On the structural basis for ionic selectivity among Na+, K+, and Ca2+ in the voltage-gated sodium channel

Détails

ID Serval
serval:BIB_ABF0AF7FFC93
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
On the structural basis for ionic selectivity among Na+, K+, and Ca2+ in the voltage-gated sodium channel
Périodique
Biophysical Journal
Auteur(s)
Favre  I., Moczydlowski  E., Schild  L.
ISSN
0006-3495 (Print)
Statut éditorial
Publié
Date de publication
12/1996
Volume
71
Numéro
6
Pages
3110-25
Notes
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S. --- Old month value: Dec
Résumé
Voltage-sensitive sodium channels and calcium channels are homologous proteins with distinctly different selectivity for permeation of inorganic cations. This difference in function is specified by amino acid residues located within P-region segments that link presumed transmembrane elements S5 and S6 in each of four repetitive Domains I, II, III, and IV. By analyzing the selective permeability of Na+, K+, and Ca2+ in various mutants of the mu 1 rat muscle sodium channel, the results in this paper support the concept that a conserved motif of four residues contributed by each of the Domains I-IV, termed the DEKA locus in sodium channels and the EEEE locus in calcium channels, determines the ionic selectivity of these channels. Furthermore, the results indicate that the Lys residue in Domain III of the sodium channel is the critical determinant that specifies both the impermeability of Ca2+ and the selective permeability of Na+ over K+. We propose that the alkylammonium ion of the Lys(III) residue acts as an endogenous cation within the ion binding site/selectivity filter of the sodium channel to tune the kinetics and affinity of inorganic cation binding within the pore in a manner analogous to ion-ion interactions that occur in the process of multi-ion channel conduction.
Mots-clé
Alanine Amino Acid Sequence Animals Calcium/metabolism Calcium Channels/*chemistry/*physiology Cell Membrane/physiology Conserved Sequence Female Kinetics Membrane Potentials Models, Chemical Muscle, Skeletal/physiology Mutagenesis, Site-Directed Oocytes/physiology Point Mutation Potassium/metabolism Rabbits Rats Recombinant Proteins/metabolism Sequence Homology, Amino Acid Sodium/metabolism Sodium Channels/*chemistry/*physiology Substrate Specificity Xenopus laevis
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 13:55
Dernière modification de la notice
20/08/2019 16:15
Données d'usage