CELL SIGNALING IN C ELEGANS

线虫中的细胞信号传导

• 批准号: 6237527
• 负责人: STEWART KIM
• 金额: $ 20.27万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-01 至 1998-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6237527
• 关键词: Caenorhabditis elegans; biological signal transduction; cell cell interaction; confocal scanning microscopy; cytology; developmental genetics; enzyme activity; epitope mapping; female reproductive system; gene expression; gene interaction; gene mutation; genetic regulation; guanosine monophosphate; immunoprecipitation; protein structure function; protein tyrosine kinase; receptor expression; sex differentiation; site directed mutagenesis; stainings; western blottings

Cell signaling plays a fundamental role in controlling cell growth and differentiation during development. In C. elegans, one of the best understood examples of cell signaling occurs during the induction of the vulva in the hermaphrodite. Vulval development provides an opportunity to study cell signaling in vivo at single cell resolution, since induction is the result of communication between a single regulatory cell (the anchor cell) and a set of six responding cells (the vulval precursor cells). Many genes that function in the vulval cell signaling pathway have already been identified, and most are similar to genes involved in receptor tyrosine kinase pathways in mammals and Drosophila; including let-23 (a receptor tyrosine kinase gene), let-60 (a ras homolog) and mpk-1 (a MAP kinase homolog). This project began when the exciting observation was made that lin-2, a gene required for vulval induction in C. elegans, is similar to membrane- associated guanylate kinase genes (referred to as MAGUK genes) that have previously been identified in Drosophila and mammals. Studies with the C. elegans lin-2 gene provide the first direct evidence that a MAGUK gene interacts with a receptor tyrosine kinase pathway. Other MAGUK proteins may likewise interact with receptor tyrosine kinase pathways in other organisms, and elucidating the role of MAGUK proteins in signal transduction will uncover new steps in this important cell signaling pathway. One of the broad goals of this proposal is to determine how lin-2 functions during vulval cell signaling in C. elegans. Vulval development provides an ideal system for investigating the link between MAGUK proteins and signal transduction, since lin-2 function can be analyzed in the context of a well-characterized tyrosine kinase signaling pathway in which many of the genes have already been identified. By analyzing how lin-2 interacts with these other vulval signaling genes, the step in the signaling cascade that requires lin-2 function will be determined. Furthermore, a combined molecular, genetic and biochemical approach will be used to determine which of the LIN-2 protein domains and predicted enzymatic activities are required for proper cell signaling in vivo. Finally, the interactions between LIN-2 and other proteins involved in the same cellular process as LIN-2 (LIN-7 and LIN-10) will be studied. The proposed investigation of the role of lin-2 and interacting genes during vulval induction is directly relevant to abnormal signaling processes leading to tumor formation. lin-2 is similar to the Drosophila discs-large gene, which functions as a tumor suppressor gene in imaginal disc cells. Our work shows that lin-2 interacts with a highly conserved receptor tyrosine kinase signaling pathway, and constitutive activation of similar pathways in mammalian cells is oncogenic. For example, let-23, sem-5, let-60, lin-45 and lin-31 are "proto-oncogenes" since they are similar to mammalian receptor tyrosine kinase oncogenes, the crk oncogene, ras, raf and the Qin oncogene, respectively.

细胞信号传导在控制细胞生长和增殖中起着重要作用。 发展过程中的差异。In C. elegans，one of the best最好 细胞信号传导的理解的实例发生在细胞信号传导的诱导期间。 雌雄同体的阴户外阴发育提供了一个机会， 在单细胞分辨率下研究体内细胞信号传导，因为诱导是 单个调节单元（锚）之间通信的结果 细胞）和一组六个响应细胞（外阴前体细胞）。 许多在外阴细胞信号通路中起作用的基因已经 已被鉴定，并且大多数与受体相关基因相似 哺乳动物和果蝇中的酪氨酸激酶途径;包括let-23（a 受体酪氨酸激酶基因）、let-60（ras同源物）和mpk-1（MAP 激酶同源物）。 这个项目开始时，令人兴奋的观察，林-2，一个 外阴诱导所需的基因。elegans，is similar类似to membrane膜- 相关的鸟苷酸激酶基因（称为MAGUK基因）， 之前在果蝇和哺乳动物中发现过。与C. elegans lin-2基因提供了MAGUK基因 与受体酪氨酸激酶途径相互作用。其他MAGUK蛋白 同样可能与其他受体酪氨酸激酶途径相互作用 生物，并阐明MAGUK蛋白在信号转导中的作用 转导将揭示这一重要细胞信号传导的新步骤 通路 这项提案的主要目标之一是确定lin-2如何 在C.优雅的外阴发育 为研究MAGUK蛋白之间的联系提供了理想的系统 和信号转导，因为lin-2的功能可以在 在一个充分表征的酪氨酸激酶信号通路的背景下， 许多基因已经被确认。通过分析林二号是如何 与其他外阴信号基因相互作用， 将确定需要LIN-2功能的信号级联。 此外，结合分子、遗传和生物化学方法将 用于确定LIN-2蛋白质结构域中的哪一个， 酶活性是体内适当细胞信号传导所必需的。 最后，LIN-2和其他蛋白质之间的相互作用参与了 将研究与LIN-2（LIN-7和LIN-10）相同的细胞过程。 lin-2和相互作用基因的作用的研究 与异常信号直接相关 导致肿瘤形成的过程。lin-2与果蝇相似， discs-large基因是一种在胚胎发育中起抑癌作用的基因， 椎间盘细胞我们的工作表明lin-2与一个高度保守的 受体酪氨酸激酶信号通路，和组成性激活 在哺乳动物细胞中的类似途径是致癌的。例如，let-23， sem-5、let-60、lin-45和lin-31是“原癌基因”，因为它们 类似于哺乳动物受体酪氨酸激酶癌基因，crk癌基因， ras、raf和Qin癌基因。