Tubulin isoform composition tunes microtubule dynamics

摘要: Microtubules polymerize and depolymerize stochastically, a behavior essential for cell division, motility, differentiation. While many studies advanced our understanding of how microtubule-associated proteins tune microtubule dynamics in trans, we have yet to understand tubulin genetic diversity regulates functions. The majority vitro are performed with purified from brain tissue. This preparation is not representative found types. Here report the 4.2-A cryo-electron microscopy (cryo-EM) structure parameters α1B/βI+βIVb microtubules assembled human embryonic kidney line isoform composition characteristic fibroblasts immortalized lines. We find that these grow faster transition depolymerization less frequently compared microtubules. Cryo-EM reveals dynamic ends tapered heterodimers display lower curvatures. Interestingly, analysis EB1 distributions at suggests no differences GTP cap sizes. Last, show addition recombinant α1A/βIII tubulin, neuronal isotype overexpressed tumors, proportionally tunes Our study an important step toward dynamics.