| Project Detail |
Mechanistic insight into chromosome separation during cell division
Genomic integrity is key to preserving the genetic information to progeny during cell division. Cells achieve it through a complex process known as chromosome segregation. Errors in this process can lead to chromosomal losses and cause miscarriages, birth defects as well as cancers. Funded by the European Research Council, the CHROMSEG project aims to dissect the molecular mechanism of chromosome segregation. Researchers will investigate how chromosomes bind to microtubules and recruit other proteins to facilitate faithful chromosome separation. The work addresses a fundamental question in molecular biology which has puzzled researchers for years and is integral to the propagation of life.
Accurate chromosome segregation during cell division requires bipolar attachment of sister-chromatids to microtubules emanating from opposite spindle poles and maintenance of sister-chromatid cohesion until all chromosomes achieve bi-orientation. Two chromosomal sites regulate these processes: centromeres, the microtubule attachment sites defined by the enrichment of CENP-A nucleosomes, and the inner centromere, a region between the sister-chromatids that recruits enzymatic activities (kinases, phosphatases and motor proteins). The inner centromere associated enzymes selectively stabilise chromosome-microtubule attachments suitable for chromosome bi-orientation, control sister chromatid cohesion and achieve timely chromosome segregation. Errors in these processes can lead to aneuploidy, a numerical chromosomal aberration implicated in miscarriages, birth defects and cancers. Using an integrative structure-function approach (X-ray crystallography, cryo electron microscopy, Crosslinking/Mass Spectrometry, biochemical/biophysical methods with human cell-line based functional assays), we will obtain detailed mechanistic understanding of: (1) how the inner centromere is assembled, (2) how the inner centromere associated interaction network recruits regulators to achieve chromosome bi-orientation and accurate segregation, and (3) how centromere identity is maintained through multiple generations. This work builds on our recently obtained exciting structural/molecular knowledge that have led to unexpected insights and new questions and will exploit our recently generated battery of molecular reagents. Outcome of our work will provide unprecedented details of centromere-mediated control of chromosome segregation and allow us to build a comprehensive mechanistic model for error-free chromosome segregation, a process that has been fascinating researchers for more than a century. |
