EF-hand, extracellular calcium-binding (EC) motif, found in secreted protein, acidic and rich in cysteine-like 1 (SPARCL1)
SPARCL1, also termed SPARC-like protein 1, or high endothelial venule protein (Hevin), or MAST 9, or SC-1, or RAGS-1, or QR1, or ECM 2, is a diversely expressed and developmentally regulated extracellular matrix glycoprotein involved in tissue repair and remodeling via interaction with the surrounding extracellular matrix (ECM) proteins. It plays a pivotal role in the corneal wound healing. SPARCL1 may function as both a tumor suppressor and as a regulator of angiogenesis. It regulates cell migration/invasion and suppresses metastasis in many cancers, including prostate cancer, colorectal cancer, gastric cancer, and breast cancer. It can bind to collagens and be counter-adhesive to wild-type dermal fibroblasts, but do not influence rates of cell proliferation. Moreover, SPARCL1 contributes to neural development and participates in remodeling events associated with neuronal degeneration following neural injury. It can influence central nervous system (CNS) development and synaptic rearrangement. SPARCL1 is the closest family member to secreted protein acidic and rich in cysteine (SPARC), but does not compensate for the absence of SPARC in the CNS. SPARC contains an N-terminal acidic 52-residue segment followed by a follistatin-like (FS) domain, and an alpha-helical EC domain with 2 unusual calcium-binding EF-hands and the collagen-binding site. SPARCL1 shares the three primary domains contained within SPARC with an expanded N-terminal domain.