pH Regulation of Connexin43: Intermediary Steps

Connexin43 的 pH 调节：中间步骤

• 批准号: 8522342
• 负责人: Mario Delmar
• 金额: $ 12.59万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8522342
• 关键词: Action Potentials; Affinity; Arrhythmia; Binding; Cardiac; Cardiac Myocytes; Cells; Chemicals; Collaborations; Connexin 43; Connexins; Data; Development; Dimerization; Electrophysiology (science); Event; Gap Junctions; Goals; Heptanol; Intervention; Ion Channel; Ischemia; Knowledge; Laboratories; Lead; Maintenance; Mediating; Molecular; Muscle Cells; Neonatal; Octanols; Organ; Pattern; Predisposition; Preparation; Process; Property; Proteins; Rattus; Regulation; Reporting; Role; Source; Tissues; Work; base; drug discovery; intermolecular interaction; monolayer; particle; pharmacophore; prevent; receptor; research study; two-dimensional; voltage

DESCRIPTION (provided by applicant): The long-term goals of our laboratory are: a) to understand the molecular mechanisms that regulate cardiac gap junctions and b) to apply that knowledge to the development of pharmacologic agents able to modify gap junction regulation and function. It is generally accepted that the carboxyl terminal is the major regulatory domain of Connexin43 (Cx43) channels. Our previous work has led to the hypothesis that regulation of Cx43 results from the binding of the carboxyl terminal (Cx43CT) domain -acting as a gating particle- to the cytoplasmic loop (Cx43CL) domain, acting as a receptor for the gating particle. Cx43CT dimerization and other intermolecular interactions involving the same domain may also participate in the process. As a key player in the regulation of gap junctions, the Cx43CT domain is a target for chemical manipulation intended to modify function. Recently, we reported the identification of a peptidic molecule, dubbed "RXPE," that bound Cx43CT with micromolar affinity and partly prevented octanol-induced and acidification-induced uncoupling in pairs of Cx43-expressing N2a cells. Preliminary data presented in this application further show that RXPE binds cardiac Cx43, facilitates the synchronization of electrical activity in monolayers of neonatal cardiac myocytes, and prevents heptanol-induced conduction block in the same preparation. It is the overall objective of this project to use RXP-E as a platform in the development of a gap junction- based pharmacophore of known cellular/molecular action, and to assess its possible efficacy in the maintenance of electrical synchrony in cardiac preparations. Specific aims are: 1: To characterize the effect of RXP-E on the molecular events mediating Cx43 regulation. 2: To analyze the actions of RXP-E on the chemical regulation of cardiac gap junctions, and on the electrophysiology of single cardiac myocytes, and 3: To assess the effect of RXP-E on cardiac action potential propagation, susceptibility to conduction block and arrhythmogenesis. Overall, these studies may lead to a better understanding of the role of gap junctions in the development of ischemia-induced arrhythmias and their possible intervention by chemical means.

描述（由申请人提供）：我们实验室的长期目标是：a）了解调节心脏间隙连接的分子机制，b）将这些知识应用于能够修改间隙连接调节和功能的药理剂的发展。人们普遍认为，羧基末端是connexin43（CX43）通道的主要调节结构域。我们先前的工作导致了以下假设：CX43的调节是由羧基末端（CX43CT）结构域的结合引起的，作为对胞质环（CX43CL）结构域的控球粒子的作用，充当了Gating粒子的受体。 CX43CT二聚化和其他涉及同一域的分子间相互作用也可能参与该过程。作为差距连接调节的关键参与者，CX43CT域是旨在修改功能的化学操作的目标。最近，我们报道了称为“ rxpe”的肽分子的鉴定，该肽分子与微摩尔亲和力结合，并部分阻止了辛醇诱导的和酸化诱导的表达CX43表达N2A细胞的解偶联。本应用程序中提供的初步数据进一步表明，RXPE结合心脏CX43，促进了新生儿心肌细胞单层中电活动的同步，并防止在同一制剂中乙醇醇诱导的传导阻滞。该项目的总体目的是将RXP-E用作已知细胞/分子作用的基于间隙连接的药效团发展的平台，并评估其在维持心脏制剂中电气同步的功效。具体目的是：1：表征RXP-E对介导CX43调节的分子事件的影响。 2：分析RXP-E对心脏间隙连接的化学调节的作用，以及单个心脏肌细胞的电生理学，以及3：评估RXP-E对心脏动作潜在传播的影响，对可传导障碍的敏感性，可导抑制和心律失常。总体而言，这些研究可能会更好地理解间隙连接在缺血引起的心律不齐的发展及其通过化学方法的干预措施中的作用。