ESE-1, an enterocyte-specific Ets transcription factor, regulates MIP-3alpha gene expression in Caco-2 human colonic epithelial cells.
We have previously shown that colonic epithelial cells are a major site of MIP-3alpha production in human colon and that enterocyte MIP-3alpha protein levels are elevated in inflammatory bowel disease. The aim of this study was to determine the molecular mechanisms regulating MIP-3alpha gene transcription in Caco-2 intestinal epithelial cells. We show that a kappaB element at nucleotides -82 to -93 of the MIP-3alpha promoter binds p50/p65 NF-kappaB heterodimers and is a major regulator of basal and interleukin-1beta (IL-1beta)-mediated gene activation. Scanning mutagenesis of the MIP-3alpha 5'-flanking region also identified two additional binding elements: Site X (nucleotides -63 to -69) and Site Y (nucleotides -143 to -154). Site X (CGCCTTC) bound Sp1 and regulated basal MIP-3alpha gene transcription. Overexpression of Sp1 increased basal luciferase activity, whereas, substitutions in the Sp1 element significantly reduced reporter activity. In contrast, Site Y (AAGCAGGAAGTT) regulated both basal and cytokine-induced gene activation and bound the Ets nuclear factor ESE-1. Substitutions in the Site Y element markedly reduced inducible MIP-3alpha reporter activity. Conversely, overexpression of ESE-1 significantly up-regulated MIP-3alpha luciferase levels. Taken together, our findings demonstrate that co-ordinate activation and binding of ESE-1, Sp1, and NF-kappaB to the MIP-3alpha promoter is required for maximal gene expression by cytokine-stimulated Caco-2 human intestinal epithelial cells.
Kwon
John H
JH
Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
Keates
Sarah
S
Simeonidis
Simos
S
Grall
Franck
F
Libermann
Towia A
TA
Keates
Andrew C
AC
D001483:Base Sequence; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism; D018938:Caco-2 Cells; D054418:Chemokine CCL20; D019742:Chemokines, CC / Q000235:genetics*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D019402:Macrophage Inflammatory Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D054399:Receptors, CCR6; D019707:Receptors, Chemokine; D016329:Sp1 Transcription Factor / Q000378:metabolism; D051705:Sp3 Transcription Factor; D015534:Trans-Activators / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D022762:CCAAT-Enhancer-Binding Proteins; C108355:CCL20 protein, human; C106311:CCR6 protein, human; D054418:Chemokine CCL20; D019742:Chemokines, CC; D004268:DNA-Binding Proteins; C105529:ELF3 protein, human; D007375:Interleukin-1; D019402:Macrophage Inflammatory Proteins; D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D054399:Receptors, CCR6; D019707:Receptors, Chemokine; D016329:Sp1 Transcription Factor; D015534:Trans-Activators; D014157:Transcription Factors; D051705:Sp3 Transcription Factor