Plant PP2C phosphatases: emerging functions in stress signaling

PP2C-type protein phosphatases are monomeric enzymes present in both prokaryotes and eukaryotes. Members of this family of phosphoprotein phosphatases are involved in the regulation of several signaling pathways. A database analysis of Arabidopsis reveals PP2Cs to be the largest protein phosphatase family in plants, with 76 members, displaying high complexity, and greatly outnumbering PP2Cs in other eukaryotes. Plant PP2Cs have been found as regulators of signal transduction pathways and also involved in development. PP2C functions emphasize the existence of sophisticated signaling pathways in plants, in which protein dephosphorylation plays a crucial role towards determining specificities.