SYNAPTIC VESICLE-ASSOCIATED CA2+/CALMODULIN-DEPENDENT PROTEIN KINASE-II IS A BINDING-PROTEIN FOR SYNAPSIN-I
SYNAPTIC VESICLE-ASSOCIATED CA2+/CALMODULIN-DEPENDENT PROTEIN KINASE-II IS A BINDING-PROTEIN FOR SYNAPSIN-I
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DOI：
10.1038/359417a0
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发表时间：
1992-10-01
期刊：
影响因子：
64.8
通讯作者：
CZERNIK, AJ
中科院分区：
文献类型：
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作者：
BENFENATI, F;VALTORTA, F;CZERNIK, AJ
突触素I是一种突触小泡相关的磷酸蛋白，参与神经递质释放的调节。钙钙调素依赖的蛋白激酶II使突触素I的羧基末端区域的两个位置磷酸化，导致突触素I从突触小泡2解离，并增加神经递质释放3，4。相反，去磷酸化形式的突触蛋白I，而不是被钙/钙调蛋白依赖蛋白激酶II磷酸化的形式，抑制神经递质释放4-6。突触素I的氨基末端区域与膜磷脂相互作用，而C末端区域与突触小泡的蛋白质组分7，8结合。在这里，我们证明了突触蛋白I的C末端区域的结合涉及一种突触小泡相关形式的钙/钙调蛋白依赖的蛋白激酶II的调节域。我们的结果表明，这种形式的激酶既作为突触蛋白I的结合蛋白，也作为一种酶使突触蛋白I磷酸化并促进其与小泡的解离。
SYNAPSIN I is a synaptic vesicle-associated phosphoprotein that is involved in the modulation of neurotransmitter release1. Ca2+ calmodulin-dependent protein kinase II, which phosphorylates two sites in the carboxy-terminal region of synapsin I, causes synapsin I to dissociate from synaptic vesicles2 and increases nerotransmitter release3,4. Conversely, the dephosphorylated form of synapsin I, but not the form phosphorylated by Ca2+/calmodulin-dependent protein kinase II, inhibits neurotransmitter release4-6. The amino-terminal region of synapsin I interacts with membrane phospholipids, whereas the C-terminal region binds to a protein component of synaptic vesicles7,8. Here we demonstrate that the binding of the C-terminal region of synapsin I involves the regulatory domain of a synaptic vesicle-associated form of Ca2+/calmodulin-dependent protein kinase II. Our results indicate that this form of the kinase functions both as a binding protein for synapsin I, and as an enzyme that phosphorylates synapsin I and promotes its dissociation from the vesicles.