Am J Physiol Cell Physiol AJP: Gastrointestinal and Liver Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 278: C182-C189, 2000;
0363-6143/00 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (16)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Sangan, P.
Right arrow Articles by Binder, H. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sangan, P.
Right arrow Articles by Binder, H. J.
Vol. 278, Issue 1, C182-C189, January 2000

Colonic H-K-ATPase alpha - and beta -subunits express ouabain-insensitive H-K-ATPase

Pitchai Sangan, Sundararajah Thevananther, Sheela Sangan, Vazhaikkurichi M. Rajendran, and Henry J. Binder

Departments of Internal Medicine and Pediatrics, Yale University, New Haven, Connecticut 06520-8019

Active K absorption in the rat distal colon is energized by an apical H-K-ATPase, a member of the gene family of P-type ATPases. The H-K-ATPase alpha -subunit (HKcalpha ) has been cloned and characterized (together with the beta -subunit of either Na-K-ATPase or gastric H-K-ATPase) in Xenopus oocytes as ouabain-sensitive 86Rb uptake. In contrast, HKcalpha , when expressed in Sf9 cells without a beta -subunit, yielded evidence of ouabain-insensitive H-K-ATPase. Because a beta -subunit (HKcbeta ) has recently been cloned from rat colon, this present study was initiated to determine whether H-K-ATPase and its sensitivity to ouabain are expressed when these two subunits (HKcalpha and HKcbeta ) are transfected into a mammalian cell expression system. Transfection of HEK-293 cells with HKcalpha and HKcbeta cDNAs resulted in the expression of HKcalpha and HKcbeta proteins and their delivery to plasma membranes. H-K-ATPase activity was identified in crude plasma membranes prepared from transfected cells and was 1) saturable as a function of increasing K concentration with a Km for K of 0.63 mM; 2) inhibited by orthovanadate; and 3) insensitive to both ouabain and Sch-28080. In parallel transfection studies with HKcalpha and Na-K-ATPase beta 1 cDNAs and with HKcalpha cDNA alone, there was expression of ouabain-insensitive H-K-ATPase activity that was 60% and 21% of that in HKcalpha /HKcbeta cDNA transfected cells, respectively. Ouabain-insensitive 86Rb uptake was also identified in cells transfected with HKcalpha and HKcbeta cDNAs. These studies establish that HKcalpha cDNA with HKcbeta cDNA express ouabain-insensitive H-K-ATPase similar to that identified in rat distal colon.

potassium absorption; epithelial transport; rat colon; rubidium-86 uptake; hydrogen-potassium-adenosinetriphosphatase


This article has been cited by other articles:


Home page
 Am. J. Physiol. Cell Physiol.Home page
N. B. Pestov, T. V. Korneenko, M. I. Shakhparonov, G. E. Shull, and N. N. Modyanov
Loss of acidification of anterior prostate fluids in Atp12a-null mutant mice indicates that nongastric H-K-ATPase functions as proton pump in vivo
Am J Physiol Cell Physiol, August 1, 2006; 291(2): C366 - C374.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
K. Kunzelmann and M. Mall
Electrolyte Transport in the Mammalian Colon: Mechanisms and Implications for Disease
Physiol Rev, January 1, 2002; 82(1): 245 - 289.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Renal Physiol.Home page
N. Laroche-Joubert, S. Marsy, and A. Doucet
Cellular origin and hormonal regulation of K+-ATPase activities sensitive to Sch-28080 in rat collecting duct
Am J Physiol Renal Physiol, December 1, 2000; 279(6): F1053 - F1059.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
V. M. Rajendran, P. Sangan, J. Geibel, and H. J. Binder
Ouabain-sensitive H,K-ATPase Functions as Na,K-ATPase in Apical Membranes of Rat Distal Colon
J. Biol. Chem., April 21, 2000; 275(17): 13035 - 13040.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
P. Sangan, S. R. Brill, S. Sangan, B. Forbush III, and H. J. Binder
Basolateral K-Cl Cotransporter Regulates Colonic Potassium Absorption in Potassium Depletion
J. Biol. Chem., September 29, 2000; 275(40): 30813 - 30816.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
N. B. Pestov, T. V. Korneenko, G. Adams, M. Tillekeratne, M. I. Shakhparonov, and N. N. Modyanov
Nongastric H-K-ATPase in rodent prostate: lobe-specific expression and apical localization
Am J Physiol Cell Physiol, April 1, 2002; 282(4): C907 - C916.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online