Phosphatidylserine synthesis in glioma C6 cells is inhibited by Ca2+ depletion from the endoplasmic reticulum: effects of 2,5-di-tert-butylhydroquinone and thimerosal.

Abstract

The effects of 2,5-di-tert-butylhydroquinone (DBHQ) and thimerosal on phosphatidylserine synthesis by the base exchange reaction and on calcium mobilization in intact glioma C6 cells were compared with that of thapsigargin, a selective inhibitor of the endoplasmic reticulum Ca(2+)-ATPase. It has been found that all these agents inhibit phosphatidylserine synthesis by 70%, but their effectiveness are different. The data show that this inhibition is caused by Ca2+ depletion of the endoplasmic reticulum, indicating that phosphatidylserine synthesis requires high concentration of Ca2+ within this structure. On this basis and on literature data, a new model for the localization of the serine base exchange enzyme in the endoplasmic reticulum membrane is proposed.

• Authors: M Wiktorek, P Sabała, M Czarny, J Barańska
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 224 Issue 3 Pg. 645-50 (Jul 25 1996) ISSN: 0006-291X [Print] United States
• PMID: 8713102 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Enzyme Inhibitors
• Hydroquinones
• Phosphatidylserines
• Terpenes
• Thimerosal
• 2,5-di-tert-butylhydroquinone
• Ionomycin
• Thapsigargin
• Calcium-Transporting ATPases
• Calcium

Topics

• Brain Neoplasms (metabolism, pathology)
• Calcium (metabolism)
• Calcium-Transporting ATPases (antagonists & inhibitors)
• Endoplasmic Reticulum (drug effects, enzymology, metabolism)
• Enzyme Inhibitors (pharmacology)
• Glioma (metabolism, pathology)
• Hydroquinones (pharmacology)
• Ionomycin (pharmacology)
• Phosphatidylserines (biosynthesis)
• Terpenes (pharmacology)
• Thapsigargin
• Thimerosal (pharmacology)
• Tumor Cells, Cultured