Component of the PAT complex, an endoplasmic reticulum (ER-resident membrane multiprotein complex that facilitates multi-pass membrane proteins insertion into membranes. The PAT complex acts as an intramembrane chaperone by directly interacting with nascent transmembrane domains (TMDs, releasing its substrates upon correct folding, and is needed for optimal biogenesis of multi-pass membrane proteins. WDR83OS/Asterix is the substrate-interacting subunit of the PAT complex, whereas CCDC47 is required to maintain the stability of WDR83OS/Asterix. The PAT complex favors the binding to TMDs with exposed hydrophilic amino acids within the lipid bilayer and provides a membrane-embedded partially hydrophilic environment in which the first transmembrane domain binds. Component of a ribosome-associated ER translocon complex involved in multi-pass membrane protein transport into the ER membrane and biogenesis. Involved in the regulation of calcium ion homeostasis in the ER. Required for proper protein degradation via the ERAD (ER-associated degradation pathway. Has an essential role in the maintenance of ER organization during embryogenesis (By similarity.