| Autor: |
Haruo Homareda, Kei Suga, Sachiko Yamamoto-Hijikata, Yoshinobu Eishi, Makoto Ushimaru, Yukichi Hara |
| Jazyk: |
angličtina |
| Rok vydání: |
2022 |
| Předmět: |
|
| Zdroj: |
Biochemistry and Biophysics Reports, Vol 32, Iss , Pp 101347- (2022) |
| Druh dokumentu: |
article |
| ISSN: |
2405-5808 |
| DOI: |
10.1016/j.bbrep.2022.101347 |
| Popis: |
The affinity for K+ of silkworm Na+/K+-ATPase, which is composed of α and β subunits, is remarkably lower than that of mammalian Na+/K+-ATPase, with a slightly higher affinity for Na+. Because the α subunit had more than 70% identity to the mammalian α subunit in the amino acid sequence, whereas the β subunit, a glycosylated protein, had less than 30% identity to the mammalian β subunit, it was suggested that the β subunit was involved in the affinities for Na+ and K+ of Na+/K+-ATPase. To confirm this hypothesis, we examined whether replacing the silkworm β subunit with the mammalian β subunit affected the affinities for Na+ and K+ of Na+/K+-ATPase. Cloned silkworm α and cloned rat β1 were co-expressed in BM-N cells, a cultured silkworm ovary-derived cell lacking endogenous Na+/K+-ATPase, to construct a hybrid Na+/K+-ATPase, in which the silkworm β subunit was replaced with the rat β1 subunit. The hybrid Na+/K+-ATPase increased the affinity for K+ by 4.1-fold and for Na+ by 0.65-fold compared to the wild-type one. Deglycosylation of the silkworm β subunit did not affect the K+ affinity. These results support the involvement of the β subunit in the Na+ and K+ affinities of Na+/K+-ATPase. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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