Cohesin Ubiquitylation and Mobilization Facilitate Stalled Replication Fork Dynamics

Mol Cell. 2017 Nov 16;68(4):758-772.e4. doi: 10.1016/j.molcel.2017.10.012. Epub 2017 Nov 9.


Replication fork integrity is challenged in conditions of stress and protected by the Mec1/ATR checkpoint to preserve genome stability. Still poorly understood in fork protection is the role played by the structural maintenance of chromosomes (SMC) cohesin complex. We uncovered a role for the Rsp5Bul2 ubiquitin ligase in promoting survival to replication stress by preserving stalled fork integrity. Rsp5Bul2 physically interacts with cohesin and the Mec1 kinase, thus promoting checkpoint-dependent cohesin ubiquitylation and cohesin-mediated fork protection. Ubiquitylation mediated by Rsp5Bul2 promotes cohesin mobilization from chromatin neighboring stalled forks, likely by stimulating the Cdc48/p97 ubiquitin-selective segregase, and its timely association to nascent chromatids. This Rsp5Bul2 fork protection mechanism requires the Wpl1 cohesin mobilizer as well as the function of the Eco1 acetyltransferase securing sister chromatid entrapment. Our data indicate that ubiquitylation facilitates cohesin dynamic interfacing with replication forks within a mechanism preserving stalled-fork functional architecture.

Keywords: Cdc148/p97; DNA replication; checkpoint; chromosome dynamics; cohesin; genome integrity; replication forks; replication stress.

MeSH terms

  • Acetyltransferases / genetics
  • Acetyltransferases / metabolism
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Chromosomal Proteins, Non-Histone / genetics
  • Chromosomal Proteins, Non-Histone / metabolism*
  • DNA Replication / physiology*
  • DNA, Fungal / biosynthesis*
  • DNA, Fungal / genetics
  • Endosomal Sorting Complexes Required for Transport / genetics
  • Endosomal Sorting Complexes Required for Transport / metabolism
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism
  • Ubiquitin-Protein Ligase Complexes / genetics
  • Ubiquitin-Protein Ligase Complexes / metabolism
  • Ubiquitination / physiology*
  • Valosin Containing Protein / genetics
  • Valosin Containing Protein / metabolism


  • Cell Cycle Proteins
  • Chromosomal Proteins, Non-Histone
  • DNA, Fungal
  • Endosomal Sorting Complexes Required for Transport
  • Intracellular Signaling Peptides and Proteins
  • Nuclear Proteins
  • RAD61 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • cohesins
  • Acetyltransferases
  • ECO1 protein, S cerevisiae
  • Ubiquitin-Protein Ligase Complexes
  • MEC1 protein, S cerevisiae
  • Protein Serine-Threonine Kinases
  • CDC48 protein, S cerevisiae
  • Valosin Containing Protein
  • RSP5 protein, S cerevisiae