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排序方式: 共有325条查询结果,搜索用时 46 毫秒
51.
Marco Bonifazi Eleni Bela Concetta Lupo Gilberto Martelli Bin Zhu Giancarlo Carli 《European journal of applied physiology and occupational physiology》1998,78(5):394-397
The aim of the present study was to evaluate the response of adrenocorticotropin ([ACTH]) and growth hormone ([GH]) concentrations
to a typical aerobic swimming set during a training season. Nine top-level male endurance swimmers (age range 17–23 years)
were tested during three training sessions occurring 6, 12 and 18 weeks after the beginning of the season. During each session,
after a standard warm-up, the swimmers performed a training set of 15 × 200-m freestyle, with 20 s of rest between repetitions,
at a predetermined individual speed. Blood samples were collected before warm-up and at the end of the training set. A few
days before each session, the individual swimming velocity corresponding to the 4 mmol · l−1 blood lactate concentration (v
4) was assessed as a standard of aerobic performance. Aerobic training affected v
4 levels, which were highest 18 weeks after the beginning of the season; at the same time, while [ACTH] response was attenuated,
[GH] response was enhanced. These results could be considered as adaptations to the exercise intensity. In our training programme,
these adaptations seemed to have occurred between the 12th and 18th weeks of the training season.
Accepted: 21 April 1998 相似文献
52.
53.
Belaïdouni N Marchal C Benarous R Besnard-Guérin C 《Biochemical and biophysical research communications》2007,357(3):688-693
The human immunodeficiency virus type 1 (HIV-1) Vpu protein binds to the CD4 receptor and targets it to the proteasome for degradation. This process requires the recruitment of human betaTrCP, a component of the Skp1-Cullin-F box (SCF) ubiquitin ligase complex, that interacts with phosphorylated Vpu molecules. Vpu, unlike other ligands of betaTrCP, has never been reported to be degraded. We provide evidence that Vpu, itself, is ubiquitinated and targeted for degradation by the proteasome. We demonstrate that the mutant Vpu2.6, which cannot interact with betaTrCP, is stable and, unlike wild-type Vpu, is not polyubiquitinated. These results suggest that betaTrCP is involved in Vpu polyubiquitination. 相似文献
54.
Clemens Schauberger Ronnie N. Glud Bela Hausmann Blandine Trouche Lois Maignien Julie Poulain Patrick Wincker Sophie Arnaud-Haond Frank Wenzhfer Bo Thamdrup 《The ISME journal》2021,15(12):3455
Hadal trench sediments are hotspots of biogeochemical activity in the deep sea, but the biogeochemical and ecological factors that shape benthic hadal microbial communities remain unknown. Here, we sampled ten hadal sites from two trench regions with a vertical resolution of down to 1 cm. We sequenced 16S rRNA gene amplicons using universal and archaea-specific primer sets and compared the results to biogeochemical parameters. Despite bathymetric and depositional heterogeneity we found a high similarity of microbial communities within each of the two trench axes, while composition at the phylum level varied strongly with sediment depth in conjunction with the redox stratification into oxic, nitrogenous, and ferruginous zones. As a result, communities of a given sediment horizon were more similar to each other across a distance of hundreds of kilometers within each trench, than to those of adjacent horizons from the same sites separated only by centimeters. Total organic carbon content statistically only explained a small part of the variation within and between trenches, and did not explain the community differences observed between the hadal and adjacent shallower sites. Anaerobic taxa increased in abundance at the top of the ferruginous zone, seeded by organisms deposited at the sediment surface and surviving burial through the upper redox zones. While an influence of other potential factors such as geographic isolation, hydrostatic pressure, and non-steady state depositional regimes could not be discerned, redox stratification and diagenesis appear to be the main selective forces that structure community composition in hadal sediments.Subject terms: Water microbiology, Microbial ecology, Microbiome, Biogeochemistry, Biogeochemistry 相似文献
55.
Glutathione peroxidase‐like enzymes cover five distinct cell compartments and membrane surfaces in Arabidopsis thaliana
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Safira Attacha David Solbach Krisztina Bela Anna Moseler Stephan Wagner Markus Schwarzländer Isabel Aller Stefanie J. Müller Andreas J. Meyer 《Plant, cell & environment》2017,40(8):1281-1295
Glutathione peroxidase‐like enzymes (GPXLs) constitute a family of eight peroxidases in Arabidopsis thaliana. In contrast to the eponymous selenocysteine glutathione peroxidases in mammalian cells that use glutathione as electron donor, GPXLs rely on cysteine instead of selenocysteine for activity and depend on the thioredoxin system for reduction. Although plant GPXLs have been implicated in important agronomic traits such as drought tolerance, photooxidative tolerance and immune responses, there remain major ambiguities regarding their subcellular localization. Because their site of action is a prerequisite for an understanding of their function, we investigated the localization of all eight GPXLs in stable Arabidopsis lines expressing N‐terminal and C‐terminal fusions with redox‐sensitive green fluorescent protein 2 (roGFP2) using confocal microscopy. GPXL1 and GPXL7 were found in plastids, while GPXL2 and GPXL8 are cytosolic nuclear. The N‐terminal target peptide of GPXL6 is sufficient to direct roGFP2 into mitochondria. Interestingly, GPXL3, GPXL4 and GPXL5 all appear to be membrane bound. GPXL3 was found exclusively in the secretory pathway where it is anchored by a single N‐terminal transmembrane domain. GPXL4 and GPXL5 are anchored to the plasma membrane. Presence of an N‐terminal myristoylation motif and genetic disruption of membrane association through targeted mutagenesis point to myristoylation as essential for membrane localization. 相似文献
56.
57.
Nico Dissmeyer Annika K. Weimer Stefan Pusch Kristof De Schutter Claire Lessa Alvim Kamei Moritz K. Nowack Bela Novak Gui-Lan Duan Yong-Guan Zhu Lieven De Veylder Arp Schnittger 《The Plant cell》2009,21(11):3641-3654
Entry into mitosis is universally controlled by cyclin-dependent kinases (CDKs). A key regulatory event in metazoans and fission yeast is CDK activation by the removal of inhibitory phosphate groups in the ATP binding pocket catalyzed by Cdc25 phosphatases. In contrast with other multicellular organisms, we show here that in the flowering plant Arabidopsis thaliana, cell cycle control does not depend on sudden changes in the phosphorylation pattern of the PSTAIRE-containing Cdk1 homolog CDKA;1. Consistently, we found that neither mutants in a previously identified CDC25 candidate gene nor plants in which it is overexpressed display cell cycle defects. Inhibitory phosphorylation of CDKs is also the key event in metazoans to arrest cell cycle progression upon DNA damage. However, we show here that the DNA damage checkpoint in Arabidopsis can also operate independently of the phosphorylation of CDKA;1. These observations reveal a surprising degree of divergence in the circuitry of highly conserved core cell cycle regulators in multicellular organisms. Based on biomathematical simulations, we propose a plant-specific model of how progression through the cell cycle could be wired in Arabidopsis. 相似文献
58.
59.
Margaret E. Brousseau John S. Millar Margaret R. Diffenderfer Chorthip Nartsupha Bela F. Asztalos Megan L. Wolfe James P. Mancuso Andres G. Digenio Daniel J. Rader Ernst J. Schaefer 《Journal of lipid research》2009,50(7):1456-1462
This study was designed to establish the mechanism responsible for the increased apolipoprotein (apo) A-II levels caused by the cholesteryl ester transfer protein inhibitor torcetrapib. Nineteen subjects with low HDL cholesterol (<40 mg/dl), nine of whom were also treated with 20 mg of atorvastatin daily, received placebo for 4 weeks, followed by 120 mg of torcetrapib daily for the next 4 weeks. Six subjects in the nonatorvastatin cohort participated in a third phase, in which they received 120 mg of torcetrapib twice daily for 4 weeks. At the end of each phase, subjects underwent a primed-constant infusion of [5,5,5-2H3]l-leucine to determine the kinetics of HDL apoA-II. Relative to placebo, torcetrapib significantly increased apoA-II concentrations by reducing HDL apoA-II catabolism in the atorvastatin (−9.4%, P < 0.003) and nonatorvastatin once- (−9.9%, P = 0.02) and twice- (−13.2%, P = 0.02) daily cohorts. Torcetrapib significantly increased the amount of apoA-II in the α-2-migrating subpopulation of HDL when given as monotherapy (27%, P < 0.02; 57%, P < 0.003) or on a background of atorvastatin (28%, P < 0.01). In contrast, torcetrapib reduced concentrations of apoA-II in α-3-migrating HDL, with mean reductions of −14% (P = 0.23), −18% (P < 0.02), and −18% (P < 0.01) noted during the atorvastatin and nonatorvastatin 120 mg once- and twice-daily phases, respectively. Our findings indicate that CETP inhibition increases plasma concentrations of apoA-II by delaying HDL apoA-II catabolism and significantly alters the remodeling of apoA-II-containing HDL subpopulations. 相似文献
60.
Presence of Anti-Microbial Antibodies in Liver Cirrhosis – A Tell-Tale Sign of Compromised Immunity?
Papp M Norman GL Vitalis Z Tornai I Altorjay I Foldi I Udvardy M Shums Z Dinya T Orosz P Lombay B Par G Par A Veres G Csak T Osztovits J Szalay F Lakatos PL 《PloS one》2010,5(9):e12957