Dominant-negative subunits reveal potassium channel families that contribute to M-like potassium currents.
J Neurosci
; 22(5): RC212, 2002 Mar 01.
Article
en En
| MEDLINE
| ID: mdl-11880533
ABSTRACT
M-currents are K+ currents generated by members of the KCNQ family of K+ channels (Wang et al., 1998). However, in some cells, M-like currents may be contaminated by members of other K+ channel gene families, such as the erg family (Meves et al., 1999; Selyanko et al., 1999). In the present experiments, we have used the acute expression of pore-defective mutants of KCNQ3 (DN-KCNQ3) and Merg1a (DN-Merg1a) as dominant negatives to separate the contributions of these two families to M-like currents in NG108-15 neuroblastoma hybrid cells and rat sympathetic neurons. Two kinetically and pharmacologically separable components of M-like current could be recorded from NG108-15 cells that were individually suppressed by DN-Merg1a and DN-KCNQ3, respectively. In contrast, only DN-KCNQ3, and not DN-Merg1a, reduced currents recorded from sympathetic neurons. Pharmacological tests suggested that the residual current in DN-KCNQ3-treated sympathetic neurons was carried by residual KCNQ channels. Ineffectiveness of DN-Merg1a in sympathetic neurons was not caused by lack of expression, as judged by confocal microscopy of Flag-tagged DN-Merg1a. These results accord with previous inferences regarding the roles of erg and KCNQ channels in generating M-like currents. This experimental approach should therefore be useful in delineating the contributions of members of these two gene families to K+ currents in other cells.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Canales de Potasio
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Familia de Multigenes
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Subunidades de Proteína
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Canales de Potasio con Entrada de Voltaje
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Genes Dominantes
Límite:
Animals
Idioma:
En
Revista:
J Neurosci
Año:
2002
Tipo del documento:
Article
País de afiliación:
Reino Unido
Pais de publicación:
EEUU
/
ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
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EUA
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UNITED STATES
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UNITED STATES OF AMERICA
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US
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USA