Dr. Elif Nur Fırat Karalar
October 18th, 2012(Thursday)
Centrosomes: Understanding their organization and regulation in cells
Centrioles are part of two distinct structures: the centrosome that organizes the interphase microtubule network and the mitotic spindle, and the basal body at the base of the primary cilium, which is a nexus for growth factor signaling pathways.
To gain molecular insights into the function and assembly of centrioles, we sought to determine the composition of the centriole proteome. Here, I describe a method that allows isolation of centrioles from the mammalian sperm cells. Proteomic analysis of this material identified known centriole proteins, as well as previously uncharacterized centriole proteins. Centrosome abnormalities are associated with a variety of human diseases including cancer. The mechanism by which cancer cells acquire an abnormal number of centrosomes is poorly understood. Here, I present evidence for missegregation of centrosomes on the spindle poles during cell division as a mechanism for centrosome number abnormalities in cancer cells. We are currently investigating the mechanisms that ensure equal segregation of centrosomes using Xenopus egg extract system and a targeted siRNA screen in mammalian cells.