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排序方式: 共有479条查询结果,搜索用时 203 毫秒
91.
Wang W Guo Y Xu M Huang HH Novikova L Larade K Jiang ZG Thayer TC Frontera JR Aires D Ding H Turk J Mathews CE Bunn HF Stehno-Bittel L Zhu H 《Biochimica et biophysica acta》2011,1812(11):1532-1541
92.
Visweswaraiah J Lageix S Castilho BA Izotova L Kinzy TG Hinnebusch AG Sattlegger E 《The Journal of biological chemistry》2011,286(42):36568-36579
The eukaryotic elongation factor 1A (eEF1A) delivers aminoacyl-tRNAs to the ribosomal A-site during protein synthesis. To ensure a continuous supply of amino acids, cells harbor the kinase Gcn2 and its effector protein Gcn1. The ultimate signal for amino acid shortage is uncharged tRNAs. We have proposed a model for sensing starvation, in which Gcn1 and Gcn2 are tethered to the ribosome, and Gcn1 is directly involved in delivering uncharged tRNAs from the A-site to Gcn2 for its subsequent activation. Gcn1 and Gcn2 are large proteins, and these proteins as well as eEF1A access the A-site, leading us to investigate whether there is a functional or physical link between these proteins. Using Saccharomyces cerevisiae cells expressing His(6)-eEF1A and affinity purification, we found that eEF1A co-eluted with Gcn2. Furthermore, Gcn2 co-immunoprecipitated with eEF1A, suggesting that they reside in the same complex. The purified GST-tagged Gcn2 C-terminal domain (CTD) was sufficient for precipitating eEF1A from whole cell extracts generated from gcn2Δ cells, independently of ribosomes. Purified GST-Gcn2-CTD and purified His(6)-eEF1A interacted with each other, and this was largely independent of the Lys residues in Gcn2-CTD known to be required for tRNA binding and ribosome association. Interestingly, Gcn2-eEF1A interaction was diminished in amino acid-starved cells and by uncharged tRNAs in vitro, suggesting that eEF1A functions as a Gcn2 inhibitor. Consistent with this possibility, purified eEF1A reduced the ability of Gcn2 to phosphorylate its substrate, eIF2α, but did not diminish Gcn2 autophosphorylation. These findings implicate eEF1A in the intricate regulation of Gcn2 and amino acid homeostasis. 相似文献
93.
Goenka R Barnett LG Silver JS O'Neill PJ Hunter CA Cancro MP Laufer TM 《Journal of immunology (Baltimore, Md. : 1950)》2011,187(3):1091-1095
94.
Brian H. Hill Colleen M. Elonen Terri M. Jicha Randall K. Kolka LaRae L. P. Lehto Stephen D. Sebestyen Lindsey R. Seifert-Monson 《Biogeochemistry》2014,120(1-3):203-224
We compared carbon (C), nitrogen (N), and phosphorus (P) concentrations in atmospheric deposition, runoff, and soils with microbial respiration [dehydrogenase (DHA)] and ecoenzyme activity (EEA) in an ombrotrophic bog and a minerotrophic fen to investigate the environmental drivers of biogeochemical cycling in peatlands at the Marcell Experimental Forest in northern Minnesota, USA. Ecoenzymatic stoichiometry was used to construct models for C use efficiency (CUE) and decomposition (M), and these were used to model respiration (Rm). Our goals were to determine the relative C, N, and P limitations on microbial processes and organic matter decomposition, and to identify environmental constraints on ecoenzymatic processes. Mean annual water, C, and P yields were greater in the fen, while N yields were similar in both the bog and fen. Soil chemistry differed between the bog and fen, and both watersheds exhibited significant differences among soil horizons. DHA and EEA differed by watersheds and soil horizons, CUE, M, and Rm differed only by soil horizons. C, N, or P limitations indicated by EEA stoichiometry were confirmed with orthogonal regressions of ecoenzyme pairs and enzyme vector analyses, and indicated greater N and P limitation in the bog than in the fen, with an overall tendency toward P-limitation in both the bog and fen. Ecoenzymatic stoichiometry, microbial respiration, and organic matter decomposition were responsive to resource availability and the environmental drivers of microbial metabolism, including those related to global climate changes. 相似文献
95.
The Novel Use of a Heterozygous Knockout Mouse for Embryofetal Development Assessment of a Glucokinase Activator
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Terri Mitchard Jane Stewart 《Birth defects research. Part B, Developmental and reproductive toxicology》2014,101(2):152-161
Glucokinase activators (GKAs), such as AZD1656, are designed as antihyperglycemic agents for diabetics and can cause dose‐limiting hypoglycemia in normal animals used in embryofetal development studies. Genetically modified heterozygous GK knockout (gkdel/wt) mice are less susceptible to severe GKA‐induced hypoglycemia than wild‐type mice due to their elevated baseline glucose levels. In this study, the gkdel/wt mouse was used as an alternative rodent strain for embryofetal development studies with AZD1656. Heterozygous global knockout gkdel/wt females were dosed with 20, 50, or 130 mg/kg/day of AZD1656 or vehicle for a minimum of 14 consecutive days before mating with wild‐type males and throughout organogenesis. Maternal effects were confined to slightly reduced food consumption, reduced body weight gain, and the pharmacologic effect of decreased plasma glucose. Fetuses were genotyped. Fetal weights at the high dose were slightly reduced but there was no effect on fetal survival. There were two specific major malformations, omphalocele and right‐sided aortic arch, with increased fetal incidence in mid‐ and high‐dose fetuses (e.g., omphalocele fetal incidence of 0.6, 0.7, 4.6, and 2% across the dose groups) plus increased incidences of minor abnormalities and variants indicative of either delayed or disturbed development. Fetal weight and abnormalities were unaffected by fetal genotype. The fetal effects are considered hypoglycemia related. There was no effect on embryofetal survival in the gkdel/wt mouse at AZD1656 exposures, which were 70× higher than those causing 75% fetal death in rabbits. This illustrates the value of genetically modified animals in unraveling target versus chemistry‐related effects. 相似文献
96.
Christie Fitch-Rogalsky Whitney Steber Michael Mahler Terri Lupton Liam Martin Susan G. Barr Dianne P. Mosher James Wick Marvin J. Fritzler 《PloS one》2014,9(4)
Background
The referral of patients with positive anti-nuclear antibody (ANA) tests has been criticized as an inappropriate use of medical resources. The utility of a positive ANA test in a central triage (CT) system was studied by determining the autoantibody profiles and clinical diagnoses of patients referred to rheumatologists through a CT system because of a positive ANA test.Methods
Patients that met three criteria were included: (1) referred to Rheumatology CT over a three year interval; (2) reason for referral was a “positive ANA”; (3) were evaluated by a certified rheumatologist. The CT clinical database was used to obtain demographic and clinical information and a serological database was used to retrieve specific ANA and/or extractable nuclear antigen (ENA) test results. Clinical information was extracted from the consulting rheumatologist''s report.Results
15,357 patients were referred through the CT system; 643 (4.1%) of these because of a positive ANA and of these 263 (40.9%) were evaluated by a certified rheumatologist. In 63/263 (24%) of ANA positive patients, the specialist provided a diagnosis of an ANA associated rheumatic disease (AARD) while 69 (26.2%) had no evidence of any disease; 102 (38.8%) had other rheumatologic diagnoses and 29 (11%) had conditions that did not meet AARD classification criteria. Of ANA positive archived sera, 15.1% were anti-DFS70 positive and 91.2% of these did not have an AARD.Conclusions
This is the first study to evaluate the serological and clinical features of patients referred through a CT system because of a positive ANA. The spectrum of autoantibody specificities was wide with anti-Ro52/TRIM21 being the most common autoantibody detected. Approximately 15% of referrals had only antibodies to DFS70, the vast majority of which did not have clinical evidence for an AARD. These findings provide insight into the utility of autoantibody testing in a CT system. 相似文献97.
98.
Terri J. Harford Atossa Shaltouki Crystal M. Weyman 《Apoptosis : an international journal on programmed cell death》2010,15(1):71-82
We have previously reported that the level of MyoD expression correlates with the level of apoptosis that occurs in a subpopulation
of skeletal myoblasts induced to differentiate by serum withdrawal. Herein we document that MyoD expression contributes to
the level of apoptosis in myoblasts and fibroblasts in response to a variety of apoptotic stimuli. Specifically, re-expression
of MyoD in skeletal myoblasts rendered defective for both differentiation and apoptosis by the expression of oncogenic Ras
restores their ability to undergo both differentiation and apoptosis in response to serum withdrawal. Further, using a fibroblast
cell line expressing an estrogen receptor:MyoD fusion protein, we have determined that addition of estrogen sensitizes these
fibroblasts to apoptosis induced by serum withdrawal, or by treatment with etoposide or thapsigargin. RNAi mediated silencing
of MyoD in either 23A2 or C2C12 myoblasts renders these cells resistant to apoptosis induced by serum withdrawal, or by treatment
with etoposide or thapsigargin. Finally, MyoD mediated regulation of the apoptotic response to these various stimuli, in both
myoblasts and fibroblasts, correlates with the level of induction of the pro-apoptotic Bcl2 family member PUMA. 相似文献
99.
Joana M. Murad Susanne H. Baumeister Lillian Werner Heather Daley Hélène Trébéden-Negre Jake Reder Charles L. Sentman David Gilham Frederic Lehmann Sarah Snykers Marie-Louise Sentman Terri Wade Adam Schmucker Michael W. Fanger Glenn Dranoff Jerome Ritz Sarah Nikiforow 《Cytotherapy》2018,20(7):952-963
Background aims
Adoptive cell therapy employing natural killer group 2D (NKG2D) chimeric antigen receptor (CAR)-modified T cells has demonstrated preclinical efficacy in several model systems, including hematological and solid tumors. We present comprehensive data on manufacturing development and clinical production of autologous NKG2D CAR T cells for treatment of acute myeloid leukemia and multiple myeloma (ClinicalTrials.gov Identifier: NCT02203825). An NKG2D CAR was generated by fusing native full-length human NKG2D to the human CD3ζ cytoplasmic signaling domain. NKG2D naturally associates with native costimulatory molecule DAP10, effectively generating a second-generation CAR against multiple ligands upregulated during malignant transformation including MIC-A, MIC-B and the UL-16 binding proteins.Methods
CAR T cells were infused fresh after a 9-day process wherein OKT3-activated T cells were genetically modified with replication-defective gamma-retroviral vector and expanded ex vivo for 5 days with recombinant human interleukin-2.Results
Despite sizable interpatient variation in originally collected cells, release criteria, including T-cell expansion and purity (median 98%), T-cell transduction (median 66% CD8+ T cells), and functional activity against NKG2D ligand-positive cells, were met for 100% of healthy donors and patients enrolled and collected. There was minimal carryover of non–T cells, particularly malignant cells; both effector memory and central memory cells were generated, and inflammatory cytokines such as granulocyte colony-stimulating factor, RANTES, interferon-γ and tumor necrosis factor-α were selectively up-regulated.Conclusions
The process resulted in production of required cell doses for the first-in-human phase I NKG2D CAR T clinical trial and provides a robust, flexible base for further optimization of NKG2D CAR T-cell manufacturing. 相似文献100.