Molecular mechanisms of kinetochore motion along a microtubule in early mitosis (360G-Wellcome-105308_Z_14_Z)

To prepare for chromosome segregation in mitosis, chromosomes must be collected to the spindle in an earlier stage of mitosis. This process is dependent on kinetochore-microtubule (KT -MT) interaction: KTs initially interact with the lateral side of a MT and move along the MT (KT sliding) towards the spindle. KT sliding is driven by KT-associated MT-minus end-directed motors, dynein in animal cells and Kar3 (Kinesin-14) in budding yeast. However, detailed mechanisms of KT sliding are not yet known. Here, I will address how Kar3 drives KT sliding along a MT in early mitosis, using budding yeast as a model organism. I will elucidate what conformation Kar3 takes (homodimer or heterodimer) at KTs, how such conformation is determined at KTs and how Kar3 is recruited to KTs. I will also recapitulate and characterize Kar3 conformation and function at KTs in vitro, using a single molecule analysis. Kar3 offers a popular model of a MT-minus end-directed kinesin, and my study will shed a new light on how a MTminus end-directed kinesin drives transport of a cargo along a MT. My study will also elucidate molecular mechanisms of KT sliding along a MT that is a biologically important but still elusive process.