mir-31 is induced by signaling via calcium and NFAT. (a) qPCR analysis of miR-31 in CD8+ T cells stimulated for 24 h with ionomycin (Iono) or with anti-CD3 plus anti-CD28 (horizontal axis) and treated with vehicle (DMSO) or cyclosporin A (CyA) (key); results are presented relative to those of unstimulated cells. (b) qPCR analysis of mR-31 in T cells infected with a lentiviral vector driving expression of constitutively active NFAT1 (CA-NFAT1) or a control lentiviral vector (Ctrl vec); results are presented relative to those of untransduced CD8+ T cells (UT). (c) Chromatin-immunoprecipitation analysis of NFAT1 in CD8+ T cells activated with anti-CD3 plus anti-CD28, followed by population expansion for 6 d in medium containing IL-2, then left untreated (Resting) or re-stimulated for 1 h with PMA and ionomycin (Restim) (left margin). Below, enlargement of three areas of enrichment for NFAT-1 binding detected in re-stimulated cells by the HOMER suite of tools for motif discovery. Top, positions of the pre-miR-31 hairpin (blue arrow, location and direction of transcription), the CpG island, and the predicted transcription start site (TSS) of Mir31. Data are representative of two experiments (error bars (a,b), s.d.).