Basolateral translocation by vasopressin of the aldosterone-induced pool of latent Na-K-ATPases is accompanied by alpha1 subunit dephosphorylation: study in a new aldosterone-sensitive rat cortical collecting duct cell line.
The regulation of plasma membrane Na(+)-K(+)-ATPases (NKA) expression by aldosterone and arginin vasopressin (AVP) in the cortical collecting duct (CCD) has been examined in a new rat CCD cell line, designated as RCCD(2). This cell line has maintained many characteristics of the CCD-in particular, the expression of the mineralocorticoid receptor. Mineralocorticoid receptor is expressed at the protein level and binds (3)H-aldosterone (approximately 15 to 20 fmol/mg protein). Short-circuit current (Isc) experiments showed approximately a twofold increase in Isc associated with a decrease in transepithelial resistance when cells were treated with aldosterone concentrations as low as 10(-9) M. This effect on Isc was significant 2 h after aldosterone addition and was still present after 24 h. It was accompanied by an increase in the amount of mRNA encoding for the alpha subunit of the epithelial sodium channel (sixfold) and the alpha1 subunit of NKA (fourfold) after 24 h of hormone treatment. In addition, mRNA expression of the serum- and glucocorticoid-induced kinase (Sgk) was increased by 10(-9) M aldosterone treatment as early as 45 min after hormone addition. As had already been documented in native CCD obtained by microdissection, incubation of RCCD(2) cells for 24 h with aldosterone resulted in the constitution of a latent pool of NKA that could be rapidly recruited by AVP (15 min). NKA biotinylation experiments and preparation of membrane fractions show that this latent pool of NKA is present in the intracellular compartment of the cells and is recruited by AVP in the basolateral membrane through a translocation process. This mechanism is accompanied by dephosphorylation of the alpha(1) catalytic subunit of NKA.
Djelidi
Sabri
S
INSERM U478, Institut Fédératif de Recherches "Cellules Epithéliales," Faculté de Médecine Xavier Bichat, Paris, France.
Beggah
Ahmed
A
INSERM U478, Institut Fédératif de Recherches "Cellules Epithéliales," Faculté de Médecine Xavier Bichat, Paris, France.
Courtois-Coutry
Nathalie
N
INSERM U478, Institut Fédératif de Recherches "Cellules Epithéliales," Faculté de Médecine Xavier Bichat, Paris, France.
Fay
Michel
M
INSERM U478, Institut Fédératif de Recherches "Cellules Epithéliales," Faculté de Médecine Xavier Bichat, Paris, France.
Cluzeaud
Francoise
F
INSERM U478, Institut Fédératif de Recherches "Cellules Epithéliales," Faculté de Médecine Xavier Bichat, Paris, France.
Viengchareun
Say
S
INSERM U478, Institut Fédératif de Recherches "Cellules Epithéliales," Faculté de Médecine Xavier Bichat, Paris, France.
Bonvalet
Jean-Pierre
JP
INSERM U478, Institut Fédératif de Recherches "Cellules Epithéliales," Faculté de Médecine Xavier Bichat, Paris, France.
Farman
Nicolette
N
INSERM U478, Institut Fédératif de Recherches "Cellules Epithéliales," Faculté de Médecine Xavier Bichat, Paris, France.
Blot-Chabaud
Marcel
M
INSERM U478, Institut Fédératif de Recherches "Cellules Epithéliales," Faculté de Médecine Xavier Bichat, Paris, France.
D000450:Aldosterone / Q000494:pharmacology / Q000502:physiology*; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D001710:Biotin / Q000378:metabolism; D002460:Cell Line; D004553:Electric Conductivity; D053503:Epithelial Sodium Channels; D017874:Immediate-Early Proteins; D007672:Kidney Cortex; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D009687:Nuclear Proteins; D010042:Ouabain / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D018161:Receptors, Mineralocorticoid / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D015222:Sodium Channels / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D014667:Vasopressins / Q000502:physiology*; D000099184:Serum-Glucocorticoid Regulated Kinases
D000450:Aldosterone; D000584:Amiloride; D001127:Arginine Vasopressin; D001710:Biotin; D053503:Epithelial Sodium Channels; D017874:Immediate-Early Proteins; D009687:Nuclear Proteins; D010042:Ouabain; D017346:Protein Serine-Threonine Kinases; D012333:RNA, Messenger; D011965:Receptors, Glucocorticoid; D018161:Receptors, Mineralocorticoid; D012964:Sodium; D015222:Sodium Channels; D000254:Sodium-Potassium-Exchanging ATPase; D014667:Vasopressins; D000099184:Serum-Glucocorticoid Regulated Kinases