title: cAMP-dependent protein kinase activation affects vasopressin V2-receptor number and internalization in LLC-PK1 renal epithelial cells.
abstract: The relationship between activation of the cAMP-dependent protein kinase (cAMP-PK) and ligand binding and internalization by the vasopressin renal (V2-type) receptor of LLC-PK1 renal epithelial cells was examined. Upon cAMP-PK activation through 1 h treatment with the cAMP analogue 8-bromo-cAMP (BrcA), a marked reduction in V2-receptor steady state number and internalization in LLC-PK1 cells was effected. In cells treated for 17 h with BrcA and hence down-regulated for cAMP-PK, the V2-receptor number was normal but internalization was markedly reduced. Cells of the LLC-PK1 mutant FIB4, which possesses about 10% parental cAMP-PK catalytic subunit activity, exhibited lower V2-receptor steady state number and internalization in comparison to untreated LLC-PK1 cells. A negative correlation was thus evident between cAMP-PK activation and V2-receptor number, and internalization. Phosphorylation by cAMP-PK may effect ligand-independent removal of receptor from the plasma membrane.
authors.affiliation: Max-Planck-Institut für Biophysik, Frankfurt am Main, Germany.
authors.forename: D A
authors.initials: DA
authors.lastname: Jans
authors.forename: B A
authors.initials: BA
authors.lastname: Hemmings
mesh_terms: D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D002460:Cell Line; D004789:Enzyme Activation; D004848:Epithelium; D007668:Kidney; D007700:Kinetics; D011494:Protein Kinases / Q000378:metabolism*; D011945:Receptors, Angiotensin / Q000187:drug effects / Q000378:metabolism*; D017483:Receptors, Vasopressin; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014667:Vasopressins / Q000378:metabolism*
chemical_list: D011945:Receptors, Angiotensin; D017483:Receptors, Vasopressin; D014667:Vasopressins; D001127:Arginine Vasopressin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D011494:Protein Kinases; D013755:Tetradecanoylphorbol Acetate; D015056:1-Methyl-3-isobutylxanthine