title: Molecular characterization and expression analysis of IκB from Haliotis discus discus.
abstract: Innate immune system relies on the recognition of pathogen associated molecular patterns present in the microbes by the pattern recognition receptors leading to the activation of signaling cascade and subsequent synthesis of cytokines. NF-κB is a major stimulus activated transcription factor, which regulates the expression of a diverse array of genes. IκB is an inhibitor of NF-κB, retaining NF-κB in an inactive state in the cytoplasm. In this study, we have reported the characterization of first abalone IκB (HdIκB). The cDNA possessed an ORF of 1200 bp coding for a protein of 400 amino acids with molecular mass of 45 kDa and isoelectric point of 4.7. HdIκB protein possessed a conserved phosphorylation site (58)DSGIFS(63) in the N-terminal region, six ankyrin repeats, and a PEST sequence in the C-terminal region. A casein kinase II phosphorylation site could also be observed in the PEST sequence. Constitutive expression of HdIκB revealed its physiological significance since NF-κB is known to be activated by various stimuli. Elevated expression of HdIκB transcripts could be observed in abalones challenged with various mitogens and live microbes. This novel characterization of abalone IκB would further be a positive approach in the affirmation of evolutionary conservation and significance of this protein as a repressor/inhibitor of a pleiotropic transcription factor like NF-κB.
authors.affiliation: Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province, Republic of Korea.
authors.forename: Saranya Revathy
authors.initials: SR
authors.lastname: Kasthuri
authors.forename: Ilson
authors.initials: I
authors.lastname: Whang
authors.forename: Umasuthan
authors.initials: U
authors.lastname: Navaneethaiyer
authors.forename: Bong-Soo
authors.initials: BS
authors.lastname: Lim
authors.forename: Cheol Young
authors.initials: CY
authors.lastname: Choi
authors.forename: Jehee
authors.initials: J
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D051550:I-kappa B Kinase / Q000737:chemistry / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D008070:Lipopolysaccharides / Q000378:metabolism; D008089:Listeria monocytogenes / Q000502:physiology; D008969:Molecular Sequence Data; D029141:Novirhabdovirus / Q000502:physiology; D009928:Organ Specificity; D010802:Phylogeny; D011070:Poly I-C / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D012908:Snails / Q000201:enzymology / Q000235:genetics* / Q000276:immunology* / Q000382:microbiology; D015854:Up-Regulation; D014733:Vibrio / Q000502:physiology
chemical_list: D008070:Lipopolysaccharides; D051550:I-kappa B Kinase; D011070:Poly I-C