Roles of scaffolding proteins in the formation of transportsome

细胞连接不仅对细胞黏附很重要，而且对信号转导也很重要。因此，我们重点研究了S-SCAM(MAGI2)、MAGI1和LNX1，它们都定位于细胞连接。我们揭示了S-SCAM在兴奋性和抑制性突触中的作用，MAGI1在肾隔膜中的作用，以及LNX1在上皮和间质转化过程中对细胞黏附分子JAM4的内吞作用。我们还鉴定了RASSF6是一个新的MAGI1结合伙伴，它介导了细胞凋亡。一种名为MST2的蛋白激酶作为支架组装包含RASSF6的复合体，并阻断RASSF6诱导的细胞凋亡。一旦MST2被激活，RASSF6就从复合体中释放出来。这一发现表明，MST2是直接调节蛋白质相互作用的动态支架。

Cell junctions are important not only for cell adhesion but also for signal transduction. Thereby, we focused on S-SCAM(MAGI2), MAGI1, and LNX1, all of which are localized at cell junctions. We revealed the roles of S-SCAM at excitatory and inhibitory synapses, of MAGI1 at kidney diaphragm, and of LNX1 in the endocytosis of a cell adhesion molecule named JAM4 during the epithelial and mesenchymal transition. We also identified RASSF6 as a new MAGI1-binding partner, which mediates apoptosis. A protein kinase named MST2 functions as a scaffold to assemble a complex including RASSF6 and blocks RASSF6-induced apoptosis. Once MST2 is activated, RASSF6 is released from the complex. This finding implies that MST2 is a dynamic scaffold to directly regulate protein interactions.