Figure 4.
Scheme of microtubule formation and dynamic instability. Microtubules consist of α- and β-heterodimers, forming a hollow tube elongating by the addition of heterodimers, forming a GTP-cap at the (+)-end of the microtubule, protecting microtubules from shrinkage. If the (+)-end loses its GTP-cap it induces microtubule shrinkage.