May play a role in cell cycle regulation. H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Binds 2 manganese ions per subunit. Predominantly expressed in stems, moderate in roots, nodes, leaves and flower buds. Belongs to the PPP phosphatase family. PP-2A subfamily.