K+ Channel Trafficking and Modulation by Mink and MiRP1

Mink 和 MiRP1 的 K 通道传输和调制

• 批准号: 8258269
• 负责人: Geoffrey W Abbott
• 金额: $ 42.85万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-04 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8258269
• 关键词: Actins; Action Potentials; Address; Adult; Age; Age of Onset; Aging; Animals; Anti-Arrhythmia Agents; Arrhythmia; Atrial Fibrillation; Biochemistry; Cadherins; Cardiac; Cardiac Myocytes; Cells; Cloning; Complex; Computer Simulation; Confocal Microscopy; Connexin 43; Data; Development; Drug Delivery Systems; Dynamin; Electron Microscopy; Electrophysiology (science); Endocytosis; Etiology; Event; Excision; Exhibits; Family; Family suidae; Functional disorder; Funding; Future; Gap Junctions; Genes; Genetic; Genetic Variation; Goals; Health; Heart; Heart Atrium; Hereditary Disease; Human; Incidence; Inherited; Intercalated disc; Life; Link; Lung; Mediating; Messenger RNA; MicroRNAs; Mink; Modeling; Molecular; Molecular Chaperones; Mus; Muscle; Muscle Cells; Mutation; Operative Surgical Procedures; Oryctolagus cuniculus; Pathology; Patients; Physiological; Physiology; Postoperative Period; Potassium; Potassium Channel; Prevention strategy; Protein Chemistry; Proteins; Regulation; Role; Simulate; Staging; Testing; Tissues; Transmembrane Domain; United States; Variant; Ventricular; Ventricular Arrhythmia; Work; base; design; improved; man; member; multi-scale modeling; patch clamp; prevent; public health relevance; research study; stem; trafficking; voltage

DESCRIPTION (provided by applicant): Voltage-gated potassium (Kv) channels repolarize excitable cells such as cardiac myocytes. Dysfunction of cardiac myocyte Kv channels causes life-threatening cardiac arrhythmias, but these channels are also useful antiarrhythmic drug targets. Thus, it is essential to understand their function, regulation and molecular composition, and determine how these differ regionally and between species. The current proposal draws from our preceding decade of work on cloning and defining the diverse physiological roles of members of the KCNE family of single- transmembrane-domain Kv channel ancillary subunits. Following our previous findings that KCNE2 mutations associate with inherited and acquired human ventricular arrhythmias, more recently we generated the kcne2 (-/-) mice line and used it to determine the primary roles of KCNE2 in adult murine ventricles - modulation of two Kv channels and their native current correlates: Kv4.2 (Ito,f) and, unexpectedly, Kv1.5 (IK,slow1). We also defined a new role for KCNE1, as an endocytic chaperone of the KCNQ1 a subunit, and found that both KCNE1 and KCNE2 can influence the a subunit composition of functional Kv channels. KCNQ1, KCNE1 and KCNE2 mutations associate with both atrial and ventricular arrhythmias. Kv1.5 mutations associate with atrial fibrillation (AF), and its function is relatively atrial-specific in human heart, potentially making it a useful target for atrial antiarrhythmics. Most forms of AF have no know genetic basis, and correlate with other factors such as aging, or following surgery to the heart or lungs. A fuller understanding of the native physiology of all these Kv subunits, and how they contribute to both inherited, and age-onset or post-surgery (acquired) forms of AF, is important to improving human cardiac health. Here, we propose to determine the roles of KCNE2 in atrial physiology and in the etiology of AF, utilizing kcne2 (-/-) mice (which exhibit pacing-induced AF), rabbit and swine models of post-operative AF, confirmatory experiments with human atrial tissue, and in silico multiscale atrial models. The studies comprise three Specific Aims. First, we will use a molecular approach to determine which atrial Kv complexes KCNE2 regulates, how its genetic disruption causes AF and Kv channel remodeling, how these mechanisms mirror post-operative AF in larger animals, and the role of Sp1, miR-1 and miR-133 in this remodeling. Second, we will use an electrophysiology/computer modeling approach to determine the function of KCNE2 in mouse and rabbit atria, compare the cellular functional effects arising from kcne2 genetic disruption and post-operative AF, and simulate the mechanistic basis for the resultant arrhythmias, from the cellular to the tissue level. Third, we will define the relationship between KCNE2, Kv1.5, and the intercalated discs (IDs), and determine why KCNE2 disruption prevents Kv1.5 ID targeting in the murine ventricles but not atria. PUBLIC HEALTH RELEVANCE: Specific potassium channels govern cardiac repolarization to end each heart-beat in a timely fashion; inherited gene variants in the genes that encode potassium channels, including KCNQ1, KCNE1 and KCNE2, cause lethal cardiac arrhythmias in man. Atrial fibrillation, which afflicts 2.5 million people in the United States, can be caused by mutation in these genes but is more commonly associated with aging and some surgical procedures. Our proposal is designed to determine the mechanistic role of potassium channels in the atrium, focusing primarily on KCNE2, and uncover molecular events leading up to dysfunction of KCNE2 in inherited and acquired forms of atrial fibrillation, in order to facilitate future antiarrhythmic therapy and prevention strategies.

描述（由申请人提供）：电压门控钾（KV）通道重极化可激发细胞，例如心肌细胞。心肌肌细胞KV通道的功能障碍会导致威胁生命的心律不齐，但这些通道也是有用的抗心律失常药物靶标。因此，必须了解它们的功能，调节和分子组成，并确定这些区域和物种之间的差异。当前的提案源于我们在克隆和定义单跨膜域KCNE家族KCNE家族KCNE家族KV辅助辅助亚基的KCNE家族成员各种生理角色方面的多种生理作用。遵循我们先前的发现，KCNE2突变与遗传和获得的人室性心律不齐相关联，最近我们生成了KCNE2（ - / - ）小鼠线，并用它来确定KCNE2在成年鼠心室中的主要作用 - 两个KV通道和两个KV通道的调制和它们的天然电流相关：KV4.2（ITO，F）和出乎意料的是KV1.5（IK，Slow1）。我们还将KCNE1的新作用定义为KCNQ1 A亚基的内吞伴侣，并发现KCNE1和KCNE2都可以影响功能性KV通道的亚基组成。 KCNQ1，KCNE1和KCNE2突变与心房和心室心律不齐相关。 KV1.5突变与房颤（AF）相关，其功能在人心脏中相对特异性，可能使其成为心房抗心律失常的有用靶标。大多数形式的AF都不知道遗传基础，并且与其他因素（例如衰老或心脏或肺部手术后）相关。对所有这些KV亚基的本地生理学以及它们如何贡献遗传以及年龄发作或术后（获得的）AF形式的AF的本地生理学有了更深入的了解，对于改善人类心脏健康至关重要。在这里，我们建议确定KCNE2在心房生理学和AF的病因中的作用，利用KCNE2（ - / - ）小鼠（表现出起搏引起的AF），兔子和猪的猪和猪的术后AF，确认性实验，并具有与之证实的，具有与之确认的，具有肯定性的实验。人心房组织，以及硅多尺度心房模型。研究包括三个具体目标。首先，我们将使用一种分子方法来确定哪些心房KV复合物可以调节KCNE2，其遗传破坏如何引起AF和KV通道的重塑，这些机制如何反映较大动物的术后AF以及SP1，MiR-1和Mir-1和Mir-1和Mir-1和Mir-133在此重塑中。其次，我们将使用电生理学/计算机建模方法来确定KCNE2在小鼠和兔心房中的功能，比较由KCNE2遗传破坏和术后AF产生的细胞功能效应，并模拟由此产生的心律失常的机械基础，该基础，是心律失常的基础。细胞到组织水平。第三，我们将定义KCNE2，KV1.5和插入式圆盘（IDS）之间的关系，并确定为什么KCNE2破坏了鼠心室中的KV1.5 ID靶向，而不是心房中的KV1.5 ID。 公共卫生相关性：特定的钾通道控制心脏复极化，以及时结束每一个心跳；编码钾通道（包括KCNQ1，KCNE1和KCNE2）的基因中的遗传基因变异，引起人类的致命心律不齐。在美国遭受250万人的折磨的房颤可能是由这些基因突变引起的，但更常见于衰老和某些手术程序。我们的建议旨在确定钾通道在中庭中的机械作用，主要集中于KCNE2，并发现导致KCNE2在遗传和获得形式的房颤形式中功能障碍的分子事件，以促进未来的未来抗心律失常治疗和预防策略。