钙调素高表达对NRK细胞中DG-PKC和cAMP-PKA水平的影响

The Effect of Overexpressing Calmodulin on The Signal Pathways of DG PKC and cAMP PKA in NRK Cells

钙调素（ＣａＭ）作为Ｃａ２＋的主要受体，对细胞增殖起重要调节作用，而且在转化细胞中ＣａＭ的水平明显高于正常细胞．ｃＡＭＰ作为一种第二信使，起着将细胞外刺激信号转化为细胞内各种生理活动的媒介作用．蛋白激酶Ａ（ＰＫＡ）则是这种转化过程中的关键激酶．蛋白激...

As the major intracellular receptor of Ca 2+ .Calmodulin presents a lot of physiological response,It is an important step in lnositol Phospholipid Signaling Pathway and plays an important role in the regulation of cell proliferation.The correlation of CaM and the two signal pathways of DG PKC and cAMP PKA in the overexpressing CaM NRK cells(NCAM cells)was studied.It showed that in the NCAM cells the level of DG was 1.6 times as much as that of NXN cells (NRK cells which were transfected vector pXJ41 neo only).The activity of total PKC in NCAM cells was also sharply increased,it was 4.6 times higher than that of control cells.On the contrary,the level of cAMP in NCAM cells was apparently lower than that of control cells.It was only 44% of that of the control.Meanwhile,the activity of PKA was strikingly decreased too,which was only 17% of that of control cells.These results showed that there was an intimate relationship among CaM,DG PKC and cAMP PKA signal pathways.In NRK cells,the correlation of CaM and DG PKC was positively cooperative.Contrasting to this,the relation of CaM and cAMP PKA was antagonistic.This indicated that the effects of CaM on cell proliferation could be accomplished by influencing the signal pathways of DG PKC and cAMP PKA.