A novel association between clustered NF-kappaB and C/EBP binding sites is required for immune regulation of mosquito Defensin genes.
A comparative analysis identified key cis-acting regulatory elements responsible for the temporal control of mosquito Defensin gene expression. The promoters of Anopheles gambiae Defensin 1 and two isoforms of Aedes aegypti Defensin A are up-regulated by immune challenge. This stimulated activity depends upon a cluster of three NF-kappaB binding sites and closely associated C/EBP-like motifs, which function as a unit for optimal promoter activity. Binding of NF-kappaB and C/EBP like transcription factors is confirmed by electrophoretic mobility shift assay, including supershifts with antibodies to C/EBP. KappaB-like motifs are abundant within antimicrobial peptide gene promoters and most are very closely associated with putative C/EBP binding sites. This novel association between NF-kappaB and C/EBP binding sites may, therefore, be of widespread significance.
Meredith
J M
JM
School of Life Sciences, Huxley Building, Keele University, Staffordshire, UK. bia36@keele.ac.uk
Munks
R J L
RJ
Grail
W
W
Hurd
H
H
Eggleston
P
P
Lehane
M J
MJ
D000330:Aedes / Q000276:immunology* / Q000378:metabolism; D000818:Animals; D000852:Anopheles / Q000276:immunology* / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism*; D002460:Cell Line; D017931:DNA Primers; D023082:Defensins / Q000276:immunology* / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation / Q000276:immunology*; D016297:Mutagenesis, Site-Directed; D016328:NF-kappa B / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D050436:Regulatory Elements, Transcriptional / Q000235:genetics; D013045:Species Specificity
D022762:CCAAT-Enhancer-Binding Proteins; D017931:DNA Primers; D023082:Defensins; D016328:NF-kappa B