Probable molecular chaperone assisting protein biosynthesis and transport in the endoplasmic reticulum (, ). Required for the proper biosynthesis and transport of pulmonary surfactant-associated protein A/SP-A, pulmonary surfactant-associated protein D/SP-D and the lipid transporter ABCA3 (By similarity). By regulating both the proper expression and the degradation through the endoplasmic reticulum-associated protein degradation pathway of these proteins plays a crucial role in pulmonary surfactant homeostasis (By similarity). Has an anti-fibrotic activity by negatively regulating the secretion of type I and type III collagens . This calcium-binding protein also transiently associates with immature PCSK6 and regulates its secretion .
Subcellular locations: Endoplasmic reticulum lumen
Widely expressed.