Fig. 1

Kinetic model of MT growth adapted from Hill, 1984 [4]. G_i and S_i are the concentrations of growing and shrinking microtubules containing i number of tubulin dimers. C₀ indicates MTs with zero length. J₁ and J₂ are the kinetic constants of growth and shrinking, respectively; k₁, k₂ are the constants for rates of growth-to-shrinking and shrinking-to-growth transitions. Growing and shrinking MTs are depicted as bars, and tubulin dimers are shown as shaded bars