Removal of RTF2 from Stalled Replisomes Promotes Maintenance of Genome Integrity

• Published in: Molecular cell Vol. 69; no. 1; pp. 24 - 35.e5
• Main Authors: Kottemann, Molly C., Conti, Brooke A., Lach, Francis P., Smogorzewska, Agata
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 04.01.2018
• Subjects: aphidicolin; Aspartic Acid Proteases - genetics; C20orf43; Cell Cycle - genetics; Cell Cycle Proteins - genetics; Cell Cycle Proteins - metabolism; Cell Line, Tumor; DDI1; DDI2; DNA - biosynthesis; DNA - genetics; DNA Damage - genetics; DNA Repair - genetics; DNA replication; DNA Replication - genetics; DNA, Single-Stranded - metabolism; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Genomic Instability - genetics; HeLa Cells; Humans; hydroxyurea; iPOND; Replication Origin - genetics; replication stress; RNA Interference; RNA, Small Interfering - genetics; RTF2; Stress, Physiological - genetics; ubiquitin proteasome system; C20orf43; DNA replication; replication stress; iPOND; hydroxyurea; aphidicolin; DDI2; DDI1; ubiquitin proteasome system; RTF2
• ISSN: 1097-2765; 1097-4164
• DOI: 10.1016/j.molcel.2017.11.035

The protection and efficient restart of stalled replication forks is critical for the maintenance of genome integrity. Here, we identify a regulatory pathway that promotes stalled forks recovery from replication stress. We show that the mammalian replisome component C20orf43/RTF2 (homologous to S. pombe Rtf2) must be removed for fork restart to be optimal. We further show that the proteasomal shuttle proteins DDI1 and DDI2 are required for RTF2 removal from stalled forks. Persistence of RTF2 at stalled forks results in fork restart defects, hyperactivation of the DNA damage signal, accumulation of single-stranded DNA (ssDNA), sensitivity to replication drugs, and chromosome instability. These results establish that RTF2 removal is a key determinant for the ability of cells to manage replication stress and maintain genome integrity. [Display omitted] •DDIs are required for cellular survival following replication stress•DDIs remove the replisome component C20orf43/RTF2 from stalled forks•RTF2 removal from stalled forks is required for genome stability Recovery of normal DNA replication after encountering obstacles to replication fork progression is a critical aspect of protecting the genome from damage. Kottemann et al. identify RTF2, a replisome component that must be removed by the proteasome shuttles DDI1 and DDI2 to allow an effective response to replication stress.