MRG15-mediated tethering of PALB2 to unperturbed chromatin protects active genes from genotoxic stress
| Autor: | Daniela Rhodes, Yuki Katou, Jean-Yves Bleuyard, Katsuhiko Shirahige, Anthony M. Couturier, Ryuichiro Nakato, Fumiko Esashi, Timothy C. Humphrey, Christine Ralf, Svenja Hester, Daniel Dominguez, Marjorie Fournier |
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| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
DNA Replication Proteomics DNA Repair Transcription Genetic DNA repair DNA damage Biology Chromosomes 03 medical and health sciences chemistry.chemical_compound Inhibitory Concentration 50 Cell Line Tumor Humans Transcription factor Gene Genetics BRCA2 Protein Multidisciplinary Genome Human Tumor Suppressor Proteins DNA replication Histone-Lysine N-Methyltransferase Biological Sciences Chromatin 030104 developmental biology HEK293 Cells chemistry Mutation Human genome Fanconi Anemia Complementation Group N Protein DNA DNA Damage HeLa Cells Protein Binding Transcription Factors |
| Popis: | The partner and localiser of BRCA2 (PALB2) plays important roles in the maintenance of genome integrity and protection against cancer. Although PALB2 is commonly described as a repair factor recruited to sites of DNA breaks, recent studies provide evidence that PALB2 also associates with unperturbed chromatin. Here, we investigated the previously poorly described role of chromatin-associated PALB2 in undamaged cells. We found that PALB2 associates with active genes through its major binding partner, MRG15, which recognizes histone H3 trimethylated at lysine 36 (H3K36me3) by the SETD2 methyltransferase. Missense mutations that ablate PALB2 binding to MRG15 confer elevated sensitivity to the topoisomerase inhibitor camptothecin (CPT) and increased levels of aberrant metaphase chromosomes and DNA stress in gene bodies, which were suppressed by preventing DNA replication. Remarkably, the level of PALB2 at genic regions was frequently decreased, rather than increased, upon CPT treatment. We propose that the steady-state presence of PALB2 at active genes, mediated through the SETD2/H3K36me3/MRG15 axis, ensures an immediate response to DNA stress and therefore effective protection of these regions during DNA replication. This study provides a conceptual advance in demonstrating that the constitutive chromatin association of repair factors plays a key role in the maintenance of genome stability and furthers our understanding of why PALB2 defects lead to human genome instability syndromes. |
| Databáze: | OpenAIRE |
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