Bradykinin-induced translocation of protein kinases C in neuroblastoma NCB-20 cell: Dependence on 1,2-diacylglycerol content and free calcium

Abstract

Bradykinin (BK)-induced production of 1,2-diacylglycerol (1,2-DG) and translocation of protein kinases C (PKCs) were examined in neuroblastoma-derived hybrid NCB-20 cells. Mass analysis of 1,2-DG exhibited a biphasic increase by 1 uM BK stimulation: the first transient phase and the second broad sustained phase. Among three subspecies of PKC expressed in these cells, types II and III were observed to translocate from cytosol to membrane in response to BK as well as PBt 2 by Western blotting analysis. Type II translocated more rapidly and distinctly than type III. However, after treatment with quin 2/AM, the second phase of 1,2-DG formation completely disappeared and PKCs translocation by BK or PBt 2 was completely abolished. BK-induced IP 3(1,4,5) formation was temporally consistent with the first transient phase of 1,2-DG formation. These findings suggest that PKCs translocation by BK stimulation is caused by 1,2-DG produced not only via phosphoinositide metabolism, but via other phospholipid breakdown which is Ca 2+-dependent.