article published yes Jamie Rickman author Christian F Düllberg author 459064DC-F248-11E8-B48F-1D18A9856A870000-0001-6335-9748 Nicholas Cade author Lewis Griffin author Thomas Surrey author MaLo department Growing microtubules are protected from depolymerization by the presence of a GTP or GDP/Pi cap. End-binding proteins of the EB1 family bind to the stabilizing cap, allowing monitoring of its size in real time. The cap size has been shown to correlate with instantaneous microtubule stability. Here we have quantitatively characterized the properties of cap size fluctuations during steadystate growth and have developed a theory predicting their timescale and amplitude from the kinetics of microtubule growth and cap maturation. In contrast to growth speed fluctuations, cap size fluctuations show a characteristic timescale, which is defined by the lifetime of the cap sites. Growth fluctuations affect the amplitude of cap size fluctuations; however, cap size does not affect growth speed, indicating that microtubules are far from instability during most of their time of growth. Our theory provides the basis for a quantitative understanding of microtubule stability fluctuations during steady-state growth. National Academy of Sciences2017 eng 0027-8424 28280102 00039760730006510.1073/pnas.1620274114 114133427 - 3432 Rickman, Jamie, Christian F Düllberg, Nicholas Cade, Lewis Griffin, and Thomas Surrey. “Steady State EB Cap Size Fluctuations Are Determined by Stochastic Microtubule Growth and Maturation.” <i>PNAS</i>. National Academy of Sciences, 2017. <a href="https://doi.org/10.1073/pnas.1620274114">https://doi.org/10.1073/pnas.1620274114</a>. Rickman J, Düllberg CF, Cade N, Griffin L, Surrey T. 2017. Steady state EB cap size fluctuations are determined by stochastic microtubule growth and maturation. PNAS. 114(13), 3427–3432. J. Rickman, C.F. Düllberg, N. Cade, L. Griffin, T. Surrey, PNAS 114 (2017) 3427–3432. Rickman J, Düllberg CF, Cade N, Griffin L, Surrey T. Steady state EB cap size fluctuations are determined by stochastic microtubule growth and maturation. <i>PNAS</i>. 2017;114(13):3427-3432. doi:<a href="https://doi.org/10.1073/pnas.1620274114">10.1073/pnas.1620274114</a> J. Rickman, C. F. Düllberg, N. Cade, L. Griffin, and T. Surrey, “Steady state EB cap size fluctuations are determined by stochastic microtubule growth and maturation,” <i>PNAS</i>, vol. 114, no. 13. National Academy of Sciences, pp. 3427–3432, 2017. Rickman, Jamie, et al. “Steady State EB Cap Size Fluctuations Are Determined by Stochastic Microtubule Growth and Maturation.” <i>PNAS</i>, vol. 114, no. 13, National Academy of Sciences, 2017, pp. 3427–32, doi:<a href="https://doi.org/10.1073/pnas.1620274114">10.1073/pnas.1620274114</a>. Rickman, J., Düllberg, C. F., Cade, N., Griffin, L., &#38; Surrey, T. (2017). Steady state EB cap size fluctuations are determined by stochastic microtubule growth and maturation. <i>PNAS</i>. National Academy of Sciences. <a href="https://doi.org/10.1073/pnas.1620274114">https://doi.org/10.1073/pnas.1620274114</a> 6602018-12-11T11:47:46Z2025-09-11T07:08:20Z