SPARC
SPARC (secreted protein acidic and cysteine rich), also known as osteonectin, BM-40, ON and ONT, is a cysteine-rich acidic protein of the extracellular matrix. It binds calcium, collagens and growth factors, and helps regulate cell growth and matrix organisation. Browse Assay Genie's current range of SPARC research reagents below, or read on for the biology behind the target.
SPARC appears to regulate cell growth through interactions with the extracellular matrix and with cytokines. It binds calcium and copper, several types of collagen, albumin, thrombospondin, PDGF and cell membranes. Two calcium-binding sites have been described: an acidic domain that binds 5 to 8 Ca(2+) ions with low affinity, and an EF-hand loop that binds a single Ca(2+) ion with high affinity.
The SPARC gene encodes a cysteine-rich, acidic, matrix-associated protein that is secreted into the extracellular space, where it is found in the extracellular matrix and basement membrane. The protein is required for the collagen in bone to become calcified, and it is also involved in extracellular matrix synthesis and in promoting changes to cell shape. HGNC places it in the SPARC family and in the secretory calcium-binding phosphoprotein family. Three transcript variants encoding different isoforms have been reported for the gene. The mouse and rat orthologues are both named Sparc.
The protein was originally named osteonectin, a name that reflects its role in bone, and it is still referred to by that name and by the aliases BM-40, ON and ONT. In cancer research, SPARC has been associated with tumour suppression, but it has also been correlated with metastasis, because the changes in cell shape it promotes can favour tumour cell invasion. This dual association makes it a frequent subject of matrix and tumour biology studies.
SPARC is required for bone collagen to become calcified, making it a key protein for studying mineralisation of the matrix.
SPARC takes part in matrix synthesis and binds several collagens and thrombospondin, linking it to matrix organisation and basement membrane biology.
SPARC has been associated with both tumour suppression and metastasis through effects on cell shape that can promote invasion.
SPARC binds PDGF and is thought to regulate cell growth through interactions with cytokines and the matrix.
SPARC appears to regulate cell growth through interactions with the extracellular matrix and cytokines. It is required for bone collagen to become calcified and is involved in matrix synthesis and in promoting changes to cell shape. It binds calcium, copper, collagens, albumin, thrombospondin and PDGF.
Osteonectin is the previous name for SPARC, reflecting its role in bone collagen calcification. BM-40, ON and ONT are further aliases listed for the gene. The current HGNC name is secreted protein acidic and cysteine rich, and all these names refer to the same protein.
SPARC has been associated with tumour suppression, but also correlated with metastasis, as changes in cell shape can promote tumour cell invasion. Mouse and rat both have an orthologous Sparc gene; check the datasheet of any product for its validated reactivity.
SPARC-like matricellular proteins and other extracellular matrix targets with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P09486; product specifications from Assay Genie datasheets.