Aldosterone regulates rapid trafficking of epithelial sodium channel subunits in renal cortical collecting duct cells via protein kinase D activation.
Mol Endocrinol
; 22(4): 881-92, 2008 Apr.
Article
en En
| MEDLINE
| ID: mdl-18202152
Aldosterone elicits rapid physiological responses in target tissues such as the distal nephron through the stimulation of cell signaling cascades. We identified protein kinase D (PKD1) as an early signaling response to aldosterone treatment in the M1-cortical collecting duct (M1-CCD) cell line. PKD1 activation was blocked by the PKC inhibitor chelerythrine chloride and by rottlerin, a specific inhibitor of PKCdelta. The activation of PKCdelta and PKCepsilon coincided with PKD1 activation and while a complex was formed between PKD1 and PKCepsilon after aldosterone treatment, there was a concurrent reduction in PKD1 association with PKCdelta. A stable PKD1 knockdown M1-CCD-derrived clone was developed in which PKD1 expression was 90% suppressed by gene silencing with a PKD1-specific siRNA. The effect of aldosterone treatment on the subcellular distribution of enhanced cyan fluorescent protein (eCFP)-tagged epithelial sodium channel (ENaC) subunits in wild type (WT) and PKD1 suppressed cells was examined using confocal microscopy. In an untreated confluent monolayer of M1-CCD cells, alpha, beta, and gamma ENaC subunits were evenly distributed throughout the cytoplasm of WT and PKD1-suppressed cells. After 2 min treatment, aldosterone stimulated the localization of each of the ENaC subunits to discrete regions within the cytoplasm of WT cells. The translocation of eCFP-ENaC subunits in WT cells was inhibited by rottlerin and the mineralocorticoid receptor (MR) antagonist spironolactone. No subcellular translocation of eCFP-ENaC subunits was observed in PKD1-suppressed cells treated with aldosterone. These data demonstrate the involvement of a novel MR/PKCdelta /PKD1 signaling cascade in the earliest ENaC subunit intracellular trafficking events that follow aldosterone treatment.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Proteína Quinasa C
/
Aldosterona
/
Canales Epiteliales de Sodio
/
Túbulos Renales Colectores
Límite:
Animals
Idioma:
En
Revista:
Mol Endocrinol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
ENDOCRINOLOGIA
Año:
2008
Tipo del documento:
Article
País de afiliación:
Irlanda