title: Co-expression of Dorsal and Rel2 Negatively Regulates Antimicrobial Peptide Expression in the Tobacco Hornworm Manduca sexta.
abstract: Nuclear factor κB (NF-κB) plays an essential role in regulation of innate immunity. In mammals, NF-κB factors can form homodimers and heterodimers to activate gene expression. In insects, three NF-κB factors, Dorsal, Dif and Relish, have been identified to activate antimicrobial peptide (AMP) gene expression. However, it is not clear whether Dorsal (or Dif) and Relish can form heterodimers. Here we report the identification and functional analysis of a Dorsal homologue (MsDorsal) and two Relish short isoforms (MsRel2A and MsRel2B) from the tobacco hornworm, Manduca sexta. Both MsRel2A and MsRel2B contain only a Rel homology domain (RHD) and lack the ankyrin-repeat inhibitory domain. Overexpression of the RHD domains of MsDorsal and MsRel2 in Drosophila melanogaster S2 and Spodoptera frugiperda Sf9 cells can activate AMP gene promoters from M. sexta and D. melanogaster. We for the first time confirmed the interaction between MsDorsal-RHD and MsRel2-RHD, and suggesting that Dorsal and Rel2 may form heterodimers. More importantly, co-expression of MsDorsal-RHD with MsRel2-RHD suppressed activation of several M. sexta AMP gene promoters. Our results suggest that the short MsRel2 isoforms may form heterodimers with MsDorsal as a novel mechanism to prevent over-activation of antimicrobial peptides.
authors: Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, USA.
authors: Xue
authors: X
authors: Zhong
authors: Department of Entomology, School of Plant Protection, Anhui Agricultural University, Hefei, Anhui 230036, China.
authors: Xiang-Jun
authors: XJ
authors: Rao
authors: Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, USA.
authors: Hui-Yu
authors: HY
authors: Yi
authors: Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, USA.|College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
authors: Xin-Yu
authors: XY
authors: Lin
authors: Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, USA.|College of Animal Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China.
authors: Xiao-Hong
authors: XH
authors: Huang
authors: Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, USA.
authors: Xiao-Qiang
authors: XQ
authors: Yu
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018402:Manduca / Q000235:genetics / Q000378:metabolism*; D016328:NF-kappa B / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D000072417:Protein Domains; D018411:Spodoptera / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D023181:Antimicrobial Cationic Peptides; D019476:Insect Proteins; D016328:NF-kappa B; D014157:Transcription Factors