Iga M, Inui M, Sobue K
Department of Neurochemistry and Neuropharmacology, Biomedical Research Center, Osaka University Medical School, Japan.
Biochem Biophys Res Commun. 1997 Feb 24;231(3):852-5. doi: 10.1006/bbrc.1997.6202.
We characterized the properties of the interaction between synapsin I and calspectin using purified proteins. The binding assay in the native state using antibodies specific to the tail region of synapsin I revealed that the binding is a high affinity with Kd of 9 nM, which is almost comparable to that of synapsin I to synaptic vesicles and to F-actin. We demonstrated that the head-middle region of synapsin I binds the NH2-terminal domain of beta subunit of calspectin, which also contains an actin binding site. Furthermore, the interaction was significantly inhibited by phosphorylation of synapsin I by cAMP-dependent protein kinase or by Ca2+, calmodulin-dependent protein kinase II. These properties of the interaction between synapsin I and calspectin may help understanding of its modulatory roles in neurotransmitter release.
我们使用纯化的蛋白质对突触结合蛋白I与钙结合蛋白的相互作用特性进行了表征。使用针对突触结合蛋白I尾部区域的特异性抗体在天然状态下进行的结合试验表明，这种结合具有高亲和力，解离常数（Kd）为9 nM，这几乎与突触结合蛋白I与突触小泡以及与F-肌动蛋白的结合亲和力相当。我们证明，突触结合蛋白I的头部-中部区域与钙结合蛋白β亚基的NH2末端结构域结合，该结构域也包含一个肌动蛋白结合位点。此外，cAMP依赖性蛋白激酶或Ca2+、钙调蛋白依赖性蛋白激酶II对突触结合蛋白I的磷酸化显著抑制了这种相互作用。突触结合蛋白I与钙结合蛋白之间相互作用的这些特性可能有助于理解其在神经递质释放中的调节作用。
