The Arabidopsis tyrosine phosphatase RLPH2 targets D-group MAP kinases

Knowing that biochemically RLPH2 is a tyrosine phosphatase, we selectively In an attempt to discover RLPH2 substrates we decided to use the power of phospho-proteomics. Immunoprecipitated tyrosine phosphorylated peptides from enriched phospho-peptide pools derived from these plant extracts. Mass spectrometry analysis revealed a dramatic enrichment of tyrosine phosphorylated peptides derived from the activation loops of a subset of Arabidopsis mitogen activated protein kinases (MPKs), specifically the D-group enzymes.