Location: HSB G-328, 10:30am (unless otherwise noted)
January 30, 2014
Marija Zanic, Yale University
Host: Stan Froehner
Microtubules are dynamic cytoskeletal polymers essential for cell division, motility, shape and intracellular transport. Remodeling of the microtubule cytoskeleton relies on precise regulation of switching between growth and shrinkage of individual polymers, behavior known as microtubule dynamic instability. I use bottom-up in vitro reconstitution approaches with purified proteins and total-internal-reflection-fluorescence microscopy to elucidate the molecular mechanisms underlying dynamic instability and its regulation. My research showed that microtubules age: the switch between growth and shrinkage requires multiple steps, allowing for greater control of microtubule length distributions. Additionally, I identified a minimal system needed for reconstitution of physiological microtubule growth rates, never previously obtained using purified components. The acceleration of growth is achieved through collective effects of two microtubule-regulating proteins, leading to fast and dynamic microtubule behavior typically observed in cells.