title: BmEts upregulates promoter activity of lebocin in Bombyx mori.
abstract: The Ets family protein BmEts is assumed to be implicated in determination of diapause in the embryogenesis of Bombyx mori. In this study, we found that expression of BmEts was increased in the fat body and other tissues of the 5th instar larvae in response to Escherichia coli injection. Cotransfection experiments using a silkworm cell line revealed that overexpression of BmEts significantly elevated the activity of lebocin promoter but not of cecropin B1, cecropin D, attacin, and moricin promoters. Activation of the lebocin promoter by BmEts was dependent on at least two κB elements and the most proximal GGAA/T motif located on the 5'-upstream region. BmEts further synergistically enhanced E. coli or BmRelish1-d2 (active form)-stimulated lebocin promoter activation. Two κB elements were also found to be involved in promoter activation by BmRelish1-d2 and in synergistic promoter activation by BmEts and BmRelish1-d2 in the silkworm cells. Specific binding of recombinant BmEts to the proximal κB element and the most proximal GGAA/T motif and interaction between BmEts and BmRelish1 were also observed. To our knowledge, this is the first report of an Ets family protein directly regulating immune-related genes in invertebrates.
authors.affiliation: Insect Mimetics Research Unit, National Institute of Agrobiological Sciences, 1-2 Owashi, Tsukuba, Ibaraki 305-8634, Japan. htanaka1@affrc.go.jp
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Tanaka
authors.forename: Aki
authors.initials: A
authors.lastname: Sagisaka
authors.forename: Kosuke
authors.initials: K
authors.lastname: Fujita
authors.forename: Seiichi
authors.initials: S
authors.lastname: Furukawa
authors.forename: Jun
authors.initials: J
authors.lastname: Ishibashi
authors.forename: Minoru
authors.initials: M
authors.lastname: Yamakawa
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000276:immunology / Q000378:metabolism; D012831:Bombyx / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology; D002460:Cell Line; D018076:DNA, Complementary / Q000276:immunology / Q000378:metabolism; D004926:Escherichia coli / Q000276:immunology; D005216:Fat Body / Q000276:immunology / Q000378:metabolism; D020869:Gene Expression Profiling; D019476:Insect Proteins / Q000276:immunology / Q000378:metabolism*; D007814:Larva / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000276:immunology / Q000378:metabolism*; D014162:Transfection; D015854:Up-Regulation
chemical_list: D023181:Antimicrobial Cationic Peptides; C119879:BmETS protein, Bombyx mori; D018076:DNA, Complementary; D019476:Insect Proteins; D014157:Transcription Factors; C095582:lebocin protein, Bombyx mori