DNA structure-specific priming of ATR activation by DNA-PKcs |
| |
| Authors: | Sophie Vidal-Eychenié Chantal Décaillet Jihane Basbous Angelos Constantinou |
| |
| Institution: | 1.Institute of Human Genetics, Unité Propre de Recherche 1142, Centre National de la Recherche Scientifique, 34396 Montpellier, France;2.Department of Biochemistry, University of Lausanne, 1066 Epalinges s/Lausanne, Switzerland |
| |
| Abstract: | Three phosphatidylinositol-3-kinase–related protein kinases implement cellular responses to DNA damage. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and ataxia-telangiectasia mutated respond primarily to DNA double-strand breaks (DSBs). Ataxia-telangiectasia and RAD3-related (ATR) signals the accumulation of replication protein A (RPA)–covered single-stranded DNA (ssDNA), which is caused by replication obstacles. Stalled replication intermediates can further degenerate and yield replication-associated DSBs. In this paper, we show that the juxtaposition of a double-stranded DNA end and a short ssDNA gap triggered robust activation of endogenous ATR and Chk1 in human cell-free extracts. This DNA damage signal depended on DNA-PKcs and ATR, which congregated onto gapped linear duplex DNA. DNA-PKcs primed ATR/Chk1 activation through DNA structure-specific phosphorylation of RPA32 and TopBP1. The synergistic activation of DNA-PKcs and ATR suggests that the two kinases combine to mount a prompt and specific response to replication-born DSBs. |
| |
| Keywords: | |
|
|
