transitions were identified and the off-diagonal spin-orbit interaction constant AdB between d3Πg and B1Δg was derived as 8.3(1) wn. For the B'1Σg+-A1Πu system, only individual band analyses for each vibrational level in the B'1Σg+ state could be done satisfactorily and Dunham parameters obtained from these effective parameters showed that the anharmonic vibrational constant ω_e x_e is anomalously small (nearly zero). Inspection of the RKR potential curves for the B'1Σg+ and X1Σg+ states revealed that an avoided crossing may occur around 30000 wn, which is responsible for the anomalous molecular constants in these two states. W. Chen, K. Kawaguchi, P. F. Bernath, and J. Tang, J. Chem. Phys., 141, 064317 (2015) M. Douay, R. Nietmann and P. F. Bernath

Analysis of E2F factors during epidermal differentiation.

PubMed

Chang, Wing Y; Dagnino, Lina

2005-01-01

The multigene E2F family of transcription factors is central in the control of cell cycle progression. The expression and activity of E2F proteins is tightly regulated transcriptionally and posttranslationally as a function of the proliferation and differentiation status of the cell. In this chapter, we review protocols designed to determine E2F mRNA abundance in tissues by in situ hybridization techniques. The ability to culture primary epidermal keratinocytes and maintain them as either undifferentiated or terminally differentiated cells allows the biochemical and molecular characterization of changes in E2F expression and activity. Thus, we also discuss in detail methods to analyze E2F protein abundance by immunoblot and their ability to bind DNA in cultured cells using electrophoretic mobility shift assays.

26 CFR 1.468B-2 - Taxation of qualified settlement funds and related administrative requirements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... related administrative requirements. 1.468B-2 Section 1.468B-2 Internal Revenue INTERNAL REVENUE SERVICE... claimants. Amounts that are distributed by a qualified settlement fund to, or on behalf of, a transferor or... transfers of property to foreign entities under section 1491. (h) Denial of credits against tax. The tax...

26 CFR 1.468B-2 - Taxation of qualified settlement funds and related administrative requirements.

Code of Federal Regulations, 2010 CFR

2010-04-01

... related administrative requirements. 1.468B-2 Section 1.468B-2 Internal Revenue INTERNAL REVENUE SERVICE... claimants. Amounts that are distributed by a qualified settlement fund to, or on behalf of, a transferor or... transfers of property to foreign entities under section 1491. (h) Denial of credits against tax. The tax...

26 CFR 1.669(b)-1 - Information requirements.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 26 Internal Revenue 8 2014-04-01 2014-04-01 false Information requirements. 1.669(b)-1 Section 1... Beginning Before January 1, 1969 § 1.669(b)-1 Information requirements. The election of a beneficiary who is... following information with respect to the operation and accounts of the foreign trust created by a U.S...

First somatic mutation of E2F1 in a critical DNA binding residue discovered in well-differentiated papillary mesothelioma of the peritoneum

PubMed Central

2011-01-01

Background Well differentiated papillary mesothelioma of the peritoneum (WDPMP) is a rare variant of epithelial mesothelioma of low malignancy potential, usually found in women with no history of asbestos exposure. In this study, we perform the first exome sequencing of WDPMP. Results WDPMP exome sequencing reveals the first somatic mutation of E2F1, R166H, to be identified in human cancer. The location is in the evolutionarily conserved DNA binding domain and computationally predicted to be mutated in the critical contact point between E2F1 and its DNA target. We show that the R166H mutation abrogates E2F1's DNA binding ability and is associated with reduced activation of E2F1 downstream target genes. Mutant E2F1 proteins are also observed in higher quantities when compared with wild-type E2F1 protein levels and the mutant protein's resistance to degradation was found to be the cause of its accumulation within mutant over-expressing cells. Cells over-expressing wild-type E2F1 show decreased proliferation compared to mutant over-expressing cells, but cell proliferation rates of mutant over-expressing cells were comparable to cells over-expressing the empty vector. Conclusions The R166H mutation in E2F1 is shown to have a deleterious effect on its DNA binding ability as well as increasing its stability and subsequent accumulation in R166H mutant cells. Based on the results, two compatible theories can be formed: R166H mutation appears to allow for protein over-expression while minimizing the apoptotic consequence and the R166H mutation may behave similarly to SV40 large T antigen, inhibiting tumor suppressive functions of retinoblastoma protein 1. PMID:21955916

The prohibitin-repressive interaction with E2F1 is rapidly inhibited by androgen signalling in prostate cancer cells

PubMed Central

Koushyar, S; Economides, G; Zaat, S; Jiang, W; Bevan, C L; Dart, D A

2017-01-01

Prohibitin (PHB) is a tumour suppressor molecule with pleiotropic activities across several cellular compartments including mitochondria, cell membrane and the nucleus. PHB and the steroid-activated androgen receptor (AR) have an interplay where AR downregulates PHB, and PHB represses AR. Additionally, their cellular locations and chromatin interactions are in dynamic opposition. We investigated the mechanisms of cell cycle inhibition by PHB and how this is modulated by AR in prostate cancer. Using a prostate cancer cell line overexpressing PHB, we analysed the gene expression changes associated with PHB-mediated cell cycle arrest. Over 1000 gene expression changes were found to be significant and gene ontology analysis confirmed PHB-mediated repression of genes essential for DNA replication and synthesis, for example, MCMs and TK1, via an E2F1 regulated pathway—agreeing with its G1/S cell cycle arrest activity. PHB is known to inhibit E2F1-mediated transcription, and the PHB:E2F1 interaction was seen in LNCaP nuclear extracts, which was then reduced by androgen treatment. Upon two-dimensional western blot analysis, the PHB protein itself showed androgen-mediated charge differentiation (only in AR-positive cells), indicating a potential dephosphorylation event. Kinexus phosphoprotein array analysis indicated that Src kinase was the main interacting intracellular signalling hub in androgen-treated LNCaP cells, and that Src inhibition could reduce this AR-mediated charge differentiation. PHB charge change may be associated with rapid dissociation from chromatin and E2F1, allowing the cell cycle to proceed. The AR and androgens may deactivate the repressive functions of PHB upon E2F1 leading to cell cycle progression, and indicates a role for AR in DNA replication licensing. PMID:28504694

M2-F3 In-flight Launch from B-52

NASA Technical Reports Server (NTRS)

1971-01-01

This photo shows the M2-F3 Lifting Body being launched from NASA's B-52 mothership at the NASA Flight Research Center (FRC--now the Dryden Flight Research Center), Edwards, California. A fleet of lifting bodies flown at the FRC from 1963 to l975 demonstrated the ability of pilots to maneuver and safely land a wingless vehicle designed to fly back to Earth from space and be landed like an aircraft at a pre-determined site. Early flight testing of the M2-F1 and M2-F2 lifting body reentry configurations had validated the concept of piloted lifting body reentry from space. When the M2-F2 crashed on May 10, 1967, valuable information had already been obtained and was contributing to new designs. NASA pilots said the M2-F2 had lateral control problems, so when the M2-F2 was rebuilt at Northrop and redesignated the M2-F3, it was modified with an additional third vertical fin -- centered between the tip fins -- to improve control characteristics. First flight of the M2-F3, with NASA pilot Bill Dana at the controls, was June 2, 1970. The modified vehicle exhibited much better lateral stability and control characteristics than before, and only three glide flights were necessary before the first powered flight on Nov. 25, 1970. Over the next 26 missions, the M2-F3 reached a top speed of l,064 mph (Mach 1.6). Highest altitude reached by vehicle was 7l,500 feet on Dec. 20, 1972, the date of its last flight, with NASA pilot John Manke at the controls. NASA donated The M2-F3 vehicle to the Smithsonian Institute in December 1973. It is currently hanging in the Air and Space Museum along with the X-15 aircraft number 1, which was its hangar partner from 1965 to 1969. NASA B-52, Tail Number 008, is an air launch carrier aircraft, 'mothership,' as well as a research aircraft platform that has been used on a variety of research projects. The aircraft, a 'B' model built in 1952 and first flown on June 11, 1955, is the oldest B-52 in flying status and has been used on some of the most

48 CFR 47.303-1 - F.o.b. origin.

Code of Federal Regulations, 2010 CFR

2010-10-01

... TRANSPORTATION Transportation in Supply Contracts 47.303-1 F.o.b. origin. (a) Explanation of delivery term. F.o.b... a port area having water transportation service) or the carrier's freight station; (3) To a U.S... rules and regulations; (4) Be responsible for any loss of and/or damage to the goods— (i) Occurring...

lncRNA-HIT promotes cell proliferation of non-small cell lung cancer by association with E2F1.

PubMed

Yu, L; Fang, F; Lu, S; Li, X; Yang, Y; Wang, Z

2017-05-01

Lung cancer is the leading cause of cancer-related death around the world. Long noncoding RNA (lncRNA) has pivotal roles in cancer occurrence and development. However, only a few lncRNAs have been functionally characterized. In the present study, we investigated the effects of lncRNA-HIT (HOXA transcript induced by TGFβ) expression on non-small cell lung cancer (NSCLC) cell phenotype with the gain-of-function and loss-of-function assays. We found that ectopic expression or knockdown of lncRNA-HIT markedly increased or decreased NSCLC cell proliferation, respectively. Moreover, we also showed that lncRNA-HIT interacted with E2F1 to regulate its target genes, such as Survivin, FOXM1, SKP2, NELL2 and DOK1. Collectively, our findings indicated that lncRNA-HIT affected the proliferation of NSCLC cells at least in part via regulating the occupancy of E2F1 in the promoter regions of its target genes. The lncRNA-HIT-E2F1 complex may be a potential target for NSCLC treatment.

PP2B/calcineurin-mediated desensitization of TRPV1 does not require AKAP150

PubMed Central

Por, Elaine D.; Samelson, Bret K.; Belugin, Sergei; Akopian, Armen N.; Scott, John D.; Jeske, Nathaniel A.

2011-01-01

Activation of protein kinases and phosphatases at the plasma membrane often initiates agonist-dependent signalling events. In sensory neurons, AKAP150 (A-kinase-anchoring protein 150) orientates PKA (protein kinase A), PKC (protein kinase C) and the Ca2+/calmodulin-dependent PP2B (protein phosphatase 2B, also known as calcineurin) towards membrane-associated substrates. Recent evidence indicates that AKAP150-anchored PKA and PKC phosphorylate and sensitize the TRPV1 (transient receptor potential subfamily V type 1 channel, also known as the capsaicin receptor). In the present study, we explore the hypothesis that an AKAP150-associated pool of PP2B catalyses the dephosphorylation and desensitization of TRPV1. Biochemical, electrophysiological and cell-based experiments indicate that PP2B associates with AKAP150 and TRPV1 in cultured TG (trigeminal ganglia) neurons. Gene silencing of AKAP150 reduces basal phosphorylation of TRPV1. However, functional studies in neurons isolated from AKAP150−/− mice indicate that the anchoring protein is not required for pharmacological desensitization of TRPV1. Behavioural analysis of AKAP150−/− mice further support this notion, demonstrating that agonist-stimulated desensitization of TRPV1 is sensitive to PP2B inhibition and does not rely on AKAP150. These findings allow us to conclude that pharmacological desensitization of TRPV1 by PP2B may involve additional regulatory components. PMID:20883208

PP2B/calcineurin-mediated desensitization of TRPV1 does not require AKAP150.

PubMed

Por, Elaine D; Samelson, Bret K; Belugin, Sergei; Akopian, Armen N; Scott, John D; Jeske, Nathaniel A

2010-12-15

Activation of protein kinases and phosphatases at the plasma membrane often initiates agonist-dependent signalling events. In sensory neurons, AKAP150 (A-kinase-anchoring protein 150) orientates PKA (protein kinase A), PKC (protein kinase C) and the Ca2+/calmodulin-dependent PP2B (protein phosphatase 2B, also known as calcineurin) towards membrane-associated substrates. Recent evidence indicates that AKAP150-anchored PKA and PKC phosphorylate and sensitize the TRPV1 (transient receptor potential subfamily V type 1 channel, also known as the capsaicin receptor). In the present study, we explore the hypothesis that an AKAP150-associated pool of PP2B catalyses the dephosphorylation and desensitization of TRPV1. Biochemical, electrophysiological and cell-based experiments indicate that PP2B associates with AKAP150 and TRPV1 in cultured TG (trigeminal ganglia) neurons. Gene silencing of AKAP150 reduces basal phosphorylation of TRPV1. However, functional studies in neurons isolated from AKAP150-/- mice indicate that the anchoring protein is not required for pharmacological desensitization of TRPV1. Behavioural analysis of AKAP150-/- mice further support this notion, demonstrating that agonist-stimulated desensitization of TRPV1 is sensitive to PP2B inhibition and does not rely on AKAP150. These findings allow us to conclude that pharmacological desensitization of TRPV1 by PP2B may involve additional regulatory components.

BID-F1 and BID-F2 domains of Bartonella henselae effector protein BepF trigger together with BepC the formation of invasome structures.

PubMed

Truttmann, Matthias C; Guye, Patrick; Dehio, Christoph

2011-01-01

The gram-negative, zoonotic pathogen Bartonella henselae (Bhe) translocates seven distinct Bartonella effector proteins (Beps) via the VirB/VirD4 type IV secretion system (T4SS) into human cells, thereby interfering with host cell signaling [1], [2]. In particular, the effector protein BepG alone or the combination of effector proteins BepC and BepF trigger massive F-actin rearrangements that lead to the establishment of invasome structures eventually resulting in the internalization of entire Bhe aggregates [2], [3]. In this report, we investigate the molecular function of the effector protein BepF in the eukaryotic host cell. We show that the N-terminal [E/T]PLYAT tyrosine phosphorylation motifs of BepF get phosphorylated upon translocation but do not contribute to invasome-mediated Bhe uptake. In contrast, we found that two of the three BID domains of BepF are capable to trigger invasome formation together with BepC, while a mutation of the WxxxE motif of the BID-F1 domain inhibited its ability to contribute to the formation of invasome structures. Next, we show that BepF function during invasome formation can be replaced by the over-expression of constitutive-active Rho GTPases Rac1 or Cdc42. Finally we demonstrate that BID-F1 and BID-F2 domains promote the formation of filopodia-like extensions in NIH 3T3 and HeLa cells as well as membrane protrusions in HeLa cells, suggesting a role for BepF in Rac1 and Cdc42 activation during the process of invasome formation.

NACA Aircraft on Lakebed - D-558-2, X-1B, and X-1E

NASA Technical Reports Server (NTRS)

1955-01-01

Early NACA research aircraft on the lakebed at the High Speed Research Station in 1955: Left to right: X-1E, D-558-2, X-1B There were four versions of the original Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the speed of sound, reaching about 700 miles per hour (Mach 1.06) and an altitude of 43,000 feet. The number 2 X-1 was modified and redesignated the X-1E. The modifications included adding a conventional canopy, an ejection seat, a low-pressure fuel system

Elongation of the Poly-γ-glutamate Tail of F420 Requires Both Domains of the F420:γ-Glutamyl Ligase (FbiB) of Mycobacterium tuberculosis*

PubMed Central

Bashiri, Ghader; Rehan, Aisyah M.; Sreebhavan, Sreevalsan; Baker, Heather M.; Baker, Edward N.; Squire, Christopher J.

2016-01-01

Cofactor F420 is an electron carrier with a major role in the oxidoreductive reactions of Mycobacterium tuberculosis, the causative agent of tuberculosis. A γ-glutamyl ligase catalyzes the final steps of the F420 biosynthesis pathway by successive additions of l-glutamate residues to F420-0, producing a poly-γ-glutamate tail. The enzyme responsible for this reaction in archaea (CofE) comprises a single domain and produces F420-2 as the major species. The homologous M. tuberculosis enzyme, FbiB, is a two-domain protein and produces F420 with predominantly 5–7 l-glutamate residues in the poly-γ-glutamate tail. The N-terminal domain of FbiB is homologous to CofE with an annotated γ-glutamyl ligase activity, whereas the C-terminal domain has sequence similarity to an FMN-dependent family of nitroreductase enzymes. Here we demonstrate that full-length FbiB adds multiple l-glutamate residues to F420-0 in vitro to produce F420-5 after 24 h; communication between the two domains is critical for full γ-glutamyl ligase activity. We also present crystal structures of the C-terminal domain of FbiB in apo-, F420-0-, and FMN-bound states, displaying distinct sites for F420-0 and FMN ligands that partially overlap. Finally, we discuss the features of a full-length structural model produced by small angle x-ray scattering and its implications for the role of N- and C-terminal domains in catalysis. PMID:26861878