权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

V-ATPase H+ PUMP REGULATION IN FUEL ENERGY SELECTION

燃料能量选择中的 V-ATPase H 泵调节

基本信息

批准号：
8475614
负责人：
Karlett J Parra
金额：
$ 28.56万
依托单位：
UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-08-01 至 2015-11-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8475614
关键词：
Acetyl Coenzyme A Acid-Base Equilibrium Address African American Alaska Native Aldehyde-Lyases American Indians Bacterial Toxins Binding Biochemical Biological Models Carbon Cell membrane Cells Chronic Kidney Failure Citrates Complement Complex Coupled Couples Defect Development Diabetes Mellitus Disease Elements Endosomes Energy Metabolism Enzymes Ethnic group Fatty Acids Fatty acid glycerol esters Fructose Functional disorder Genetic Glucose Glycolysis Goals Health Hispanics In Vitro Insulin Resistance Intercalated Cell Kidney Kidney Diseases Knowledge Link Lysosomes Macromolecular Complexes Malignant Neoplasms Malonyl Coenzyme A Measures Membrane Metabolic Metabolic Control Metabolic Diseases Metabolism Modeling Molecular Molecular Structure Nephrons Nutrient Obesity Organism Pathway interactions Physiology Process Measure Proteins Proton Pump Protons Public Health Pump Quality of life Race Regulation Research Risk Factors Saccharomyces cerevisiae Signal Transduction Sorting - Cell Movement Source Structure System Testing Vacuole Virus Warburg Effect Yeast Model System Yeasts cancer cell extracellular fatty acid metabolism fatty acid oxidation glucose metabolism in vivo insight interest kidney cell lipid metabolism lysosome membrane metabolic abnormality assessment mutant novel oxidation pH Homeostasis reconstitution response vacuolar H+-ATPase

项目摘要

DESCRIPTION (provided by applicant): V-ATPases are conserved proton pumps important to pH homeostasis. Located at the membrane of lysosomes, vacuoles and endosomes, V-ATPases sustain the acidic luminal pH needed for protein sorting and degradation; and for entry of viruses and bacterial toxins into host cells. Cells specialized for active proton secretion such as the 1-intercalated cells of the kidney nephron, express V-ATPases at the plasma membrane where they fine-tune the systemic acid-base balance. It is our goal to demonstrate the fundamental mechanisms that carefully regulate V-ATPase function and assembly in order to gain insight into how V- ATPases assist in controlling luminal, cytosolic, and extracellular pH. V-ATPases are dynamic structures that reversibly disassemble to control pH. In yeast and kidney cells, activity and V-ATPase assembly are coupled with glycolysis, but the mechanisms involved are unclear. Using yeast model systems, we have shown a novel link between V-ATPases and the glucose-fatty acid cycle, suggesting that glucose and lipid metabolism remodel pH homeostasis via effects on V-ATPases. It is our hypothesis that V-ATPase assembly is regulated as a means of maintaining cellular pH homeostasis when metabolism switches between glucose and fatty acids. We propose that a complex consisting of the V-ATPase pump and glycolytic enzymes functionally and structurally couples pH homeostasis and energy metabolism; and that metabolic control of this macromolecular structure regulates V-ATPase assembly. Three specific aims will test this model: Aim 1 will dissect the metabolic signals that link V-ATPase to the glycolytic pathway; Aim 2 will elucidate the mechanisms by which regulation of glycolytic enzymes remodels V-ATPase assembly and activity; and Aim 3 will establish how activation of the glucose-fatty acid cycle cross-talks to V-ATPases. In order to accomplish the aims proposed, this study will measure V-ATPase assembly and disassembly in vma mutants and metabolic mutants deficient in key steps of glycolysis, 2- oxidation of fatty acids, and the glucose-fatty acid cycle. Parallels will be established between intracellular levels of metabolic intermediates and dynamics of binding between V-ATPase and glycolytic enzymes enabling us to understand how V-ATPases assist cells in adjusting to metabolic changes. Because of the complexity involved in both comprehensive metabolic studies and regulation of V-ATPase pumps by reversible disassembly, S. cerevisiae is an outstanding system to address this mechanism at both the genetic and biochemical levels. By showing the contribution of V-ATPases, new insights into the mechanisms that tune fuel energy selection will emerge. Cancer cells use V-ATPases to regulate pH as a result of changes in metabolism; thus new knowledge on the mechanisms by which V-ATPases maintain pH homeostasis in cancer may be revealed. As pathophysiology of the glucose-fatty acid cycle results in metabolic disorders including diabetes and chronic kidney disease, our studies will also contribute towards their understanding.

描述（由申请人提供）：v - atp酶是对pH稳态很重要的保守质子泵。v - atp酶位于溶酶体、液泡和核内体的膜上，维持蛋白质分选和降解所需的酸性腔内pH；以及病毒和细菌毒素进入宿主细胞。专门用于活跃质子分泌的细胞，如肾肾素的1插层细胞，在质膜上表达v - atp酶，在那里它们微调全身酸碱平衡。我们的目标是证明精心调节V- atp酶功能和组装的基本机制，以便深入了解V- atp酶如何协助控制腔内，胞质和细胞外ph。V- atp酶是可逆分解以控制ph的动态结构。在酵母和肾细胞中，活性和V- atp酶组装与糖酵解相结合，但所涉及的机制尚不清楚。利用酵母模型系统，我们发现了v - atp酶与葡萄糖-脂肪酸循环之间的新联系，表明葡萄糖和脂质代谢通过对v - atp酶的影响来重塑pH稳态。我们的假设是，当代谢在葡萄糖和脂肪酸之间转换时，v - atp酶组装作为维持细胞pH稳态的一种手段受到调节。我们认为一个由v - atp酶泵和糖酵解酶组成的复合物在功能和结构上耦合了pH稳态和能量代谢；这种大分子结构的代谢控制调节了v - atp酶的组装。三个特定的目标将测试该模型：目标1将剖析连接v - atp酶与糖酵解途径的代谢信号；目的2将阐明糖酵解酶调节v - atp酶组装和活性的机制；Aim 3将确定葡萄糖-脂肪酸循环的激活如何与v - atp酶交叉对话。为了实现上述目标，本研究将测量vma突变体和缺乏糖酵解、脂肪酸2-氧化和葡萄糖-脂肪酸循环关键步骤的代谢突变体中v - atp酶的组装和拆卸。将在细胞内代谢中间体水平和v - atp酶与糖酵解酶之间的结合动力学之间建立相似之处，使我们能够了解v - atp酶如何协助细胞适应代谢变化。由于综合代谢研究和v - atp酶泵可逆分解调控的复杂性，酿酒酵母在遗传和生化水平上都是解决这一机制的杰出系统。通过展示v - atp酶的作用，对调节燃料能量选择机制的新见解将会出现。癌细胞利用v - atp酶来调节pH值，这是新陈代谢变化的结果；从而揭示v - atp酶在癌症中维持pH稳态的机制。由于葡萄糖-脂肪酸循环的病理生理导致代谢紊乱，包括糖尿病和慢性肾脏疾病，我们的研究也将有助于他们的理解。