CHARACTERIZATION OF YEAST DYANCTIN COMPLEX

酵母动态蛋白复合物的表征

• 批准号: 7420751
• 负责人: JOHN COOPER
• 金额: $ 0.29万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-20 至 2007-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7420751
• 关键词: actins; cell cycle proteins; dynein ATPase; enzyme inhibitors; microtubules; mutant; phenotype; protein kinase; proteins; yeasts

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Dynactin is a multi-subunit protein complex required for most dynein activities, proposed to serve either as a cargo adaptor or to enhance dynein motor processivity. Dynactin consists of two parts with eleven different polypeptides. 1) The actin-like Arp1 filament has conventional actin and capping protein at its barbed end and Arp11, p25, p27, and p62 at its pointed end. 2) The arm consists of p150Glued, dynamitin, and p24/22. In Saccharomyces cerevisae, homologues of several dynactin subunits have been identified, and deletion of their genes produces phenotypes identical to those of dynein null mutations. On the other hand, homologues for p24/22, p25, p27 and p62 have not been identified, and the composition of yeast dynactin has not been defined biochemically. Here, we report the discovery of an apparent p24/22 homolog in budding yeast, based on the following: 1) The null mutant has a dynein-like phenotype for spindle movement. 2) The predicted polypeptide has an appropriate size and secondary structure. 3) The null mutant is synthetic with kar9∆but not dyn1∆. 4) The protein localizes to microtubule plus ends and the spindle pole body, as seen for Nip100 / p150Glued. 5) Dynein accumulates of dynein at the plus end of microtubules in the null mutant, as seen withknown dynactin mutants. Biochemical fractionations of intact dynactin complex are underway, which may identify other subunits of yeast dynactin. Based on our current understanding, dynactin is needed to offload dynein from the plus ends to the cortex.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。Dynactin是一种多亚基蛋白复合物，大多数动力蛋白的活动所需的，建议作为货物适配器或增强动力蛋白运动的持续合成能力。Dynactin由两部分组成，具有11种不同的多肽。1)肌动蛋白样Arp 1丝在其倒刺末端具有常规肌动蛋白和帽蛋白，在其尖端具有Arp 11、p25、p27和p62。2)该臂由p150 Glued、dynamitin和p24/22组成。在酿酒酵母中，已经鉴定了几种动力蛋白亚基的同源物，并且其基因的缺失产生与动力蛋白无效突变相同的表型。另一方面，p24/22、p25、p27和p62的同源物尚未被鉴定，酵母动力蛋白的组成尚未被生物化学地确定。在这里，我们报告了在芽殖酵母中发现的一个明显的p24/22同源物，基于以下几点：1）无效突变体具有动力蛋白样表型的纺锤体运动。2)预测的多肽具有适当的大小和二级结构。3)无效突变体是与kar 9而不是dyn 1合成的。4)该蛋白定位于微管加端和纺锤体极体，如Nip 100/p150 Glued所示。5)在无效突变体中，动力蛋白在微管的正端积累，如已知的动力蛋白突变体所见。完整的dynactin复合物的生化分级分离正在进行中，这可能会识别酵母dynactin的其他亚基。根据我们目前的理解，动力蛋白需要动力肌动蛋白从正端卸载到皮层。