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。通过这些隔间的融合完成货物转移。许多蛋白质控制融合，但膜本身的作用仍然没有得到充分的研究。膜含有融合所必需的特殊脂质，PI的实验室检查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，但其机制尚不清楚。该项目的长期目标是阐明脂质修饰如何影响膜融合。该项目将使调查员能够继续培训各级科学家，包括女学生和其他代表性不足的学生。这项研究将通过向各行各业的学生广泛传播科学发现和教育来造福社会。真核细胞内稳态部分通过膜融合来维持，膜融合由SNARE蛋白催化。在融合之前，失活的SNARE复合物被Sec 18/NSF分解成单个蛋白质。PI的实验室发现磷脂酸（PA）结合Sec 18以将其从SNARE中隔离。PA磷酸酶Pah 1/Lipin 1将PA转化为甘油二酯以释放Sec 18并使其与SNARE结合。本研究的目的是对PA和Sec 18之间的相互作用进行详细分析。首先，他们将使用生物化学，生物物理和计算方法来定义Sec 18上的PA结合位点。其次，他们将阐明PA结合如何诱导Sec 18构象变化。第三，他们将测试PA在其他细胞器中对Sec 18调节的保守性。该项目的完成将确定Sec 18如何被膜调节以激活SNARE。该奖项反映了NSF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.