Molecular and genetic analysis of sanpodo

桑普多的分子和遗传分析

• 批准号: 6741914
• 负责人: James Benjamin Skeath
• 金额: $ 22.95万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6741914
• 关键词: Caenorhabditis elegans; Drosophilidae; alleles; arthropod genetics; cell cycle; cell surface receptors; confocal scanning microscopy; cytoskeletal proteins; gene expression; immunofluorescence technique; invertebrate embryology; molecular genetics; phenotype; polymerase chain reaction; protein protein interaction; protein structure function; western blottings

DESCRIPTION (provided by applicant): The feature that sets the nervous system apart from other tissues is the complexity of its cell network. This complexity is founded on the great diversity of neurons that populate a functional nervous system. Asymmetric cell divisions, in which a precursor cell divides to produce two sibling cells of distinct fates, play a central role in generating the cellular diversity found in both vertebrate and invertebrate nervous systems. Research in Drosophila has begun to elucidate the genetic and molecular basis of asymmetric divisions. These data indicate that the Notch signaling pathway acts in opposition to the membrane-associated protein Numb to mediate the asymmetric division of neural (and muscle) precursors. The present model is that Numb is asymmetrically segregated during precursor division into one sibling where it blocks Notch signaling and allows this cell to adopt the CEB1fate. The other sibling, which lacks Numb protein, receives active Notch input and adopts the CEA1cell fate. In this manner, the Notch/Numb cassette mediates the binary cell fate choice of most if not all sibling CNS neurons. Through a genetic screen we identified sanpodo as a gene that acts with the Notch pathway to mediate asymmetric divisions, sanpodo was initially characterized as the homolog of the vertebrate gene encoding the F-actin/tropomyosin binding protein, Tropomodulin. However, our data provide compelling evidence that sanpodo does not encode Tropomodulin but rather a novel four-pass transmembrane protein. The goals of this proposal are to elucidate the genetic and molecular basis through which sanpodo mediates asymmetric divisions. Specifically, we propose: (1) to confirm the molecular identity of sanpodo; (2) to complete a systematic genetic, expression and molecular analysis of sanpodo; and (3) to elucidate the molecular mechanism by which sanpodo regulates asymmetric divisions by identifying Sanpodo-interacting proteins. Mammalian homologs of Notch pathway members and numb exist. Recent genetic, expression and molecular studies suggest these factors also regulate asymmetric divisions in mammals. Thus, the elucidation of how Sanpodo function integrates with that of Notch and Numb to regulate asymmetric cell divisions is likely to provide general insights into the molecular and genetic mechanisms that create cell diversity throughout animal development.

描述（由申请人提供）：设定神经系统与其他组织的特征是其细胞网络的复杂性。这种复杂性建立在充满功能性神经系统的神经元的多样性上。不对称的细胞分裂，其中前体细胞分裂以产生两个不同命运的兄弟姐妹细胞，在产生脊椎动物和无脊椎动物神经系统中发现的细胞多样性方面起着核心作用。果蝇的研究已开始阐明不对称分裂的遗传和分子基础。这些数据表明，Notch信号通路与与膜相关的蛋白质相反，以介导神经（和肌肉）前体的不对称分裂。目前的模型是，在前体分裂期间，麻木被不对称地隔离为一个兄弟姐妹，在该兄弟姐妹中阻断了Notch信号，并允许该单元使用CEB1FATE。缺乏麻木蛋白质的另一个兄弟姐妹会收到活跃的缺口输入并采用CEA1CELL命运。通过这种方式，凹槽/麻木的盒子介导了大多数同胞中枢神经系统神经元的二元细胞命运选择。通过遗传屏幕，我们将SANPODO鉴定为与介导不对称分裂的缺口途径作用的基因，最初将SANPODO表征为编码F-肌动蛋白/真菌素结合蛋白的脊椎动物基因的同源物。但是，我们的数据提供了令人信服的证据，表明SANPODO不编码托波多林，而是一种新型的四通跨膜蛋白。该提案的目标是阐明Sanpodo介导不对称分裂的遗传和分子基础。具体而言，我们建议：（1）确认Sanpodo的分子身份； （2）完成SANPODO的系统遗传，表达和分子分析； （3）阐明了Sanpodo通过识别SANPODO相互作用蛋白来调节不对称分裂的分子机制。存在Notch途径成员和麻木的哺乳动物同源物。最近的遗传，表达和分子研究表明，这些因素还调节哺乳动物的不对称分裂。因此，阐明SANPODO功能如何与Notch和Numb的功能整合以调节不对称细胞分裂的功能可能会提供对分子和遗传机制的一般见解，从而在整个动物发育中创造细胞多样性。