Identification of the β-subunit for nongastric H-K-ATPase in rat anterior prostate
| Autor: | Nikolay B. Pestov, Mikhail I. Shakhparonov, Nikolai N. Modyanov, Tatyana V. Korneenko, Hao Zhao, Rossen Radkov |
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| Rok vydání: | 2004 |
| Předmět: |
Male
Physiology Protein subunit ATPase Biology H(+)-K(+)-Exchanging ATPase Rats Sprague-Dawley Prostate medicine Animals Protein Isoforms RNA Messenger chemistry.chemical_classification Reverse Transcriptase Polymerase Chain Reaction Cell Membrane Cell Biology Apical membrane Immunohistochemistry Cell Compartmentation Rats Protein Subunits Enzyme medicine.anatomical_structure Biochemistry Membrane protein chemistry biology.protein ATP1B1 |
| Zdroj: | American Journal of Physiology-Cell Physiology. 286:C1229-C1237 |
| ISSN: | 1522-1563 0363-6143 |
| DOI: | 10.1152/ajpcell.00393.2003 |
| Popis: | The structural organization of nongastric H-K-ATPase, unlike that of closely related Na-K-ATPase and gastric H-K-ATPase, is not well characterized. Recently, we demonstrated that nongastric H-K-ATPase α-subunit (αng) is expressed in apical membranes of rodent prostate. Its highest level, as well as relative abundance, with respect to α1-isoform of Na-K-ATPase, was observed in anterior lobe. Here, we aimed to determine the subunit composition of nongastric H-K-ATPase through the detailed analysis of the expression of all known X-K-ATPase β-subunits in rat anterior prostate (AP). RT-PCR detects transcripts of β-subunits of Na-K-ATPase only. Measurement of absolute protein content of these three β-subunit isoforms, with the use of quantitative Western blotting of AP membrane proteins, indicates that the abundance order is β1> β3≫ β2. Immunohistochemical experiments demonstrate that β1is present predominantly in apical membranes, coinciding with αng, whereas β3is localized in the basolateral compartment, coinciding with α1. This is the first direct demonstration of the αng-β1colocalization in situ indicating that, in rat AP, αngassociates only with β1. The existence of αng-β1complex has been confirmed by immunoprecipitation experiments. These results indicate that β1-isoform functions as the authentic subunit of Na-K-ATPase and nongastric H-K-ATPase. Putatively, the intracellular polarization of X-K-ATPase isoforms depends on interaction with other proteins. |
| Databáze: | OpenAIRE |
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