Abstract
ERp57 is a ubiquitous ER chaperone that has disulfide isomerase activity. Here, we found that both ERp57 and gastric H+,K+-ATPase are expressed in a sample derived from the apical canalicular membranes of parietal cells. Overexpression of ERp57 in HEK293 cells stably expressing H +,K+-ATPase significantly increased the ATPase activity without changing the expression level of H+,K+-ATPase. Interestingly, overexpression of a catalytically inactive mutant of ERp57 (C57S/C60S/C406S/C409S) in the cells also increased H+,K +-ATPase activity. In contrast, knockdown of endogenous ERp57 in H+,K+-ATPase-expressing cells significantly decreased ATPase activity without changing the expression level of H+,K +-ATPase. Overexpression and knockdown of ERp57 had no significant effect on the expression and function of Na+,K+-ATPase. These results suggest that ERp57 positively regulates H+,K +-ATPase activity apart from its chaperoning function.
Original language | English |
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Pages (from-to) | 3898-3905 |
Number of pages | 8 |
Journal | FEBS Letters |
Volume | 587 |
Issue number | 24 |
DOIs | |
State | Published - 2013/12/11 |
Keywords
- ERp57
- Gastric mucosa
- H,K-ATPase
- Molecular chaperone
- Parietal cell
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology