Structure-based analysis of the guanine nucleotide exchange factor SmgGDS reveals armadillo-repeat motifs and key regions for activity and GTPase binding.

ABSTRACT: Small GTPases are molecular switches that have critical biological roles and are controlled by GTPase-activating proteins and guanine nucleotide exchange factors (GEFs). The smg GDP dissociation stimulator (SmgGDS) protein functions as a GEF for the RhoA and RhoC small GTPases. SmgGDS has various regulatory roles, including small GTPase trafficking and localization and as a molecular chaperone, and interacts with many small GTPases possessing polybasic regions. Two SmgGDS splice variants, SmgGDS-558 and SmgGDS-607, differ in GEF activity and binding affinity for RhoA depending on the lipidation state, but the reasons for these differences are unclear. Here we determined the crystal structure of SmgGDS-558, revealing a fold containing tandem copies of armadillo repeats not present in other

SUBMITTER: Shimizu H 

PROVIDER: S-EPMC5555202 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature