Two functionally diverse gamma tubulin core complexes

中心体是微管组织的主要中心，也是人们最了解的中心 (MTOCs)在动物细胞中。编码关键中心体的基因突变 蛋白质影响发育过程，导致综合征性小头畸形， 原始侏儒症和其他遗传性疾病。一个主要的监管者 中心体和其他MTOC的微管是一种高度保守的微管蛋白-微管蛋白(-tuBulin)。 以及专门催化微管启动的微管蛋白变异体 聚合物组装。-微管蛋白与γ-微管蛋白复合体的相互作用 (GCPs)形成环状络合物(-TURC)。我们发现了两种截然不同的-Turc 在果蝇的睾丸中：传统的在整个生命周期中是必不可少的 生物体，以及第二个未鉴定的，其唯一的GCP亚基是 在晚期睾丸中表达，是精子运动所必需的。这是第一次 一个生物体中-TURC核心复合体多样性的已知案例。我们建议 为了确定新的睾丸特异性-TURC的亚基组成和 确定它是否可以与常规的蛋白组装成杂交的GCP-Turcs。 我们将确定这两种-TURC的MT成核特性并确定 新的睾丸特异变异体在精子活力中的作用。其结果是 本项目将是对这一必要的MT功能的新理解 生物化学和体内的核素复合体。

Centrosomes are the major and best-understood microtubule-organizing centers (MTOCs) in animal cells. Mutations in genes that encode key centrosomal proteins impact developmental processes leading to syndromic microcephaly, primordial dwarfisms, and other inherited disorders. A major regulator of microtubules at centrosomes and other MTOCs is -tubulin, a highly conserved and tubulin variant that is specialized in catalyzing the initiation of microtubule polymer assembly. -tubulin associates with gamma tubulin complex proteins (GCPs) to form a ring complex (-TuRC). We found two distinct types of -TuRCs in Drosophila testis: the conventional one that is essential throughout the organism, and a second uncharacterized one whose unique GCP subunits are expressed in late stage testis and are required for sperm motility. This is the first known case of diversity of -TuRC core complexes in one organism. We propose to determine the subunit composition of the new testis-specific -TuRC and determine if it can assemble hybrid -TuRCs with the conventional GCP proteins. We will ascertain the MT nucleation properties of both -TuRCs and determine the role for the novel testis-specific variant in sperm motility. The outcomes of this project will be a new understanding of the functions of this essential MT nucleator complex biochemically and in vivo.