title: Regulation of transcription of the Aedes albopictus cecropin A1 gene: A role for p38 mitogen-activated protein kinase.
abstract: Regulation of the Aedes albopictus cecropin A1 promoter was studied to provide insight into the transcriptional control of this antimicrobial peptide (AMP) gene in mosquitoes. Gene expression levels of cecropin A1 increased in A. albopictus C6/36 cells in response to heat-killed Escherichiacoli. Reporter gene assays incorporating -757 to +32 of the A. albopictus cecropin A1 promoter revealed that E. coli could induce expression in these cells with more pronounced expression than that seen with lipopolysaccharide (LPS). Analysis of deletion constructs demonstrated that the 5' boundary of the regulatory region for the activation of this AMP was located between -173 and -64. Western blotting with anti-phospho-specific antibodies demonstrated that p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) were activated by LPS, whereas only p38 MAPK was activated by E. coli. Moreover, pharmacological experiments revealed that pre-incubation of cells with the p38 MAPK inhibitor SB203580 resulted in a striking activation of the cecropin A1 promoter following immune challenge, demonstrating that p38 MAPK negatively regulates cecropin A1 promoter activity. Finally the region required for the negative regulation by p38 MAPK was identified as being between -173 and -64. This report is the first to show involvement of the p38 MAPK pathway in the negative regulation of AMP production in a mosquito.
authors.affiliation: School of Life Sciences, Kingston University, Kingston upon Thames, Surrey KT1 2EE, UK.
authors.forename: Alice E
authors.initials: AE
authors.lastname: Moon
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Walker
authors.forename: Stephen
authors.initials: S
authors.lastname: Goodbourn
mesh_terms: D000330:Aedes / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D000818:Animals; D045163:Antibodies, Phospho-Specific / Q000032:analysis; D054807:Cecropins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D004926:Escherichia coli / Q000737:chemistry; D015870:Gene Expression / Q000187:drug effects* / Q000276:immunology; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006358:Hot Temperature; D007093:Imidazoles / Q000494:pharmacology; D007113:Immunity, Innate; D019476:Insect Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000276:immunology / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008156:Luciferases / Q000032:analysis; D020935:MAP Kinase Signaling System / Q000187:drug effects* / Q000235:genetics / Q000276:immunology; D050296:Microbial Viability; D011401:Promoter Regions, Genetic / Q000187:drug effects* / Q000276:immunology; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism*
chemical_list: D045163:Antibodies, Phospho-Specific; D054807:Cecropins; D007093:Imidazoles; D019476:Insect Proteins; D008070:Lipopolysaccharides; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D008156:Luciferases; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580