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961.
962.
ER translocation intermediates are adjacent to a nonglycosylated 34-kD integral membrane protein 总被引:1,自引:0,他引:1 下载免费PDF全文
We have used the homobifunctional cross-linking reagent disuccinimidyl suberate (DSS) to identify proteins that are adjacent to nascent polypeptides undergoing translocations across mammalian rough ER. Translocation intermediates were assembled by supplementing cell free translations of truncated mRNAs with the signal recognition particle (SRP) and microsomal membrane vesicles. Two prominent cross-linked products of 45 and 64 kD were detected. The 64-kD product was obtained when the cell free translation contained SRP, while formation of the 45-kD product required both SRP and translocation competent microsomal membrane vesicles. In agreement with previous investigators, we suggest that the 64-kD product arises by cross-linking of the nascent polypeptide to the 54-kD subunit of SRP. The 45-kD product resists alkaline extraction from the membrane, so we conclude that the 11-kD nascent polypeptide has been crosslinked to an integral membrane protein of approximately 34 kD (imp34). The cross-linked product does not bind to ConA Sepharose, nor is it sensitive to endoglycosidase H digestion; hence imp34 is not identical to the alpha or beta subunits of the signal sequence receptor (SSR). We propose that imp34 functions in concert with SSR to form a translocation site through which nascent polypeptides pass in traversing the membrane bilayer of the rough endoplasmic reticulum. 相似文献
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964.
Regional management units for marine turtles: a novel framework for prioritizing conservation and research across multiple scales 总被引:2,自引:0,他引:2
Wallace BP DiMatteo AD Hurley BJ Finkbeiner EM Bolten AB Chaloupka MY Hutchinson BJ Abreu-Grobois FA Amorocho D Bjorndal KA Bourjea J Bowen BW Dueñas RB Casale P Choudhury BC Costa A Dutton PH Fallabrino A Girard A Girondot M Godfrey MH Hamann M López-Mendilaharsu M Marcovaldi MA Mortimer JA Musick JA Nel R Pilcher NJ Seminoff JA Troëng S Witherington B Mast RB 《PloS one》2010,5(12):e15465
Background
Resolving threats to widely distributed marine megafauna requires definition of the geographic distributions of both the threats as well as the population unit(s) of interest. In turn, because individual threats can operate on varying spatial scales, their impacts can affect different segments of a population of the same species. Therefore, integration of multiple tools and techniques — including site-based monitoring, genetic analyses, mark-recapture studies and telemetry — can facilitate robust definitions of population segments at multiple biological and spatial scales to address different management and research challenges.Methodology/Principal Findings
To address these issues for marine turtles, we collated all available studies on marine turtle biogeography, including nesting sites, population abundances and trends, population genetics, and satellite telemetry. We georeferenced this information to generate separate layers for nesting sites, genetic stocks, and core distributions of population segments of all marine turtle species. We then spatially integrated this information from fine- to coarse-spatial scales to develop nested envelope models, or Regional Management Units (RMUs), for marine turtles globally.Conclusions/Significance
The RMU framework is a solution to the challenge of how to organize marine turtles into units of protection above the level of nesting populations, but below the level of species, within regional entities that might be on independent evolutionary trajectories. Among many potential applications, RMUs provide a framework for identifying data gaps, assessing high diversity areas for multiple species and genetic stocks, and evaluating conservation status of marine turtles. Furthermore, RMUs allow for identification of geographic barriers to gene flow, and can provide valuable guidance to marine spatial planning initiatives that integrate spatial distributions of protected species and human activities. In addition, the RMU framework — including maps and supporting metadata — will be an iterative, user-driven tool made publicly available in an online application for comments, improvements, download and analysis. 相似文献965.
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967.
For several millennia, the willow tree and salicin have been associated with salicylic acid, the key precursor molecule that has contributed to the discovery of acetylsalicylic acid, traded as aspirin. These molecules have been shown to possess phyto- and chemotherapeutic activities as analgesic drugs. In recent decades, aspirin has become the focus of extensive investigation into antiproliferative and anticancer activities. The historical steps that led to the discovery of aspirin, and its antiproliferative and anticancer potential are highlighted in this review. 相似文献
968.
Modelling cytomegalovirus replication patterns in the human host: factors important for pathogenesis
Regoes RR Bowen EF Cope AV Gor D Hassan-Walker AF Prentice HG Johnson MA Sweny P Burroughs AK Griffiths PD Bonhoeffer S Emery VC 《Proceedings. Biological sciences / The Royal Society》2006,273(1596):1961-1967
Human cytomegalovirus can cause a diverse range of diseases in different immunocompromised hosts. The pathogenic mechanisms underlying these diseases have not been fully elucidated, though the maximal viral load during infection is strongly correlated with the disease. However, concentrating on single viral load measures during infection ignores valuable information contained during the entire replication history up to the onset of disease. We use a statistical model that allows all viral load data sampled during infection to be analysed, and have applied it to four immunocompromised groups exhibiting five distinct cytomegalovirus-related diseases. The results show that for all diseases, peaks in viral load contribute less to disease progression than phases of low virus load with equal amount of viral turnover. The model accurately predicted the time of disease onset for fever, gastrointestinal disease and pneumonitis but not for hepatitis and retinitis, implying that other factors may be involved in the pathology of these diseases. 相似文献
969.
Differential expression within the LOX gene family in ripening kiwifruit 总被引:10,自引:0,他引:10
Zhang B Chen K Bowen J Allan A Espley R Karunairetnam S Ferguson I 《Journal of experimental botany》2006,57(14):3825-3836
970.