SPARC/Testican, calcium-binding domain

Definition

This entry represents the calcium-binding domain found in SPARC (Secreted Protein Acidic and Rich in Cysteine) and Testican (also known as SPOCK; or SParc/Osteonectin, Cwcv and Kazal-like domains) proteins. SPARC proteins are down-regulated in various tumours and may have a tumour-suppressor function [[cite:PMID:18459035], [cite:PMID:17325739]]. Testican-3 appears to be a novel regulator that reduces the activity of matrix metalloproteinase (MMP) in adult T-cell leukemia (ATL) PMID:19144404. This cysteine-rich domain is responsible for the anti-spreading activity of human urothelial cells. This extracellular calcium-binding domain is rich in α-helices and contains two EF-hands that each coordinates one Ca2+ ion, forming a helix-loop-helix structure that not only drives the conformation of the protein but is also necessary for biological activity. The anti-spreading activity was dependent on the coordination of Ca2+ by a Glu residue at the Z position of EF-hand 2 PMID:16121393.

7 human proteins with this domain

Each is a reviewed human protein in the Seroatlas serome and a potential autoantibody target; this domain groups them into one antibody-relevant category. Every entry links to its own record.

Download CSV (7 proteins: gene, accession, name)

• SMOC1
• SMOC2
• SPARC
• SPARCL1
• SPOCK1
• SPOCK2
• SPOCK3