In excitable cells, voltage-gated potassium channels play an important role in regulating the duration of the action potential. We hypothesize that the targeting of channels to particular membrane microdomains and their organization in macromolecular complexes allow cells to increase the efficiency of their response to extracellular signals. The work proposed in this application is directed towards understanding the molecular mechanisms underlying the trafficking and turnover of Kv1.5 and KV2.1 potassium channels. We propose to characterize the macromolecular complex (channelosome) that modulates the function of a delayed rectifier potassium channel, Kv1.5. We will use a combination of biochemical and molecular tools, patch-clamp analyses, and in vivo mouse models to pursue the following specific aims: (1) To determine the mechanisms that regulate trafficking of Kv1.5 polypeptide to caveolae, specifically to characterize the interactions between Kv1.5 and caveolin-3 (Cav-3) and SAP97. (2) To examine the role of posttranslational modifications on the trafficking, assembly, and stability on Kv1.5/Cav-3/SAP97 macromolecular complex. To map the site of interactions between SAP97 and Cav-3 and prove that this interaction contributes to the targeting of Kv1.5 to caveolae. (3) To characterize the role of N-terminal cysteines of Kv2.1 and their posttranslational modifications in regulating the assembly, trafficking, and gating of Kv2.1. The work outlined in this application should greatly increase our understanding of the regulation of expression of Kv1.5 and Kv2.1. ? ?

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL062328-08
Application #
7324756
Study Section
Electrical Signaling, Ion Transport, and Arrhythmias Study Section (ESTA)
Program Officer
Wang, Lan-Hsiang
Project Start
2000-04-01
Project End
2009-11-30
Budget Start
2007-12-01
Budget End
2009-11-30
Support Year
8
Fiscal Year
2008
Total Cost
$355,567
Indirect Cost
Name
Rhode Island Hospital
Department
Type
DUNS #
075710996
City
Providence
State
RI
Country
United States
Zip Code
02903
Choi, Bum-Rak; Li, Weiyan; Terentyev, Dmitry et al. (2018) Transient Outward K+ Current (Ito) Underlies the Right Ventricular Initiation of Polymorphic Ventricular Tachycardia in a Transgenic Rabbit Model of Long-QT Syndrome Type 1. Circ Arrhythm Electrophysiol 11:e005414
Jindal, Hitesh K; Folco, Eduardo J; Liu, Gong Xin et al. (2008) Posttranslational modification of voltage-dependent potassium channel Kv1.5: COOH-terminal palmitoylation modulates its biological properties. Am J Physiol Heart Circ Physiol 294:H2012-21
Roder, Karim; Koren, Gideon (2006) The K+ channel gene, Kcnb1: genomic structure and characterization of its 5'-regulatory region as part of an overlapping gene group. Biol Chem 387:1237-46
Folco, Eduardo J; Roder, Karim; Mitchell, Gary F et al. (2003) ""Cardiac memory"": a struggle against forgetting. Circ Res 93:384-6