Scc2/Nipbl hops between chromosomal cohesin rings after loading.

Journal article

The cohesin complex mediates DNA-DNA interactions both between (sister chromatid cohesion) and within chromosomes (DNA looping). It has been suggested that intra-chromosome loops are generated by extrusion of DNAs through the lumen of cohesin's ring. Scc2 (Nipbl) stimulates cohesin's ABC-like ATPase and is essential for loading cohesin onto chromosomes. However, it is possible that the stimulation of cohesin's ATPase by Scc2 also has a post-loading function, for example driving loop extrusion. Using fluorescence recovery after photobleaching (FRAP) and single- molecule tracking, we show that Scc2 binds dynamically to chromatin, principally through an association with cohesin. Scc2's movement within chromatin is consistent with a 'stop-and-go' or 'hopping' motion. We suggest that a low diffusion coefficient, a low stoichiometry relative to cohesin, and a high affinity for chromosomal cohesin enables Scc2 to move rapidly from one chromosomal cohesin complex to another, performing a function distinct from loading.

Authors: Rhodes, J; Mazza, D; Nasmyth, K; Uphoff, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: eLife Sciences
• Journal: eLife More from this journal
• Volume: 6
• Pages: e30000
• Publication date: 2017-09-01
• Acceptance date: 2017-09-08
• DOI: 10.7554/elife.30000
• EISSN: 2050-084X
• Pmid: 28914604
• Language: English
• Keywords: chromosomes; human; genes