The meiotic role of SIK19p in yeast

描述（由申请人提供）：减数分裂与减数分裂之间的根本差异 有丝分裂染色体分离是在减数分裂I中，姐妹染色单体移动， 作为一个单元连接到主轴的一个极点，而不是像在 分裂。通过减数分裂I姐妹染色单体的持续连锁是 通过染色体在着丝粒区域的结合完成， 着丝粒的发展，允许两个染色单体作为一个单位移动， 主轴的一极。减数分裂特异性粘附素的定位， Rec8p对着丝粒的作用对姐妹染色单体的维持至关重要 减数分裂I的凝聚力，而Mam1p是动粒所必需的 发展，但调节凝聚力和姐妹的分子基础 减数分裂中的动粒仍然是一个谜。最近，它被证明 酿酒酵母的S1k19蛋白对于 通过减数分裂I维持姐妹染色单体联合。两个可能 已经提出Slkl9p在减数分裂中的作用。一是推广姐姐 染色单体的凝聚力在着丝粒，也许是通过保护Rec8p在这一点上， 从中期I到后期I过渡的降解区域。第二 是控制姐妹动粒发育，使得姐妹染色单体共享 在整个减数分裂I中具有单一功能的动粒。该提案涉及 这些模型通过四组实验。首先，提出实验 使用染色质免疫沉淀法来探索着丝粒 Slkl9p和Mamip的定位，以及它们相互依赖， 与Centromere的联系CDEII着丝粒元件在 减数分裂动粒功能将从遗传学角度和通过研究进行探索 与Slkl9p的联系第二，我们将测试Slk 19p是否控制 姐妹染色单体着丝粒凝聚与Rec8p的关系 并通过使用细胞生物学测定来监测建立， SLK19突变体中姐妹染色单体着丝粒联合的维持。的 第三组实验旨在确定 在减数分裂中与Slkl9p相互作用的蛋白质。一个双混合屏幕将是 执行。亲和层析将用于纯化Slkl9p和相关的 来自减数分裂细胞的蛋白质。一种遗传学方法将被用来识别高拷贝 SLK19部分功能丧失突变体的抑制子。最后，我们将探讨 Slkl9p通过以下方式调节：1）Spo 13 p 2）可能与泛素缀合或 泛素样蛋白，3）靶向Cdh 1p和Amaip的降解， 4)Espip降解，Espip是一种通过剪切触发后期I的蛋白酶 粘着蛋白

DESCRIPTION (provided by applicant): A fundamental difference between meiotic and mitotic chromosome segregation is that in meiosis I, sister chromatids move as a unit to one pole of the spindle rather than separating as they do in mitosis. Sustained linkage of sister chromatids through meiosis I is accomplished by association of the chromatids at the centromere region and development of kinetochores that allow both chromatids to be moved as a unit to one pole of the spindle. The localization of the meiosis-specific cohesin, Rec8p, to the centromeres is essential for maintenance of sister chromatid cohesion through meiosis I, and Mam1p is necessary for kinetochore development, but the molecular basis for the regulation of cohesion and sister kinetochores in meiosis remains a mystery. Recently, it has been demonstrated that the S1k19 protein of Saccharomyces cerevisiae is essential for the maintenance of sister chromatid association through meiosis I. Two possible roles have been suggested for Slkl9p in meiosis. The first is to promote sister chromatid cohesion at the centromeres, perhaps by protecting Rec8p in this region from degradation at the metaphase I to anaphase I transition. The second is to control sister kinetochore development, such that sister chromatids share a single functional kinetochore throughout meiosis I. This proposal addresses these models through four sets of experiments. First, experiments are proposed that use the chromatin immuno-precipitation method to explore the centromeric localization of Slkl9p and Mamip, and their dependence upon each other for association with the centromere. The role of the CDEII centromere element in meiotic kinetochore function will be explored genetically and through studies of its association with Slkl9p. Second, we will test whether Slk 19p controls sister chromatid centromere cohesion by monitoring its relationship with Rec8p and by using cell biological assays to monitor the establishment and maintenance of sister chromatid centromere association in slkl9 mutants. The third set of experiments is designed to determine the identities of the proteins that interact with Slkl9p in meiosis. A two-hybrid screen will be performed. Affinity chromatography will be used to purify Slkl9p and associated proteins from meiotic cells. A genetic approach will used to identify high copy suppressors of slkl9 partial loss-of-function mutants. Finally, we will explore the regulation of Slkl9p by: 1) Spo 13p 2) possible conjugation to ubiquin or ubiquitin-like proteins, 3) targetting for degradation by Cdh 1p and Amaip and 4) degradation by Espip, the protease that triggers anaphase I by clipping cohesin proteins.