A genetically encoded microtubule bundler for causal dissection of microtubule bundling in cells.
| Title: | A genetically encoded microtubule bundler for causal dissection of microtubule bundling in cells. |
|---|---|
| Authors: | Watari S; Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan.; Department of Cell Biology and Center for Cell Dynamics, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, USA.; Chinen T; Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan.; Kunitatsu Y; Department of Electrical Engineering, Graduate School of Engineering, Nagoya University, Aichi 464-8601, Japan.; Saitou T; Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.; Takahashi Y; Department of Electrical Engineering, Graduate School of Engineering, Nagoya University, Aichi 464-8601, Japan.; Research Institute for Quantum and Chemical Innovation, Institutes of Innovation for Future Society, Nagoya University, Nagoya 464-8601, Japan.; WPI Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa 920-1192, Japan.; Matsuura K; Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan.; Center for Research on Green Sustainable Chemistry, Tottori University, Tottori 680-8552, Japan.; Inoue T; Department of Cell Biology and Center for Cell Dynamics, Johns Hopkins University School of Medicine, 855 North Wolfe Street, Baltimore, MD 21205, USA.; Inaba H; Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan.; Center for Research on Green Sustainable Chemistry, Tottori University, Tottori 680-8552, Japan.; Chromosome Engineering Research Center, Tottori University, Tottori, Japan. |
| Source: | BioRxiv : the preprint server for biology [bioRxiv] 2026 Jan 23. Date of Electronic Publication: 2026 Jan 23. |
| Publication Type: | Journal Article; Preprint |
| Language: | English |
| Journal Info: | Country of Publication: United States NLM ID: 101680187 Publication Model: Electronic Cited Medium: Internet ISSN: 2692-8205 (Electronic) Linking ISSN: 26928205 NLM ISO Abbreviation: bioRxiv Subsets: PubMed not MEDLINE |
| Abstract: | Microtubule (MT) bundling is a conserved organizational feature of the cytoskeleton that accompanies MT stabilization. MT bundling is suggested to engage with diverse cellular processes, including mitosis, migration, and axon morphogenesis. Although microtubule-associated proteins are known to induce MT bundling, whether bundling itself is sufficient to alter MT properties and cellular behavior has remained difficult to address due to the lack of tools that selectively manipulate MT bundling in living cells. Here, we describe the development of a genetically encoded, protein-based "MT-Bundler" by coupling an MT-binding motif to a biologically inert oligomerization scaffold, enabling direct and tunable crosslinking of intracellular MTs. The expression of MT-Bundler consisting of MAP4 and Azami-Green not only drove robust MT bundling but also conferred marked resistance to depolymerization and elevated MT acetylation. Functionally, enforced MT bundling disrupts cell division and migration and suppresses neurite and axon outgrowth. To confirm the causal relationship behind these findings, we further engineered MT-Bundlers to make them chemically and optically inducible to permit rapid, reversible, and spatiotemporally precise control of MT bundling. Acute induction of MT bundling triggers a rapid increase in MT acetylation, implying bundling as an upstream organizational cue that promotes luminal access of the acetyltransferase ATAT1. Notably, MT stabilization persists even in the absence of acetylation, demonstrating that bundling itself is sufficient to mechanically stabilize MTs. Together, these results identify MT bundling as a primary determinant of MT stability and modification, establishing MT-Bundlers as a versatile tool to dissect the mechanistic basis of MT bundling in living cells. |
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| Grant Information: | R35 GM149329 United States GM NIGMS NIH HHS |
| Entry Date(s): | Date Created: 20260206 Date Completed: 20260218 Latest Revision: 20260219 |
| Update Code: | 20260219 |
| PubMed Central ID: | PMC12871790 |
| DOI: | 10.64898/2026.01.22.700042 |
| PMID: | 41648166 |
| Database: | MEDLINE |
Journal Article; Preprint