| First Author | Mathews PM | Year | 1995 |
| Journal | Am J Physiol | Volume | 268 |
| Issue | 5 Pt 1 | Pages | C1207-14 |
| PubMed ID | 7762614 | Mgi Jnum | J:26578 |
| Mgi Id | MGI:74022 | Doi | 10.1152/ajpcell.1995.268.5.C1207 |
| Citation | Mathews PM, et al. (1995) Primary structure and functional expression of the mouse and frog alpha-subunit of the gastric H(+)-K(+)-ATPase. Am J Physiol 268(5 Pt 1):C1207-14 |
| abstractText | The H(+)-K(+)-ATPase of the gastric parietal cells is responsible for the acidification of the stomach lumen. This heterodimeric protein belongs to the family of cation-translocating P-type ATPases, which includes the closely related Na(+)-ATPase. We have cloned the alpha-subunit cDNA of the Xenopus and murine gastric H(+)-K(+)-ATPase (alpha H-K). We have expressed Xenopus and murine alpha H-K along with the previously cloned gastric H(+)-K(+)-ATPase beta-subunit of rabbit (beta H-K) in Xenopus oocytes by cRNA injection. An antibody directed against the beta H-K coimmunoprecipitates under nondenaturing conditions the alpha H-K of both species, demonstrating assembly of the alpha/beta complex. Additionally, we demonstrate the presence of K(+)-transporting H(+)-K(+)-ATPase in the plasma membrane of oocytes by 86Rb- uptake. The H(+)-K(+)-ATPase-mediated K+ uptake was inhibited by the gastric H(+)-K(+)-ATPase inhibitor Sch-28080, but not by ouabain, and shows K(+)-dependent activation (K1/2 approximately 2 mM). Furthermore, H(+)-K(+)-ATPase-expressing oocytes show a Sch-28080 inhibitable proton extrusion. Our data indicate that the expressed H(+)-K(+)-ATPase behaves functionally in oocytes as in the gastric gland. |
