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Cited by 8Microtubule and mitosis dynamicsCancer Treatment and PharmacologyAdvanced Electron Microscopy Techniques and Applications

Microtubules in the axon are GDP bound but adopt a stable GTP-like expanded state

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Zehr, Elena A., Sun, Shufeng, Sarbanes, Stephanie L., Roll-Mecak, Antonina·2026·Nature Structural & Molecular Biology
DOI 10.1038/s41594-026-01787-7PMC PMC13095656
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Abstract

Microtubules scaffold cells, supporting signaling and cargo transport. They assemble from GTP–tubulin, which hydrolyzes to GDP–tubulin during polymerization. GTP–microtubule lattices are stable; GDP lattices depolymerize rapidly. In vitro, hydrolysis triggers lattice compaction. Lattice spacing regulates motors and microtubule-associated proteins; however, the conformation of tubulin in microtubules in cells is unknown. Here, we present the atomic-resolution cryo-electron microscopy structure of human microtubules in situ, in the axons of human cortical neurons derived from induced pluripotent stem cells (iPS cells). Our 2.7-Å-resolution reconstruction delineates bound water molecules and reveals that axonal microtubules adopt an expanded GTP-like lattice, despite being GDP bound. Using cryo-electron tomography and power spectrum analysis, we find that, unlike in axons, microtubules in undifferentiated iPS cells are compacted. Therefore, lattice expansion is part of neuronal differentiation. Our work provides molecular insights into neurogenesis and has implications for understanding microtubule stability and effector recruitment in neurons.

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  • Recent work reported that axonal microtubules in human iPSC-derived neurons are GDP-bound yet adopt an expanded, GTP-like lattice, indicating that lattice spacing is not determined solely by nucleotide state.

    “Recent work reported that axonal microtubules in human iPSC-derived neurons are GDP-bound yet adopt an expanded, GTP-like lattice, indicating that lattice spacing is not determined solely by nucleotide state52.”

    From Ghost Neuron preparation unlocks high-resolution structural mapping of intracellular architecture in axons (2026) · cites this paper as [52]

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Cited by

Sorted by citations

Authors
Zehr, E. A., Sun, S., Sarbanes, S. L., & Roll-Mecak, A.
Affiliations
National Institute of Neurological Disorders and Stroke (US)
ORCID
Venue
Nature Structural & Molecular Biology
Publisher
Springer Science and Business Media LLC
Published
2026-04
Volume
33
Issue
4
Pages
631-640
ISSN
  • 1545-9985 (ISSN-L)
  • 1545-9993
DOI
10.1038/s41594-026-01787-7
PMC
PMC13095656
OpenAlex
W7151889715
Cited by
8
References
3
Citations by year
2026: 8
FWCI
22.04
Type
journal article
Language
en
Open access
Licence
Locations
  • Nature Structural & Molecular Biology (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • PubMed Central (publishedVersion, cc-by)
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › Microtubule and mitosis dynamics
  • Health Sciences › Medicine › Oncology › Cancer Treatment and Pharmacology
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Structural Biology › Advanced Electron Microscopy Techniques and Applications
Keywords
microtubules, axons, GDP-tubulin, GTP hydrolysis, tubulin conformation, neuronal differentiation, induced pluripotent stem cells, cortical neurons, microtubule stability, microtubule-associated proteins, neurogenesis
MeSH terms
Axons, Guanosine Diphosphate, Guanosine Triphosphate, Humans, Microtubules, Neurons, Tubulin, Cryoelectron Microscopy, Neurogenesis, Induced Pluripotent Stem Cells

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