Title: Calcineurin
CAS Registry Number: 9025-75-6
CAS Name: Phosphoprotein phosphatase
Literature References: Ca2+/calmodulin dependent ser-thr phosphatase that participates in many signalling pathways involved in gene regulation or biological responses to external stimuli in various organisms and cell types. Highly conserved heterodimer from yeast to humans comprised of a 58-69 kDa catalytic and calmodulin binding subunit A, calcineurin A, and a 16-19 kDa regulatory subunit B, calcineurin B. Isoln: J. H. Wang, R. Desai, Biochem. Biophys. Res. Commun. 72, 926 (1976). Purification: C. B. Klee, M. H. Krinks, Biochemistry 17, 120 (1978); and phosphatase activity: C. B. Klee et al., Proc. Natl. Acad. Sci. USA 76, 6270 (1979). Review of early work: C. B. Klee, J. Haiech, Ann. N.Y. Acad. Sci. 1980, 43-54; of role in neuronal cells and brain injury: M. Morioka et al., Prog. Neurobiol. 58, 1-30 (1999). Review of structure and function: C. B. Klee et al., J. Biol. Chem. 273, 13367-13370 (1998); J. Aramburu et al., Curr. Top. Cell. Regul. 36, 237-295 (2000).
Calcipotriene Calciseptine Calcitonin Calcium 2-Ethylbutanoate Calcium 3-Aurothio-2-propanol-1-sulfonate

Crystallographic structure of calcineurin heterodimer composed of the catalytic (PPP3CA and regulatory (PPP3R1) subunits.[1]

Calcineurin (CN) is a protein phosphatase also known as protein phosphatase 3, and calcium-dependent serine-threonine phosphatase.[2] It activates the T cells of the immune system and can be blocked by drugs. Calcineurin activates nuclear factor of activated T cell, cytoplasmic (NFATc), a transcription factor, by dephosphorylating it. The activated NFATc is then translocated into the nucleus, where it upregulates the expression of interleukin 2 (IL-2), which, in turn, stimulates the growth and differentiation of T cell response. Calcineurin is the target of a class of drugs called calcineurin inhibitors, which includes cyclosporine, pimecrolimus and tacrolimus.