Single locus phosphoproteomics reveals phosphorylation of RPA-1 is required for generation of single-strand DNA following a break at a subtelomeric locus

Emilia Mclaughlin (1) , Annick Dujeancourt-Henry (1) , Thibault Chaze (2) , Quentin Giai Gianetto (2, 3) , Mariette Matondo (2) , Michael D Urbaniak (4) , Lucy Glover (1)

1 Biologie moléculaire des Trypanosomes - Trypanosome Molecular Biology
2 Plateforme de Protéomique / Proteomics platform
3 Hub Bioinformatique et Biostatistique - Bioinformatics and Biostatistics HUB
4 Division of Biomedical and Life Sciences, Faculty of Health and Medicine

Damage to the genetic material of the cell poses a universal threat to all forms of life. Central to the DNA damage response (DDR) is a phosphorylation signalling cascade that leads to the co-ordination of the cellular response to a DNA break. Identifying the proteins that are phosphorylated is crucial to understanding the mechanisms underlying this DDR. We have used SILAC-based quantitative phosphoproteomics to profile changes in phosphorylation site abundance following a single double strand break (DSB) at a chromosome internal locus and the subtelomeric bloodstream form expression site in Trypanosoma brucei . We report >6500 phosphorylation sites, including a core set of 211 DSB responsive phosphorylation sites. Along with phosphorylation of canonical DNA damage factors, we find that there is a striking distinction between the proteins phosphorylated in response to a chromosome internal DSB and one at the active BES and describe a single phosphorylation event on Replication factor A (RPA) 1 that is required for efficient resection at a bloodstream form expression site.

Keywords: Phosphoproteomics; Trypanosoma brucei; DNA damage

Domains: Life Sciences [q-bio]

Emilia Mclaughlin, Annick Dujeancourt-Henry, Thibault Chaze, Quentin Giai Gianetto, Mariette Matondo, et al.. Single locus phosphoproteomics reveals phosphorylation of RPA-1 is required for generation of single-strand DNA following a break at a subtelomeric locus. 2023. ⟨pasteur-04093539⟩