Minichromosome maintenance protein (Mcm) 10 is a part of the eukaryotic replication machinery and highly conserved throughout evolution. As a multivalent DNA scaffold, Mcm10 coordinates the action of proteins that are indispensable for lagging strand synthesis, such as the replication clamp, proliferating cell nuclear antigen (PCNA). The binding between Mcm10 and PCNA serves an essential function during DNA elongation and is mediated by the ubiquitination of Mcm10. Here we map lysine 372 as the primary attachment site for ubiquitin on S. cerevisiae Mcm10. Moreover, we identify five additional lysines that can be ubiquitinated. Mutation of lysine 372 to arginine ablates ubiquitination of overexpressed protein and causes sensitivity to the replication inhibitor hydroxyurea in cells that are S-phase checkpoint compromised. Together, these findings reveal the high selectivity of the ubiquitination machinery that targets Mcm10 and that ubiquitination has a role in suppressing replication stress.
Bibliographical noteFunding Information:
We would like to thank members of the Bielinsky laboratory for helpful discussions. This work was supported by NIH grant GM074917 (AKB), an IDeA Award from NIGMS (SDB) and a NSU Faculty Research Grant (SDB). The authors wish to acknowledge technical support by Alex Pretti and the Center for Mass Spectrometry and Proteomics at the University of Minnesota.
© 2016 The Authors
- 9-1-1 checkpoint clamp
- DNA replication