Novel Map Reveals Complexity of Human DNA Damage Repair System

A team of scientists led by researchers at the University of California San Diego School of Medicine has unveiled a map of protein assemblies in the DNA damage response—called DDRAM for DNA damage response assemblies map—that showcases the intricate system by which the human body addresses and repairs DNA damage—a key factor in numerous diseases. This discovery provides a deeper understanding of the DNA damage response (DDR) and opens up new possibilities for therapeutic interventions in diseases related to defects in DDR.

To maintain genome integrity and support normal cellular functions, cells have evolved a complex network of cell-cycle checkpoints and DNA repair mechanisms collectively known as DDR. Defects in DDR are associated with cancer and heritable neurological disorders characterized by unstable DNA. Hence, comprehending the intricacies of DDR is crucial for developing effective treatments.

Trey Ideker, senior author of the paper published in Cell Systems, explains that the challenge lies in the complexity of DDR, which involves numerous proteins assembling in different ways to address diverse issues. The research team aimed to gain a comprehensive understanding of DDR to facilitate targeted interventions.

By utilizing affinity purification mass spectrometry and multi-omics data, the scientists constructed a novel map that reveals the hierarchical organization of 605 proteins in 109 assemblies involved in DDR. Unlike previous maps, which relied on conflicting literature or focused on well-studied mechanisms, this map offers a broader perspective and incorporates new DDR-associated proteins linked to stress, transport, and chromatin functions within cells.

The research team has developed interactive software that enables scientists to investigate specific proteins and DDR interactions of interest. Additionally, the map can be integrated into machine learning systems to tackle broader questions, such as the role of DDR in the genotype-to-phenotype transition and how external factors like drug exposure affect DDR.

The study's first author, Anton Kratz, emphasizes two key findings. First, approximately 50% of the proteins included in the data-driven map were not present in previous literature-curated maps, highlighting the importance of a data-driven approach. Second, DDR membership is not binary but exists on a continuum, extending to stress, transport, and chromatin functions. This continuum is quantified in the map, shedding light on the diverse roles of DDR.