Structural state recognition facilitates tip tracking of EB1 at growing microtubule ends

eLife

Kyle White¹  Naomi Courtemanche²  Courtney Coombes³  Marija Zanic³  Melissa K Gardner³  Sneha Parmar³  Taylor A Reid³  Soumya Mukherjee³  Mark McClellan³  Rebecca R Goldblum⁴ 

[1] Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, United States;Department of Cell and Developmental Biology, Vanderbilt University, Nashville, United States;Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, United States;Medical Scientist Training Program, University of Minnesota, Minneapolis, United States;

关键词: microtubule;    tip tracking;    EB1;    systems modeling;    diffusion;    tubulin;   

DOI  :  10.7554/eLife.48117

来源: DOAJ

【 摘 要 】

The microtubule binding protein EB1 specifically targets the growing ends of microtubules in cells, where EB1 facilitates the interactions of cellular proteins with microtubule plus-ends. Microtubule end targeting of EB1 has been attributed to high-affinity binding of EB1 to GTP-tubulin that is present at growing microtubule ends. However, our 3D single-molecule diffusion simulations predicted a ~ 6000% increase in EB1 arrivals to open, tapered microtubule tip structures relative to closed lattice conformations. Using quantitative fluorescence, single-molecule, and electron microscopy experiments, we found that the binding of EB1 onto opened, structurally disrupted microtubules was dramatically increased relative to closed, intact microtubules, regardless of hydrolysis state. Correspondingly, in cells, the blunting of growing microtubule plus-ends by Vinblastine was correlated with reduced EB1 targeting. Together, our results suggest that microtubule structural recognition, based on a fundamental diffusion-limited binding model, facilitates the tip tracking of EB1 at growing microtubule ends.

【 授权许可】

Unknown