title: Expression and characterization of hypoxia-inducible factor (HIF)-3alpha in human kidney: suppression of HIF-mediated gene expression by HIF-3alpha.
abstract: Hypoxia inducible factors (HIFs) are heterodimeric transcription factors that regulate a number of adaptive responses to low oxygen tension. They are composed of alpha- and beta-subunits that belong to the basic helix-loop-helix-PAS superfamily. Here we examined the expression of HIF-alpha subunit proteins in the human kidney and found that, in addition to HIF-1alpha and -2alpha, HIF-3alpha was also expressed. The sequence analysis revealed that, like mouse HIF-3alpha, human HIF-3alpha has high similarity with HIF-1alpha and -2alpha in the bHLH and PAS domains, but lacks structures for transactivation found in the C-terminus of HIF-1alpha and -2alpha. Furthermore, we performed reporter gene analysis and showed that HIF-3alpha suppresses hypoxia-inducible HIF-mediated gene expression. HIF-3alpha might be a negative regulator of hypoxia-inducible gene expression in the human kidney.
authors.affiliation: Department of Public Health and Molecular Toxicology, School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan. haras@pharm.kitasato-u.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Hara
authors.forename: J
authors.initials: J
authors.lastname: Hamada
authors.forename: C
authors.initials: C
authors.lastname: Kobayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Kondo
authors.forename: N
authors.initials: N
authors.lastname: Imura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D051017:Apoptosis Regulatory Proteins; D051792:Basic Helix-Loop-Helix Proteins; D019556:COS Cells; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D007668:Kidney / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D012097:Repressor Proteins; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection; D000099162:Endothelial PAS Domain-Containing Protein 1
chemical_list: D051017:Apoptosis Regulatory Proteins; D051792:Basic Helix-Loop-Helix Proteins; D010100:Oxygen; D021122:Protein Subunits; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D000099162:Endothelial PAS Domain-Containing Protein 1; C116973:HIF3A protein, human; C444643:Hif3a protein, mouse