Grant: CIHR New Investigator

The most critical moment in the life of a cell is when it separates its replicated chromosomes into two daughter cells. Errors in the timing of this event can be catastrophic and lead to the damage and loss of chromosomes, both of which can lead to the generation of a cancerous cell. A similar error in a maturing egg can lead to devastating chromosomal disorders, like Down syndrome. How do cells integrate different signals, such as the size and environment of the cell, or if the cell's chromosomes are fully replicated and properly attached to the division machinery, to determine when to separate its chromosomes? My hypothesis is that a complex of proteins, called the anaphase promoting complex or APC, keeps track of this information by the addition or removal of special marks, called phosphorylation, on members of this complex. I want to determine how many different marks there are, how they change during the life of the cell and what happens when they are never added. Understanding how the APC keeps track of this information will lead to a greater understanding of why errors occur during chromosome separation and how we can prevent these errors from ever happening.