title: Abolishment of bradykinin-induced calcium oscillations in ras-transformed fibroblasts by the expression of 80 kDa diacylglycerol kinase.
abstract: Our previous study showed bradykinin-induced periodic Ca2+ changes (Ca2+ oscillations) in v-Ki-ras-transformed NIH/3T3 (DT) cells in which protein kinase C (PKC) activity is partially down-regulated by a sustained high level of 1,2-diacylglycerol (DAG) [FEBS Lett. (1991) 281, 263-266]. In the present study, DAG kinase with 80 kDa mass (80K DGK) has been successfully transfected in DT cells, which exhibited enhanced cellular DAG kinase activities, decreased cellular DAG contents, and increased PKC activities compared to the control vector-transfected cells. Furthermore, these DGK-transfectants showed strong inhibition in bradykinin-induced Ca2+ oscillations. The results suggest that the sustained DAG increase down-regulates the PKC activity, thereby leading to the induction of Ca2+ oscillations in DT cells.
authors.affiliation: Department of Biochemistry, Gifu University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Fu
authors.forename: Y
authors.initials: Y
authors.lastname: Sugimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Okano
authors.forename: H
authors.initials: H
authors.lastname: Kanoh
authors.forename: Y
authors.initials: Y
authors.lastname: Nozawa
mesh_terms: D016475:3T3 Cells; D000818:Animals; D015152:Blotting, Northern; D001920:Bradykinin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002461:Cell Line, Transformed; D019852:Diacylglycerol Kinase; D015536:Down-Regulation; D005347:Fibroblasts / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D011905:Genes, ras; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D051379:Mice; D010770:Phosphotransferases / Q000096:biosynthesis / Q000378:metabolism*; D010957:Plasmids; D011493:Protein Kinase C / Q000378:metabolism; D015290:Second Messenger Systems / Q000502:physiology; D014162:Transfection
chemical_list: D007527:Isoenzymes; D010770:Phosphotransferases; D019852:Diacylglycerol Kinase; D011493:Protein Kinase C; D001920:Bradykinin; D002118:Calcium