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Overview
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Cross-references
SPARC/Testican, calcium-binding domain (IPR019577)
Short name: SPARC/Testican_Ca-bd-dom
Overlapping homologous superfamilies
- EF-hand domain pair (IPR011992)
Domain relationships
- SPARC/Testican, calcium-binding domain (IPR019577)
- SMOC-2, extracellular calcium-binding domain (IPR037640)
Description
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 [PMID: 18459035, 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 alpha-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].
GO terms
Biological Process
No terms assigned in this category.
Molecular Function
GO:0005509 calcium ion binding
Cellular Component
No terms assigned in this category.
Contributing signatures
- PF10591 (SPARC_Ca_bdg)