Integral membrane component of ER-derived COPII-coated vesicles; functions in ER to Golgi transport; forms a complex with Ssp120p that may function in transport of plasma membrane glycoproteins through the early secretory pathway; lectin with proposed role recognizing and targeting misfolded, O-mannosylated proteins for ER-associated degradation (ERAD); interacts with the Hrd1p ubiquitin ligase complex; contains an N-terminal carbohydrate recognition domain