title: An animal model to evaluate the function and regulation of the adaptively evolving stress protein SEP53 in oesophageal bile damage responses.
abstract: Squamous epithelium in mammals has evolved an atypical stress response involving down-regulation of the classic HSP70 protein and induction of sets of proteins including one named SEP53. This atypical stress response might be due to the unusual environmental pressures placed on squamous tissue. In fact, SEP53 plays a role as an anti-apoptotic factor in response to DNA damage induced by deoxycholic acid stresses implicated in oesophageal reflux disease. SEP53 also has a genetic signature characteristic of an adaptively and rapidly evolving gene, and this observation has been used to imply a role for SEP53 in immunity. Physiological models of squamous tissue are required to further define the regulation and function of SEP53. We examined whether porcine squamous epithelium would be a good model to study SEP53, since this animal suffers from a bile-reflux disease in squamous oesophageal tissue. We have (1) cloned and sequenced the porcine SEP53 locus from porcine bacterial artificial chromosome genomic DNA, (2) confirmed the strikingly divergent nature of the C-terminal portion of the SEP53 gene amongst mammals, (3) discovered that a function of the conserved N-terminal domain of the gene is to maintain cytoplasmic localisation, and (4) examined SEP53 expression in normal and diseased porcine pars oesophagea. SEP53 expression in porcine tissue was relatively confined to gastric squamous epithelium, consistent with its expression in normal human squamous epithelium. Immunohistochemical staining for SEP53 protein in normal and damaged pars oesophagea demonstrated significant stabilisation of SEP53 protein in the injured tissue. These results suggest that porcine squamous epithelium would be a robust physiological model to examine the evolution and function of the SEP53 stress pathway in modulating stress-induced responses in squamous tissue.
authors.affiliation: CRUK p53 Signal Transduction Group, University of Edinburgh, South Crewe Road, Edinburgh, UK.
authors.forename: Lenny
authors.initials: L
authors.lastname: Nelson
authors.forename: Susan
authors.initials: S
authors.lastname: Anderson
authors.forename: Alan L
authors.initials: AL
authors.lastname: Archibald
authors.forename: Susan
authors.initials: S
authors.lastname: Rhind
authors.forename: Zen H
authors.initials: ZH
authors.lastname: Lu
authors.forename: Alison
authors.initials: A
authors.lastname: Condie
authors.forename: Neal
authors.initials: N
authors.lastname: McIntyre
authors.forename: Jill
authors.initials: J
authors.lastname: Thompson
authors.forename: Rudolf
authors.initials: R
authors.lastname: Nenutil
authors.forename: Borek
authors.initials: B
authors.lastname: Vojtesek
authors.forename: C Bruce A
authors.initials: CB
authors.lastname: Whitelaw
authors.forename: Tom J
authors.initials: TJ
authors.lastname: Little
authors.forename: Ted
authors.initials: T
authors.lastname: Hupp
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001646:Bile / Q000378:metabolism*; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D004848:Epithelium / Q000378:metabolism / Q000473:pathology*; D004947:Esophagus / Q000033:anatomy & histology* / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013552:Swine
chemical_list: C418764:CRNN protein, human; D008565:Membrane Proteins; D009363:Neoplasm Proteins