(A) Microtubule associated proteins (MAPs) that alter microtubule dynamics. Tip-tracking proteins (top) can be specific to either the plus- or minus-end, and can alter either microtubule growth rates, growth lifetimes, or both (denoted by arrows). Motors and microtubule severing enzymes (bottom) can enhance lattice turnover and enable formation of GTP islands. Motor binding can also drive expansion of the lattice.
(B) Mammalian microtubules are formed from a number of different α- and β-tubulin isotypes, creating a mosaic microtubule lattice. Each isotype has its own unique impact on the structure, kinetics, and stability of the microtubules. Each tubulin isotype can be post-translationally modified, which can influence microtubule structure and dynamics.