InterPro domain: IPR020422

Dual specificity phosphatases (DUSPs) are members of the superfamily of protein tyrosine phosphatases [ 1 , 2 ]. They remove the phosphate group from both phospho-tyrosine and phospho-serine/threonine residues. They are structurally similar to tyrosine-specific phosphatases but with a shallower active site cleft and a distinctive active site signature motif, HCxxGxxR [ 3 , 4 , 5 ]. They are characterized as VHR- [ 6 , 7 ] or Cdc25-like [ 8 , 9 ].

In general, DUSPs are classified into the following subgroups [ 10 ]:

• Slingshot phosphatases
• Phosphatase of regenerating liver (PRL)
• Cdc14 phosphatases
• Phosphatase and tensin homologue deleted on chromosome 10 (PTEN)-like and myotubularin phosphatases
• Mitogen-activated protein kinase phosphatases (MKPs)
• Atypical DUSPs

Tyrosine specific protein phosphatases (PTPases) ( 3.1.3.48 ) contain two conserved cysteines, the second one has been shown to be absolutely required for activity. This entry represents the PTPase domain that centre on the active site cysteine. A number of conserved residues in its immediate vicinity have also been shown to be important. This domain can be found in dual specificity phosphatases.

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2. Protein tyrosine phosphatases in the human genome. Cell 117, 699-711
3. Structure and function of the protein tyrosine phosphatases. Trends Biochem. Sci. 21, 413-7
4. The catalytic role of Cys124 in the dual specificity phosphatase VHR. J. Biol. Chem. 269, 28084-90
5. Protein tyrosine phosphatases: mechanism of catalysis and substrate specificity. Adv. Enzymol. Relat. Areas Mol. Biol. 68, 1-36
6. The "VH1-like" dual-specificity protein tyrosine phosphatases. Mol. Cells 8, 2-11
7. Crystal structure of the dual specificity protein phosphatase VHR. Science 272, 1328-31
8. Cloning and sequencing of a pig cdc25 tyrosine phosphatase cDNA. J. Anim. Sci. 73, 630
9. Protein tyrosine phosphatases: their roles in signal transduction. Recent Prog. Horm. Res. 51, 405-14; discussion 415
10. Dual-specificity phosphatases: critical regulators with diverse cellular targets. Biochem. J. 418, 475-89