NF-kappa B/Rel family members regulating the ICAM-1 promoter in monocytic THP-1 cells.
A kappa B-site was identified in the promoter of the intercellular adhesion molecule-1 (ICAM-1) gene, which is involved in regulation of ICAM-1 expression by tumor necrosis factor alpha (TNF-alpha) and glucocorticoids. We now report on the transcription factors which bind and transactivate this enhancer sequence. In vitro, the ICAM-1 kappa B site appeared to bind RelA and c-Rel homodimers as well as heterodimers with NF-kappa B1, but weakly NF-kappa B1 homodimers. In addition, both RelA and c-Rel, but not NF-kappa B1, were shown to transactivate an ICAM-1 kappa B-reporter construct. In monocytic THP-1 cells TNF-alpha induced two nuclear complexes which in vitro bound to the ICAM-1 kappa B site. Using antibodies in an electrophoretic mobility supershift assay, one of these complexes was shown to contain NF-kappa B1 and RelA, and to bind with higher affinity to the consensus kappa B site in the HIV long terminal repeat. The second complex contained RelA, and exhibited higher affinity towards the ICAM-1 kappa B than to the HIV kappa B site. The glucocorticoid receptor was shown to repress activity of both the RelA homodimer and the NF-kappa B1/RelA heterodimer. We argue that in vivo RelA homodimers are likely to play a dominant role in TNF-alpha-induced ICAM-1 transcription in monocytic cells.
Wissink
S
S
Hubrecht Laboratory, Netherlands Institute for Developmental Biology, Nijmegen, The Netherlands.
van de Stolpe
A
A
Caldenhoven
E
E
Koenderman
L
L
van der Saag
P T
PT
D000818:Animals; D019556:COS Cells; D002460:Cell Line; D005938:Glucocorticoids / Q000378:metabolism; D016325:HIV Long Terminal Repeat; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics*; D009000:Monocytes / Q000166:cytology / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D020569:Proto-Oncogene Proteins c-rel; D051996:Transcription Factor RelA; D051841:Transcription Factor RelB; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation
D005938:Glucocorticoids; D016328:NF-kappa B; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D020569:Proto-Oncogene Proteins c-rel; C497593:RELB protein, human; D051996:Transcription Factor RelA; D014157:Transcription Factors; D018799:Intercellular Adhesion Molecule-1; D051841:Transcription Factor RelB