The study for the function of synapsins in Synaptic vesicles and secretory granules

突触蛋白在突触囊泡中的研究突触蛋白组成了一个突触囊泡蛋白家族，对调节神经递质的释放至关重要。在所有突触素中，只有两个结构域是保守的：一个短的N-末端A结构域，只有一个cAMP依赖的蛋白激酶(PKA)和CaM Kinase I的磷酸化位点，以及一个大的中央C结构域，它与ATP结合，可能是酶的。通过这项研究拨款，我们试图证明突触素的C-结构域作为一种ATPase发挥作用，以及哪些未知底物与突触素合作。为了达到这些目的，我们采用了酵母双杂交系统和大鼠的cDNA文库。我们仍在分析一些候选蛋白质。一个神经内分泌细胞分泌颗粒分选机制的项目嗜铬粒蛋白A(CGA)被限制性地转运到神经内分泌细胞中受调节的分泌颗粒。由于CGA易于与分泌蛋白结合的特性可能是其向分泌颗粒分选所必需的，因此我们使用酵母双杂交系统筛选其结合伙伴蛋白。结果表明，SgIII能与CgA结合，并通过多种内分泌细胞间的特异性相互作用将CgA导向分泌颗粒。

A project of Synapsin in Synaptic vesiclesSynapsins constitute a family of synaptic vesicle proteins essential for regulating neurotransmitter release. Only two domains are conserved in all synapsins : a short N-terminal A domain with a single phosphorylation site for cAMP-dependent protein kinase (PKA) and CaM Kinase I, and a large central C domain that binds ATP and may be enzymatic. With this research grant, we tried to show that the C-domain of synapsins works as an ATPase and which unknown substrates co-laborate with synapsins. For these aims, we employed a yeast two-hybrid system with rat cDNA library. We are still analysing some candidate proteins.A project of Sorting Mechanisms to Secretory Granule in Neuroendocrine CellsChromogranin A (CgA) is transported restrictedly to regulated secretory granules in neuroendocrine cells. Because the binding-prone property of CgA with secretory proteins may be essential for its sorting to secretory granules, we screened its binding partner proteins using a yeast two-hybrid system. As results, we identified that SgIII binds to CgA and directs CgA to secretory granules by specific interactions in various endocrine cells.