Modulation of KCNQ1 channel activity

KCNQ1 通道活性的调节

基本信息

批准号：
10330452
负责人：
ROBERT S KASS
金额：
$ 40.83万
依托单位：
UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-05-01 至 2023-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10330452
关键词：
A kinase anchoring protein AKAP9 gene Action Potentials Adaptor Signaling Protein Adenylate Cyclase Affect Area Arrhythmia Basic Science Binding Cardiac Cardiac Myocytes Clinical Complex Coupling Cryoelectron Microscopy Cyclic AMP-Dependent Protein Kinases Dependence Disease Dissection Ensure Familial atrial fibrillation Fluorometry Heart Heart Rate Human Induced Mutation Ion Channel Kinetics Life Link Long QT Syndrome Macromolecular Complexes Maps Membrane Potentials Molecular Molecular Chaperones Molecular Conformation Mutation Nerve PDE4D3 phosphodiesterase Pathologic Phosphatidylinositol 4,5-Diphosphate Phosphorylation Physiological Physiology Potassium Potassium Channel Protein phosphatase Proteins Regulation Role Short QT syndrome Signal Transduction Signaling Molecule Structure Sudden Death Syndrome Testing Time Translating Variant Ventricular Work beta-adrenergic receptor drug development experimental study mutant nanobodies novel public health relevance response voltage voltage clamp

项目摘要

Modified Project Summary/Abstract Section I{KS}, the slowly activating delayed rectifier potassium (K[+]) current in the heart is critical importance to human physiology as evident from the fact that mutations in either its α (KCNQ1) or β (KCNE1) subunit have been linked to multiple cardiac arrhythmia syndromes, including long QT syndrome (LQTS); short QT syndrome; and familial atrial fibrillation. The I{KS} channel is upregulated during sympathetic stimulation by PKA phosphorylation, which contributes critically to the physiological shortening of cardiac action potentials in response to sympathetic nerve activity. This shortening is necessary to ensure adequate ventricular filling time with accompanying increases in heart rate. It is also during sympathetic stimulation that most sudden deaths from LQTS occur. Understanding the mechanisms that underlie these mutation-induced arrhythmia syndromes requires unraveling the molecular interactions between KCNQ1 and KCNE1 within the context of normal and disease altered I{KS} channels. But to date, the critical questions of how KCNE1 alters KCNQ1 channel gating and how I{KS} channels are modulated by PKA are still not fully answered. Our previous work has revealed that Beta-AR regulation of channels requires assembly of a macromolecular complex that includes both KCNQ1 and KCNE1, as well as the adaptor protein Yotiao (AKAP 9). We will here use novel nanobodies to deliver regulatory domains of PKA directly to the KCNQ1/KCNE1 channel with and without co-assembly with AKAP9. These experiments will allow dissection of the critical role of AKAP9 in the delivery of signaling molecules to KCNQ1/KCNE1 from additional putative modulatory roles of the AKAP in modulating channel function post phosphorylation. In the recent CryoEM structure of KCNQ1 putative interacting residues between KCNQ1 and KCNE1 map between the VSD and PD, suggesting that KCNE1 is located in this area of the KCNQ1 structure. We will test whether KCNQ1 and KCNQ1/KCNE1 channels open using different gating hinges in S6. We will here also identify KCNQ1-KCNE1 interacting residues and determine whether these residues affect the different gating hinges. PKA has been shown to alter the voltage dependence, sub-conductance occupancy, and kinetics of I{KS} channels. Using voltage clamp fluorometry together with mutations and PIP2 depletion that uncouple the VSD and PD, we will determine whether PKA affect the VSD, PD, and/or VSD-to-PD coupling in I{KS} channels. The anticipated results of these experiments will provide a structural basis for control by PKA and KCNE1 of the physiological function of this critical ion channel and will also provide novel targets for the development of drugs to modulate its activity. This would be a milestone toward mutation-specific treatments of diseases, such as cardiac arrhythmias, caused by mutations in KCNQ1 and KCNE1.

修改的项目摘要/摘要部分 i {ks}，在心脏中缓慢激活的延迟整流钾（K [+]）对人类生理学至关重要，这证明了以下事实：其α（KCNQ1）或β（KCNE1）亚基的突变已与多个心脏心动过律综合症（包括长期Qt syndromeme）相关。短QT综合征；和家族性心房颤动。在通过PKA磷酸化的交感神经刺激期间，I {KS}通道进行了更新，这对响应交感神经活动的心脏动作电位的物理缩短了急需。这种缩短对于确保足够的心室填充时间随着参与的心率增加而缩短。同时也是在同情刺激期间，大多数LQT突然死亡。了解这些突变引起的心律不齐综合征的基础的机制需要在正常和疾病改变I {KS}通道的情况下揭示KCNQ1和KCNE1之间的分子相互作用。但是迄今为止，KCNE1如何改变KCNQ1通道门控以及我{KS}频道的关键问题仍未得到充分回答。我们以前的工作表明通道的β-AR调节需要组装包括KCNQ1和KCNE1的大分子复合物以及衔接蛋白Yotiao（AKAP 9）。在这里，我们将使用新颖的纳米化合物将PKA的调节域直接传递到具有与AKAP9共同组装的KCNQ1/KCNE1通道。这些实验将允许解剖AKAP9在将信号分子传递到KCNQ1/KCNE1中的关键作用，从AKAP的其他假定调节作用中，AKAP在调节磷酸化后调节通道功能中的其他假定调节作用。在KCNQ1推定的相互作用残基之间KCNQ1和KCNE1映射之间VSD和PD之间的冷冻结构中，这表明KCNE1位于KCNQ1结构的这一区域中。我们将测试使用S6中不同门控铰链打开KCNQ1和KCNQ1/KCNE1通道。我们还将确定KCNQ1-KCNE1相互作用的电阻，并确定这些电阻是否影响不同的门控铰链。已显示PKA可以改变I {KS}通道的电压依赖性，亚导率占用和动力学。使用电压夹具荧光测定法以及使VSD和PD取消的突变和PIP2部署，我们将确定PKA是否影响I {KS}通道中的VSD，PD和/或VSD-TO-PD耦合。这些实验的预期结果将为PKA和KCNE1控制该关键离子通道的物理功能，为控制药物调节其活性的开发提供新的目标。这将是由KCNQ1和KCNE1突变引起的疾病突变特异性治疗的里程碑。

项目成果

期刊论文数量（22）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Cardiac Delayed Rectifier Potassium Channels in Health and Disease.

DOI：
10.1016/j.ccep.2016.01.004
发表时间：
2016-06
期刊：
Cardiac electrophysiology clinics
影响因子：
0
作者：
Chen L;Sampson KJ;Kass RS
通讯作者：
Kass RS

Pharmacological rescue of specific long QT variants of KCNQ1/KCNE1 channels.

DOI：
10.3389/fphys.2022.902224
发表时间：
2022
期刊：
FRONTIERS IN PHYSIOLOGY
影响因子：
4
作者：
Zou, Xinle;Wu, Xiaoan;Sampson, Kevin J.;Colecraft, Henry M.;Larsson, H. Peter;Kass, Robert S.
通讯作者：
Kass, Robert S.

Using fluorescence to understand β subunit-NaV channel interactions.

使用荧光来了解 β 亚基-NaV 通道相互作用。