Small G-protein Regulation of Calcium Channels

小 G 蛋白对钙通道的调节

• 批准号: 8695923
• 负责人: Henry M. Colecraft
• 金额: $ 30.4万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8695923
• 关键词: Address; Adult; Alzheimer' s Disease; Arrhythmia; Binding; Biochemical; Breathing; Calcium; Calcium Channel; Cardiac Myocytes; Cell membrane; Cells; Charge; Data; Disease; Dynamin; Electrophysiology (science); Endocytosis; Engineering; Family; Family member; Fluorescence Resonance Energy Transfer; Heart; Homeostasis; Hypertension; Individual; Light; Molecular; Molecular Biology; Monomeric GTP-Binding Proteins; Pain; Parkinson Disease; Physiological; Physiology; Probability; Protein Inhibition; Protein Isoforms; Proteins; Rattus; Reagent; Recombinants; Regulation; Relative (related person); Surface; Therapeutic; Therapeutic Index; Tissues; Work; channel blockers; density; design; inhibitor/antagonist; insight; nervous system disorder; novel; painful neuropathy; public health relevance; research study; sensor; small molecule; trafficking; voltage

DESCRIPTION (provided by applicant): High-voltage-activated calcium (CaV1/CaV2) channels are necessary for the function of excitable cells. Molecules that inhibit CaV1/CaV2 channels powerfully regulate physiology, and are important or potential therapeutics for many serious diseases including: hypertension, neuropathic pain, cardiac arrhythmias, and Parkinson's disease. CaV1/CaV2 channels are potently inhibited by a four-member family of monomeric G- proteins known as RGK (Rad, Rem, Rem2, Gem/Kir) proteins. RGKs are expressed in excitable tissues, and their expression level often changes correlatively with disease, suggesting their strong regulation of CaV1/CaV2 has broad patho-physiological implications. Engineered RGKs have potential therapeutic applications as genetically-encoded CaV channel blockers (CCBs) for a broad range of diseases. For specific applications, genetically encoded inhibitors may provide a higher therapeutic index than traditional small molecule CCBs because they can be locally expressed, thereby achieving effective CaV channel block while minimizing off- target effects. The precise molecular mechanisms by which RGKs inhibit CaV1/CaV2 channels are not well- understood. Our preliminary data hint at a surprising degree of customization and complexity where distinct RGK proteins differentially use multiple mechanisms and structural determinants to inhibit individual CaV1/CaV2 channel isoforms. Precise understanding of the mechanisms underlying customized RGK inhibition of CaV1/CaV2 channels is critical for insights into the patho-physiological ramifications of this channel regulation, as well as efforts to engineer useful new genetically-encoded CCBs. Our long-term objective is to furnish fundamental understanding of the diverse molecular mechanisms and structural determinants underlying RGK inhibition of CaV1/CaV2 channels and to bridge these insights to: (i) a new appreciation of the patho-physiological implications of this channel modulation; and (ii) the design of novel, useful genetically-encoded CCBs as potential therapeutics. We combine whole-cell and single-channel electrophysiology, fluorescence resonance energy transfer (FRET), molecular biology, channel engineering, and biochemical approaches to address three specific Aims: (1) Dissect mechanisms the RGK protein, Rem, uses to inhibit recombinant CaV1.2 channels. (2) Determine and contrast mechanisms of RGK inhibition across the CaV1/CaV2 channel family. (3) Dissect mechanisms of RGK inhibition of native CaV1.2 channels in cardiomyocytes.

描述（由申请人提供）：高压活化钙（CaV1/CaV2）通道是可兴奋细胞功能所必需的。抑制CaV1/CaV2通道的分子有力地调节生理，是许多严重疾病的重要或潜在的治疗方法，包括：高血压、神经性疼痛、心律失常和帕金森病。CaV1/CaV2通道被称为RGK （Rad, Rem, Rem2, Gem/Kir）蛋白的单体G蛋白四成员家族有效抑制。RGKs在可兴奋组织中表达，其表达水平经常与疾病相关变化，表明其对CaV1/CaV2的强调控具有广泛的病理生理意义。工程RGKs作为基因编码的CaV通道阻滞剂（CCBs）在广泛的疾病中具有潜在的治疗应用。对于特定的应用，基因编码抑制剂可能比传统的小分子ccb提供更高的治疗指数，因为它们可以局部表达，从而实现有效的CaV通道阻断，同时最大限度地减少脱靶效应。RGKs抑制CaV1/CaV2通道的确切分子机制尚不清楚。我们的初步数据暗示了令人惊讶的定制程度和复杂性，其中不同的RGK蛋白不同地使用多种机制和结构决定因素来抑制单个CaV1/CaV2通道亚型。精确理解定制的RGK抑制CaV1/CaV2通道的机制对于深入了解这种通道调节的病理生理后果以及努力设计有用的新的遗传编码ccb至关重要。我们的长期目标是提供对RGK抑制CaV1/CaV2通道的多种分子机制和结构决定因素的基本理解，并将这些见解与以下方面联系起来：(1)对其病理生理意义的新认识