Level of constitutively expressed BMAL1 affects the robustness of circadian oscillations
Abstract The circadian rhythm is a biological oscillation of physiological activities with a period of approximately 24 h, that is driven by a cell-autonomous oscillator called the circadian clock. The current model of the mammalian circadian clock is based on a transcriptional-translational negativ...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2022-11-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-022-24188-4 |
| _version_ | 1797983913125085184 |
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| author | Apirada Padlom Daisuke Ono Rio Hamashima Yuko Furukawa Takashi Yoshimura Taeko Nishiwaki-Ohkawa |
| author_facet | Apirada Padlom Daisuke Ono Rio Hamashima Yuko Furukawa Takashi Yoshimura Taeko Nishiwaki-Ohkawa |
| author_sort | Apirada Padlom |
| collection | DOAJ |
| description | Abstract The circadian rhythm is a biological oscillation of physiological activities with a period of approximately 24 h, that is driven by a cell-autonomous oscillator called the circadian clock. The current model of the mammalian circadian clock is based on a transcriptional-translational negative feedback loop in which the protein products of clock genes accumulate in a circadian manner and repress their own transcription. However, several studies have revealed that constitutively expressed clock genes can maintain circadian oscillations. To understand the underlying mechanism, we expressed Bmal1 in Bmal1-disrupted cells using a doxycycline-inducible promoter and monitored Bmal1 and Per2 promoter activity using luciferase reporters. Although the levels of BMAL1 and other clock proteins, REV-ERBα and CLOCK, showed no obvious rhythmicity, robust circadian oscillation in Bmal1 and Per2 promoter activities with the correct phase relationship was observed, which proceeded in a doxycycline-concentration-dependent manner. We applied transient response analysis to the Bmal1 promoter activity in the presence of various doxycycline concentrations. Based on the obtained transfer functions, we suggest that, at least in our experimental system, BMAL1 is not directly involved in the oscillatory process, but modulates the oscillation robustness by regulating basal clock gene promoter activity. |
| first_indexed | 2024-04-11T06:54:49Z |
| format | Article |
| id | doaj.art-a04a9a2982724449921bdb41ed21e67d |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-04-11T06:54:49Z |
| publishDate | 2022-11-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-a04a9a2982724449921bdb41ed21e67d2022-12-22T04:39:04ZengNature PortfolioScientific Reports2045-23222022-11-0112111310.1038/s41598-022-24188-4Level of constitutively expressed BMAL1 affects the robustness of circadian oscillationsApirada Padlom0Daisuke Ono1Rio Hamashima2Yuko Furukawa3Takashi Yoshimura4Taeko Nishiwaki-Ohkawa5Laboratory of Animal Integrative Physiology, Graduate School of Bioagricultural Sciences, Nagoya UniversityDepartment of Neuroscience II, Research Institute of Environmental Medicine, Nagoya UniversityLaboratory of Animal Integrative Physiology, Graduate School of Bioagricultural Sciences, Nagoya UniversityInstitute of Transformative Bio-Molecules (WPI-ITbM), Nagoya UniversityLaboratory of Animal Integrative Physiology, Graduate School of Bioagricultural Sciences, Nagoya UniversityLaboratory of Animal Integrative Physiology, Graduate School of Bioagricultural Sciences, Nagoya UniversityAbstract The circadian rhythm is a biological oscillation of physiological activities with a period of approximately 24 h, that is driven by a cell-autonomous oscillator called the circadian clock. The current model of the mammalian circadian clock is based on a transcriptional-translational negative feedback loop in which the protein products of clock genes accumulate in a circadian manner and repress their own transcription. However, several studies have revealed that constitutively expressed clock genes can maintain circadian oscillations. To understand the underlying mechanism, we expressed Bmal1 in Bmal1-disrupted cells using a doxycycline-inducible promoter and monitored Bmal1 and Per2 promoter activity using luciferase reporters. Although the levels of BMAL1 and other clock proteins, REV-ERBα and CLOCK, showed no obvious rhythmicity, robust circadian oscillation in Bmal1 and Per2 promoter activities with the correct phase relationship was observed, which proceeded in a doxycycline-concentration-dependent manner. We applied transient response analysis to the Bmal1 promoter activity in the presence of various doxycycline concentrations. Based on the obtained transfer functions, we suggest that, at least in our experimental system, BMAL1 is not directly involved in the oscillatory process, but modulates the oscillation robustness by regulating basal clock gene promoter activity.https://doi.org/10.1038/s41598-022-24188-4 |
| spellingShingle | Apirada Padlom Daisuke Ono Rio Hamashima Yuko Furukawa Takashi Yoshimura Taeko Nishiwaki-Ohkawa Level of constitutively expressed BMAL1 affects the robustness of circadian oscillations Scientific Reports |
| title | Level of constitutively expressed BMAL1 affects the robustness of circadian oscillations |
| title_full | Level of constitutively expressed BMAL1 affects the robustness of circadian oscillations |
| title_fullStr | Level of constitutively expressed BMAL1 affects the robustness of circadian oscillations |
| title_full_unstemmed | Level of constitutively expressed BMAL1 affects the robustness of circadian oscillations |
| title_short | Level of constitutively expressed BMAL1 affects the robustness of circadian oscillations |
| title_sort | level of constitutively expressed bmal1 affects the robustness of circadian oscillations |
| url | https://doi.org/10.1038/s41598-022-24188-4 |
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