Titre :

Kir4.1/Kir5.1 channel forms the major K + channel in the basolateral membrane of mouse renal collecting duct principal cells

Auteur(s) :

Lachheb, Sahran [Auteur]
Cluzeaud, Françoise [Auteur]
Centre de recherche sur l'Inflammation [CRI (UMR_S_1149 / ERL_8252 / U1149)]
Bens, Marcelle [Auteur]
Centre de recherche biomédicale Bichat-Beaujon [CRB3]
Genete (Admin), Mathieu [Auteur]
Évolution, Écologie et Paléontologie (Evo-Eco-Paleo) - UMR 8198 [Evo-Eco-Paléo (EEP)]
Hibino, Hiroshi [Auteur]
Lourdel, Stéphane [Auteur]
Centre de Recherche des Cordeliers [CRC (UMR_S 872)]
Kurachi, Yoshihisa [Auteur]
Vandewalle, Alain [Auteur]
Centre de recherche sur l'Inflammation [CRI (UMR_S_1149 / ERL_8252 / U1149)]
Teulon, Jacques [Auteur]
Centre de Recherche des Cordeliers [CRC (UMR_S 872)]
Paulais, Marc [Auteur]
Centre de Recherche des Cordeliers [CRC]

Titre de la revue :

AJP Renal Physiology

Pagination :

F1398-F1407

Éditeur :

American Physiological Society

Date de publication :

2008-06

ISSN :

0363-6127

Discipline(s) HAL :

Sciences du Vivant [q-bio]
Sciences du Vivant [q-bio]/Biologie cellulaire

Résumé en anglais : [en]

K(+) channels in the basolateral membrane of mouse cortical collecting duct (CCD) principal cells were identified with patch-clamp technique, real-time PCR, and immunohistochemistry. In cell-attached membrane patches, three ...
Lire la suite >K(+) channels in the basolateral membrane of mouse cortical collecting duct (CCD) principal cells were identified with patch-clamp technique, real-time PCR, and immunohistochemistry. In cell-attached membrane patches, three K(+) channels with conductances of approximately 75, 40, and 20 pS were observed, but the K(+) channel with the intermediate conductance (40 pS) predominated. In inside-out membrane patches exposed to an Mg(2+)-free medium, the current-voltage relationship of the intermediate-conductance channel was linear with a conductance of 38 pS. Addition of 1.3 mM internal Mg(2+) had no influence on the inward conductance (G(in) = 35 pS) but reduced outward conductance (G(out)) to 13 pS, yielding a G(in)/G(out) of 3.2. The polycation spermine (6 x 10(-7) M) reduced its activity on inside-out membrane patches by 50% at a clamp potential of 60 mV. Channel activity was also dependent on intracellular pH (pH(i)): a sigmoid relationship between pH(i) and channel normalized current (NP(o)) was observed with a pK of 7.24 and a Hill coefficient of 1.7. By real-time PCR on CCD extracts, inwardly rectifying K(+) (Kir)4.1 and Kir5.1, but not Kir4.2, mRNAs were detected. Kir4.1 and Kir5.1 proteins cellularly colocalized with aquaporin 2 (AQP2), a specific marker of CCD principal cells, while AQP2-negative cells (i.e., intercalated cells) showed no staining. Dietary K(+) had no influence on the properties of the intermediate-conductance channel, but a Na(+)-depleted diet increased its open probability by approximately 25%. We conclude that the Kir4.1/Kir5.1 channel is a major component of the K(+) conductance in the basolateral membrane of mouse CCD principal cells.Lire moins >

Langue :

Anglais

Vulgarisation :

Non

Collections :

• Évolution, Écologie et Paléontologie (Evo Eco Paleo) - UMR 8198

Source :

Harvested from HAL