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Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins
Published on: September 28, 2012
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BRD4 directs mitotic cell division by inhibiting DNA damage
Biorxiv : the Preprint Server for Biology
|August 7, 2023
Summary
Bromodomain 4 (BRD4) is essential for normal cell growth, regulating cell cycle progression and DNA repair. Its absence causes slow growth, replication failure, and DNA damage in mouse cells.
Area of Science:
- Epigenetics
- Molecular Biology
- Cell Biology
Background:
- Bromodomain 4 (BRD4) is known to regulate transcription and cancer cell proliferation by binding to acetylated histones.
- The specific role of BRD4 in normal cellular growth and development has not been fully understood.
Approach:
- Investigated the function of BRD4 in normal cell growth using mouse embryonic fibroblasts with a conditional Brd4 knockout (KO).
- Analyzed cell cycle progression, DNA replication, mitosis, and DNA damage in Brd4KO cells compared to wild-type cells.
- Examined the expression of cell cycle genes, histone genes, centromere/kinetochore proteins, R-loop formation genes, and DNA damage response (DDR) genes.
Key Points:
- Brd4KO cells exhibited significantly slower growth, failed to complete DNA replication and mitosis, and showed extensive DNA damage.
- BRD4 is required for the expression of over 450 cell cycle genes, including those critical for genome replication and chromosomal segregation.
- BRD4 is essential for the expression of genes involved in R-loop formation and the DNA damage response (DDR).
- BRD4 constitutively occupies genes regulating R-loop, DDR, and cell cycle progression.
Conclusions:
- BRD4 acts as a master regulator of normal cell growth.
- BRD4 epigenetically marks genes involved in R-loop formation, DNA damage response, and cell cycle progression, ensuring their proper expression and function.
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