May have a role in the recovery or adaptation response of photoreceptors. May have a role in diverse sensory neurons and in development. 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. Activated by calcium. In the embryo it is almost exclusively expressed in the peripheral nervous system, within sensory neurons of cranial and dorsal root ganglia. Otherwise found in fetal inner ear and a small group of neurons in the midbrain/pons junction. Up-regulated at 12.3 dpc in dorsal root ganglia (DRG) and in some sensory cranial ganglia. A slightly decreased expression could still be detected in sensory ganglia at 16.5 dpc. It is not known if expression in sensory neurons persists in adult life. Belongs to the PPP phosphatase family.