Fig. 2

Action of Cl⁻ on dynamics of tubulin polymerization and depolymerization. A Cl⁻ suppresses conversion of GTP-ß-tubulin to GDP-ß-tubulin by inhibiting GTPase. B a In most cells, tubulin is present in concentrations of 10–20 μM, favoring the assembly of microtubules at the plus end. In filaments with slower growth rates, there is less lateral interaction between protofilaments. The inherent curvature of the GDP-tubulin dimer surface gives the appearance of fraying at this end. b High [Cl⁻]_c stabilizes GTP-ß-tubulin by blocking GTPase activity [21], and leads to a condition of a higher concentrations of GTP-tubulin dimers. Thus, tubulin polymerization is promoted at the plus end by forming a rigid GTP-cap. c GTPase increases at low [Cl⁻]_c. This leads to concerted GTP hydrolysis, weakening the tubulin dimer interactions, and rapidly disassembling tubulin polymerization. This figure is produced using the result obtained in a report by Nakajima et al. [21] combining information shown in ‘What is microtubule dynamic instability?’ by MBINFO DEFINING MECHANOBIOLOGY (see the information shown in “https://www.mechanobio.info/cytoskeleton-dynamics/what-is-the-cytoskeleton/what-are-microtubules/what-microtubule-dynamic-instability/#what-is-microtubule-dynamic-instability”) under a Creative Commons Attribution-NonCommercial 4.0 International License