title: Cloning and characterization of the proximal promoter region of rainbow trout (Oncorhynchus mykiss) interleukin-6 gene.
abstract: Interleukin-6 (IL6) is a pleiotropic cytokine with important immunoregulatory functions. Its expression is inducible in immune cells and tissues of several fish species. We also found that IL6 mRNA abundance was significantly increased in spleen, liver, and gill of rainbow trout after experimental infection with Aeromonas salmonicida. Genomic DNA sequences of IL6 orthologs from three salmonid species revealed a conserved exon/intron structure and a high overall nucleotide identity of >88%. To uncover key mechanisms regulating IL6 expression in salmonid fish, we amplified a fragment of the proximal IL6 promoter from rainbow trout and identified in-silico conserved binding sites for NF-κB and CEBP. The activity of this IL6 promoter fragment was analyzed in the established human embryonic kidney line HEK-293. Luciferase- and GFP-based reporter systems revealed that the proximal IL6 promoter is activated by Escherichia coli. Essentially, both reporter systems proved that NF-κB p50, but not NF-κB p65 or CEBP, activates the IL6 promoter fragment. Truncation of this fragment caused a significant decrease in IL6 promoter activation. This characterization of the proximal promoter of the IL6-encoding gene provides basic knowledge about the IL6 gene expression in rainbow trout.
authors.affiliation: Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
authors.forename: Merle D
authors.initials: MD
authors.lastname: Zante
authors.affiliation: Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Borchel
authors.affiliation: Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Brunner
authors.affiliation: Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany.
authors.forename: Tom
authors.initials: T
authors.lastname: Goldammer
authors.affiliation: Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany. Electronic address: rebl@fbn-dummerstorf.de.
authors.forename: Alexander
authors.initials: A
authors.lastname: Rebl
mesh_terms: D048409:Aeromonas salmonicida / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D004926:Escherichia coli / Q000502:physiology; D004927:Escherichia coli Infections / Q000235:genetics / Q000382:microbiology / Q000662:veterinary; D005393:Fish Diseases / Q000235:genetics* / Q000382:microbiology; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016905:Gram-Negative Bacterial Infections / Q000235:genetics / Q000382:microbiology / Q000662:veterinary*; D015850:Interleukin-6 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D052002:NF-kappa B p50 Subunit / Q000235:genetics / Q000378:metabolism; D017686:Oncorhynchus mykiss; D011401:Promoter Regions, Genetic / Q000235:genetics; D020317:Salmo salar / Q000235:genetics / Q000378:metabolism; D012487:Salmonidae / Q000235:genetics* / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D015850:Interleukin-6; D052002:NF-kappa B p50 Subunit
keywords: Cytokines; IL6; Luciferase reporter assay; NF-κB p50; Teleost