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941.
Papillomavirus E6 proteins are adapters that change the function of cellular regulatory proteins. The bovine papillomavirus type 1 E6 (BE6) binds to LXXLL peptide sequences termed LD motifs (consensus sequence LDXLLXXL) on the cellular protein paxillin that is a substrate of Src and focal adhesion kinases. Anchorage-independent transformation induced by BE6 required both paxillin and BE6-binding LD motifs on paxillin but was independent of the major tyrosine phosphorylation sites of paxillin. The essential role of paxillin in transformation by BE6 highlights the role of paxillin in the transduction of cellular signals that result in anchorage-independent cell proliferation. 相似文献
942.
Yap MW Lindemann D Stanke N Reh J Westphal D Hanenberg H Ohkura S Stoye JP 《Journal of virology》2008,82(11):5429-5439
Foamy viruses (FVs) are unconventional retroviruses with a replication strategy that is significantly different from orthoretroviruses and bears some homology to that of hepadnaviruses. Although some cellular proteins, such as APOBEC3, have been reported to block FVs, no restriction by Trim5alpha has been described to date. The sensitivity of three FV isolates of human-chimpanzee or prototypic (PFV), macaque (SFVmac), and feline (FFV) origin to a variety of primate Trim5alphas was therefore tested. PFV and SFVmac were restricted by Trim5alphas from most New World monkeys, but not from other primates, whereas FFV-based vectors were restricted by Trim5alphas from the great apes gorilla and orangutan. Trim5alphas from Old World monkeys did not restrict any FV isolate tested. Capuchin Trim5alpha was unique, as it restricted SFVmac and FFV but not PFV. Trim5alpha specificity for FVs was determined by the B30.2 domain, interestingly involving, in some instances, the same residues of the variable regions previously implicated as major determinants for human immunodeficiency virus type 1 restriction. FVs with chimeric Gags were made to map the viral determinants of sensitivity to restriction. The N-terminal half of the Gag molecule was found to contain the regions that control susceptibility. This region most likely corresponds to the capsid of conventional retroviruses. Due to their unique replication strategy, FVs should provide a valuable new system to examine the mechanism of retroviral restriction by Trim5alpha. 相似文献
943.
944.
Gibson KN Vick LG Palma AC Carrasco FM Taub D Ramos-Fernández G 《American journal of primatology》2008,70(5):485-489
We describe two cases of infanticide, two suspected infanticides, and a forced copulation by familiar resident males in two populations of wild spider monkeys (Ateles belzebuth chamek and A. geoffroyi yucatanensis). These are the first known infanticides and forced copulation in spider monkeys. Data were gathered from four neighboring communities of spider monkeys in Manu National Park at the Cocha Cashu Biological Station, Peru and two communities in the Otoch Ma'ax Yetel Kooh Reserve at Punta Laguna, Mexico, during intensive field studies of over 2,000 hr each. These are rare behaviors, but results suggest that mating history and sexual coercion are important in spider monkey social relationships. 相似文献
945.
Wijnhoven TJ van de Westerlo EM Smits NC Lensen JF Rops AL van der Vlag J Berden JH van den Heuvel LP van Kuppevelt TH 《Glycoconjugate journal》2008,25(2):177-185
Heparinoids are used in the clinic as anticoagulants. A specific pentasaccharide in heparinoids activates antithrombin III,
resulting in inactivation of factor Xa and–when additional saccharides are present–inactivation of factor IIa. Structural
and functional analysis of the heterogeneous heparinoids generally requires advanced equipment, is time consuming, and needs
(extensive) sample preparation. In this study, a novel and fast method for the characterization of heparinoids is introduced
based on reactivity with nine unique anti-heparin antibodies. Eight heparinoids were biochemically analyzed by electrophoresis
and their reactivity with domain-specific anti-heparin antibodies was established by ELISA. Each heparinoid displayed a distinct
immunoprofile matching its structural characteristics. The immunoprofile could also be linked to biological characteristics,
such as the anti-Xa/anti-IIa ratio, which was reflected by reactivity of the heparinoids with antibodies HS4C3 (indicative
for 3-O-sulfates) and HS4E4 (indicative for domains allowing anti-factor IIa activity). In addition, the immunoprofile could be indicative
for heparinoid-induced side-effects, such as heparin-induced thrombocytopenia, as illustrated by reactivity with antibody
NS4F5, which defines a very high sulfated domain. In conclusion, immunoprofiling provides a novel, fast, and simple methodology
for the characterization of heparinoids, and allows high-throughput screening of (new) heparinoids for defined structural
and biological characteristics. 相似文献
946.
Alicia Lundby Lasse Steen Ravn Jesper Hastrup Svendsen Stig Hauns S?ren-Peter Olesen Nicole Schmitt 《Cellular physiology and biochemistry》2008,21(1-3):47-54
BACKGROUND: Atrial fibrillation (AF) is the most common cardiac rhythm disorder with a lifetime risk for development of 25% for people aged 40 or older. In this study we aim for the functional assessment of a mutation in KCNE3 identified in a proband with early-onset lone AF. METHODS: Screening of genomic DNA from the proband led to identification of a KCNE3 V17M missense mutation. We heterologously expressed the accessory channel subunit in Xenopus laevis oocytes together with its known interacting potassium channel alpha-subunits. Further, we applied RT-PCR on human total RNA from left and right atria and ventricle. RESULTS: Electrophysiological recordings revealed an increased activity of Kv4.3/KCNE3 and Kv11.1/KCNE3 generated currents by the mutation, thereby conferring susceptibility of mutation carriers to faster cardiac action potential repolarization and thus vulnerability to re-entrant wavelets in the atria and thereby AF. CONCLUSION: Here we report a novel mutation in KCNE3 identified in a proband with early-onset lone AF possibly leading to gain-of-function of several cardiac currents. We suggest abnormalities in the KCNE3 gene as a potential genetic risk factor for initiation and/or maintenance of AF. 相似文献
947.
948.
Richard A Barras A Younes AB Monfilliette-Dupont N Melnyk P 《Bioconjugate chemistry》2008,19(7):1491-1495
In order to graft an amphiphilic polysaccharide to lipid nanocapsules, we present here a new method of dextran lipidation. The lipidation strategy is based on the formation of an oxime linkage between the amphiphilic hydroxylamine C16E20ONH2 and the reductive end of a 40 kDa dextran. This chemoselective reaction allows us to control the lipidation site and the number of lipid introduced on the dextran molecule. This new amphiphilic dextran was used to coat the surface of lipid nanocapsules. The coating efficiency was followed by dynamic light scattering and the presence of the polysaccharide was confirmed by (1)H NMR and observed by electronic microscopy. 相似文献
949.
Khalfallah O Faucon-Biguet N Nardelli J Meloni R Mallet J 《Gene expression patterns : GEP》2008,8(3):148-154
The human zinc finger protein 191 (ZNF191) is a Krüppel-like protein and can specifically interact with the widespread TCAT motif which constitutes the HUMTH01 microsatellite in the tyrosine hydroxylase (TH) gene (encoding the rate-limiting enzyme in the synthesis of catecholamines). Allelic variations of HUMTH01 are known to have a quantitative silencing effect on TH gene expression and to correlate with quantitative and qualitative changes in the binding by ZNF191. This factor has been isolated from bone marrow and promyelocytic leukemia cell lines indicating that ZNF191 also plays a role in hematopoiesis. Thus, ZNF191 could participate in the regulation of several genes implicated in different functions. Moreover, mice that are deficient in Zfp191, the murine homologue of ZNF191, have been shown to be severely retarded in development and to die approximately at embryonic day 7.5. In order to gain further insight into its biological functions, we have analysed the localisation of Zfp191 throughout mouse development. Expression was detected early during embryogenesis in ectodermal, endodermal, mesodermal and extra-embryonic tissues. In particular, Zfp191 was observed in the developing central nervous system. Interestingly, its expression levels were prominent in areas of proliferation such as the subventricular zone. Zfp191 expression pattern during development can account for the phenotypic features of Zfp191(-/-) embryos. 相似文献
950.
West Nile virus (WNV) infection can be fatal to many bird species, including numerous raptors, though population- and ecosystem-level
impacts following introduction of the virus to North America have been difficult to document. Raptors occupy a diverse array
of habitats worldwide and are important to ecosystems for their role as opportunistic predators. We documented initial (primary)
WNV infection and then regularly measured WNV-specific neutralizing antibody titers in 16 resident raptors of seven species,
plus one turkey vulture. Most individuals were initially infected and seroconverted between July and September of 2003, though
three birds remained seronegative until summer 2006. Many of these birds became clinically ill upon primary infection, with
clinical signs ranging from loss of appetite to moderate neurological disease. Naturally induced WNV neutralizing antibody
titers remained essentially unchanged in some birds, while eight individuals experienced secondary rises in titer presumably
due to additional exposures at 1, 2, or 3 years following primary infection. No birds experienced clinical signs surrounding
or following the time of secondary exposure, and therefore antibodies were considered protective. Results of this study have
implications for transmission dynamics of WNV and health of raptor populations, as well as the interpretation of serologic
data from free-ranging and captive birds. Antibodies in raptors surviving WNV may persist for multiple years and protect against
potential adverse effects of subsequent exposures. 相似文献