Mechanism and function of a novel actin nucleator

新型肌动蛋白成核剂的机制和功能

• 批准号: 7085980
• 负责人: R DYCHE MULLINS
• 金额: $ 25.52万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-01 至 2010-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7085980
• 关键词: Drosophilidae; actins; arthropod genetics; biochemical evolution; cell nucleus; cytoskeletal proteins; egg /ovum; intermolecular interaction; molecular assembly /self assembly; molecular polarity; mutant; protein protein interaction; protein structure; protein structure function

DESCRIPTION (provided by applicant): We recently showed that the product of the Drosophila spire gene, p150-Spir (Spir) nucleates actin filament formation by a unique mechanism (Quinlan et al., 2005). We recently discovered that Spir binds directly to members of another class of actin nucleators, the Cappuccino-family formins (Preliminary Results). This result is consistent with previous genetic studies indicating that the two proteins operate in the same pathway to specify both anterior-posterior and dorsal-ventral axes of developing embryos (Manseau and Schupach, 1989) and localization studies demonstrating that they have identical expression patterns in embryonic and adult mammalian tissues (Schumacher et al., 2004). Spir- and Cappuccino-family proteins are conserved across metazoan species from fruitflies to humans and in mammals and every organism known to express a Spir-family protein also expresses a Cappuccino-family formin. Despite their conservation and their importance in development, however, the function and regulation of Spir and Capu are not well understood. Our results suggest that the activities of Spir and Cappuccino are directly coupled and that they may function together in vivo as a single filament-forming complex. Our long-term goal is to understand how these actin nucleation factors work together to determine polarity of oocytes and embryos. Our short-term goals are to understand the activities of Spir and Capu alone and in complex. We will also investigate a potential mechanism by which the two proteins may be targeted in vivo. Specifically, we will: 1. Determine the mechanism of actin nucleation by Spir. 2. Characterize the interaction of Cappuccino with actin. 3. Characterize the interaction between Spir and Cappuccino. 4. Characterize the interaction of the Spir FYVE domain with lipids.

描述（由申请人提供）：我们最近表明，果蝇基因的产物P150-SpiR（SPIR）通过独特的机制形成了肌动蛋白丝形成（Quinlan等，2005）。我们最近发现，螺旋直接与另一类肌动蛋白成核器的成员结合，即卡布奇诺氏菌formins（初步结果）。该结果与以前的遗传研究一致，表明两种蛋白质在相同的途径中起作用，以指定发育胚胎的前后和背腹轴（Manseau和Schupach，1989），并且本地化研究表明它们在胚胎和成年妈妈和成年妈妈和成年妈妈组织中具有相同的表达模式（Schumamalian Thermant）（Schumacher等）。从果蝇到人类和哺乳动物中，刺激性和卡布奇诺氏蛋白蛋白在多宗种类中保守，并且每个已知表达螺旋蛋白质的生物也表达了cabepcuccino-formin formin。尽管它们的保护和在发展中的重要性，但尚未很好地理解Spir和Capu的功能和调节。我们的结果表明，螺旋和卡布奇诺菌的活性是直接耦合的，并且它们可以在体内作为单个丝形成络合物一起起作用。我们的长期目标是了解这些肌动蛋白成核因子如何共同确定卵母细胞和胚胎的极性。我们的短期目标是仅仅了解Spir and Capu的活动，并且很复杂。我们还将研究一种潜在的机制，通过该机制可以在体内靶向两种蛋白质。具体而言，我们将：1。确定螺旋肌动蛋白成核的机理。 2。表征卡布奇诺与肌动蛋白的相互作用。 3。表征螺旋和卡布奇诺咖啡之间的相互作用。 4。表征Spir Fyve结构域与脂质的相互作用。