Terada M, Yasuda H, Kogawa S, Maeda K, Haneda M, Hidaka H, Kashiwagi A, Kikkawa R
The Third Department of Medicine, Shiga University of Medical Science, Otsu, Japan.
J Neurochem. 1998 Dec;71(6):2600-6. doi: 10.1046/j.1471-4159.1998.71062600.x.
In spite of the clarification in the temporal and spatial expression pattern of a cyclin-dependent kinase (Cdk) 5 and its neuron-specific activator, p35, in the CNS, it remains to be elucidated in the PNS. In addition, it is not known whether Cdk5 activity exists in the PNS. Therefore, we have examined their expression and activity in the PNS by immunoblot analysis, immunohistochemistry, and in vitro kinase assay. Immunoblot analysis indicated the expression of Cdk5 and p35 proteins in dorsal root ganglion (DRG) and sciatic nerve alike in the CNS. By immunohistochemistry, both proteins were shown to be present in the cell body and axon (sciatic nerve) of both DRG neurons and anterior horn cells. A co-immunoprecipitation study indicated the in vivo association between Cdk5 and p35 in both DRG and sciatic nerve. However, Cdk5 kinase activity was found only in DRG, but not in sciatic nerve. These results suggest that Cdk5 kinase activity exists and functions physiologically in the PNS and may be regulated by unknown mechanisms other than the availability of p35 as reported in developing brains.
尽管细胞周期蛋白依赖性激酶（Cdk）5及其神经元特异性激活剂p35在中枢神经系统中的时空表达模式已得到阐明，但在周围神经系统中仍有待阐明。此外，尚不清楚周围神经系统中是否存在Cdk5活性。因此，我们通过免疫印迹分析、免疫组织化学和体外激酶测定，研究了它们在周围神经系统中的表达和活性。免疫印迹分析表明，Cdk5和p35蛋白在中枢神经系统的背根神经节（DRG）和坐骨神经中均有表达。通过免疫组织化学，两种蛋白均显示存在于DRG神经元和前角细胞的细胞体和轴突（坐骨神经）中。一项共免疫沉淀研究表明，Cdk5和p35在DRG和坐骨神经中均存在体内关联。然而，仅在DRG中发现了Cdk5激酶活性，而在坐骨神经中未发现。这些结果表明，Cdk5激酶活性在周围神经系统中存在并具有生理功能，可能受发育中的大脑中报道的除p35可用性之外的未知机制调节。
