Developmental control of spindle positioning in embryos

胚胎中纺锤体定位的发育控制

基本信息

批准号：
6865387
负责人：
LESILEE S. ROSE
金额：
$ 26.52万
依托单位：
UNIVERSITY OF CALIFORNIA AT DAVIS
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-04-01 至 2008-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6865387
关键词：
Caenorhabditis elegans G protein biological signal transduction cell cycle cell cycle proteins cellular polarity cytogenetics developmental genetics immunoprecipitation mitotic spindle apparatus mutant protein localization protein sequence protein structure function video microscopy yeast two hybrid system

项目摘要

DESCRIPTION (provided by applicant): Proper positioning of the mitotic spindle is essential for a number of developmental processes, including asymmetric divisions in which a polarized cell divides to produce daughters with different fates. This project addresses the mechanisms by which the conserved PAR polarity proteins and a downstream intermediate, LET-99, regulate spindle position during asymmetric divisions in the model organism Caenorhabditis elegans. Several hypotheses about LET-99 function will be tested. In Aim 1, the genetic pathway by which the PAR proteins localize LET-99 in a cortical band will be determined by examining LET-99 localization in mutant backgrounds. In addition, the regions of the LET-99 protein that are necessary and sufficient for cortical and asymmetric localization will be identified using transgenes. In Aim 2, the hypothesis that the cortical LET-99 band controls spindle positioning will be tested by time-lapse video microscopy of mutants with altered LET-99 distributions. Aim 3 will test the hypothesis that LET-99 antagonizes the G protein signaling pathway that functions in spindle positioning. Genetic interactions will be examined and possible associations between LET-99 and components of the G protein pathway will be assayed using co-immunoprecipitations and two-hybrid assays. In Aim 4, the hypothesis that the spn-2 gene acts with LET-99 to antagonize G protein signaling will be tested. In the long term, these studies will lead to an in-depth understanding of the molecular mechanisms that coordinate polarity and spindle orientation. Asymmetric divisions are important to the development of all multcellular organisms, and the PAR proteins are conserved in many organisms, including humans. Thus, insights gained from this work will be of wide relevance and could also aid in the understanding of developmental abnormalities that lead to cancer or other disorders.

描述（由申请人提供）：有丝分裂纺锤体的正确定位对于许多发育过程至关重要，包括不对称分裂，其中极化细胞分裂产生具有不同命运的子代。该项目研究了模型生物秀丽隐杆线虫中保守的 PAR 极性蛋白和下游中间体 LET-99 在不对称分裂过程中调节纺锤体位置的机制。将测试有关 LET-99 功能的几个假设。在目标 1 中，将通过检查突变背景中的 LET-99 定位来确定 PAR 蛋白将 LET-99 定位在皮质带中的遗传途径。此外，将使用转基因来鉴定皮质和不对称定位所必需且充分的 LET-99 蛋白区域。在目标 2 中，皮质 LET-99 带控制纺锤体定位的假设将通过 LET-99 分布改变的突变体的延时视频显微镜进行测试。目标 3 将检验 LET-99 拮抗在纺锤体定位中起作用的 G 蛋白信号传导途径的假设。将检查遗传相互作用，并使用免疫共沉淀和双杂交分析来分析 LET-99 和 G 蛋白途径成分之间可能的关联。在目标 4 中，将测试 spn-2 基因与 LET-99 共同作用以拮抗 G 蛋白信号传导的假设。从长远来看，这些研究将有助于深入了解协调极性和纺锤体方向的分子机制。不对称分裂对于所有多细胞生物体的发育都很重要，并且 PAR 蛋白在包括人类在内的许多生物体中是保守的。因此，从这项工作中获得的见解将具有广泛的相关性，并且还可以帮助理解导致癌症或其他疾病的发育异常。