2019 Fiscal Year Research-status Report
Translation control of circadian rhythms
| Project/Area Number |
18K14755
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| Research Institution | Osaka University |
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Principal Investigator |
MILLIUS ARTHUR 大阪大学, 免疫学フロンティア研究センター, 特任研究員(常勤) (80624858)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Keywords | Ribosome profiling / Circadian rhythms / Period2 / Translational Repression / uORF / RNA / Regnase |
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| Outline of Annual Research Achievements |
Defects in circadian rhythms are related to health problems, such as obesity, cancer, and depression, and understanding how RNA translation is regulated is important for developing new treatments. We used ribosome profiling to understand RNA translation in liver over a 24-h period and found that ribosomes bound to upstream open reading frames (uORFs) in circadian mRNAs to repress their translation. In addition, we found that Regnase 4 is a rhythmically expressed RNA-binding endonuclease and targets circadian mRNAs for degradation by binding 3'UTRs. We are developing a machine-learning model to understand how the Regnase proteins bind different RNA structures to cleave and degrade RNA.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
In collaboration with the Ueda lab, we mutated the Per2 uORF using Crispr/Cas9 in wild-type mice and generated four homozygous mutant mice (two males and two females) in the F0 generation. We backcrossed these mice to wild-type mice and are now analyzing the behavioral rhythms in light-dark conditions. In the Akira lab, we used ribosome profiling to compare translation between wild-type liver tissue and isolated hepatocytes and are now analyzing translation in hepatocytes and bone marrow macrophages of several Regnase mutant mouse models. In the Standley lab, we are using machine learning to develop predictive software to understand the suite of 3'UTRs that Regnase family proteins may target.
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| Strategy for Future Research Activity |
We plan to phenotype the homozygous Per2 mutant mice for activity rhythms and expression of Per2 in the liver and brain. We hypothesize that mutant mice will be less resistant to jet-lag, and we will conduct an artificial jet-lag experiment. In addition, we are analyzing the function of a circadian-expressed RNA-binding endonuclease protein called Regnase 4. We are generating Regnase 4 KO mice and plan to use ribosome profiling to understand how translation is altered in Regnase mutant mice.
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| Causes of Carryover |
I transferred my affiliation from RIKEN to iFReC at Osaka University on April 1, 2019 to collaborate more closely with the labs of Daron Standley and Shizuo Akira. I am studying how a circadian Regnase family member Regnase 4 degrades circadian mRNAs and developing a model to predict 3'UTR targets of Regnase proteins. Therefore, I using some of my FY2019 budget for ribosome profiling sequencing costs in the Akira and Standley labs in FY2020.
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Research Products
(1 results)
