Title:
Condensin-based chromosome organization

 

Speaker:
Tatsuya Hirano
Chromosome Dynamics Laboratory, RIKEN, Japan

 

Abstract:
The assembly of mitotic chromosomes, each composed of a pair of rod-shaped chromatids, is an essential prerequisite for accurate transmission of the genome during cell division. It is not fully understood, however, how this fundamental process might be achieved and regulated in the cell. Two decades ago, by using Xenopus (African toad) egg cell-free extracts in which mitotic chromosomes can be assembled in a test tube, we discovered the condensin complex (now known as condensin I). This and subsequent studies established that condensin I is the key player in the process of mitotic chromosome assembly, from yeast to humans, and that a second condensin complex (condensin II) is an auxiliary factor that is utilized differently among different species. Most recently, we have devised an in vitro system in which mitotic chromosomes can be reconstituted by mixing a simple substrate with only six purified factors including condensin I. In this talk, I will start with historical backgrounds of chromosome research, and move on to discuss most recent findings regarding how condensins and nucleosomes might collaborate to assemble fully compacted chromosomes.

 

References:
Kinoshita, K., T. J. Kobayashi, and T. Hirano, Dev. Cell. 33:94-106 (2015).
Shintomi, K., T. S. Takahashi, and T. Hirano, Nat. Cell Biol. 17:1014-1023 (2015).
Hirano, T., Cell. 164:847-857 (2016)