Stimulation of ouabain‐sensitive 86Rb+ uptake and Na+,K+‐ATPase α‐subunit phosphorylation by a cAMP‐dependent signalling pathway in intact cells from rat kidney cortex

FEBS Letters

Carranza, Maria Luisa²  Féraille, Eric²  Favre, Hervé²  Kiroytcheva, Militza¹  Rousselot, Martine² 

[1] Clinic of Nephrology, Alexandrovska University Hospital, 1 Georgy Sofiisky Str., 1431 Sofia, Bulgaria;Division of Néphrology, Hôpital Cantonal Universitaire, 24 rue Micheli du Crest, CH-1211 Genève 14, Switzerland

关键词: Na+;    K+-ATPase;    Rubidium uptake;    Protein phosphorylation;    cAMP analog;    Forskolin;    Rat kidney cortex;   

DOI  :  10.1016/0014-5793(96)01121-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We investigated in intact cortical kidney tubules the role of PKA-mediated phosphorylation in the short-term control of Na⁺,K⁺-ATPase activity. The phosphorylation level of Na⁺,K⁺-ATPase was evaluated after immunoprecipitation of the enzyme from ³²P-labelled cortical tubules and the cation transport activity of Na⁺,K⁺-ATPase was measured by ouabain-sensitive ⁸⁶Rb⁺ uptake. Incubation of cells with CAMP analogues (8-bromo-cAMP, dibutyryl-cAMP) or with forskolin plus 3-isobutyl-1-methylxanthine increased the phosphorylation level of the Na⁺,K⁺-ATPase α-subunit and stimulated ouabain-sensitive ⁸⁶Rb⁺ uptake. Inhibition of PKA by H-89 blocked the effects of dibutyryl-cAMP on both phosphorylation and ⁸⁶Rb⁺ uptake processes. The results suggest that phosphorylation by PKA stimulates the Na⁺,K⁺-ATPase activity.

【 授权许可】

Unknown