GENE 540 Midterm: Mitotic Spindles & Cohesins
Document Summary
Microtubules (mt) capture chromosomes by attaching to the kinetochore, a protein structure at the centromere. During prophase the centrosome migrates on opposite sides of the cell; then both of them will make microtubules in prometaphase. Then the microtubules will capture the chromosomes by attaching to the kinetochore; each sister chromatid has a kinetochore (microtubules attach here) First, there is microtubules polymerization and depolymerization. When dynein (attached to the membrane) walk towards the negative end, they are pulling in the entire structure. Microtubules will pull the sister chromatids apart; the regulation system needs to make sure that microtubules are attached appropriately with the correct kinetochore. Hence there has to be some sort of regulatory mechanism. The microtubules are attached to the kinetochore via the ndc80 protein complex. This strengthens the mt-kinetochore interaction bound mt remain bound: the tension is thought to pull the ndc80 phosphorylation sites away from the aurora.
