Ubiquitin-Dependent Mechanisms in DNA Damage Response

The cellular response to DNA damage relies on a finely tuned network of post-translational modifications in which ubiquitin plays a central role. Following the induction of DNA double-strand breaks, specialised E3 ubiquitin ligases initiate site-specific ubiquitylation of histones H2A and H2AX around the lesion, creating binding platforms for repair factors and decision-making proteins. Amplification of the ubiquitin signal by factors such as RNF168 promotes recruitment of 53BP1 to favour non-homologous end-joining, whereas BRCA1-BARD1-catalysed ubiquitylation primes chromatin for homologous recombination. Deubiquitinases counterbalance this activity by removing ubiquitin conjugates to refine the spatial and temporal aspects of repair, prevent aberrant recombination and regulate pathway choice. Crosstalk between ubiquitin and ubiquitin-binding domains further amplifies and directs repair foci formation, ensuring genome integrity. These mechanisms underpin cell-cycle checkpoints, influence sensitivity to chemotherapy and radiation, and have profound implications for cancer biology and therapeutic resistance. Advances in structural biology, proteomics and live-cell imaging have elucidated how dynamic cycles of ubiquitylation and deubiquitylation choreograph the DNA damage response, offering new avenues to modulate repair processes in disease.

Research from Nature Portfolio

Recent studies have identified USP48 as a histone H2A-specific deubiquitinase that selectively removes the BRCA1-mediated ubiquitin mark at sites of double-strand breaks. Biochemical analysis reveals that USP48 activity is modulated by an auxiliary ubiquitin, highlighting a layered regulatory mechanism. In cellular models, loss of USP48 leads to extended DNA end resection, altered 53BP1 positioning and a shift in repair pathway usage towards mutagenic single-strand annealing, whereas its expression preserves genome stability by restraining excessive homologous recombination. These findings position USP48 as a critical antagonist of BRCA1-driven ubiquitylation and a potential target to fine-tune DNA repair fidelity.

Ubiquitin-Dependent Mechanisms in DNA Damage Response publication trend

The graph below shows the total number of articles in ubiquitin-dependent mechanisms in dna damage response across all publications each year (not limited to Nature Index journals).

Technical terms

Ubiquitin: A small regulatory protein that is covalently attached to substrates to direct cellular processes, including DNA repair.

E3 ubiquitin ligase: An enzyme that catalyses transfer of ubiquitin from an E2 conjugating enzyme to a specific substrate, determining site-specific ubiquitylation.

Deubiquitinase (DUB): A protease that removes ubiquitin moieties from target proteins, modulating the duration and extent of ubiquitin signals.

Chromatin ubiquitylation: The addition of ubiquitin to histone proteins within nucleosomes, creating platforms for recruitment of DNA repair factors.

Homologous recombination (HR): A high-fidelity DNA repair pathway that uses an undamaged sister chromatid as a template to restore broken DNA.

Non-homologous end-joining (NHEJ): A DNA repair pathway that directly ligates broken DNA ends without the need for extensive homology, often resulting in small insertions or deletions.

References

1. USP48 restrains resection by site-specific cleavage of the BRCA1 ubiquitin mark from H2A. Nature Communications (2018).
2. Mechanisms of RNF168 nucleosome recognition and ubiquitylation. Molecular Cell (2024).
3. USP3 promotes DNA damage response and chemotherapy resistance through stabilizing and deubiquitinating SMARCA5 in prostate cancer. Cell Death & Disease (2024).
4. CAMK2D serves as a molecular scaffold for RNF8-MAD2 complex to induce mitotic checkpoint in glioma. Cell Death & Differentiation (2023).