Regulation of the AAA+ protein Sec18 through membrane lipid modification

真核细胞被划分为细胞器，通过膜运输囊泡的运输进行通信。货物的转移是通过这些舱室的融合完成的。许多蛋白质控制融合，但膜本身的作用仍未得到充分研究。膜含有对融合至关重要的特殊脂质，PI的实验室研究这些脂质如何影响融合过程中的蛋白质功能。改变脂质含量会对融合产生负面影响，但机制尚不清楚。该项目的长期目标是阐明脂质修饰如何影响膜融合。该项目将允许研究人员继续培训各级科学家，包括女性和其他代表性不足的学生。这项研究将科学发现和教育广泛地传播给各行各业的学生，从而造福社会。真核细胞的稳态部分是通过膜融合维持的，而膜融合是由SNARE蛋白催化的。在融合之前，无活性的SNARE复合体被Sec18/NSF分解成单个蛋白。PI的实验室发现磷脂酸（PA）与Sec18结合，将其与SNAREs隔离。PA磷酸酶Pah1/Lipin1将PA转化为二酰基甘油以释放Sec18并允许其参与SNAREs。本研究的目的是对PA和Sec18之间的相互作用进行详细的分析。首先，他们将使用生化、生物物理和计算方法来确定Sec18上PA的结合位点。其次，他们将阐明pa结合如何诱导Sec18构象变化。第三，他们将测试PA在其他细胞器中对Sec18调控的保守性。这个项目的完成将定义Sec18是如何被膜调节来激活SNAREs的。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Eukaryotic cells are compartmentalized into organelles that communicate through the trafficking of membranous transport vesicles. Cargo transfer is finalized through the fusion of these compartments. Many proteins control fusion, yet the role of the membrane itself remains under-examined. Membranes contain specialized lipids that are essential for fusion and the PI's lab examines how these lipids affect protein function during fusion. Altering lipid content negatively affects fusion, however the mechanisms are unknown. The long-term goal of this project is to elucidate how lipid modification affects membrane fusion. The project will allow the investigator to continue his training of scientists at all levels, including female and other underrepresented students. This research will benefit society by spreading scientific discovery and education broadly to students from all walks of life. Eukaryotic cellular homeostasis is maintained in part through membrane fusion, which is catalyzed by SNARE proteins. Prior to fusion, inactive SNARE complexes are disassembled into individual proteins by Sec18/NSF. The PI's lab discovered that phosphatidic acid (PA) binds Sec18 to sequester it from SNAREs. The PA phosphatase Pah1/Lipin1 converts PA to diacylglycerol to release Sec18 and allows it to engage SNAREs. The objective of this research is to undertake a detailed analysis of the interactions between PA and Sec18. First, they will use biochemical, biophysical and computational approaches to define the PA binding sites on Sec18. Second, they will elucidate how PA-binding induces Sec18 conformational changes. Third, they will test conservation of Sec18 regulation by PA in other organelles. The completion of this project will define the how Sec18 is regulated by the membrane to activate SNAREs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.