Appears to regulate cell growth through interactions with the extracellular matrix and cytokines. Binds calcium and copper, several types of collagen, albumin, thrombospondin, PDGF and cell membranes. There are two calcium binding sites; an acidic domain that binds 5 to 8 Ca(2+) with a low affinity and an EF-hand loop that binds a Ca(2+) ion with a high affinity. In or around the basement membrane. Expressed at high levels in tissues undergoing morphogenesis, remodeling and wound repair. N-glycosylated. Belongs to the SPARC family.