title: Cloning and characterization of a homologue of the alpha inhibitor of NF-kappaB in Rainbow trout (Oncorhynchus mykiss).
abstract: A homologue of IkappaBalpha, the alpha member of the IkappaB family of NF-kappaB inhibitors, was identified in a Rainbow trout suppression subtractive hybridization library enriched in sequences up-regulated in cultured leukocytes after lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNFalpha) stimulation. The full-length cDNA was isolated and sequenced. The predicted amino acid sequence is 61.5% similar and 54% identical to human IkappaBalpha, while only 42% similar and 35% identical to IkappaBbeta, and 38% similar and 32% identical to IkappaBvarepsilon. Rainbow trout IkappaBalpha contains a central ankyrin repeat domain required for its interaction with NF-kappaB and a putative PEST-like sequence in the C-terminus. Expression of IkappaBalpha is up-regulated by LPS and TNFalpha treatment, two known activators of NF-kappaB, suggesting the existence of an autoregulatory loop in fish, as is the case for mammals. These results confirm the existence of the NF-kappaB signalling pathway in fish and suggest a similar functional interaction between IkappaBalpha and NF-kappaB.
authors.affiliation: National Diagnostics Centre, National University of Ireland, Galway, Ireland.
authors.forename: A
authors.initials: A
authors.lastname: Sangrador-Vegas
authors.forename: T J
authors.initials: TJ
authors.lastname: Smith
authors.forename: M T
authors.initials: MT
authors.lastname: Cairns
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D006801:Humans; D020672:I-kappa B Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D017686:Oncorhynchus mykiss / Q000276:immunology*; D010766:Phosphorylation; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; C000606204:NFKBIA protein, human; C000606205:Nfkbia protein, mouse; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha