InterPro domain: IPR019577
General Information
- Identifier IPR019577
- Description SPARC/Testican, calcium-binding domain
- Number of genes 16
- Gene duplication stats Loading...
- Associated GO terms GO:0005509
Abstract
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 [ 1 , 2 ]. Testican-3 appears to be a novel regulator that reduces the activity of matrix metalloproteinase (MMP) in adult T-cell leukemia (ATL) [ 3 ].
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 [ 4 ].
1. The role of the matricellular protein SPARC in the dynamic interaction between the tumor and the host. Cancer Metastasis Rev. 27, 523-37
2. Tumor-suppressor function of SPARC-like protein 1/Hevin in pancreatic cancer. Neoplasia 9, 8-17
3. Testican 3 expression in adult T-cell leukemia. Leuk. Res.
4. The C-terminal Ca2+-binding domain of SPARC confers anti-spreading activity to human urothelial cells. J. Cell. Physiol. 206, 211-20