title: Synergistic regulation of the mouse orphan nuclear receptor SHP gene promoter by CLOCK-BMAL1 and LRH-1.
abstract: Small heterodimer partner (SHP; NR0B2) is an orphan nuclear receptor and acts as a repressor for wide variety of nuclear hormone receptors. We demonstrated here that mouse SHP mRNA showed a circadian expression pattern in the liver. Transient transfection of the mSHP promoter demonstrated that CLOCK-BMAL1, core circadian clock components, bound to E-box (CACGTG), and stimulated the promoter activity by 4-fold. Liver receptor homologue-1 (LRH-1; NR5A2) stimulated the mSHP promoter, and CLOCK-BMAL1 synergistically enhanced the LRH-1-mediated transactivation. Interestingly, SHP did not affect the CLOCK-BMAL1-mediated promoter activity, but strongly repressed the synergistic activation of CLOCK-BMAL1 and LRH-1. Furthermore, in vitro pull-down assays revealed the existence of direct protein-protein interaction between LRH-1 and CLOCK. In summary, this study shows that CLOCK-BMAL1, LRH-1 and SHP coordinately regulate the mSHP gene to generate the circadian oscillation. The cyclic expression of mSHP may affect daily activity of other nuclear receptors and contribute to circadian liver functions.
authors.affiliation: Shinshu University Graduate School of Medicine, Institute on Aging and Adaptation, Department of Aging Medicine and Geriatrics, Matsumoto 390-8621, Japan.
authors.forename: Ako
authors.initials: A
authors.lastname: Oiwa
authors.forename: Tomoko
authors.initials: T
authors.lastname: Kakizawa
authors.forename: Takahide
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Koh
authors.initials: K
authors.lastname: Yamashita
authors.forename: Wei
authors.initials: W
authors.lastname: Jiang
authors.forename: Teiji
authors.initials: T
authors.lastname: Takeda
authors.forename: Satoru
authors.initials: S
authors.lastname: Suzuki
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hashizume
mesh_terms: D056930:ARNTL Transcription Factors; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D056926:CLOCK Proteins; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D002940:Circadian Rhythm; D019281:Dimerization; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation; D006801:Humans; D008099:Liver / Q000378:metabolism; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008813:Mice, Inbred ICR; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D056930:ARNTL Transcription Factors; D051792:Basic Helix-Loop-Helix Proteins; D056926:CLOCK Proteins; D008156:Luciferases; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators; C538960:BMAL1 protein, human; C538961:Bmal1 protein, mouse; C431936:Nr5a2 protein, mouse; C099713:nuclear receptor subfamily 0, group B, member 2; C538943:CLOCK protein, human; C538944:Clock protein, mouse