A distributed residue network permits conformational binding specificity in a conserved family of actin remodelers

Autor: Theresa Hwang, Sara S Parker, Samantha M Hill, Meucci W Ilunga, Robert A Grant, Ghassan Mouneimne, Amy E Keating
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: eLife, Vol 10 (2021)
Druh dokumentu: article
ISSN: 2050-084X
DOI: 10.7554/eLife.70601
Popis: Metazoan proteomes contain many paralogous proteins that have evolved distinct functions. The Ena/VASP family of actin regulators consists of three members that share an EVH1 interaction domain with a 100 % conserved binding site. A proteome-wide screen revealed photoreceptor cilium actin regulator (PCARE) as a high-affinity ligand for ENAH EVH1. Here, we report the surprising observation that PCARE is ~100-fold specific for ENAH over paralogs VASP and EVL and can selectively bind ENAH and inhibit ENAH-dependent adhesion in cells. Specificity arises from a mechanism whereby PCARE stabilizes a conformation of the ENAH EVH1 domain that is inaccessible to family members VASP and EVL. Structure-based modeling rapidly identified seven residues distributed throughout EVL that are sufficient to differentiate binding by ENAH vs. EVL. By exploiting the ENAH-specific conformation, we rationally designed the tightest and most selective ENAH binder to date. Our work uncovers a conformational mechanism of interaction specificity that distinguishes highly similar paralogs and establishes tools for dissecting specific Ena/VASP functions in processes including cancer cell invasion.
Databáze: Directory of Open Access Journals