Inhibition of CDP-DG:iNositol transferase by inostamycin

Masaya Imoto, Yoshiko Taniguchi, Kazuo Umezawa

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)


Inostamycin, a novel microbial secondary metabolite, inhibited [3H]inositol and 32P1 incorporation into phosphatidylinositol (PtdIns) induced by epidermal growth factor (EGF) in cultured A431 cells, the IC50 being 0.5 μg/ml, without inhibiting macromolecular synthesis. The drug inhibited cellular inositol phosphate formation only when it was added at the same time as labeled inositol. It was found to inhibit in vitro CDP-DG:inositol transferase activity of the A431 cell membrane, the IC50 being about 0.02 μg/ml. It did not inhibit tyrosine kinase, PtdIns phospholipase C, or PtdIns kinase. Therefore, inhibition of PtdIns turnover by inostamycin must be due to the inhibition of CDP-DG:inositol transferase. Thus, inostamycin is a novel inhibitor of CDP-DG:inositol transferase.

Original languageEnglish
Pages (from-to)299-302
Number of pages4
JournalJournal of biochemistry
Issue number2
Publication statusPublished - 1992 Aug

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology


Dive into the research topics of 'Inhibition of CDP-DG:iNositol transferase by inostamycin'. Together they form a unique fingerprint.

Cite this