Mechanism for regulating cell surface distribution of Na+,K(+)-ATPase in polarized epithelial cells.
Restriction of sodium, potassium adenosine triphosphatase (Na+,K(+)-ATPase) to either the apical or basal-lateral membrane domain of polarized epithelial cells is fundamental to vectorial ion and solute transport in many tissues and organs. A restricted membrane distribution of Na+,K(+)-ATPase in Madin-Darby canine kidney (MDCK) epithelial cells was found experimentally to be generated by preferential retention of active enzyme in the basal-lateral membrane domain and selective inactivation and loss from the apical membrane domain, rather than by vectorial targeting of newly synthesized protein from the Golgi complex to the basal-lateral membrane domain. These results show how different distributions of the same subunits of Na+,K(+)-ATPase may be generated in normal polarized epithelial and in disease states.
Hammerton
R W
RW
Department of Molecular and Cellular Physiology, Stanford University School of Medicine, CA 94305-5426.
Krzeminski
K A
KA
Mays
R W
RW
Ryan
T A
TA
Wollner
D A
DA
Nelson
W J
WJ
D000818:Animals; D001665:Binding Sites; D002450:Cell Communication; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology* / Q000502:physiology; D016764:Cell Polarity; D004285:Dogs; D004848:Epithelium / Q000201:enzymology / Q000502:physiology; D007700:Kinetics; D010042:Ouabain / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase