calcineurinës

Calcineurin is a calcium and calmodulin-dependent protein phosphatase. It plays a crucial role in various cellular processes, most notably in T-cell activation and immune responses. When intracellular calcium levels rise, calmodulin binds to calcineurin, activating its phosphatase activity. This activation leads to the dephosphorylation of several target proteins, including the nuclear factor of activated T cells (NFAT). NFAT is a transcription factor that, upon dephosphorylation by calcineurin, translocates to the nucleus and promotes the expression of genes involved in T-cell proliferation and cytokine production.

Beyond immunity, calcineurin is involved in muscle development, neuronal function, and cardiac hypertrophy. Its broad cellular impact makes it a significant target for therapeutic intervention. For instance, immunosuppressive drugs like cyclosporine and tacrolimus work by inhibiting calcineurin, thereby preventing T-cell activation and reducing transplant rejection. However, this inhibition also carries the risk of opportunistic infections. Research continues to explore the intricate signaling pathways regulated by calcineurin and its potential as a therapeutic target for a range of diseases.