FUNCTION OF THE CYTOSKELETAL PROTEINS IN VIVO

这项研究的目的是了解 不同的细胞形状，以及为什么这种形状在恶性肿瘤发生时被破坏 转型 这项工作的重点是一个核心组成部分， 所有真核细胞共有的细胞骨架，微管。 这些 在所有细胞类型中，其结构几乎相同， 微管蛋白是最保守的蛋白质之一。 尽管如此，微管在细胞器中的排列方式， 不同的性质、结构和功能。 其中信息 它指定了这种多样性，同时仍然保持高度的 微管结构的保守方面是一个主要的问题， 了解细胞质的正常和病理组织。 的 拟议的研究针对两种可能的解释，这些 事件：首先，微管蛋白之间确实存在的多样性是 足以解释微管的多样性;第二， 与微管相互作用的微管成分是 专门组织。 提出的这些实验利用了 强大的酵母遗传学，S.酿酒酵母，分析功能 微管蛋白结构变化的后果，并使用这些 结果，以确定在体内与微管蛋白相互作用的基因产物。 产生具有广泛表型的突变的方案将是 用于研究α微管蛋白和鉴定第二位点回复突变体。 的 两种功能可互换微管蛋白的细胞质分化 将详细研究基因产物。 另一个域结构 微管蛋白将被研究，以确定一段微管蛋白的功能作用。 特别感兴趣的序列。 外源微管蛋白基因的导入 酵母和动物细胞将允许鉴定 通过拯救功能相互作用的蛋白质。 总体而言，拟议 研究应提供有关详细信息的重要信息 细胞质中结构和功能的基础分子相互作用 和有丝分裂微管。 最终，这种理解应该会导致 病理状态下功能丧失的详细机制，例如 癌

The goal of the proposed research is to understand the molecular basis for different cell shape, and why that shape is disrupted upon malignant transformation. The work focuses on one central component of the cytoskeleton common to all eukaryotic cells, the microtubules. These structures are virtually identical in all cell types and their major components, the tubulins, are among the most conserved of proteins. Nevertheless, microtubules are arranged in organelles of dramatically diverse properties, structures, and functions. Where the information resides that specifies this diversity while still maintaining the highly conserved aspects of microtubule structure is a major question in understanding normal and pathological organization of the cytoplasm. The proposed research is directed at two possible explanations for these events: first, that the diversity that does exist among the tubulins is sufficient to explain the diversity of microtubules; and second, that minor microtubule components, interacting with microtubules are the origin of specialized organization. These experiments proposed take advantage of the powerful genetics of yeast, S. cerevisiae, to analyze functional consequences of structural changes in tubulins, and to use those consequences to identify gene products that interact with tubulins in vivo. A scheme for generating mutations with a broad range of phenotypes will be used to study alpha tubulins, and to identify second-site revertants. The cytoplasmic differentiation of two functionally-interchangeable tubulin gene products will be studied in detail. Domain structure of another tubulin will be studied, to identify the functional role of a stretch of sequence of particular interest. Introduction of foreign tubulin genes into both yeast and animal cells will allow permit identification of proteins that interact by rescuing function. Overall, the proposed research should provide significant information about the detailed molecular interaction that underlie structure and function in cytoplasmic and mitotic microtubules. Eventually, this understanding should lead to a detailed mechanism for loss of function in pathological states, such as cancer.