F. Cornelius et N. Logvinenko, FUNCTIONAL REGULATION OF RECONSTITUTED NA,K-ATPASE BY PROTEIN-KINASE-A PHOSPHORYLATION, FEBS letters, 380(3), 1996, pp. 277-280
Reconstituted Na+,K+-ATPase from either pig kidney or shark rectal gla
nds was phosphorylated by cAMP dependent protein kinase, PKA. The stoi
chiometry was similar to 0.9 mole P-i/mole alpha-subunit in the pig ki
dney enzyme and similar to 0.2 mol P-i/mol alpha-subunit in the shark
enzyme, In shark Na+, K+-ATPase PKA phosphorylation increased the maxi
mum hydrolytic activity for cytoplasmic Na+ activation and extracellul
ar K+ activation without affecting the apparent K-m values, In contras
t, no significant functional effect after PKA phosphorylation was obse
rved in pig kidney Na+,K+-ATPase.