Phosphorylation of the catalytic subunit of Na+,K(+)-ATPase inhibits the activity of the enzyme. |
| |
| Authors: | A M Bertorello A Aperia S I Walaas A C Nairn P Greengard |
| |
| Affiliation: | Department of Pediatrics, St. Göran''s Children''s Hospital, Karolinska Institutet, Stockholm, Sweden. |
| |
| Abstract: | ![]()
We have examined two distinct protein kinases, cAMP-dependent protein kinase and protein kinase C, for their ability to phosphorylate and regulate the activity of three different types of Na+,K(+)-ATPase preparation. cAMP-dependent protein kinase phosphorylated purified shark rectal gland Na+,K(+)-ATPase to a stoichiometry of approximately 1 mol of phosphate per mol of alpha subunit. Protein kinase C phosphorylated purified shark rectal gland Na+,K(+)-ATPase to a stoichiometry of approximately 2 mol of phosphate per mol of alpha subunit. The phosphorylation by each of the kinases was associated with an inhibition of Na+,K(+)-ATPase activity of about 40-50%. These two protein kinases also inhibited the activity of a partially purified preparation of Na+,K(+)-ATPase from rat renal cortex and the activity of Na+,K(+)-ATPase present in preparations of basolateral membrane vesicles from rat renal cortex. |
| |
| Keywords: | |
|
|
