Primary structure of the cAMP-dependent phosphorylation site of the plasma membrane calcium pump |
| |
| Authors: | P H James M Pruschy T E Vorherr J T Penniston E Carafoli |
| |
| Institution: | Laboratory of Biochemistry, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland. |
| |
| Abstract: | The primary structure of a region of the erythrocyte plasma membrane calcium pump which is phosphorylated by the cAMP-dependent protein kinase has been determined. The sequence is A-P-T-K-R-N-S-S(P)-P-P-P-S-P-D. The site is located between the calmodulin binding domain and the C-terminus of the ATPase. The ATPase is phosphorylated only at this site by the cAMP-dependent protein kinase, and the phosphorylation is inhibited by calmodulin. The effect of the phosphorylation is to decrease the Km for Ca2+ of the purified ATPase from about 10 microM to about 1.4 microM and to increase the Vmax of ATP hydrolysis about 2-fold. |
| |
| Keywords: | |
|
|
