Component of the endoplasmic reticulum (ER) quality control system called ER-associated degradation (ERAD) and involved in ubiquitin-dependent degradation of misfolded endoplasmic reticulum proteins. Functions as an ERAD substrate-recruiting factor that recognizes misfolded proteins for the HRD1 E3 ubiquitin ligase complex. Targets the misfolded LRR receptor kinase BRI1. Interacts with OS9. Belongs to the sel-1 family.