title: Transcriptional and post-translational regulation of mouse cation transport regulator homolog 1.
abstract: Recently, cation transport regulator homolog 1 (Chac1) has been identified as a novel pro-apoptotic factor in cells under endoplasmic reticulum (ER) stress. Of the three major ER stress sensors, it is suggested that ATF4 participates in the transcriptional regulation of Chac1 gene expression. The precise characterization of the Chac1 promoter, however, has not yet been elucidated. In this study, we detected the induction of Chac1 mRNA expression using DNA array analysis and RT-PCR of thapsigargin (Tg)-inducible genes in Neuro2a cells. Chac1 mRNA expression was also induced immediately following treatment with tunicamycin (Tm) and brefeldin A. Characterization of the mouse Chac1 promoter activity using a luciferase reporter assay revealed that the CREB/ATF element and amino acid response element in the mouse Chac1 promoter are functional and respond to Tm stimulation and ATF4 overexpression. Mutations in either element in the Chac1 promoter did not inhibit the responsiveness of this promoter to Tm and ATF4; however, mutations in both of these elements dramatically decreased the basal activity and response to ER stress stimuli. In addition to the transcriptional regulation, we found that Chac1 protein expression was only detected in the presence of MG132, a proteasome inhibitor, even though mouse Chac1 gene was transiently overexpressed in Neuro2a cells. Taken together, we are the first to demonstrate the transcriptional and post-translational regulation of Chac1 expression in a neuronal cell line.
authors.affiliation: Department of Biomolecular Science, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu 501-1193, Japan. oohashi@gifu-u.ac.jp
authors.forename: Kentaro
authors.initials: K
authors.lastname: Oh-Hashi
authors.forename: Yuki
authors.initials: Y
authors.lastname: Nomura
authors.forename: Kiyo
authors.initials: K
authors.lastname: Shimada
authors.forename: Hisashi
authors.initials: H
authors.lastname: Koga
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hirata
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Kiuchi
mesh_terms: D051701:Activating Transcription Factor 4 / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D045744:Cell Line, Tumor; D017630:Connexins / Q000235:genetics* / Q000378:metabolism; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D059865:Endoplasmic Reticulum Stress / Q000235:genetics; D005786:Gene Expression Regulation / Q000235:genetics*; D047908:Intracellular Signaling Peptides and Proteins; D007976:Leupeptins / Q000494:pharmacology; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D009447:Neuroblastoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D011401:Promoter Regions, Genetic / Q000235:genetics; D014176:Protein Biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019284:Thapsigargin / Q000494:pharmacology; D014158:Transcription, Genetic; D014415:Tunicamycin / Q000494:pharmacology; D005722:gamma-Glutamylcyclotransferase
chemical_list: C081452:Atf4 protein, mouse; D017630:Connexins; D015853:Cysteine Proteinase Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D007976:Leupeptins; D014415:Tunicamycin; D051701:Activating Transcription Factor 4; D019284:Thapsigargin; C586183:Chac1 protein, mouse; D005722:gamma-Glutamylcyclotransferase; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde