Nuclear factor of activated T cells (NFAT) signalling plays important regulatory roles, primarily within immune cells, but also in other cell types such as neurons and muscle cells. The NFAT family consists of multiple isoforms, with NFATc1-c4 and NFAT5 being the best-characterized members with different isoforms exhibiting distinct tissue-specific expression patterns and roles, particularly in immune responses. For example, NFATc1 is critical for T-cell activation, whilst NFATc2 regulates production of cytokines such as IL-2 and IL-4. NFAT5, also known as TonEBP (Tonicity-responsive enhancer-binding protein), is a unique member of the family and is involved in the osmotic stress response and maintenance of cellular osmolarity. NFAT5 regulates genes encoding osmo-protective molecules including ion transporters (e.g., sodium/myo-inositol cotransporter), and chaperone proteins (e.g., heat shock proteins). NFATs in immune cells exist in an inactive form in the cytoplasm and are generally activated in response to elevated intracellular calcium levels. In T cells, the rise in calcium occurs through the T-cell receptor (TCR) signalling pathway, triggered when T cells encounter antigen-presenting cells (APCs) displaying antigens. Upon TCR stimulation and the subsequent increase in intracellular calcium, the calcium-dependent phosphatase calcineurin is activated. Calcineurin dephosphorylates NFAT proteins at serine residues within a conserved motif, exposing their nuclear localization signal (NLS). This allows NFAT proteins to enter the nucleus and bind specific DNA sequences termed NFAT response elements (NREs) in the promoters of target genes, with binding leading to transcriptional activation. NFAT proteins often cooperate with other transcription factors, such as AP-1 (Activator Protein-1) and NF-κB (Nuclear Factor-κB), to regulate gene expression. This cooperation enhances the specificity and strength of the transcriptional response to immune signals. Although NFAT proteins control the expression of genes involved in T-cell activation, proliferation, differentiation, and cytokine production, they are also essential for the development and function of various other immune cell types, including B cells, and natural killer cells. Once activated, NFAT regulates the expression of genes involved in immune responses, including interleukins (IL-2, IL-4, IL-5) and immune cell surface receptors. In T cells NFAT activation is required for the transcription of IL-2, a key cytokine that promotes T cell proliferation and differentiation, whilst in B cells NFAT influences antibody production and class switching in response to antigen exposure. NFATc2 and NFATc3 also regulate the expression of CD28, a co-stimulatory receptor on T cells. CD28 engagement with its ligands (e.g., CD80 and CD86) on antigen-presenting cells provides a second signal to T cells, enhancing their activation and proliferation. To prevent sustained activation, NFAT proteins are exported back into the cytoplasm, where they are re-phosphorylated and inactivated. This nuclear export is mediated by kinases, such as GSK-3β. Overall, NFAT signalling is regulated by several mechanisms, including the levels of intracellular calcium, the activity of calcineurin, and inhibitory proteins, such as NFAT-interacting protein kinases (NIKs). NFAT signalling is targeted by certain drugs, particularly immunosuppressive agents used in transplantation and autoimmune disease treatment. Drugs like cyclosporine and tacrolimus inhibit calcineurin activity, thereby preventing NFAT activation and dampening immune responses. We offer a comprehensive product catalogue of research tools for investigating NFAT, including NFAT2 antibodies, NFATC4 antibodies, ILF3 antibodies, NFAT1 antibodies, and NFAT4 antibodies. Explore our full NFAT product range below and discover more, for less.