Inhibition of DUSP13B Phosphatase Activity by PTP Inhibitor V

Protein tyrosine phosphorylation is a reversible post-translational modification that plays an important role in signal transduction pathways.1 The phosphorylation state of a protein is a result of coordinated action of protein kinases and protein phosphatases. Protein phosphatases are known to mainly control the rate and duration of the signals, while protein kinases are known to control the amplitude of the signals.2 Protein phosphatases can be divided into three groups according to their sequence, structure, and catalytic mechanism: classic Ser/Thr phosphatases, protein Tyr phos-phatases (PTP), and the Asp-based protein phosphatases.3 Dual-specificity phosphatases (DUSPs) are a subfamily of PTP, which dephosphorylate phospho-Ser,-Thr, and-Tyr. The DUSP13 gene located on chromosome 10q22.2 encodes two atypical DUSPs: DUSP13A/MDSP (muscle