14-3-3 蛋白

介绍了14－3－3蛋白的基本结构和功能,并简要概述了14－3－3蛋白在信号转导,细胞周期调控以及前体蛋白的折叠与运输过程中的作用机理。     

NIF3类超家族蛋白

NIF3(NGG1p interacting factor 3)类超家族蛋白是一个含有NIF3结构域的超家族,从细菌到哺乳动物存在着较高的保守性。编码该家族蛋白质的mRNA广泛存在于生物的各种组织中。该家族蛋白属于α/β蛋白,该类蛋白质通过自身形成二聚体或与其他蛋白质结合形成复合物发挥生物学功能。现已证明该家族蛋白多与基因的转录有关,在一些哺乳动物中还在神经分化中起关键作用。最近研究表明它还和一些人类疾病有关。虽然该家族蛋白数量众多,广泛存在,但多数为假想蛋白,对其相关功能的研究较少,被归属为"未知功能蛋白质"。也正是因为该家族蛋白数量众多,广泛存在,功能未知,它们已经引起了人们越来越大的研究兴趣。     

Establishment of a Feline T-Lymphoblastoid Cell Line Susceptible to Feline Immunodeficiency Viruses

A feline T-lymphoblastoid cell line susceptible to feline immunodeficiency viruses (FIV) was established and designated as Yu-1 cells. Yu-1 cells continued to grow over one year with more than 100 successive passages in the presence of human recombinant interleukin-2. Surface antigens of Yu-1 cells were feline Pan-T+, CD4+, and CD8. Susceptibility of Yu-1 cells to FIV strains were higher than that of the primary culture of the feline peripheral blood mononuclear cells, indicating that this cell line should be useful for isolation, propagation, and neutralization test of FIV.     

Two G3 Feline Rotavirus Strains Lacking Cross-Neutralization Reactions Represent Distinct Subtypes of Serotype G3

Two feline rotavirus strains, FRV-1 and FRV64, that have been shown to lack cross-neutralization reactions despite the sharing of serotype G3 were examined by plaque-reduction neutralization assays in relation to other G3 strains originating from cats, dogs, humans and monkeys. While FRV-1 and human G3 strains constituted one subtype (G3A), FRV64, canine strains and simian strains constituted another subtype (G3B).     

Feline Calicivirus Capsid Protein Expression and Capsid Assembly in Cultured Feline Cells

The capsid protein of feline calicivirus (FCV) was expressed by using plasmids containing cytomegalovirus, simian virus 40, or T7 promoters. The strongest expression was achieved with the T7 promoter and coinfection with vaccinia virus expressing the T7 RNA polymerase (MVA/T7pol). The FCV precursor capsid protein was processed to the mature-size protein, and these proteins were assembled in to virus-like particles.     

Feline immunodeficiency virus tropism

Feline immunodeficiency virus (FIV) induces a disease similar to acquired immunodeficiency syndrome (AIDS) in cats, yet in contrast to human immunodeficiency virus (HIV), CD4 is not the viral receptor. We identified a primary receptor for FIV as CD134 (OX40), a T cell activation antigen and costimulatory molecule. CD134 expression promotes viral binding and renders cells permissive for viral entry, productive infection, and syncytium formation. Infection is CXCR4-dependent, analogous to infection with X4 strains of HIV. Thus, despite the evolutionary divergence of the feline and human lentiviruses, both viruses use receptors that target the virus to a subset of cells that are pivotal to the acquired immune response. Further, we applied the new method for FIV receptor to Ebola virus entry factors with some modifications, and identified receptor-type tyrosine kinases, Axl and Dtk (members of Tyro3 family). Distribution of the molecules matches well with the Ebola virus tropism.     

Feline Ventricular Ganglion Cells

IN mammals, with the exception of artiodactyls and cetaceans, it is generally accepted that intrinsic cardiac ganglion cells are confined distally by the atrioventricular groove¹. This is interpreted as indicating that vagal influence is limited to the atrial and specialized tissues and this concept is supported by much physiological evidence. It has been suggested that, in dogs, the vagi exert a direct negative inotropic effect on the ventricles², although Furnival et al.³ found that this effect was relatively insignificant. Morphologists have, however, reported ventricular ganglion cells in primates^4–6. We offer here morphological evidence for the existence of ventricular ganglion cells in the cat.     

Structural Proteins of Adenovirus-Associated Virus Type 3

Three major structural proteins were found in adenovirus-associated virus (AAV) type 3H virions which were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weights of the polypeptides were determined to be approximately 66,000 (VP1), 80,000 (VP2), and 92,000 (VP3). The component having a molecular weight of 66,000 comprised about 80% of the total virion protein in the major AAV-3H particle, and the other two components comprised about 10% each. Proteins of the same molecular weight were found in the minor dense AAV-3H virion, but the 80,000- and 92,000-molecular-weight components were present at about one-half the concentration. The AAV-3H virion contains about 72 molecules of VP1 and 8 and 7 molecules of VP2 and VP3, respectively.