Calcineurin is a Ca2+ and calmodulin-regulated protein phosphatase that is
important in Ca2+-mediated signal transduction. Recent application of the p
owerful techniques of molecular genetics has demonstrated that calcineurin
is involved in the regulation of critical biological processes such as T ce
ll activation, muscle hypertrophy, memory development, glucan synthesis, io
n homeostasis, and cell cycle control. Notably, specific transcription fact
ors have been shown to play a key role in regulating these functions, and t
heir calcineurin-mediated dephosphorylation and nuclear translocation appea
r to be a central event in the signal transduction pathways. This review fo
cuses on recent process in these areas and discusses the evidence for cross
-talk between calcineurin and other signaling pathways.