Okadaic acid reverses the inhibitory effect of protein kinase C on alkaline phosphatase activity in osteoblast-like cells

Yasuko Watanabe, Osamu Kozawa, Atsushi Suzuki, Jun Kotoyori, Yoshiaki Ito, Yutaka Oiso

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

We previously reported that fetal calf serum-induced alkaline phosphatase activity is suppressed due to the activation of protein kinase C in osteoblast-like MC3T3-E1 cells (Miwa et al. (1991) Bone Miner. 14, 15-25; Kotoyori et al. (1994) Horm. Metab. Res. 26, 116-118). In the present study, we examined the effect of okadaic acid, a potent and specific inhibitor of protein phosphatase type 1 and 2A, on fetal calf serum-induced alkaline phosphatase activity in MC3T3-E1 cells. The pretreatment with okadaic acid enhanced the fetal calf serum-induced alkaline phosphatase activity in a dose-dependent manner in the range between 0.1 and 5 nM. 1-Norokadaone, a less potent analogue of okadaic acid, had little effect on the fetal calf serum-induced alkaline phosphatase activity. Okadaic acid partially reversed the suppression of fetal calf serum-induced alkaline phosphatase activity by 12-O-tetradecanoylphorbol-13-acetate, a protein kinase C activator. The effect of okadaic acid was dose-dependent in the range between 0.1 and 5 nM. The patterns of the dosedependency of both okadaic acid effects on fetal calf serum-induced alkaline phosphatase activity and on the suppression by 12-O-tetradecanoylphorbol-13-acetate were similar. These results strongly suggest that protein phosphatase type 1 and/or 2A act as a regulator of alkaline phosphatase activity at a point downstream from protein kinase C in osteoblast-like cells.

Original languageEnglish
Pages (from-to)115-118
Number of pages4
JournalMolecular and Cellular Endocrinology
Volume103
Issue number1-2
DOIs
Publication statusPublished - 07-1994
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology
  • Endocrinology

Fingerprint Dive into the research topics of 'Okadaic acid reverses the inhibitory effect of protein kinase C on alkaline phosphatase activity in osteoblast-like cells'. Together they form a unique fingerprint.

Cite this