The cell biology of ion pumps: sorting and regulation.
The physiologic function of an ion pump is determined, in part, by its subcellular localization and by the cellular mechanisms that modulate its activity. The Na,K-ATPase and the gastric H,K-ATPase are two 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 intra-molecular interactions govern these proteins' trafficking, distribution and catalytic capacity.
Dunbar
L A
LA
Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT 06525, USA.
Caplan
M J
MJ
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D016764:Cell Polarity / Q000502:physiology; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure; D005753:Gastric Mucosa / Q000378:metabolism; D017506:H(+)-K(+)-Exchanging ATPase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016623:Ion Pumps / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000502:physiology; D021381:Protein Transport / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013270:Stomach / Q000648:ultrastructure
D016623:Ion Pumps; D020033:Protein Isoforms; D017506:H(+)-K(+)-Exchanging ATPase; D000254:Sodium-Potassium-Exchanging ATPase