|
|||||
|
|
Methionine Aminopeptidase II: A Molecular Chaperone for Sarcoplasmic Reticulum Calcium ATPase |
|
| Authors: | Shunsuke Noguchi Tohru Komiya Hiroshi Eguchi Akira Shirahata Jun-ichi Nikawa Masaru Kawamura |
| Institution: | (1) Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, Iizuka 820-8502, Japan;(2) Department of Biological Function, Graduate School of Science, Osaka City University, Sumiyoshi, Osaka 558-8585, Japan;(3) Department of Pediatrics, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan;(4) Department of Cell Biology, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan |
| Abstract: | The monoclonal antibody to the β-subunit of H+/K+-ATPase (mAbHKβ) cross-reacts with a protein that acts as a molecular chaperone for the structural maturation of sarcoplasmic reticulum (SR) Ca2+-ATPase. We partially purified a mAbHKβ-reactive 65-kDa protein from Xenopus ovary. After in-gel digestion and peptide sequencing, the 65-kDa protein was identified as methionine aminopeptidase II (MetAP2). The effects of MetAP2 on SR Ca2+-ATPase expression were examined by injecting the cRNA for MetAP2 into Xenopus oocytes. Immunoprecipitation and pulse-chase experiments showed that MetAP2 was transiently associated with the nascent SR Ca2+-ATPase. Synthesis of functional SR Ca2+-ATPase was facilitated by MetAP2 and prevented by injecting an antibody specific for MetAP2. These results suggest that MetAP2 acts as a molecular chaperone for SR Ca2+-ATPase synthesis. |
| Keywords: | Ca2 +-ATPase Molecular chaperone Methionine aminopeptidase Na+/K+-ATPase H+/K+-ATPase Xenopus oocyte |
| 本文献已被 PubMed SpringerLink 等数据库收录！ | |