The Zebrafish Period2 Protein Positively Regulates the Circadian Clock through Mediation of Retinoic Acid Receptor (RAR)-related Orphan Receptor α (Rorα)
- 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
-
- ARNTL Transcription Factors/genetics
- ARNTL Transcription Factors/metabolism*
- Animals
- Blotting, Western
- Chromatin Immunoprecipitation
- Circadian Clocks/physiology*
- Embryo, Nonmammalian
- Eye Proteins/genetics
- Eye Proteins/metabolism*
- Immunoenzyme Techniques
- Mice
- Motor Activity
- Period Circadian Proteins/genetics
- Period Circadian Proteins/metabolism*
- RNA, Messenger/genetics
- Real-Time Polymerase Chain Reaction
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism*
- Receptors, Retinoic Acid/genetics
- Receptors, Retinoic Acid/metabolism*
- Response Elements/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Transcriptional Activation
- Zebrafish
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism*
- 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 ROR± 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.