dual specificity phosphatase domain of fungal dual specificity protein phosphatase SDP1, MSG5, and similar proteins
This family is composed of fungal dual specificity protein phosphatases (DUSPs) including Saccharomyces cerevisiae SDP1 and MSG5, and Schizosaccharomyces pombe Pmp1. function as a protein-serine/threonine phosphatase (EC 3.1.3.16) and a protein-tyrosine-phosphatase (EC 3.1.3.48). They deactivate MAPKs by dephosphorylating the threonine and tyrosine residues in the conserved Thr-Xaa-Tyr motif residing in their activation sites. SDP1 is oxidative stress-induced and dephosphorylates MAPK substrates such as SLT2. MSG5 dephosphorylates the Fus3 and Slt2 MAPKs operating in the mating and cell wall integrity (CWI) pathways, respectively. Pmp1 is responsible for dephosphorylating the CWI MAPK Pmk1. These phosphatases bind to their target MAPKs through a conserved IYT motif located outside of the dual specificity phosphatase domain.