H2O + O-phospho-L-seryl-[protein] = L-seryl-[protein] + phosphate H2O + O-phospho-L-threonyl-[protein] = L-threonyl-[protein] + phosphate Isoform alpha and isoform beta are expressed both maternally and zygotically. Zygotic expression is present throughout embryogenesis and fades by first larval instar. Expression levels at all stages are low. Belongs to the PP2C family.