Cytosolic rat brain synapsin I is a diacylglycerol kinase.
Cytosolic rat brain synapsin I is a diacylglycerol kinase.
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胞质大鼠脑突触蛋白 I 是一种二酰基甘油激酶。
DOI：
10.1073/pnas.88.14.6137
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发表时间：
1991
影响因子：
11.1
通讯作者：
J. Besterman
中科院分区：
文献类型：
--
作者：
D. Kahn;J. Besterman
二酰基甘油（DG）的磷酸化是由DG激酶催化的反应，可能在终止蛋白激酶c介导的效应诱导信号中起关键作用。突触蛋白1是细胞内蛋白激酶的主要靶点，被认为参与轴突末端神经递质的释放。我们提出了几条证据，表明大鼠脑突触素除了这个作用外，还可能具有DG激酶的功能。纯化后的大鼠脑DG激酶经胰蛋白酶消化后，产生了与synapsin 1中三个区域序列相同的三个主要片段。使用兔抗synapsin多克隆抗血清，洗脱后的突触蛋白免疫反应谱与DG激酶纯化最后一步的柱状组分活性完全一致。与synapsin一样，纯化后的酶是一种强碱性蛋白，等电点大于10.0。最后，将DG激酶与高度纯化的细菌胶原酶（一种部分降解富含脯氨酸和甘氨酸的突触蛋白的酶）孵育，导致DG激酶活性和突触蛋白免疫反应性同时丧失。我们的结论是，胞浆大鼠脑突触素能够发挥DG激酶的功能。
The phosphorylation of diacylglycerol (DG), a reaction catalyzed by DG kinase, may be critical in the termination of effector-induced signals mediated by protein kinase C. Synapsin I is a principal target of intracellular protein kinases and is thought to be involved in the release of neurotransmitter from axon terminals. We present several lines of evidence which indicate that rat brain synapsin, in addition to this role, may function as a DG kinase. Purified rat brain DG kinase was digested with trypsin, which produced three major fragments whose sequence was identical to three regions in synapsin I. Using a rabbit anti-synapsin polyclonal antiserum, the elution profile of synapsin immunoreactivity coincided exactly with that of DG kinase activity in column fractions from the final step in the DG kinase purification procedure. As is the case with synapsin, the purified enzyme was a strongly basic protein with an isoelectric point greater than 10.0. Finally, incubating the DG kinase with highly purified bacterial collagenase, an enzyme that partially degrades the proline- and glycine-rich synapsin, resulted in the simultaneous loss of DG kinase activity and synapsin immunoreactivity. We conclude that cytosolic rat brain synapsin is capable of functioning as a DG kinase.