Investigating Regulation of Integral Membrane Protein Cofactor Biosynthesis using

研究整合膜蛋白辅因子生物合成的调控

• 批准号: 8101689
• 负责人: Ronald F Peck
• 金额: $ 11.49万
• 依托单位: LAWRENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-03-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8101689
• 关键词: Affect; Alzheimer' s Disease; Anabolism; Animals; Apoproteins; Archaea; Bacteria; Bacteriorhodopsins; Binding; Biochemical; Biochemical Pathway; Biological Models; Cell Respiration; Cells; Complex; Data; Disease; Electrons; Ensure; Enzymes; Equilibrium; Eukaryota; Eye; Family; Food Energy; Gene Deletion; Genes; Genetic; Genetic Transcription; Goals; Growth; Halobacterium salinarium; Hour; Human; Individual; Integral Membrane Protein; Life; Light; Mediating; Membrane; Membrane Proteins; Microbe; Microbial Rhodopsins; Mitochondria; Modeling; Molecular; Opsin; Organism; Oxygen; Pathway interactions; Phototransduction; Process; Production; Protein Biosynthesis; Proteins; Proton Pump; Regulation; Research; Retinal; Retinitis Pigmentosa; Rhodopsin; Site; System; Transcriptional Regulation; Vitamin A; Work; bacterio-opsin; base; biological systems; cofactor; cytochrome c oxidase; insight; interdisciplinary approach; member; novel; pH gradient; physical process; prevent; protein complex; small molecule; stoichiometry; tool

DESCRIPTION (provided by applicant): Integral membrane protein complexes consisting of proteins and small molecules that act as cofactors are ubiquitous and vitally important for organisms. For example, cytochrome oxidase is a mitochondrial complex that catalyzes the delivery of electrons to oxygen to allow cellular respiration. Rhodopsin is found in the eyes of many animals, including humans, and consists of an opsin membrane protein and a Vitamin A retinal cofactor. In these systems, an exquisite balance of protein and cofactor is maintained. Disruptions in this balance are thought to be causative factors for diseases such as Alzheimer's and retinitis pigmentosa. The proposed project describes a multidisciplinary approach to characterize a novel mechanism for coordinated synthesis of proteins and cofactors for integral membrane complexes. We will take advantage of the simple bacteriorhodopsin (BR) protein-cofactor complex in the microbe Halobacterium salinarum to potentially provide insight into how coordination is achieved in more complex systems. BR functions as a light-driven proton pump in the halophilic archaeon H. salinarum, and allows the organism to generate usable cellular energy under conditions where low oxygen prevents aerobic respiration. BR is the simplest possible membrane protein complex consisting of a single retinal cofactor bound to a single protein, bacterioopsin (BO). Under low oxygen conditions, H. salinarum rapidly induces BR biosynthesis, and this induction necessarily requires increased production of both the protein, BO, and the cofactor, retinal. In the proposed work, we explore how H. salinarum proteins interact to coordinate the synthesis of BO and retinal. Our preliminary results suggest that this coordination occurs by a novel mechanism where BO, not bound by retinal, inhibits an alternate biochemical pathway to only allow precursor molecules to be used for retinal synthesis. To investigate this mechanism, we will use genetic and biochemical approaches to characterize enzymes that catalyze the synthesis of the retinal cofactor and related molecules. We will then identify which retinal precursors or enzymes interact with BO. Lastly, we will structurally characterize the interaction between BO and these molecules. PUBLIC HEALTH RELEVANCE: Molecular complexes consisting of proteins and cofactors are critical to our everyday life, such as complexes that enable the physical processes that allow us to see or to gain energy from food. Unfortunately, these cofactors and proteins can occasionally get out of balance, leading to diseases such as retinitis pigmentosa and Alzheimer's. The proposed research will study a simple molecular complex in a model system, in order to help us understand the mechanisms that operate in our own bodies to keep proteins and their cofactors in the correct balance.

描述（由申请人提供）：