Molecular mechanism of neural plastic changes in signal transduction, with special reference to the role of cGMP

本研究在哺乳动物交感神经节中发现：1)环(c) GMP在毒蕈碱刺激下增加，2)cGMP诱导长时间的去极化，3)检测到g激酶活性，4)发现m. w. 87K特异性g激酶底物。87K蛋白被鉴定为MARCKS，它是在大脑中发现的一种特定的c激酶底物。从神经节突触传递的缓慢可塑性变化的角度讨论了G-激酶和c -激酶磷酸化MARCKS的作用。内源性功能蛋白被认为与神经递质的胞外释放有关，通过在原代培养中交感神经元之间形成的新生突触进行分析。提示肌球蛋白轻链激酶（MLCK）对突触前末端非肌球蛋白II的磷酸化以及随后肌球蛋白与肌动蛋白的相互作用可能参与了神经递质的释放过程。

In the present study carried out in mammalian sympathetic ganglia, it was found that 1) cyclic (c) GMP was increased in response to muscarinic stimulation, 2) cGMP induced a long-lasting depolarization, 3) G-kinase activity was detected, and 4) specific G-kinase substrate of m. w. 87K was discovered. 87K protein was identified as MARCKS which was found in the brain as a specific C-kinase sub-strate. Roles of the phosphorylation of MARCKS by G- and C-kinases were discussed in terms of slow plastic changes in ganglionic synaptic transmission.Analyzes of endogenous functional proteins which were thought to be related to the exocytotic release of neurotransmitters were performed using de novo synapses formed between sympathetic neurons in primary culture.It was suggested that phosphorylation of non-muscle myosin II in the presynaptic terminals by myosin light chain kinase (MLCK) and subsequent interaction of myosin with actin might be involved in the process of neurotransmitter release.