.Stat.M ech.(2007)L05004 ournal of Statistical Mechanics: An IOP and SISSA journalJ Theory and Experiment LETTER Dynamics of microtubule instabilities

doi:10.1088/1742-5468/2007/05/L05004 Abstract. We investigate an idealized model of microtubule dynamics that involves: (i) attachment of guanosine triphosphate (GTP) at rate λ, (ii) conversion of GTP to guanosine diphosphate (GDP) at rate 1, and (iii) detachment of GDP at rate μ. As a function of these rates, a microtubule can grow steadily or its length can fluctuate wildly. For μ = 0, we find the exact tubule and GTP cap length distributions, and power-law length distributions of GTP and GDP islands. For μ =∞, we argue that the time between catastrophes, where the microtubule shrinks to zero length, scales as eλ. We also discuss the nature of the phase boundary between a growing and shrinking microtubule