SUMO modification regulates inactivation of the voltage-gated potassium channel Kv1.5

被引:120
作者
Benson, Mark D. [1 ]
Li, Qiu-Ju [1 ]
Kieckhafer, Katherine [1 ]
Dudek, David [1 ]
Whorton, Matthew R. [1 ]
Sunahara, Roger K. [1 ]
Iniguez-Lluhi, Jorge A. [1 ]
Martens, Jeffrey R. [1 ]
机构
[1] Univ Michigan, Sch Med, Dept Pharmacol, Ann Arbor, MI 48109 USA
关键词
electrical excitability; posttranslational modification; transmembrane protein; ubiquitin-like modifier;
D O I
10.1073/pnas.0606702104
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
The voltage-gated potassium (Kv) channel Kv1.5 mediates the I-Kur repolarizing current in human atrial myocytes and regulates vascular tone in multiple peripheral vascular beds. Understanding the complex regulation of Kv1.5 function is of substantial interest because it represents a promising pharmacological target for the treatment of atrial fibrillation and hypoxic pulmonary hypertension. Herein we demonstrate that posttranslational modification of Kv1.5 by small ubiquitin-like modifier (SUMO) proteins modulates Kv1.5 function. We have identified two membrane-proximal and highly conserved cytoplasmic sequences in Kv1.5 that conform to established SUMO modification sites in transcription factors. We find that Kv1.5 interacts specifically with the SUMO-conjugating enzyme Ubc9 and is a target for modification by SUMO-1, -2, and -3 in vivo. In addition, purified recombinant Kv1.5 serves as a substrate in a minimal in vitro reconstituted SUMOylation reaction. The SUMO-specific proteases SENP2 and Ulp1 efficiently deconjugate SUMO from Kv1.5 in vivo and in vitro, and disruption of the two identified target motifs results in a loss of the major SUMOconjugated forms of Kv1.5. In whole-cell patch-clamp electrophysiological studies, loss of Kv1.5 SUMOylation, by either disruption of the conjugation sites or expression of the SUMO protease SENP2, leads to a selective approximate to 15-mV hyperpolarizing shift in the voltage dependence of steady-state inactivation. Reversible control of voltage-sensitive channels through SUMOylation constitutes a unique and likely widespread mechanism for adaptive tuning of the electrical excitability of cells.
引用
收藏
页码:1805 / 1810
页数:6
相关论文
共 51 条
[21]   A structural interpretation of voltage-gated potassium channel inactivation [J].
Kurata, Harley T. ;
Fedida, David .
PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY, 2006, 92 (02) :185-208
[22]   KChAP/Kvβ1.2 interactions and their effects on cardiac Kv channel expression [J].
Kuryshev, YA ;
Wible, BA ;
Gudz, TI ;
Ramirez, AN ;
Brown, AM .
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY, 2001, 281 (01) :C290-C299
[23]  
KURYSHEV YA, 2000, AM J PHYSIOL, V278, pC941
[24]   Protein kinase A phosphorylation alters Kvβ1.3 subunit-mediated inactivation of the Kv1.5 potassium channel [J].
Kwak, YG ;
Hu, NN ;
Wei, J ;
George, AL ;
Grobaski, TD ;
Tamkun, MM ;
Murray, KT .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1999, 274 (20) :13928-13932
[25]   Phosphorylation is required for alteration of Kv1.5 K+ channel function by the Kvβ1.3 subunit [J].
Kwak, YG ;
Navarro-Polanco, RA ;
Grobaski, T ;
Gallagher, DJ ;
Tamkun, MM .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1999, 274 (36) :25355-25361
[26]   The insulin-sensitive glucose transporter, GLUT4, interacts physically with Daxx - Two proteins with capacity to bind Ubc9 and conjugated to SUMO1 [J].
Lalioti, VS ;
Vergarajauregui, S ;
Pulido, D ;
Sandoval, IV .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2002, 277 (22) :19783-19791
[27]   Surface expression of Kv1 channels is governed by a C-terminal motif [J].
Li, DQ ;
Takimoto, K ;
Levitan, ES .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2000, 275 (16) :11597-11602
[28]   A new protease required for cell-cycle progression in yeast [J].
Li, SJ ;
Hochstrasser, M .
NATURE, 1999, 398 (6724) :246-251
[29]   Crystal structure of a mammalian voltage-dependent Shaker family K+ channel [J].
Long, SB ;
Campbell, EB ;
MacKinnon, R .
SCIENCE, 2005, 309 (5736) :897-903
[30]   A novel ubiquitin-like modification modulates the partitioning of the Ran-GTPase-activating protein RanGAP1 between the cytosol and the nuclear pore complex [J].
Matunis, MJ ;
Coutavas, E ;
Blobel, G .
JOURNAL OF CELL BIOLOGY, 1996, 135 (06) :1457-1470