Journal
CURRENT BIOLOGY
Volume 16, Issue 15, Pages 1571-1578Publisher
CELL PRESS
DOI: 10.1016/j.cub.2006.06.068
Keywords
-
Categories
Ask authors/readers for more resources
Cohesin is a multisubunit protein complex that links sister chromatids from replication until segregation [1, 2]. The lack of obvious cohesin-targeting-specific sequences on DNA [3-5], as well as cohesin's molecular arrangement as a large ring [6-8], has led to the working hypothesis that cohesin acts as a direct topological linker [9, 10]. To preserve the identity of sister chromatids, such a linkage would need to stably persist throughout the entire S and G2 phases of the cell cycle. Unexpectedly, cohesin binds chromatin already in telophase, and a large fraction dissociates from chromosomes during prophase in a phosphorylation-dependent manner [11-17], whereas initiation of anaphase requires proteolytic cleavage of only a small fraction of cohesin [18,19]. These observations raised the question of how and when cohesin interacts with chromatin during the cell cycle. Here, we report a cell-cycle dependence in the stability of cohesin binding to chromatin. Using photobleaching and quantitative live-cell imaging, we identified several cohesin pools with different chromatin binding stabilities. Although all chromatin bound cohesin dissociated after a mean residence time of less than 25 min before replication, about one-third of cohesin was bound much more stably after S phase and persisted until metaphase, consistent with long-lived links mediating cohesion between sister chromatids.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available