The nucleolar protein GNL3 prevents resection of stalled replication forks.

Faithful DNA replication requires specific proteins that protect replication forks and so prevent the formation of DNA lesions that may damage the genome. Identification of new proteins involved in this process is essential to understand how DNA lesions accumulate in cancer cells and how they tolerate them. Here, we show that human GNL3/nucleostemin, a GTP-binding protein localized mostly in the nucleolus and highly expressed in cancer cells, prevents nuclease-dependent resection of nascent DNA in response to replication stress.