Dynamics of Microtubule Growth and Catastrophe
We investigate a simple model of microtubule dynamics in which a microtubuleevolves by: (i) attachment of guanosine triphosphate (GTP) to its end at ratelambda, (ii) irreversible conversion of GTP to guanosine diphosphate (GDP) atrate 1, and (iii) detachment of GDP from the microtubule end at rate mu. Asa function of these elemental rates, a microtubule can grow steadily or itslength can fluctuate wildly. A master equation approach is developed tocharacterize these rich features. For mu=0, we find the exact tubule and GTPcap length distributions, as well as power-law length distributions of GTPand GDP islands. For mu=oo, we find the average time between catastrophes,where the microtubule shrinks to zero length, and the size distribution ofavalanches (sequence of consecutive GDP detachment events).
work in collaboration with T. Antal, P. Krapivsky, B. Chakraborty, and M. Mailman