title: Identifying target genes of the aryl hydrocarbon receptor nuclear translocator (Arnt) using DNA microarray analysis.
abstract: The aryl hydrocarbon receptor nuclear translocator (Arnt) is a basic helix-loop-helix (bHLH) protein that also contains a Per-Arnt-Sim (PAS) domain. In addition to forming heterodimers with many other bHLH-PAS proteins, including the aryl hydrocarbon receptor (AhR) and hypoxia-inducible factors 1alpha, 2alpha and 3alpha, Arnt can also form homodimers when expressed from its cDNA in vitro or in vivo. However, target genes of the Arnt/Arnt homodimer remain to be identified. In this study, we have elucidated the profile of genes responsive to the reintroduction of Arnt expression in an Arnt-deficient mouse hepatoma cell line (c4), using DNA microarray analysis. The expression of 27 genes was upregulated by 1.5-fold or more in c4 cells infected with a retroviral vector expressing mouse Arnt, while no genes were found to be downregulated. Among the upregulated genes, BCL2/adenovirus E1B 19 kDa-interacting protein 1 (NIP3), serine (or cysteine) proteinase inhibitor, clade E, member 1 (PAI1), and N-myc downstream regulated-like (NDR1), were confirmed to be induced by Arnt using real-time PCR. We also found that the 5' promoter region of 15 out of 20 upregulated genes contain the type 2 E-box 5'-CACGTG-3' Arnt/Arnt binding sequence, consistent with the notion that they represent target genes for Arnt.
authors.affiliation: Department of Pathology and Laboratory Medicine, and Jonsson Comprehensive Cancer Center, University of California, Los Angeles, CA 90095, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Shengli
authors.initials: S
authors.lastname: Shi
authors.forename: Ruixue
authors.initials: R
authors.lastname: Zhang
authors.forename: Oliver
authors.initials: O
authors.lastname: Hankinson
mesh_terms: D000818:Animals; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator / Q000378:metabolism / Q000502:physiology*; D045744:Cell Line, Tumor; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology*; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: D051784:Aryl Hydrocarbon Receptor Nuclear Translocator