Chen C C, Chen W C
Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
Brain Res. 1996 Jun 24;725(1):75-80. doi: 10.1016/0006-8993(96)00336-8.
Protein kinase C (PKC) activity, Western blot analysis of PKC alpha, -beta and -gamma, endogenous substrate protein phosphorylation and Western blot analysis of neuromodulin were studied in the cortex, striatum, hippocampus and cerebellum of mouse brain after pentylenetetrazol-induced chemoshock. The PKC isozymes and endogenous substrates in the crude cytosolic and membrane fractions of these four brain regions were partially purified by DE-52 columns eluted with buffer containing 100 or 200 mM KCl. Almost the same PKC activity in the cortex, striatum, hippocampus and cerebellum was found. This kinase activity was increased in the membrane fractions of hippocampus from chemoshocked mice, while that in other brain regions was not changed. On further analysis by immunoblotting, this increased activity was found to be due to the increase of PKC gamma isozyme. The in vitro phosphorylation of neuromodulin was also found to be increased in the hippocampus of chemoshocked mice, while the level of neuromodulin was not changed after chemoshock. Therefore, an increase of PKC gamma alone, but not neuromodulin, in the hippocampus contributed to the increased phosphorylation of this substrate in chemoshocked mice.
在戊四氮诱导化学性休克后，对小鼠脑皮质、纹状体、海马和小脑中的蛋白激酶C（PKC）活性、PKCα、-β和-γ的蛋白质免疫印迹分析、内源性底物蛋白磷酸化以及神经调节蛋白的蛋白质免疫印迹分析进行了研究。通过用含100或200 mM KCl的缓冲液洗脱的DE-52柱，对这四个脑区的粗胞质和膜部分中的PKC同工酶和内源性底物进行了部分纯化。在皮质、纹状体、海马和小脑中发现了几乎相同的PKC活性。化学性休克小鼠海马膜部分的这种激酶活性增加，而其他脑区的活性未改变。通过免疫印迹进一步分析发现，这种活性增加是由于PKCγ同工酶的增加。化学性休克小鼠海马中神经调节蛋白的体外磷酸化也被发现增加，而化学性休克后神经调节蛋白的水平未改变。因此，化学性休克小鼠海马中仅PKCγ增加，而非神经调节蛋白增加，导致了该底物磷酸化增加。
