Ubiquitous heterodimeric human Calcineurin is Ca(2+)/calmodulin-regulated protein phosphatase involved in many biologic activities as a modifier of phosphorylation status. Composed of widely expressed or tissue-restricted 55-60-kDa calmodulin-binding catalytic subunit (PPP Phosphatase/PP-2B Family) and conserved 19-kD Ca(2+)-sensitive regulatory subunit, Calcineurin appears to regulate glycolytic metabolism, nuclear translocation of NFATC1 transcription factor, sperm motility, and dopaminergic signal transduction and NMDA receptor-dependent synaptic plasticity. (NCI) [ ]