Phosphorylation of the Na+,K+-ATPase and the H+,K+-ATPase.
Phosphorylation is a widely used, reversible means of regulating enzymatic activity. Among the important phosphorylation targets are the Na(+),K(+)- and H(+),K(+)-ATPases that pump ions against their chemical gradients to uphold ionic concentration differences over the plasma membrane. The two pumps are very homologous, and at least one of the phosphorylation sites is conserved, namely a cAMP activated protein kinase (PKA) site, which is important for regulating pumping activity, either by changing the cellular distribution of the ATPases or by directly altering the kinetic properties as supported by electrophysiological results presented here. We further review the other proposed pump phosphorylations.
Poulsen
Hanne
H
Danish National Research Foundation, Centre for Membrane Pumps in Cells and Disease-PUMPKIN, Aarhus University, Department of Molecular Biology, Denmark. pn@mb.au.dk
Morth
Preben
P
Egebjerg
Jan
J
Nissen
Poul
P
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001665:Binding Sites; D018360:Crystallography, X-Ray; D055724:Electrophysiological Phenomena; D017506:H(+)-K(+)-Exchanging ATPase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D021122:Protein Subunits; D017386:Sequence Homology, Amino Acid; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D021122:Protein Subunits; D017506:H(+)-K(+)-Exchanging ATPase; D000254:Sodium-Potassium-Exchanging ATPase