A proximal kappaB site in the IL-23 p19 promoter is responsible for RelA- and c-Rel-dependent transcription.
IL-23 is a heterodimeric cytokine composed of a unique p19 subunit and a common p40 subunit is shared with IL-12. IL-23 promotes the inflammatory response by inducing the expansion of CD4(+) cells producing IL-17. The regulation of p19 gene expression has been less studied than that of p40 subunit expression, which in macrophages is well known to be dependent on NF-kappaB. To clarify the role of NF-kappaB in expression of the p19 gene, we analyzed mRNA levels in NF-kappaB-deficient macrophages. As reported to occur in dendritic cells, p19 expression was dramatically reduced in c-rel-deficient macrophages. Moreover, we found that p19 expression was halved in rela-deficient macrophages, but it was enhanced in p52-deficient macrophages. The p19 promoter contains three putative kappaB sites, located at nt -642 to -632 (kappaB-642), nt -513 to -503 (kappaB-513), and nt -105 to -96 (kappaB-105), between the transcription start site and -937 bp upstream in the p19 promoter region. Although EMSA analysis indicated that both kappaB-105 and kappaB-642, but not kappaB-513, bound to NF-kappaB in vitro, luciferase-based reporter assays showed that the most proximal kappaB site, kappaB-105, was uniquely indispensable to the induction of p19 transcription. Chromatin immunoprecipitation demonstrated in vivo association of RelA, c-Rel, and p50 with kappaB-105 of the p19 promoter. These results provide the evidence that the association of RelA and c-Rel with the proximal kappaB site in the p19 promoter is required to induce of p19 expression.
Mise-Omata
Setsuko
S
Technology and Development Team for BioSignal Program, Subteam for BioSignal Integration, RIKEN BioResource Center, RIKEN Tsukuba Institute, Tsukuba, Japan.
Kuroda
Etsushi
E
Niikura
Junko
J
Yamashita
Uki
U
Obata
Yuichi
Y
Doi
Takahiro S
TS
D000818:Animals; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D053762:Interleukin-12 Subunit p40 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D020381:Interleukin-17 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D053760:Interleukin-23 Subunit p19 / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D008264:Macrophages / Q000276:immunology / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding; D020569:Proto-Oncogene Proteins c-rel / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D020218:Response Elements / Q000502:physiology*; D051996:Transcription Factor RelA / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology*
C508841:Il23a protein, mouse; D053762:Interleukin-12 Subunit p40; D020381:Interleukin-17; D053760:Interleukin-23 Subunit p19; D016328:NF-kappa B; D020569:Proto-Oncogene Proteins c-rel; C498144:Rela protein, mouse; D051996:Transcription Factor RelA