title: A novel Arnt-interacting protein Ainp2 enhances the aryl hydrocarbon receptor signalling.
abstract: In an effort to better understand the Ah receptor nuclear translocator (Arnt)-dependent signaling mechanisms, we employed a phage display system to identify Arnt-interacting peptides. Human liver cDNA library was utilized to screen for Arnt-interacting peptides using an Arnt construct fused to thioredoxin (TH-ArntCDelta418). Two clones, namely Ainp1 and Ainp2 (Arnt-interacting peptide), were identified and subsequently Ainp2 was further characterized. Ainp2 interacts with TH-ArntCDelta418 in the GST pull-down and mammalian two-hybrid assays. Northern blot results revealed that Ainp2 is predominantly expressed in human liver. The putative full-length Ainp2 cDNA sequence was subsequently cloned using RACE PCR. Endogenous expression of Ainp2 was found in Jurkat cells at the mRNA and protein levels. Results from the transient transfection studies using a DRE-driven reporter plasmid and the real-time QPCR experiments examining the endogenous CYP1A1 expression showed that Ainp2 enhances the 3-methylchloranthrene-induced activity in HepG2 cells, suggesting that Ainp2 plays a role in the Arnt-dependent function
authors.affiliation: Department of Pharmaceutics and Medicinal Chemistry, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA 95211, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: Tony C
authors.initials: TC
authors.lastname: Luu
authors.forename: William k
authors.initials: Wk
authors.lastname: Chan
mesh_terms: D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006242:Haptoglobins; D022781:Hepatocytes / Q000378:metabolism*; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D019169:Jurkat Cells; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C497442:HIF1A protein, human; C485359:HP protein, human; D006242:Haptoglobins; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009687:Nuclear Proteins; D018336:Receptors, Aryl Hydrocarbon; D014157:Transcription Factors