Molecular mechanisms of voltage-gated proton channels

电压门控质子通道的分子机制

• 批准号: 7987166
• 负责人: Hans Peter Larsson
• 金额: $ 37.29万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-20 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7987166
• 关键词: Affect; Amino Acids; Asthma; Behavior; Blood Cells; Cells; Charge; Co-Immunoprecipitations; Coiled-Coil Domain; Cysteine; Data; Deletion Mutation; Development; Dimerization; Disease; Drug Delivery Systems; Environment; Epithelium; Financial compensation; Fluorescence Resonance Energy Transfer; Future; Generations; Goals; Grant; Immune system; Inflammatory Response; Kinetics; Lead; Lung; Macrophage Activation; Mammalian Cell; Measures; Membrane; Microglia; Molecular; Movement; Mutate; Mutation; Natural Immunity; Pathology; Pathway interactions; Phagocytes; Phagocytosis; Phagosomes; Play; Positioning Attribute; Potassium; Process; Property; Proteins; Protons; Reactive Oxygen Species; Regulation; Research; Research Personnel; Respiratory Burst; Rest; Role; Series; Skeletal Muscle; Structure; Techniques; Testing; Therapeutic Intervention; Transmembrane Domain; Work; apical membrane; base; cell type; dimer; experience; immune function; insight; macrophage; novel; pathogen; public health relevance; voltage

DESCRIPTION (provided by applicant): Voltage-gated proton (HV) channels have been found in many mammalian cell types, including blood cells, lung epithelia, skeletal muscle, and microglia. Of particular importance, HV channels have been shown to play a crucial role in blood cells: HV channels in macrophages are essential for the generation of reactive oxygen species during the respiratory burst, which is critical to the process of phagocytosis and the destruction of foreign pathogens. Our long-term goal is to understand the molecular mechanism of HV channel function in macrophages and other cell types. Recently, the molecular identify of HV channels was discovered. HV was found to be homologous to the voltage-sensing domain (VSD) of voltage-gated potassium (Kv) channels. Kv channels are tetrameric channels with 6 transmembrane (TM) segments and a pore domain. However, HV channels have only the first 4 TMs and lack a typical pore domain. We recently showed that HV channels are dimers, with each subunit having its own proton pathway. Many questions about their molecular function remain unanswered. How do two HV subunits come together to form a dimeric HV channel? How does voltage activate HV channels and how does macrophage activation alter the activity of HV channels? What constitutes the proton permeation pathway in HV channels? The research objectives of this grant are to determine the mechanism of dimerization of HV subunits, to determine how dimerization affects the activity and cooperativity of HV subunits, and to identify residues lining the proton conduction pathway in HV channels. The results of the proposed work will provide a greater understanding of the structure of the voltage-gated proton channel HV and will provide a first step in understanding how the activity of this protein is regulated. The proposed work is highly significant to understanding the basis of innate immunity as well as the pathology underlying asthma. HV is a crucial component in the function of phagocytes of the immune system, and it is also an important factor in the lungs during asthma. A greater understanding of the structure and regulation of HV will therefore provide new insight into the role that this protein plays in both disease and in normal immune function, and could provide novel avenues for therapeutic intervention in a number of pathologies. Most significantly, the regulation of HV could be a potential drug target for modulating the inflammatory response of the immune system as well as for the treatment of asthma. PUBLIC HEALTH RELEVANCE: The voltage-gated proton (HV) channel is a crucial component in the function of phagocytotic blood cells of the immune system, as well as an important factor in the lungs during asthma. The results from the proposed study will lead to a greater understanding of the structure and regulation of HV to provide new insight into the role that this protein plays in both disease and in normal immune function, thereby providing novel avenues for therapeutic intervention in a number of pathologies. Most significantly, the regulation of Hv could be a potential drug target for modulating the inflammatory response of the immune system, as well as for the treatment of asthma.

描述（由申请人提供）：在许多哺乳动物细胞类型中发现了电压门控质子（HV）通道，包括血细胞，肺上皮，骨骼肌和小胶质细胞。特别重要的是，HV通道已被证明在血细胞中起着至关重要的作用：巨噬细胞中的HV通道对于在呼吸爆发期间产生活性氧是必不可少的，这对于吞噬作用和外源性病原体的破坏至关重要。我们的长期目标是了解巨噬细胞和其他细胞类型中HV通道功能的分子机制。最近，发现了HV通道的分子识别。发现HV与电压门控钾（KV）通道的电压感应结构域（VSD）同源。 KV通道是具有6个跨膜（TM）段和一个孔结构域的四聚体通道。但是，HV通道只有前4个TM，并且缺乏典型的孔域。我们最近表明，HV通道是二聚体，每个亚基都有其自身的质子途径。有关其分子功能的许多问题仍未得到解答。两个HV亚基如何组合在一起形成二聚体HV通道？电压如何激活HV通道，巨噬细胞激活如何改变HV通道的活性？什么构成了HV通道中质子渗透途径？该赠款的研究目标是确定HV亚基的二聚化机理，以确定二聚化如何影响HV亚基的活性和协同性，并确定HV通道中质子传导途径的残基。拟议工作的结果将对电压门控质子通道HV的结构有更深入的了解，并将为理解该蛋白质的活性如何调节提供第一步。拟议的工作对于理解先天免疫以及哮喘的病理学的基础非常重要。 HV是免疫系统吞噬细胞功能的关键成分，它也是哮喘期间肺部的重要因素。因此，对HV的结构和调节有了更大的了解，将为该蛋白质在疾病和正常免疫功能中所起的作用提供新的见解，并可以为许多病理学提供治疗干预的新途径。最重要的是，HV的调节可能是调节免疫系统炎症反应以及哮喘治疗的潜在药物靶标。 公共卫生相关性：电压门控质子（HV）通道是免疫系统吞噬血细胞功能的关键组成部分，也是哮喘期间肺部的重要因素。拟议研究的结果将使人们对HV的结构和调节有更深入的了解，以提供有关该蛋白在疾病和正常免疫功能中起作用的作用的新见解，从而为在许多病理中提供了新的治疗干预途径。最重要的是，HV的调节可能是调节免疫系统炎症反应以及哮喘治疗的潜在药物靶标。