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Non-circadian expression masking clock-driven weak transcription rhythms in U2OS cells.

ABSTRACT: U2OS cells harbor a circadian clock but express only a few rhythmic genes in constant conditions. We identified 3040 binding sites of the circadian regulators BMAL1, CLOCK and CRY1 in the U2OS genome. Most binding sites even in promoters do not correlate with detectable rhythmic transcript levels. Luciferase fusions reveal that the circadian clock supports robust but low amplitude transcription rhythms of representative promoters. However, rhythmic transcription of these potentially clock-controlled genes is masked by non-circadian transcription that overwrites the weaker contribution of the clock in constant conditions. Our data suggest that U2OS cells harbor an intrinsically rather weak circadian oscillator. The oscillator has the potential to regulate a large number of genes. The contribution of circadian versus non-circadian transcription is dependent on the metabolic state of the cell and may determine the apparent complexity of the circadian transcriptome.

SUBMITTER: Hoffmann J

PROVIDER: S-EPMC4090172 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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Non-circadian expression masking clock-driven weak transcription rhythms in U2OS cells.

Hoffmann Julia J Symul Laura L Shostak Anton A Fischer Tamás T Naef Felix F Brunner Michael M

PloS one 20140709 7

U2OS cells harbor a circadian clock but express only a few rhythmic genes in constant conditions. We identified 3040 binding sites of the circadian regulators BMAL1, CLOCK and CRY1 in the U2OS genome. Most binding sites even in promoters do not correlate with detectable rhythmic transcript levels. Luciferase fusions reveal that the circadian clock supports robust but low amplitude transcription rhythms of representative promoters. However, rhythmic transcription of these potentially clock-contro ...[more]

PMID: 25007071

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Non-circadian expression masking clock-driven weak transcription rhythms in U2OS cells

Project description:U2OS cells harbor a circadian clock but express only a few rhythmic genes in constant conditions. We identified 3040 binding sites of the circadian regulators BMAL1, CLOCK and CRY1 in the U2OS genome. Most binding sites even in promoters do not correlate with detectable rhythmic transcript levels. Luciferase fusions reveal that the circadian clock supports robust but low amplitude transcription rhythms of representative promoters. However, rhythmic transcription of these potentially clock-controlled genes is masked by non-circadian transcription that overwrites the weaker contribution of the clock in constant conditions. Our data suggest that U2OS cells harbor an intrinsically rather weak circadian oscillator. The oscillator has the potential to regulate a large number of genes. The contribution of circadian versus non-circadian transcription is dependent on the metabolic state of the cell and may determine the apparent complexity of the circadian transcriptome. Analysis of temporal expression profiles of 5708 expressed genes in synchronized U2OS cells.

2014-05-23 | GSE57891 | GEO

Non-circadian expression masking clock-driven weak transcription rhythms in U2OS cells

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Circadian rhythms of fetal liver transcription persist in the absence of canonical circadian clock gene expression rhythms in vivo.

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