Identification of the client-binding site on the Golgi membrane protein adaptor Vps74/yGOLPH3.

ABSTRACT: Vps74 and its mammalian counterpart GOLPH3 are COPI associated protein sorting adaptors that function to maintain the cisternal distributions of a diversity of Golgi integral membrane protein clients by binding to their short cytoplasmically exposed N-termini. Here, we identify the client-binding site on yeast GOLPH3 (Vps74) which maps to two evolutionarily conserved loops on the membrane-facing surface, and includes residues mediating binding of GOLPH3s to PI4P, as well as the membrane-binding β hairpin. As an orthogonal approach, we isolated an inhibitory anti-Vps74 nanobody (which also binds to GOLPH3s) with which we corroborate the client-binding site and reveal that Sac1 and Arf1 binding to Vps74 blocks client access. We also identify an additional mode for the recruitment of Vps74 to

SUBMITTER: Lesniak AM 

PROVIDER: S-EPMC12478125 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature