Tuesday, April 28, 2009

Kinetochore geometry defined by cohesion within the centromere

Article
Nature 458, 852-858 (16 April 2009) | doi:10.1038/nature07876; Received 9 September 2008; Accepted 12 February 2009


Kinetochore geometry defined by cohesion within the centromere
Takeshi Sakuno1,2, Kenji Tada1,3 & Yoshinori Watanabe1,3

Laboratory of Chromosome Dynamics, Institute of Molecular and Cellular Biosciences,
Promotion of Independence for Young Investigators,
Graduate Program in Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Yayoi, Tokyo 113-0032, Japan
Correspondence to: Yoshinori Watanabe1,3 Correspondence and requests for materials should be addressed to Y.W. (Email: ywatanab@iam.u-tokyo.ac.jp).


Top of pageAbstractDuring cell division microtubules capture chromosomes by binding to the kinetochore assembled in the centromeric region of chromosomes. In mitosis sister chromatids are captured by microtubules emanating from both spindle poles, a process called bipolar attachment, whereas in meiosis I sisters are attached to microtubules originating from one spindle pole, called monopolar attachment. For determining chromosome orientation, kinetochore geometry or structure might be an important target of regulation. However, the molecular basis of this regulation has remained elusive. Here we show the link between kinetochore orientation and cohesion within the centromere in fission yeast Schizosaccharomyces pombe by strategies developed to visualize the concealed cohesion within the centromere, and to introduce artificial tethers that can influence kinetochore geometry. Our data imply that cohesion at the core centromere induces the mono-orientation of kinetochores whereas cohesion at the peri-centromeric region promotes bi-orientation. Our study may reveal a general mechanism for the geometric regulation of kinetochores, which collaborates with previously defined tension-dependent reorientation machinery.

No comments: