Direct observation of autoubiquitination for an integral membrane ubiquitin ligase in ERAD.

ABSTRACT: The endoplasmic reticulum associated degradation (ERAD) pathway regulates protein quality control at the endoplasmic reticulum. ERAD of lumenal and membrane proteins requires a conserved E3 ubiquitin ligase, called Hrd1. We do not understand the molecular configurations of Hrd1 that enable autoubiquitination and the subsequent retrotranslocation of misfolded protein substrates from the ER to the cytosol. Here, we have established a generalizable, single-molecule platform that enables high-efficiency labeling, stoichiometry determination, and functional assays for any integral membrane protein. Using this approach, we directly count Hrd1 proteins reconstituted into individual proteoliposomes. We report that Hrd1 assembles in different oligomeric configurations with mostly monomers and dimer

SUBMITTER: Moochickal Assainar B 

PROVIDER: S-EPMC10864399 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature