Pull-down combined with proteomic strategy reveals functional diversity of synaptotagmin I.
Pull-down combined with proteomic strategy reveals functional diversity of synaptotagmin I.
复制标题
Pull-down结合蛋白质组策略揭示了突触结合蛋白I的功能多样性
作者：
Guo T;Duan Z;Chen J;Xie C;Wang Y;Chen P;Wang X
突触结合蛋白I （Syt I）在大脑中含量最多，参与多种细胞过程。其两个C2结构域C2A和C2B是主要功能区。本研究采用下拉结合蛋白质组学策略鉴定C2结构域相互作用蛋白，以全面了解C2结构域的生物学作用，从而了解Syt I的功能多样性。共鉴定了135个与Syt I的C2结构域相互作用的非冗余蛋白。其中，32种和64种蛋白分别仅与C2A或C2B结构域结合，39种蛋白同时与C2A或C2B结构域结合。与C2A相比，C2B可以结合更多的蛋白质，特别是参与突触传递和代谢调节的蛋白质。功能分析表明，Syt I可能通过与其他蛋白的相互作用，对囊泡膜运输、突触传递、代谢调节、催化、跨膜运输和结构形成等多种细胞过程产生影响。这些结果表明Syt I的功能多样性高于之前的预期，它的两个结构域可能协同或独立地介导相同和不同的细胞过程，并且C2B结构域在Syt I的功能中可能比C2A发挥更重要的作用。这项工作不仅进一步加深了我们对Syt I的功能多样性及其两个C2结构域之间功能差异的理解。同时也为进一步的相关研究提供了重要线索。
Synaptotagmin I (Syt I) is most abundant in the brain and is involved in multiple cellular processes. Its two C2 domains, C2A and C2B, are the main functional regions. Our present study employed a pull-down combined with proteomic strategy to identify the C2 domain-interacting proteins to comprehensively understand the biological roles of the C2 domains and thus the functional diversity of Syt I. A total of 135 non-redundant proteins interacting with the C2 domains of Syt I were identified. Out of them, 32 and 64 proteins only bound to C2A or C2B domains, respectively, and 39 proteins bound to both of them. Compared with C2A, C2B could bind to many more proteins particularly those involved in synaptic transmission and metabolic regulation. Functional analysis indicated that Syt I may exert impacts by interacting with other proteins on multiple cellular processes, including vesicular membrane trafficking, synaptic transmission, metabolic regulation, catalysis, transmembrane transport and structure formation, etc. These results demonstrate that the functional diversity of Syt I is higher than previously expected, that its two domains may mediate the same and different cellular processes cooperatively or independently, and that C2B domain may play even more important roles than C2A in the functioning of Syt I. This work not only further deepened our understanding of the functional diversity of Syt I and the functional differences between its two C2 domains, but also provided important clues for the further related researches.