CHROMOSOME MOVEMENT IN PROMETAPHASE

描述（改编自申请人的摘要）：动粒 介导染色体沿着微管的运动， 有丝分裂纺锤体 Cyert抗体，它是针对一个 不完全表征的磷酸化表位，结合到 染色体的着丝粒在前中期在一个前所未有的， 有趣的方式。 染色体移向中期板 在前导动粒上强烈表达磷酸化表位， 在拖尾动粒上弱。 这个微分表达式 表位可能反映了调节染色体运动的生化途径 和有丝分裂的进程。 两个相互竞争的假设 Cyert抗体识别的表位的分子性质将 得到考验 首先，抗体识别调节磷酸化 一种能驱动或引导染色体运动的蛋白质。 二是 表位识别磷酸酶的酶中间体， 在着丝粒上的差异调节。 本申请的目的是 （1）研究磷酸化表位的表达如何在细胞中变化， 与染色体运动和有丝分裂进程的关系;（2） 确定激酶和磷酸酶如何调节该表达;（3） 识别含有表位的蛋白质;以及（4）了解 有丝分裂纺锤体中的位置和机械信号 转化为调节染色体运动的生化信息 并通过有丝分裂进行。 这些目标将通过以下方式实现： 免疫化学分离、分级分离和分子表征 动粒蛋白质。 这些努力将得到 活细胞中染色体行为的分析，免疫标记研究， 染色体的显微操作，抗体的显微注射 和抑制剂。

DESCRIPTION (adapted from applicant's abstract): The kinetochore mediates the movement of chromosomes along the microtubules of the mitotic spindle. The Cyert antibody, which is directed to an incompletely characterized, phosphorylated epitope, binds to the kinetochores of chromosomes in prometaphase in a unprecedented and intriguing manner. Chromosomes moving toward the metaphase plate express the phospho-epitope strongly on the leading kinetochore but weakly on the trailing kinetochore. This differential expression of the epitope may reflect a biochemical pathway regulating chromosome movement and the progression of mitosis. Two competing hypotheses for the molecular nature of the epitope recognized by the Cyert antibody will be tested. First, the antibody recognizes a regulatory phosphorylation on a protein that powers or guides chromosome movement. Second, the epitope recognizes an enzymatic intermediate of a phosphatase that is differentially regulated at kinetochores. The aims of this application are: (1) to examine how expression of the phospho-epitope changes in relation to chromosome movement and mitotic progression; (2) to determine how kinases and phosphatases regulate that expression; (3) to identify the proteins that contain the epitope; and (4) to understand how positional and mechanical signals in the mitotic spindle are converted to biochemical information that regulates chromosome movement and progression through mitosis. These aims will be achieved by immunochemical isolation, fractionation, and molecular characterization of kinetochore proteins. These efforts will be complemented by the analysis of chromosome behavior in live cells, immunolabeling studies, micromanipulation of chromosomes, and the microinjection of antibodies and inhibitors.