Department of Pediatric Surgery and Laboratory of Stem Cell Biology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China.
Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.
PLoS Biol. 2020 May 26;18(5):e3000746. doi: 10.1371/journal.pbio.3000746. eCollection 2020 May.
Members of the Tre2-Bub2-Cdc16 (TBC) family often function to regulate membrane trafficking and to control signaling transductions pathways. As a member of the TBC family, TBC1D23 is critical for endosome-to-Golgi cargo trafficking by serving as a bridge between Golgi-bound golgin-97/245 and the WASH/FAM21 complex on endosomal vesicles. However, the exact mechanisms by which TBC1D23 regulates cargo transport are poorly understood. Here, we present the crystal structure of the N-terminus of TBC1D23 (D23N), which consists of both the TBC and rhodanese domains. We show that the rhodanese domain is unlikely to be an active sulfurtransferase or phosphatase, despite containing a putative catalytic site. Instead, it packs against the TBC domain and forms part of the platform to interact with golgin-97/245. Using the zebrafish model, we show that impacting golgin-97/245-binding, but not the putative catalytic site, impairs neuronal growth and brain development. Altogether, our studies provide structural and functional insights into an essential protein that is required for organelle-specific trafficking and brain development.
Tre2-Bub2-Cdc16（TBC）家族的成员通常具有调节膜运输和控制信号转导途径的功能。TBC1D23 作为 TBC 家族的一员，通过在高尔基结合的 golgin-97/245 和内体小泡上的 WASH/FAM21 复合物之间充当桥梁，对于内体到高尔基体货物运输至关重要。然而，TBC1D23 调节货物运输的确切机制尚不清楚。在这里，我们展示了 TBC1D23（D23N）的 N 端的晶体结构，该结构包含 TBC 和硫辛酰胺结构域。我们表明，尽管含有假定的催化位点，但硫辛酰胺结构域不太可能是活性硫转移酶或磷酸酶。相反，它与 TBC 结构域结合并形成与 golgin-97/245 相互作用的平台的一部分。使用斑马鱼模型，我们表明，影响 golgin-97/245 结合，但不是假定的催化位点，会损害神经元的生长和大脑发育。总之，我们的研究为特定细胞器运输和大脑发育所必需的重要蛋白质提供了结构和功能上的见解。
