Calcineurin

Calcineurin (from Latin Calx/Calcis = lime) plays an important role in signal transduction through the T-cell receptor. The enzyme has a significant influence on the function of T and B lymphocytes. Calcineurin posphorylates NF-AT (nuclear factor of activated T cells), a transcription factor of T lymphocytes, which induces the transcription of various characteristic genes, which are responsible for the synthesis of interleukins (especially interleukin-1 and -2). This is where the calcineurin inhibitors ciclosporin and tacrolism intervene. Complexes between Ciclosporin and Ciclophilin and between tacrolism and FKBP12 bind to calcineurin and inhibit phosphatase activity. The inhibition of calcineurin in turn blocks the calcium-induced activation of NF-AT.

Calcineurin consists of a catalytic and a regulatory subunit. The catalytic subunit is activated by binding a calcium-calmodulin complex (calmodulin).

In mice, it has been shown that calcineurin also plays an important role in the transition from short-term to long-term memory.

1. Gonzales-Guerra E et al (2014) Immunohistochemical studies of calretinin in normal skin and cautaeous adnexak prolferations. Am J Dermatopathol 34: 1491-1505

2. Yu SJ et al (2015) Calcineurin signaling: lessons from Candida species.
   FEMS Yeast Res PubMed PMID: 25878052.