title: NFAT1 C-terminal domains are necessary but not sufficient for inducing cell death.
abstract: The proteins belonging to the nuclear factor of activated T cells (NFAT) family of transcription factors are expressed in several cell types and regulate genes involved in differentiation, cell cycle and apoptosis. NFAT proteins share two conserved domains, the NFAT-homology region (NHR) and a DNA-binding domain (DBD). The N- and C-termini display two transactivation domains (TAD-N and TAD-C) that have low sequence similarity. Due to the high sequence conservation in the NHR and DBD, NFAT members have some overlapping roles in gene regulation. However, several studies have shown distinct roles for NFAT proteins in the regulation of cell death. The TAD-C shows low sequence similarity among NFAT family members, but its contribution to specific NFAT1-induced phenotypes is poorly understood. Here, we described at least two regions of NFAT1 TAD-C that confer pro-apoptotic activity to NFAT1. These regions extend from amino acids 699 to 734 and 819 to 850 of NFAT1. We also showed that the NFAT1 TAD-C is unable to induce apoptosis by itself and requires a functional DBD. Furthermore, we showed that when fused to NFAT1 TAD-C, NFAT2, which is associated with cell transformation, induces apoptosis in fibroblasts. Together, these results suggest that the NFAT1 TAD-C includes NFAT death domains that confer to different NFAT members the ability to induce apoptosis.
authors.affiliation: Program of Cellular Biology, Brazilian National Cancer Institute, Rio de Janeiro, Brazil.
authors.forename: Douglas V
authors.initials: DV
authors.lastname: Faget
authors.forename: Pedro I
authors.initials: PI
authors.lastname: Lucena
authors.forename: Bruno K
authors.initials: BK
authors.lastname: Robbs
authors.forename: João P B
authors.initials: JP
authors.lastname: Viola
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D015153:Blotting, Western; D017931:DNA Primers / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation / Q000235:genetics*; D005840:Gentian Violet; D051379:Mice; D005810:Multigene Family / Q000235:genetics*; D050778:NFATC Transcription Factors / Q000235:genetics*; D041681:NIH 3T3 Cells; D010957:Plasmids / Q000235:genetics; D017434:Protein Structure, Tertiary; D015534:Trans-Activators / Q000235:genetics*
chemical_list: D017931:DNA Primers; D050778:NFATC Transcription Factors; C494007:Nfatc2 protein, mouse; D015534:Trans-Activators; D005840:Gentian Violet