IDENTIFICATION OF CIS-ACTING REGULATORY ELEMENTS CONTROLLING INTERLEUKIN-4 GENE-EXPRESSION IN T-CELLS - ROLES FOR NF-Y AND NF-ATC

Activity of the murine interleukin-4 (IL-4) promoter was localized to several cis-acting elements present within the first 300 bp from the t ranscriptional initiation site. Five repeated elements, P0 to P4, that share the common consensus ATTTTCCNNT were located between -40 and -2 50, and each was shown to interact with the T-cell-specific factor NF( P). These distinct P sites appear functionally interchangeable and coo peratively confer cyclosporin A-sensitive and ionomycin-inducible prom oter activity. NF(P) may be closely related to the cytoplasmic compone nt of NF-AT (nuclear factor of activated T cells), a T-cell-specific f actor essential for IL-2 gene transcription, as judged from indistingu ishable molecular weights and protease fragmentation patterns of UV-ph otolabeled factors. Also, we identified an element in the IL-4 promote r with homology to the Y box common to all major histocompatibility co mplex class II gene promoters. Our data show that the IL-4 promoter Y box -114CTGATTGG-107 significantly enhances overall promoter activity, since point mutations within this element diminish promoter activity by 85%. The factor binding this region is indistinguishable from the c loned nuclear factor NF-Y, as judged from interactions with specific a nti-NF-Y monoclonal and polyclonal antibodies. Last, we point out the presence of two sites that share sequence identity to the OAP region o f the ARRE-1 site within the IL-2 promoter (K. S. Ullman, W. M. Flanag an, C. A. Edwards, and G. R. Crabtree, Science 254:558-562, 1991). The se regions, -85GTGTAATA-78 and -245GTGTAATT-238, reside adjacent to th e NF(P) binding sites P1 and P4 and bind a distinct nuclear factor.