Plays a role in the inducible expression of cytokine genes in T-cells, especially in the induction of the IL-2 or IL-4 gene transcription (PubMed:9388475). Also controls gene expression in embryonic cardiac cells. Could regulate not only the activation and proliferation but also the differentiation and programmed death of T-lymphocytes as well as lymphoid and non-lymphoid cells (By similarity). Required for osteoclastogenesis and regulates many genes important for osteoclast differentiation and function (PubMed:23990468, PubMed:26644563). Member of the multicomponent NFATC transcription complex that consists of at least two components, a pre-existing cytoplasmic component NFATC2 and an inducible nuclear component NFATC1. Other members such as NFATC4, NFATC3 or members of the activating protein-1 family, MAF, GATA4 and Cbp/p300 can also bind the complex. NFATC proteins bind to DNA as monomers (By similarity). Interacts with HOMER2 and HOMER3; this interaction may compete with calcineurin/PPP3CA-binding and hence prevent NFATC1 dephosphorylation and activation (By similarity). Interacts with TLE6/GRG6 (PubMed:23990468). Cytoplasmic for the phosphorylated form and nuclear after activation that is controlled by calcineurin-mediated dephosphorylation. Rapid nuclear exit of NFATC is thought to be one mechanism by which cells distinguish between sustained and transient calcium signals. The subcellular localization of NFATC plays a key role in the regulation of gene transcription (By similarity). Nuclear translocation of NFATC1 is enhanced in the presence of TNFSF11 (PubMed:26644563). Nuclear translocation is decreased in the presence of FBN1 which can bind and sequester TNFSF11 (PubMed:24039232). Expressed in the submandibular gland (at protein level) (PubMed:21435446). Expressed in basal epidermal cells (at protein level) (PubMed:19626032). Expressed in spleen, lung, skeletal muscle, thymus and skin (PubMed:9388475). Weakly expressed in heart, brain, liver and kidney. Not expressed in testis (PubMed:10072529). Expressed in osteoclasts (PubMed:23990468). Expressed at low levels at 7 dpc and increases until 17 dpc. At 17 dpc, strongly expressed in thymus, lung and submandibular gland and weakly in skeletal muscle and heart (PubMed:9388475). Expressed in the developing heart at 13.5 and 16.5 dpc, during the transition from spongy to compact myocardium (PubMed:17198697). Inducibly expressed in T-lymphocytes upon activation of the T-cell receptor (TCR) complex. Induced after addition of phorbol 12-myristate 13-acetate (PMA) (PubMed:9388475, PubMed:10072529). Expressed during osteoclastogenesis, its induction and activation is regulated by TNFSF11/RANKL (PubMed:16968888, PubMed:23990468, PubMed:26644563). Rel Similarity Domain (RSD) allows DNA-binding and cooperative interactions with AP1 factors. The N-terminal transactivation domain (TAD-A) binds to and is activated by Cbp/p300. The dephosphorylated form contains two unmasked nuclear localization signals (NLS), which allow translocation of the protein to the nucleus (By similarity). Phosphorylated by NFATC-kinase and GSK3B; phosphorylation induces NFATC1 nuclear exit and dephosphorylation by calcineurin promotes nuclear import. Phosphorylation by PKA and DYRK2 negatively modulates nuclear accumulation, and promotes subsequent phosphorylation by GSK3B or casein kinase 1 (By similarity). Produced by alternative initiation at Met-37 of isoform Alpha.