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bioRxiv · 10.1101/590869

Mechanisms of motor-independent membrane remodeling driven by dynamic microtubules

Rodriguez-Garcia, R.·Volkov, V. A.·Chen, C.-Y.·Katrukha, E. A.·Olieric, N.·Aher, A.·Grigoriev, I.·Preciado Lopez, M.·Steinmetz, M. O.·Kapitein, L. C.·Koenderink, G.·Dogterom, M.·Akhmanova, A.
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Abstract

Microtubule-dependent organization of membranous organelles, such as the endoplasmic reticulum, occurs through motor-based pulling and by coupling microtubule dynamics to membrane remodeling. How highly transient protein-protein interactions occurring at growing microtubule tips can induce load-bearing processive motion is currently unclear. Here, we reconstituted membrane tubulation in a minimal system with giant unilamellar vesicles, dynamic microtubules, End-Binding (EB) proteins and a membrane-targeted protein that interacts with EBs and microtubules. We showed that these components are sufficient to drive membrane remodeling by three mechanisms: membrane tubulation by growing microtubule ends, motor-independent membrane sliding along microtubule shafts and pulling by shrinking microtubules. Experiments and modeling demonstrated that the first two mechanisms can be explained by adhesion-driven biased membrane spreading on microtubules. Force spectroscopy revealed that attachments to growing and shrinking microtubule ends can sustain forces of [~]0.5 and [~]5 pN, respectively. Rapidly exchanging molecules that connect membranes to dynamic microtubules can thus bear sufficient load to induce membrane deformation and motility.

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Rodriguez-Garcia, R., Volkov, V. A., Chen, C.-Y., Katrukha, E. A., Olieric, N., Aher, A., Grigoriev, I., Preciado Lopez, M., Steinmetz, M. O., Kapitein, L. C., Koenderink, G., Dogterom, M., Akhmanova, A.. 2019-03-27. Mechanisms of motor-independent membrane remodeling driven by dynamic microtubules. https://doi.org/10.1101/590869

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