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bioRxiv · 10.1101/2024.01.17.576037

In-Depth Mapping of DNA-PKcs Signaling Uncovers Conserved Features of Its Kinase Specificity

Marshall, S.·Navarro, M.·Ascencao, C.·Smolka, M. B.
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Abstract

DNA-PKcs is a DNA damage sensor kinase with established roles in DNA double-strand break repair via non-homologous end joining. Recent studies have revealed additional roles of DNA-PKcs in the regulation of transcription, translation and DNA replication. However, the substrates through which DNA-PKcs regulates these processes remain largely undefined. Here we utilized quantitative phosphoproteomics to generate a high coverage map of DNA-PKcs signaling in response to ionizing radiation and mapped its interplay with the ATM kinase. Beyond the detection of the canonical S/T-Q phosphorylation motif, we uncovered a non-canonical mode of DNA-PKcs signaling targeting S/T-{psi}-D/E motifs. Cross-species analysis in mouse pre-B and human HCT116 cell lines revealed splicing factors and transcriptional regulators phosphorylated at this novel motif, several of which contain SAP domains. These findings expand the list of DNA-PKcs and ATM substrates and establish a novel preferential phosphorylation motif for DNA-PKcs that connects it to proteins involved in nucleotide processes and interactions.

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Marshall, S., Navarro, M., Ascencao, C., Smolka, M. B.. 2024-01-20. In-Depth Mapping of DNA-PKcs Signaling Uncovers Conserved Features of Its Kinase Specificity. https://doi.org/10.1101/2024.01.17.576037

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