MECHANISMS OF VIRAL PATHOGENESIS

大GTP酶（Mr= 70，000 - 100，000）的新家族包括 以下蛋白质：脊椎动物的干扰素诱导的Mx蛋白; 果蝇的组成性微管结合蛋白发动蛋白， 脊椎动物;酵母的线粒体蛋白MGM 1，和细胞质 酵母VPS 1/SPO 15蛋白。尽管序列有惊人的相似性， 这些蛋白质在它们的生物学功能上有很大的不同， 基因模型 我们研究的目标是更精确地定义 生物化学和功能参数的脊椎动物成员，这是 蛋白质家族 在某些物种中，如大鼠或小鼠，Mx蛋白表现出活性 对这些物种不重要的病毒，这表明 蛋白质的主要功能可能不是抑制病毒。 支持 根据这一提示，我们发现大鼠抗VSV蛋白Mx2 在体外以核苷酸依赖的方式结合微管， 因此，Mx2可能在细胞过程中发挥作用， Mx2的抗病毒作用可能只是一种副产品 关于这种细胞作用，发动蛋白的确切功能尚不清楚， 脊椎动物，但似乎是在内吞作用（例如，在 神经肌肉接头），为了从遗传学上定义 动力蛋白的功能，我们计划在 鼠标 为此，我们分离了基因组粘粒和λ噬菌体 对应于小鼠动力蛋白基因的克隆。 大鼠大肠杆菌Mx蛋白的纯化大肠杆菌让我们 开始对它们的酶特性进行详细的生化分析。 纯化的制剂也已用于产生多克隆抗体。 兔抗血清，并获得初步的结构信息， 温度，场发射扫描透射电子显微镜 (Dr. Brian Andrews，LN）. 这些将有助于阐明机制 抑制病毒的机制

A novel family of large GTPases (Mr=70,000-100,000) includes the following proteins: the interferon-inducible Mx proteins of vertebrates; the constitutive, microtubule-binding protein dynamin of Drosophila and vertebrates; the mitochondrial protein MGM1 of yeast, and the cytoplasmic protein VPS1/SPO15 of yeast. Despite striking sequence similarities, these proteins differ widely in their biological functions as defined by genetic models. The goal of our studies is to define more precisely the biochemical and functional parameters of the vertebrate members of this family of proteins. In some species, such as rats or mice, Mx proteins show activities against viruses that are of no importance to those species, suggesting the proteins' primary function may not be to inhibit viruses. In support of this suggestion, we have found that the anti-VSV protein Mx2 of rats binds microtubules in vitro in a nucleotide-dependent fashion similar to rat dynamin, Thus, Mx2 may have a role in cellular processes involving microtubules, and the antiviral action of Mx2 may merely be a byproduct of such a cellular role, the precise function of dynamin is not known for vertebrates but appears to be in endocytosis (for instance at the neuromuscular junction) in Drosophila, In order to genetically define the function of dynamin, we plan to generate a dynamin null-mutation in the mouse. To this end, we have isolated genomic cosmid and lambda phage clones corresponding to the mouse dynamin gene. Purification of rat Mx proteins derived from E. coli allowed us to initiate a detailed biochemical analysis of their enzymatic properties. The purified preparations also have been used to generate polyclonal rabbit antisera and to obtain initial structural information by low temperature, field emission scanning-transmission electron microscopy (Dr. Brian Andrews,LN). These will be useful to elucidate the mechanism by which viruses are inhibited.