Publication — IRIC

Structure of the DOCK2-ELMO1 complex provides insights into regulation of the auto-inhibited state.

DOCK (dedicator of cytokinesis) proteins are multidomain guanine nucleotide exchange factors (GEFs) for RHO GTPases that regulate intracellular actin dynamics. DOCK proteins share catalytic (DOCKDHR2) and membrane-associated (DOCKDHR1) domains. The structurally-related DOCK1 and DOCK2 GEFs are specific for RAC, and require ELMO (engulfment and cell motility) proteins for function. The N-terminal RAS-binding domain (RBD) of ELMO (ELMORBD) interacts with RHOG to modulate DOCK1/2 activity. Here, we determine the cryo-EM structures of DOCK2-ELMO1 alone, and as a ternary complex with RAC1, together with the crystal structure of a RHOG-ELMO2RBD complex. The binary DOCK2-ELMO1 complex adopts a closed, auto-inhibited conformation. Relief of auto-inhibition to an active, open state, due to a conformational change of the ELMO1 subunit, exposes binding sites for RAC1 on DOCK2DHR2, and RHOG and BAI GPCRs on ELMO1. Our structure explains how up-stream effectors, including DOCK2 and ELMO1 phosphorylation, destabilise the auto-inhibited state to promote an active GEF.

Date de publication
10 juillet 2020
Chercheurs
Chang L, Yang J, Jo CH, Boland A, Zhang Z, McLaughlin SH, Abu-Thuraia A, Killoran RC, Smith M, Côté JF, Barford D
Référence PubMed
Nat Commun 2020;11(1):3464
ID PubMed
32651375
Affiliation
MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.