title: The N-terminal half of the Drosophila Rel/NF-kappaB factor Relish, REL-68, constitutively activates transcription of specific Relish target genes.
abstract: The Rel/NF-kappaB transcription factor Relish is a major regulator of the antimicrobial response in Drosophila. Upon immune challenge, Relish is cleaved to generate two fragments, the DNA-binding transcription factor REL-68 and the IkappaB-like REL-49. Using transgenic fly strains we show here that overexpression of REL-68 separately from REL-49 is sufficient to activate strong constitutive transcription of the Diptericin gene, but little constitutive or inducible transcription of Attacin and Cecropin, two other Relish target genes. Their transcription may therefore require additional modifications of Relish. However, phosphorylation of the conserved serine residue S431 is not involved in such modifications. This is unlike p65 and Dorsal, which are modulated by phosphorylation at their homologous site. In contrast to other IkappaB proteins, overexpression of REL-49 had no inhibitory effect on Relish-dependent transcription. Instead, we propose that the C-terminal IkappaB-like domain executes a scaffolding and recruiting function for full activation of Relish.
authors.affiliation: Umeå Centre for Molecular Pathogenesis, Umeå University, Umeå, Sweden.
authors.forename: Magda-Lena
authors.initials: ML
authors.lastname: Wiklund
authors.forename: Stefanie
authors.initials: S
authors.lastname: Steinert
authors.forename: Anna
authors.initials: A
authors.lastname: Junell
authors.forename: Dan
authors.initials: D
authors.lastname: Hultmark
authors.forename: Svenja
authors.initials: S
authors.lastname: Stöven
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D054807:Cecropins / Q000276:immunology / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D019476:Insect Proteins / Q000276:immunology / Q000378:metabolism; D008969:Molecular Sequence Data; D010766:Phosphorylation / Q000276:immunology / Q000502:physiology; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
chemical_list: D054807:Cecropins; C054756:DptA protein, Drosophila; D029721:Drosophila Proteins; D019476:Insect Proteins; C101626:Rel protein, Drosophila; D014157:Transcription Factors; C039711:attacin antibacterial protein, insect