Intracellular calcium release mediated by two muscarinic receptor subtypes

FEBS Letters

Neher, Erwin³  Marty, Alain²  Numa, Shosaku¹  Fukuda, Kazuhiko¹  Kubo, Tai¹ 

[1] Departments of Medical Chemistry and Molecular Genetics, Kyoto University, Faculty of Medicine, Kyoto 606, Japan;Laboratoire de Neurobiologie, Ecole Normale Superieure, F-75230 Paris Cédex 05, France;Max-Planck-Institut für biophysikalische Chemie, D-3400 Göttingen, FRG

关键词: Muscarinic acetylcholine receptor subtype;    Ca2+ release;    Ca2+-activated current;    M current;    (Neuroblastoma-glioma hybrid cell);    mAChR;    muscarinic acetylcholine receptor;    ACh;    acetylcholine;    QNB;    quinuclidinyl benzilate;    PI;    phosphoinositides;   

DOI  :  10.1016/0014-5793(88)80345-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Four subtypes of muscarinic acetylcholine receptor (mAChR) were stably expressed in neuroblastoma-glioma hybrid cells (NG108-15). By combining fluorescent indicator dye (fura-2) studies with electrophysiological measurements it is shown that stimulation of mAChR I and mAChR III readily leads to release of calcium from intracellular stores and to associated conductance changes, whereas stimulation of mAChR II and mAChR IV exerts no such effect. Dose-response curves describing the amplitude or the delay of the calcium rise induced by acetylcholine suggest that the apparent affinity of mAChR III for its agonist is higher by about one order of magnitude than that of mAChR I. Ionic substitution experiments and current fluctuation analysis indicate that calcium activates a K⁺-specific conductance of ‘small’ single-channel amplitude similar to the SK type [1]. Furthermore, an outward current (M current) suppressed by activation of mAChR I and mAChR III has a single-channel amplitude corresponding to a conductance of approximately 3 pS.

【 授权许可】

Unknown