Ion pumps in polarized cells: sorting and regulation of the Na+, K+- and H+, K+-ATPases.
The physiologic function of an ion transport protein is determined, in part, by its subcellular localization and by the cellular mechanisms that modulate its activity. The Na(+),K(+)-ATPase and the H(+),K(+)-ATPases are closely related members of the P-type family of ion transporting ATPases. Despite their homology, these pumps are sorted to different domains in polarized epithelial cells, and their enzymatic activities are subject to distinct regulatory pathways. The molecular signals responsible for these properties have begun to be elucidated. It appears that a complex array of inter- and intramolecular interactions govern trafficking, distribution, and catalytic capacities of these proteins.
Dunbar
L A
LA
Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
Caplan
M J
MJ
D000818:Animals; D015971:Gene Expression Regulation, Enzymologic; D017506:H(+)-K(+)-Exchanging ATPase / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007477:Ions; D008958:Models, Molecular; D011485:Protein Binding; D015398:Signal Transduction; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry / Q000378:metabolism*
D007477:Ions; D017506:H(+)-K(+)-Exchanging ATPase; D000254:Sodium-Potassium-Exchanging ATPase