RAB GEFs exchange GTP for GDP on RABs / TRAPPIII protein complex / Golgi vesicle transport / protein secretion / intracellular transport / long-term memory / Golgi apparatus / cytoplasm 類似検索 - 分子機能
Trafficking protein particle complex subunit 11 / Trafficking protein particle complex subunit 11, C-terminal / Foie gras liver health family 1 / Gryzun, putative Golgi trafficking 類似検索 - ドメイン・相同性
Trafficking protein particle complex subunit 11 類似検索 - 構成要素
ジャーナル: EMBO J / 年: 2021 タイトル: Cryo-EM structure of metazoan TRAPPIII, the multi-subunit complex that activates the GTPase Rab1. 著者: Antonio Galindo / Vicente J Planelles-Herrero / Gianluca Degliesposti / Sean Munro / 要旨: The TRAPP complexes are nucleotide exchange factors that play essential roles in membrane traffic and autophagy. TRAPPII activates Rab11, and TRAPPIII activates Rab1, with the two complexes sharing a ...The TRAPP complexes are nucleotide exchange factors that play essential roles in membrane traffic and autophagy. TRAPPII activates Rab11, and TRAPPIII activates Rab1, with the two complexes sharing a core of small subunits that affect nucleotide exchange but being distinguished by specific large subunits that are essential for activity in vivo. Crystal structures of core subunits have revealed the mechanism of Rab activation, but how the core and the large subunits assemble to form the complexes is unknown. We report a cryo-EM structure of the entire Drosophila TRAPPIII complex. The TRAPPIII-specific subunits TRAPPC8 and TRAPPC11 hold the catalytic core like a pair of tongs, with TRAPPC12 and TRAPPC13 positioned at the joint between them. TRAPPC2 and TRAPPC2L link the core to the two large arms, with the interfaces containing residues affected by disease-causing mutations. The TRAPPC8 arm is positioned such that it would contact Rab1 that is bound to the core, indicating how the arm could determine the specificity of the complex. A lower resolution structure of TRAPPII shows a similar architecture and suggests that the TRAPP complexes evolved from a single ur-TRAPP.