MODULATION BY PROTEIN-KINASE-A OF A CLONED RAT-BRAIN POTASSIUM CHANNEL EXPRESSED IN XENOPUS-OOCYTES

被引:34
作者
WILSON, GG
ONEILL, CA
SIVAPRASADARAO, A
FINDLAY, JBC
WRAY, D
机构
[1] UNIV LEEDS,DEPT PHARMACOL,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND
[2] UNIV LEEDS,DEPT BIOCHEM & MOLEC BIOL,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND
来源
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY | 1994年 / 428卷 / 02期
基金
英国惠康基金;
关键词
POTASSIUM CHANNEL; NEURONAL; PROTEIN KINASE A; PHOSPHORYLATION; POINT MUTATION; XENOPUS OOCYTE;
D O I
10.1007/BF00374857
中图分类号
Q4 [生理学];
学科分类号
071003 ;
摘要
A potassium channel from rat brain was expressed in Xenopus oocytes in order to study modulation of channel function by phosphorylation via protein kinase A. Application of 8-Br-cAMP to oocytes expressing the drk1 channel (with the first 139 amino acids of the N terminus delected, Delta Ndrk1) caused a voltage-independent elevation of current amplitude, which was not seen for endogenous currents or for wild-type full-length drk1 channel. This effect on Delta Ndrk1 was blocked by pre-injection of oocytes with Walsh-peptide protein kinase A inhibitor, suggesting mediation via protein kinase A. The protein kinase inhibitor also reduced both Delta Ndrk1 and full-length drk1 currents. Substitution of the serine residues by alanine at one or both of the two consensus protein kinase A phosphorylation sites on the C terminus (residues 440 and 492) of Delta Ndrk1 resulted in a loss of function of the expressed channels. These results indicate that phosphorylation via protein kinase A modulates drk1 channel function and that both consensus phosphorylation sites seems to be essential for channels to function.
引用
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页码:186 / 193
页数:8
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