Expression pattern and functional characteristics of two novel splice variants of the two-pore-domain potassium channel TREK-2

被引:83
作者
Gu, WL
Schlichthörl, G
Hirsch, JR
Engels, H
Karschin, C
Karschin, A
Derst, C
Steinlein, OK
Daut, J
机构
[1] Univ Marburg, Inst Physiol, D-35037 Marburg, Germany
[2] Univ Bonn, Inst Humangenet, D-53111 Bonn, Germany
[3] Univ Munster, D-48149 Munster, Germany
[4] Univ Wurzburg, Inst Physiol, D-97070 Wurzburg, Germany
来源
JOURNAL OF PHYSIOLOGY-LONDON | 2002年 / 539卷 / 03期
关键词
D O I
10.1113/jphysiol.2001.013432
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
Two novel alternatively spliced isoforms of the human two-pore-domain potassium channel TREK-2 were isolated from cDNA libraries of human kidney and fetal brain. The cDNAs of 2438 base pairs (bp) (TREK-2b) and 2559 bp (TREK-2c) encode proteins of 508 amino acids each. RT-PCR showed that TREK-2b is strongly expressed in kidney (primarily in the proximal tubule) and pancreas, whereas TREK-2c is abundantly expressed in brain. In situ hybridization revealed a very distinct expression pattern of TREK-2c in rat brain which partially overlapped with that of TREK-1. Expression of TREK-2b and TREK-2c in human embryonic kidney (HEK) 293 cells showed that their single-channel characteristics were similar. The slope conductance at negative potentials was 163 +/- 5 pS for TREK-2b and 179 +/- 17 pS for TREK-2c. The mean open and closed times of TREK-2b at -84 mV were 133 +/- 16 and 109 +/- 11 mus, respectively. Application of forskolin decreased the whole-cell current carried by TREK-2b and TREK-2c. The sensitivity to forskolin was abolished by mutating a protein kinase A phosphorylation site at position 364 of TREK-2c (construct S364A). Activation of protein kinase C (PKC) by application of phorbol-12-myristate-13-acetate (PMA) also reduced whole-cell current. However, removal of the putative TREK-2b-specific PKC phosphorylation site (construct T7A) did not affect inhibition by PMA. Our results suggest that alternative splicing of TREK-2 contributes to the diversity of two-pore-domain K+ channels.
引用
收藏
页码:657 / 668
页数:12
相关论文
共 45 条
[11]   Genomic and functional characteristics of novel human pancreatic 2P domain K+ channels [J].
Girard, C ;
Duprat, F ;
Terrenoire, C ;
Tinel, N ;
Fosset, M ;
Romey, G ;
Lazdunski, M ;
Lesage, F .
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 2001, 282 (01) :249-256
[12]   Potassium leak channels and the KCNK family of two-P-domain subunits [J].
Goldstein, SAN ;
Bockenhauer, D ;
O'Kelly, I ;
Zilberberg, N .
NATURE REVIEWS NEUROSCIENCE, 2001, 2 (03) :175-184
[13]   Volatile anesthetics activate the human tandem pore domain baseline K+ channel KCNK5 [J].
Gray, AT ;
Zhao, BB ;
Kindler, CH ;
Winegar, BD ;
Mazurek, MJ ;
Xu, J ;
Chavez, RA ;
Forsayeth, JR ;
Yost, CS .
ANESTHESIOLOGY, 2000, 92 (06) :1722-1730
[14]   Expression pattern in brain of TASK-1, TASK-3, and a tandem pore domain K+ channel subunit, TASK-5, associated with the central auditory nervous system [J].
Karschin, C ;
Wischmeyer, E ;
Preisig-Müller, R ;
Rajan, S ;
Derst, C ;
Grzeschik, KH ;
Daut, J ;
Karschin, A .
MOLECULAR AND CELLULAR NEUROSCIENCE, 2001, 18 (06) :632-648
[15]   TASK-5, a new member of the tandem-pore K+ channel family [J].
Kim, D ;
Gnatenco, C .
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 2001, 284 (04) :923-930
[16]   Cloning and functional expression of a novel cardiac two-pore background K+ channel (cTBAK-1) [J].
Kim, D ;
Fujita, A ;
Horio, Y ;
Kurachi, Y .
CIRCULATION RESEARCH, 1998, 82 (04) :513-518
[17]   TASK-3, a new member of the tandem pore K+ channel family [J].
Kim, Y ;
Bang, H ;
Kim, D .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2000, 275 (13) :9340-9347
[18]   Molecular and functional properties of two-pore-domain potassium channels [J].
Lesage, F ;
Lazdunski, M .
AMERICAN JOURNAL OF PHYSIOLOGY-RENAL PHYSIOLOGY, 2000, 279 (05) :F793-F801
[19]   Human TREK2, a 2P domain mechano-sensitive K+ channel with multiple regulations by polyunsaturated fatty acids, lysophospholipids, and Gs, Gi, and Gq protein-coupled receptors [J].
Lesage, F ;
Terrenoire, C ;
Romey, G ;
Lazdunski, M .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2000, 275 (37) :28398-28405
[20]   Dimerization of TWIK-1 K+ channel subunits via a disulfide bridge [J].
Lesage, F ;
Reyes, R ;
Fink, M ;
Duprat, F ;
Guillemare, E ;
Lazdunski, M .
EMBO JOURNAL, 1996, 15 (23) :6400-6407