Difference between revisions of "Phosphatase Subfamily Tensin"
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Tensins are long proteins, with an N-terminal phosphatase domain followed immediately by a PTEN_C2 domain, which acts as a lipid-binding domain. They have a poorly conserved middle region, SH2 and usually PTB domains at the C-terminus. Human TNS2 (TENC1) and many invertebrate Tensins also have an N-terminal C1 domain. Humans also have a homologous TNS4 protein which is N-terminally truncated and has lost the phosphatase domain. The phosphatase domain is quite divergent and often can not be picked by Pfam or SMART. | Tensins are long proteins, with an N-terminal phosphatase domain followed immediately by a PTEN_C2 domain, which acts as a lipid-binding domain. They have a poorly conserved middle region, SH2 and usually PTB domains at the C-terminus. Human TNS2 (TENC1) and many invertebrate Tensins also have an N-terminal C1 domain. Humans also have a homologous TNS4 protein which is N-terminally truncated and has lost the phosphatase domain. The phosphatase domain is quite divergent and often can not be picked by Pfam or SMART. | ||
| − | TNS1 and TNS2 are predicted to be catalytically inactive, given the arginine residue is replaced by asparagine and lysine at CX<sub>5</sub>R motif, respectively. But, the catalytic activity of TNS2 has been reported | + | TNS1 and TNS2 are predicted to be catalytically inactive, given the arginine residue is replaced by asparagine and lysine at CX<sub>5</sub>R motif, respectively. But, the catalytic activity of TNS2 has been reported. These may function as binding domains for phosphatidyl inositols. |
| − | + | The functions of the phosphatase domain are not well understood: | |
| − | + | * TNS1. The phosphatase domain can bind to PPP1CA in focal adhesions <cite>Eto07</cite>. | |
| + | * TNS2. TNS2 induced in vivo dephosporylation of phosphatidylinositol 3,4,5-trisphosphate, though the activity could not be replaced in vitro <cite>Hafizi</cite>. Another report <cite>Koh</cite> showed TNS2 protein tyrosine phosphatase activity on IRS-1. | ||
| − | The | + | ===Functions=== |
| + | Tensins are localized to integrin-mediated focal adhesions. The PTB domain binds to the cytoplasmic region of integrins, and N-terminal regions bind actin. The SH2 domain interacts with a variety of tyrosine-phosphorylated proteins, including PI3K, FAK, and p130Cas. Several tensins are linked to cell migration and metastasis suppression and to signaling downstream of receptor tyrosine kinases. | ||
===References=== | ===References=== | ||
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#Hafizi pmid=20678486 | #Hafizi pmid=20678486 | ||
#Koh pmid=23401856 | #Koh pmid=23401856 | ||
| + | #Eto07 pmid=17435217 | ||
</biblio> | </biblio> | ||
Revision as of 16:16, 2 October 2015
Phosphatase Classification: Superfamily CC1: Family PTEN: Subfamily Tensin
Tensins are PTEN-related phosphatases involved in integrin signaling.
Evolution
Tensins are found throughout holozoa. The domain combination is under dramatic changes during evolution. Drosophilids have a truncated ortholog (blistery) which lacks the phosphatase domain, though the full-length form is seen in mosquitoes. One of the four human members, TNS4, is also truncated. See domain section below.
Domain Structure
Tensins are long proteins, with an N-terminal phosphatase domain followed immediately by a PTEN_C2 domain, which acts as a lipid-binding domain. They have a poorly conserved middle region, SH2 and usually PTB domains at the C-terminus. Human TNS2 (TENC1) and many invertebrate Tensins also have an N-terminal C1 domain. Humans also have a homologous TNS4 protein which is N-terminally truncated and has lost the phosphatase domain. The phosphatase domain is quite divergent and often can not be picked by Pfam or SMART.
TNS1 and TNS2 are predicted to be catalytically inactive, given the arginine residue is replaced by asparagine and lysine at CX5R motif, respectively. But, the catalytic activity of TNS2 has been reported. These may function as binding domains for phosphatidyl inositols.
The functions of the phosphatase domain are not well understood:
- TNS1. The phosphatase domain can bind to PPP1CA in focal adhesions [1].
- TNS2. TNS2 induced in vivo dephosporylation of phosphatidylinositol 3,4,5-trisphosphate, though the activity could not be replaced in vitro [2]. Another report [3] showed TNS2 protein tyrosine phosphatase activity on IRS-1.
Functions
Tensins are localized to integrin-mediated focal adhesions. The PTB domain binds to the cytoplasmic region of integrins, and N-terminal regions bind actin. The SH2 domain interacts with a variety of tyrosine-phosphorylated proteins, including PI3K, FAK, and p130Cas. Several tensins are linked to cell migration and metastasis suppression and to signaling downstream of receptor tyrosine kinases.
References
Error fetching PMID 23401856:
Error fetching PMID 17435217:
- Error fetching PMID 17435217:
- Error fetching PMID 20678486:
- Error fetching PMID 23401856:
