2. Academic Validation
  3. SPRTN protease and checkpoint kinase 1 cross-activation loop safeguards DNA replication

SPRTN protease and checkpoint kinase 1 cross-activation loop safeguards DNA replication

  • Nat Commun. 2019 Jul 17;10(1):3142. doi: 10.1038/s41467-019-11095-y.
Swagata Halder 1,  Ignacio Torrecilla 1,  Martin D Burkhalter 2 3,  Marta Popović 1 4,  John Fielden 1,  Bruno Vaz 1,  Judith Oehler 1,  Domenic Pilger 1,  Davor Lessel 5,  Katherine Wiseman 1,  Abhay Narayan Singh 1,  Iolanda Vendrell 1 6,  Roman Fischer 6,  Melanie Philipp 2 3,  Kristijan Ramadan 7
Affiliations

Affiliations

  • 1 Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK.
  • 2 Institute of Biochemistry and Molecular Biology, Ulm University, Albert-Einstein-Allee 11, 89081, Ulm, Germany.
  • 3 Department of Experimental and Clinical Pharmacology and Pharmacogenomics, University of Tübingen, 72074, Tübingen, Germany.
  • 4 Institute Ruder Boškovic, Bijenička Cesta 54, 10000, Zagreb, Croatia.
  • 5 Institute of Human Genetics, University Medical Center Hamburg-Eppendorf, 20246, Hamburg, Germany.
  • 6 TDI Mass Spectrometry Laboratory, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7FZ, UK.
  • 7 Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK. [email protected].
PMID: 31316063 DOI: 10.1038/s41467-019-11095-y
Abstract

The SPRTN metalloprotease is essential for DNA-protein crosslink (DPC) repair and DNA replication in vertebrate cells. Cells deficient in SPRTN protease exhibit DPC-induced replication stress and genome instability, manifesting as premature ageing and liver Cancer. Here, we provide a body of evidence suggesting that SPRTN activates the ATR-CHK1 phosphorylation signalling cascade during physiological DNA replication by proteolysis-dependent eviction of Chk1 from replicative chromatin. During this process, SPRTN proteolyses the C-terminal/inhibitory part of Chk1, liberating N-terminal Chk1 kinase active fragments. Simultaneously, Chk1 full length and its N-terminal fragments phosphorylate SPRTN at the C-terminal regulatory domain, which stimulates SPRTN recruitment to chromatin to promote unperturbed DNA replication fork progression and DPC repair. Our data suggest that a SPRTN-CHK1 cross-activation loop plays a part in DNA replication and protection from DNA replication stress. Finally, our results with purified components of this pathway further support the proposed model of a SPRTN-CHK1 cross-activation loop.

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