Abolishment of bradykinin‐induced calcium oscillations in ras‐transformed fibroblasts by the expression of 80 kDa diacylglycerol kinase

[摘要]

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.

[学科分类] 生物化学/生物物理

[关键词] Diacylglycerol;Diacylglycerol kinase;Protein kinase C;Ca2+ oscillation;ras-Transformed NIH/3T3 cell line (DT)