The GXGXG motif in the pICln protein is not important for the nucleotide sensitivity of the pICln‐induced Cl− current in Xenopus oocytes

FEBS Letters

Eggermont, Jan¹  Voets, Thomas¹  Nilius, Bernd¹  Buyse, Gunnar¹  Droogmans, Guy¹ 

[1] Katholieke Universiteit Leuven, Laboratorium voor Fysiologie Campus Gasthuisberg O and N, B-3000 Leuven, Belgium

关键词: Anion channel;    Oocyte;    Cyclic adenosine monophosphate;   

DOI  :  10.1016/S0014-5793(98)00334-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

It has been proposed that the pI_Cln protein forms a nucleotide-sensitive plasma membrane anion channel with a GXGXG motif being an essential component of the extracellular nucleotide-binding site. To evaluate this hypothesis, we have performed voltage-clamp experiments on Xenopus laevis oocytes injected with RNA encoding a rat mutant pI_Cln in which the three glycines of the putative nucleotide-binding site have been changed into alanines (G54A; G56A; G58A). The injected oocytes displayed outwardly rectifying anion currents, which were voltage-dependently blocked by extracellular cAMP, but which were not affected by removal of extracellular Ca²⁺. Furthermore, the mutation did not affect the voltage-dependent inactivation. We therefore conclude that there is no evidence in favour of an extracellular nucleotide-binding site in pI_Cln.

【 授权许可】

Unknown