Description
The mammalian dual-specificity protein-tyrosine phosphatase VHR (for VH1-related) has been identified as a novel regulator of extracellular regulated kinases (ERKs). Vaccinia Virus VH1-related Phosphatase (VHR), also known as Dual-Specificity Phosphatase 3 (DUSP3), removes phosphate groups from tyrosine, serine, and threonine residues. It belongs to a family of phosphatases that selectively dephosphorylate MAP kinases. VHR has been shown to act as a phosphatase for several members of the MAP kinase family including ERK1, ERK2, and JNK. It is a target for the ZAP-70 kinase, and phosphorylation of VHR at tyrosine 138 leads to a downregulation of ERK2 activity. Its welldefined biochemistry has made VHR useful in screening assays for compounds that inhibit phosphatases