Cohesin is a ring‐shaped protein complex that plays a crucial role in sister chromatid cohesion and gene expression. The dynamic association of cohesin with chromatin is essential for these functions. However, the exact nature of cohesin dynamics, particularly cohesin translocation, remains unclear. We evaluated the dynamics of individual cohesin molecules on DNA and found that the cohesin core complex possesses an intrinsic ability to traverse DNA in an adenosine triphosphatase (ATPase)‐dependent manner. Translocation ability is suppressed in the presence of Wapl‐Pds5 and Sororin; this suppression is alleviated by the acetylation of cohesin and the action of mitotic kinases. In Xenopus laevis egg extracts, cohesin is translocated on unreplicated DNA in an ATPase‐ and Smc3 acetylation‐dependent manner. Cohesin movement changes from bidirectional to unidirectional when cohesin faces DNA replication; otherwise, it is incorporated into replicating DNA without being translocated or is dissociated from replicating DNA. This study provides insight into the nature of individual cohesin dynamics and the mechanisms by which cohesin achieves cohesion in different chromatin contexts.
Single‐molecule observations of individual cohesin rings on DNA define how regulatory factors such as acetylation, Wapl‐Pds5, and Sororin, as well as DNA replication influence cohesin translocation in vitro and in Xenopus egg extracts.
Scc2‐Scc4‐dependent topological loading of cohesin is required for cohesin translocation along DNA.
Acetylation of cohesin by Esco1 (or Xenopus XEco2) promotes cohesin translocation along DNA and chromatin.
Cohesin translocation is suppressed by Wapl‐Pds5 and Sororin, and facilitated by Aurora B‐mediated phosphorylation.
Cohesin is preferentially present and translocated in nucleosome‐poor region of unreplicated chromatin.
Upon DNA replication, cohesin is either (i) stalled and incorporated into replicating DNA, (ii) translocated with replication, or (iii) dissociated from replicating DNA.
- Received September 19, 2016.
- Revision received November 4, 2016.
- Accepted November 7, 2016.
- © 2016 The Authors