Bertrand_1993_Proc.Natl.Acad.Sci.U.S.A_90_6971

Reference

Title : Mutations at two distinct sites within the channel domain M2 alter calcium permeability of neuronal alpha 7 nicotinic receptor - Bertrand_1993_Proc.Natl.Acad.Sci.U.S.A_90_6971
Author(s) : Bertrand D , Galzi JL , Devillers-Thiery A , Bertrand S , Changeux JP
Ref : Proc Natl Acad Sci U S A , 90 :6971 , 1993
Abstract :

The relative permeability for sodium, potassium, and calcium of chicken alpha 7 neuronal nicotinic receptor was investigated by mutagenesis of the channel domain M2. Mutations in the "intermediate ring" of negatively charged residues, located at the cytoplasmic end of M2 (site 1), reduce calcium permeability without significantly modifying other functional properties (activation and desensitization) of the receptor; a similar change of ion selectivity is also noticed when mutations at site 1 are done in the context of a receptor mutant that conducts ions in a desensitized state. Moreover, mutations of two adjacent rings of leucines at the synaptic end of M2 (site 2) have multiple effects. They abolish calcium permeability, increase the apparent affinity for acetylcholine by 10- to 100-fold, augment Hill numbers (up to 4.6-5.0) of acetylcholine dose-response relationships, slow rates of ionic response onset, and lower the extent of desensitization. Mutations at these two topographically distinct sites within M2 selectively alter calcium transport without affecting the relative permeabilities for sodium and potassium.

PubMedSearch : Bertrand_1993_Proc.Natl.Acad.Sci.U.S.A_90_6971
PubMedID: 7688468

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Citations formats

Bertrand D, Galzi JL, Devillers-Thiery A, Bertrand S, Changeux JP (1993)
Mutations at two distinct sites within the channel domain M2 alter calcium permeability of neuronal alpha 7 nicotinic receptor
Proc Natl Acad Sci U S A 90 :6971

Bertrand D, Galzi JL, Devillers-Thiery A, Bertrand S, Changeux JP (1993)
Proc Natl Acad Sci U S A 90 :6971