视黄酸诱导HL-60细胞分化后胞浆及核中蛋白激酶C活性和底物的改变

CHANGES OF THE SUBSTRATE AND ACTIVITY OF PROTEIN KINASE C IN THE CYTOSOL AND NUCLEUS OF HL-60 CELLS AFTER RETINOIC ACID-INDUCED DIFFERENTIATION

本文观察视黄酸诱导HL-60细胞分化后胞浆及核中蛋白激酶C活性和底物的变化。视黄酸诱导分化后,胞浆中蛋白激酶C活性升高,而核中则降低;胞浆中蛋白激酶C的底物减少,而核中蛋白激酶C底物的种类没有改变,但21kD的蛋白激酶C底物的磷酸化明显减弱。进一步分析表明,21kD蛋白是0.75mol/L高氯酸可溶蛋白。结果提示胞浆和核中蛋白激酶C及其底物的变化,可能与视黄酸对HL-60细胞的诱导分化作用有关。

The changes of protein kinase C and its substrates in the cytosol and nuclei upon retinoic acid-induced differentiation of HL-60 cells were studies by incubation of [γ-32P]ATP with proteins in vitro. The activity of protein kinase C in the cytosol rose,and that in the nuclei declined after differentiation. The substrates of protein kinase C in the cytosol of HL-60 cells were 75 kD,67kD,47kD,40kD and 21kD proteins,and 35kD protein was the substrate of proteinkinase C detectable in the retinoic acid-treated cytosol. The main protein kinase C substratesin HL-60 nuclei were 94kD,67kD,40kD,31kD and 21kD proteins,and the same substrateswere detected in the retinoic acid-treated nuclei,but the phosphorylation of the 21kD protein was markedly decreased . Further analysis showed that the 21kD protein was 0. 75mol/L PCA soluble protein. These results suggest that the differential changes of proteinkinase C and its substrates in the cytosol and nuclei may involve in retinoic acid-induced differentiation of HL-60 cells.