Molecular characterization of Mybbp1a as a co-repressor on the Period2 promoter
| Autor: | Katsutaka Oishi, Yasuhiro Hara, Yoshiaki Onishi, Norio Ishida, Akiyoshi Fukamizu, Koyomi Miyazaki |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
endocrine system
animal structures Response element Circadian clock CLOCK Proteins Repressor Cell Cycle Proteins E-box Biology Cell Line Histones Mice Genetics Animals Promoter Regions Genetic Sarcoma 180 Molecular Biology Regulation of gene expression Flavoproteins Lysine Nuclear Proteins RNA-Binding Proteins Period Circadian Proteins Molecular biology Circadian Rhythm Cryptochromes DNA-Binding Proteins Repressor Proteins Gene Expression Regulation Trans-Activators Carrier Proteins Chromatin immunoprecipitation Transcription Factors |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 0305-1048 |
| DOI: | 10.1093/nar/gkn1013 |
| Popis: | The circadian clock comprises transcriptional feedback loops of clock genes. Cryptochromes are essential components of the negative feedback loop in mammals as they inhibit CLOCK-BMAL1-mediated transcription. We purified mouse CRY1 (mCRY1) protein complexes from Sarcoma 180 cells to determine their roles in circadian gene expression and discovered that Myb-binding protein 1a (Mybbp1a) interacts with mCRY1. Mybbp1a regulates various transcription factors, but its role in circadian gene expression is unknown. We found that Mybbp1a functions as a co-repressor of Per2 expression and repressed Per2 promoter activity in reporter assays. Chromatin immunoprecipitation (ChIP) assays revealed endogenous Mybbp1a binding to the Per2 promoter that temporally matched that of mCRY1. Furthermore, Mybbp1a binding to the Per2 promoter correlated with the start of the down-regulation of Per2 expression and with the dimethylation of histone H3 Lys9, to which it could also bind. These findings suggest that Mybbp1a and mCRY1 can form complexes on the Per2 promoter that function as negative regulators of Per2 expression. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|