The Zebrafish Period2 Protein Positively Regulates the Circadian Clock through Mediation of Retinoic Acid Receptor (RAR)-related Orphan Receptor ? (Ror?)
- Authors
- Wang, M., Zhong, Z., Zhong, Y., Zhang, W., Wang, H.
- ID
- ZDB-PUB-150324-1
- Date
- 2015
- Source
- The Journal of biological chemistry 290(7): 4367-4382 (Journal)
- Registered Authors
- Wang, Han, Zhang, Wei
- Keywords
- Circadian Clock, Gene Regulation, Rev-ErbAα (NR1D1), Transgenic, Zebrafish, Rorα, Period2
- MeSH Terms
-
- Response Elements/genetics
- Circadian Clocks/physiology*
- Receptors, Retinoic Acid/genetics
- Receptors, Retinoic Acid/metabolism*
- Period Circadian Proteins/genetics
- Period Circadian Proteins/metabolism*
- Animals
- Eye Proteins/genetics
- Eye Proteins/metabolism*
- Motor Activity
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism*
- Embryo, Nonmammalian
- Transcriptional Activation
- Reverse Transcriptase Polymerase Chain Reaction
- ARNTL Transcription Factors/genetics
- ARNTL Transcription Factors/metabolism*
- Immunoenzyme Techniques
- Zebrafish
- Blotting, Western
- Chromatin Immunoprecipitation
- RNA, Messenger/genetics
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism*
- Mice
- Real-Time Polymerase Chain Reaction
- PubMed
- 25544291 Full text @ J. Biol. Chem.
We report the characterization of a null mutant for zebrafish circadian clock gene period2 (per2) generated by transcription activator-like effector nuclease and a positive role of PER2 in vertebrate circadian regulation. Locomotor experiments showed that per2 mutant zebrafish display reduced activities under light-dark and 2-h phase delay under constant darkness, and quantitative real time PCR analyses showed up-regulation of cry1aa, cry1ba, cry1bb, and aanat2 but down-regulation of per1b, per3, and bmal1b in per2 mutant zebrafish, suggesting that Per2 is essential for the zebrafish circadian clock. Luciferase reporter assays demonstrated that Per2 represses aanat2 expression through E-box and enhances bmal1b expression through the Ror/Rev-erb response element, implicating that Per2 plays dual roles in the zebrafish circadian clock. Cell transfection and co-immunoprecipitation assays revealed that Per2 enhances bmal1b expression through binding to orphan nuclear receptor Rorα. The enhancing effect of mouse PER2 on Bmal1 transcription is also mediated by RORą even though it binds to REV-ERBα. Moreover, zebrafish Per2 also appears to have tissue-specific regulatory roles in numerous peripheral organs. These findings help define the essential functions of Per2 in the zebrafish circadian clock and in particular provide strong evidence for a positive role of PER2 in the vertebrate circadian system.