First Author | Takemoto N | Year | 1997 |
Journal | Int Immunol | Volume | 9 |
Issue | 9 | Pages | 1329-38 |
PubMed ID | 9310836 | Mgi Jnum | J:43360 |
Mgi Id | MGI:1097540 | Doi | 10.1093/intimm/9.9.1329 |
Citation | Takemoto N, et al. (1997) Four P-like elements are required for optimal transcription of the mouse IL-4 gene: involvement of a distinct set of nuclear factor of activated T cells and activator protein-1 family proteins. Int Immunol 9(9):1329-38 |
abstractText | We previously identified the P sequence as a critical regulatory element of the human IL-4 promoter. In the mouse IL-4 promoter, there are five elements homologous to the human P sequence designated conserved lymphokine element 0 (CLE0), P, P2, P3 and P4. To characterize the role of these P-like elements and their binding factors in the native promoter, we did transient transfection and electrophoretic mobility shift assays (EMSA). Transfection of EL-4 cells with the IL-4 promoter-reporter constructs carrying mutated P-like elements showed that four P-like elements, CLE0, P, P2 and P4, but not P3, were required for optimal activation of the IL-4 promoter. EMSA showed that both constitutive and inducible complexes bound to CLE0, P, P2 and P4, whereas only a constitutive complex bound to P3. In competition and antibody supershift assays in EMSA, complexes formed with P or P2 proved to contain nuclear factor of activated T cells (NFAT) family proteins as major components. Activator protein (AP)-1 family proteins interacted with CLE0, P, P2 and P4. NFAT/AP-1 complex formed only with P and P2. Cross-competition assays among the P-like elements revealed element-specific and common complexes. Six tandem repeats of the P element linked to the SV40 promoter responded to phorbol 12-myristate 13-acetate, while that of other elements did not. It would thus appear that components of each P-like element-binding complexes are not identical and may coordinately contribute to transcriptional activity. |