Abstract
Monoubiquitination of the FANCD2 protein is a key step in the Fanconi anemia (FA) tumor suppressor pathway, coinciding with this molecule's accumulation at sites of genome damage. Strong circumstantial evidence points to a requirement for the BRCA1 gene product in this step. Here, we show that the purified BRCA1/BARD1 complex, together with E1 and UbcH5a, is sufficient to reconstitute the monoubiquitination of FANCD2 in vitro. Although siRNA-mediated knockdown of BRCA1 in human cells results in defective targeting of FANCD2 to sites of DNA damage, it does not lead to a defect in FANCD2 ubiquitination. Furthermore, ablation of the RING finger domains of either BRCA1 or BARD1 in the chicken B cell line DT40 also leaves FANCD2 modification intact. Consequently, while BRCA1 affects the accumulation of FANCD2 at sites of DNA damage, BRCA1/BARD1 E3 ligase activity is not essential for the monoubiquitination of FANCD2.
Original language | English |
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Pages (from-to) | 247-254 |
Number of pages | 8 |
Journal | Molecular Cell |
Volume | 12 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jul 2003 |
Keywords
- Animals
- BRCA1 protein
- Carrier proteins
- Cell-free system
- DNA damage
- Fanconi anemia
- Fanconi anemia complementation group D2 protein
- Gene expression regulation, Neoplastic
- HeLa cells
- Humans
- Iron-binding proteins
- Ligases
- Mutation
- Nuclear proteins
- Protein structure, Tertiary
- RNA, Small interfering
- Tumor suppressor proteins
- Ubiquitin
- Ubiquitin-conjugating Enzymes
- Ubiquitin-protein ligases