BRCA1-BARD1 complex
Definition
Target type: cellularcomponent
A heterodimeric complex comprising BRCA1 and BARD1, which possesses ubiquitin ligase activity and is involved in genome maintenance, possibly by functioning in surveillance for DNA damage. [PMID:12787778]
The BRCA1-BARD1 complex is a crucial component of the DNA damage response (DDR) pathway, primarily functioning in the repair of double-strand DNA breaks (DSBs) via homologous recombination (HR). This complex localizes to the nucleus and resides in various cellular compartments, actively participating in several key processes:
1. **Nuclear foci formation:** Upon DNA damage, BRCA1-BARD1 accumulates at sites of DSBs, forming distinct nuclear foci. These foci represent sites of active DNA repair, where the complex interacts with other DDR proteins to coordinate the repair process.
2. **Chromatin remodeling:** The complex plays a critical role in chromatin remodeling, facilitating access of repair machinery to the damaged DNA. This involves interactions with various chromatin-associated proteins, including histone modifiers and DNA helicases.
3. **Regulation of DNA repair pathways:** BRCA1-BARD1 functions as a central hub in the HR pathway, orchestrating the recruitment and activation of key repair factors, such as RAD51, a crucial recombinase.
4. **Cell cycle checkpoint control:** The complex also contributes to the cell cycle checkpoint, ensuring that damaged DNA is repaired before cell division. It does this by interacting with proteins involved in cell cycle regulation, preventing the progression of the cell cycle if DNA repair is incomplete.
5. **Ubiquitination and SUMOylation:** The BRCA1-BARD1 complex exhibits ubiquitin ligase activity, playing a role in the ubiquitination and SUMOylation of various DDR proteins. This post-translational modification regulates the activity and stability of these proteins, influencing the overall DDR response.
The BRCA1-BARD1 complex, therefore, acts as a dynamic multi-functional entity within the nucleus, essential for maintaining genomic integrity and preventing tumorigenesis.'
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Proteins (2)
| Protein | Definition | Taxonomy |
|---|---|---|
| BRCA1-associated RING domain protein 1 | A BRCA1-associated RING domain protein 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q99728] | Homo sapiens (human) |
| Breast cancer type 1 susceptibility protein | A breast cancer type 1 susceptibility protein that is encoded in the genome of human. [PRO:DNx] | Homo sapiens (human) |
Compounds (1)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| beta-thujaplicin | beta-thujaplicin : A monoterpenoid that is cyclohepta-2,4,6-trien-1-one substituted by a hydroxy group at position 2 and an isopropyl group at position 4. Isolated from Thuja plicata and Chamaecyparis obtusa, it exhibits antimicrobial activities. beta-thujaplicin: structure | cyclic ketone; enol; monoterpenoid | antibacterial agent; antifungal agent; antineoplastic agent; antiplasmodial drug; plant metabolite |