Metalloprotease SPRTN/DVC1 Orchestrates Replication-Coupled DNA-Protein Crosslink Removal

Cytotoxicity of DNA-protein crosslinks (DPCs) is ascribed largely to their ability to block the progression of DNA replication fork. DPCs are frequently occurring in cells, either as a consequence of metabolism or exogenous agents. The mechanism of DPCs removal is not completely understood. Here, we characterize SPRTN (DVC1) as specialised DNA-dependent metalloprotease for DPC removal in humans. SPRTN has an N-terminal metalloprotease domain that cleaves various DNA binding substrate during S-phase progression. SPRTN is a part of replisome and removes DPCs during DNA replication fork progression, thus protecting proliferative cells from DPCs toxicity. Ruijs-Aalfs Syndrome (RJALS) patient cells with monogenic mutations in SPRTN are hypersensitive to DPC-inducing agents due to DPC removal defect and DNA replication fork stalling. We propose a model where SPRTN protease forms specialised DNA-replication coupled DPC removal pathway essential for DNA replication fork progression and genome stability. We conclude RJALS is the first human syndrome linked to this pathway