6tgb

Publication Abstract from PubMed

DOCK (dedicator of cytokinesis) proteins are multidomain guanine nucleotide exchange factors (GEFs) for RHO GTPases that regulate intracellular actin dynamics. DOCK proteins share catalytic (DOCK(DHR2)) and membrane-associated (DOCK(DHR1)) 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 (ELMO(RBD)) 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-ELMO2(RBD) 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 DOCK2(DHR2), 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.

Structure of the DOCK2-ELMO1 complex provides insights into regulation of the auto-inhibited state.,Chang L, Yang J, Jo CH, Boland A, Zhang Z, McLaughlin SH, Abu-Thuraia A, Killoran RC, Smith MJ, Cote JF, Barford D Nat Commun. 2020 Jul 10;11(1):3464. doi: 10.1038/s41467-020-17271-9. PMID:32651375^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.