HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 291/2/C366    most recent 00042.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (5) Citing Articles via Google Scholar Google Scholar Articles by Pestov, N. B. Articles by Modyanov, N. N. Search for Related Content PubMed PubMed Citation Articles by Pestov, N. B. Articles by Modyanov, N. N.

MEMBRANE TRANSPORTERS, ION CHANNELS, AND PUMPS

Loss of acidification of anterior prostate fluids in Atp12a-null mutant mice indicates that nongastric H-K-ATPase functions as proton pump in vivo

¹Department of Physiology, Pharmacology, Metabolism, and Cardiovascular Sciences, Medical University of Ohio, Toledo, Ohio; ²Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia; and ³Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio

Submitted 31 January 2006 ; accepted in final form 23 February 2006

The physiological functions of nongastric (colonic) H-K-ATPase (gene symbol Atp12a), unlike those of Na-K-ATPase and gastric H-K-ATPase, are poorly understood. It has been suggested that it pumps Na⁺ more efficiently than H⁺; however, so far, there is no direct evidence that it pumps H⁺ in vivo. Previously, we found that the nongastric H-K-ATPase -subunit is expressed in apical membranes of rodent anterior prostate epithelium, in a complex with the Na-K-ATPase ₁-subunit. Here we report the effects of Atp12a gene ablation on polarization of the ₁-subunit and secretory function of the anterior prostate. In nongastric H-K-ATPase-deficient prostate, the Na-K-ATPase -subunit resided exclusively in basolateral membranes; however, the ₁-subunit disappeared from apical membranes, demonstrating that ₁ is an authentic subunit of nongastric H-K-ATPase in vivo and that apical localization of ₁ in the prostate is completely dependent on its association with the nongastric H-K-ATPase -subunit. A remarkable reduction in acidification of anterior prostate fluids was observed: pH 6.38 ± 0.14 for wild-type mice and 6.96 ± 0.10 for homozygous mutants. These results show that nongastric H-K-ATPase is required for acidification of luminal prostate fluids, thereby providing a strong in vivo correlate of previous functional expression studies demonstrating that it operates as a proton pump.

hydrogen-potassium-adenosinetriphosphatase; male accessory glands; proton transport; sorting

This article has been cited by other articles:

				T. Shibata, H. Hibino, K. Doi, T. Suzuki, Y. Hisa, and Y. Kurachi Gastric type H+,K+-ATPase in the cochlear lateral wall is critically involved in formation of the endocochlear potential Am J Physiol Cell Physiol, November 1, 2006; 291(5): C1038 - C1048. [Abstract] [Full Text] [PDF]