细胞外钙调素对烟草悬浮培养细胞蛋白质磷酸化作用的影响

用液体闪烁计数法研究了细胞外钙调素对烟草悬浮培养细胞质蛋白质磷酸化的作用。结果表明烟草细胞细胞质蛋白质磷酸化活性在细胞培养过程中逐渐增加，达到最高峰后又开始下降。在细胞质蛋白质磷酸化强度高峰时，加入抗CaM血清后，细胞质蛋白质磷酸化活性受到了部分抑制。加抗CaM血清后再补加CaM能够部分解除抗CaM血清对细胞质部分与细胞核部分蛋白质磷酸化的抑制作用。外加纯化钙调素可以引起烟草悬浮培养细胞细胞质蛋白质磷酸化的活性增强，并且这种增强作用具有时间（高峰为70min）与剂量（最适为CaM10-7mmol/L）依赖性。CaM引起的细胞质蛋白质磷酸化变化与红光所引起的细胞质蛋白质磷酸化变化在时间进程上是不相同的。

The Effects of Extracellular Calmodulin on Protein Phosphorylation in Cytoplasmic Fraction from Suspension-cultured Tobacco(Nicotiana tobacum L.) Cells

The effects of extracellular calmodulin on the activity of protein phosphorylation were studied in suspension-cultured tobacco cells.The activity of protein phosphorylation in cytoplasmic fraction increased gradually as measured in different culture days, as it reaches peak then decrease(Fig.1). On its peak day, the activity of protein phosphorylation could be blocked by the anti-CaM serum(Fig.2), and addition of exogenous purified CaM could eliminate the inhibitory effects of anti-CaM serum(Fig.3).The activity of protein phosphorylation of cytoplasmic fraction from suspension-cultured tobacco cells was also activated by pure CaM.The activation was time-(Fig.6) and dose-dependent(Fig.4).The extracellular CaM induced activation of protein phosphorylation was different from red light induced one(Fig.7) with respect to their time courses.