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Titolo:
Molecular determinants of membrane potential dependence in vertebrate gap junction channels
Autore:
Reviila, A; Bennett, MVL; Barrio, LC;
Indirizzi:
Hosp Ramon y Cajal, Dept Invest, Consejo Super Invest Cient, Neurol Expt Unidad, Madrid 28034, Spain Hosp Ramon y Cajal Madrid Spain 28034 l Expt Unidad, Madrid 28034, Spain Yeshiva Univ Albert Einstein Coll Med, Dept Neurosci, Bronx, NY 10461 USA Yeshiva Univ Albert Einstein Coll Med Bronx NY USA 10461 nx, NY 10461 USA
Titolo Testata:
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
fascicolo: 26, volume: 97, anno: 2000,
pagine: 14760 - 14765
SICI:
0027-8424(200012)97:26<14760:MDOMPD>2.0.ZU;2-8
Fonte:
ISI
Lingua:
ENG
Soggetto:
TO-CELL CHANNELS; XENOPUS OOCYTES; VOLTAGE; CONDUCTANCE; CONNEXIN-32; EXPRESSION; PROTEINS; CALCIUM; PH;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Barrio, LC Hosp Ramon y Cajal, Dept Invest, Consejo Super Invest Cient, Neurol Expt Unidad, Carretera Colmenar Viejo Km 9, Madrid 28034, Spain Hosp Ramon y Cajal Carretera Colmenar Viejo Km 9 Madrid Spain 28034
Citazione:
A. Reviila et al., "Molecular determinants of membrane potential dependence in vertebrate gap junction channels", P NAS US, 97(26), 2000, pp. 14760-14765

Abstract

The conductance, g(j), of many gap junctions depends on voltage between the coupled cells (transjunctional voltage, V-j) with little effect of the absolute membrane potential (V-m) in the two cells; others show combined V-j and V-m dependence. We examined the molecular determinants of V-m dependence by using rat connexin 43 expressed in paired Xenopus oocytes. These junctions have, in addition to V-j dependence, V-m dependence such that equal depolarization of both cells decreases g(j). The dependence of g(j) on V-m was abolished by truncation of the C-terminal domain (CT) at residue 242 but not at 257. There are two charged residues between 242 and 257. In full-length Cx43, mutations neutralizing either one of these charges, Arg243Gln andAsp245Gln, decreased and increased V-m dependence, respectively, suggesting that these residues are part of the V-m sensor. Mutating both residues together abolished V-m dependence, although there is no net change in charge. The neutralizing mutations, together or separately, had no effect on V-j dependence. Thus, the voltage sensors must differ. However, V-j gating was somewhat modulated by V-m, and V-m gating was reduced when the V-j gate was closed. These data suggest that the two forms of voltage dependence are mediated by separate but interacting domains.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 03/07/20 alle ore 16:50:53