Lectin which functions in endoplasmic reticulum (ER) quality control and ER-associated degradation (ERAD). May bind terminally misfolded non-glycosylated proteins as well as improperly folded glycoproteins, retain them in the ER, and possibly transfer them to the ubiquitination machinery and promote their degradation. Possible targets include TRPV4 (By similarity). Interacts (via C-terminus) with CPNE6 (via second C2 domain); this interaction occurs in a calcium-dependent manner in vitro (By similarity). Component of the HRD1 complex, which comprises at least SYNV1/HRD1, DERL1/2, FAM8A1, HERPUD1/HERP, OS9, SEL1L and UBE2J1. FAM8A1 is stabilized by interaction with SYNV1, which prevents its proteasomal degradation. OS9 and UBE2J1 recruitment to the complex may be mediated by SEL1L (By similarity). Through this complex, may interact with ERLEC1 and HSPA5 (By similarity). Interacts with HSP90B1 (By similarity). Interacts with CREB3 (By similarity). Intramolecular disulfide bonds. N-glycosylated. Belongs to the OS-9 family.