anti-DUSP3/VHR, mAb (ARM-1)

Protein tyrosine phosphatases (PTPs) are a group of enzymes that remove phosphate groups from phosphorylated tyrosine residues on proteins. Together with tyrosine kinases, PTPs regulate the phosphorylation state of many important signaling molecules, such as the MAP kinase family. Recently, increasing attention has been focused on the growing family of PTPs. Like PTKs, PTPs have been implicated in cell signaling, cell growth and proliferation, and oncogenic transformation. Moreover, some PTPs can be involved in cell cycle regulation and embryogenesis. Dual specificity phosphatases (DSPs) are an emerging subclass of the protein tyrosine phosphatase (PTP) gene superfamily, which appears to be selective for dephosphorylating the critical phosphothreonine and phosphotyrosine residues. The prototypical DSP is the VH1 gene in vaccinia virus expressed in late-stage viral infection. A shallow active site pocket in VHR allows for the hydrolysis of phosphorylated serine, threonine, or tyrosine protein residues, whereas the deeper active site of protein tyrosine phosphatases (PTPs) restricts substrate specificity to only phosphotyrosine. This protein shows activity both toward tyrosine-protein phosphate as well as with serine-protein phosphate.