Hydrolysis-deficient mosaic microtubules as faithful mimics of the GTP cap

Juan Estévez-Gallego (), Thorsten B. Blum, Felix Ruhnow, María Gili, Silvia Speroni, Raquel García-Castellanos, Michel O. Steinmetz and Thomas Surrey ()
Additional contact information
Juan Estévez-Gallego: The Barcelona Institute of Science and Technology
Thorsten B. Blum: Paul Scherrer Institut
Felix Ruhnow: The Barcelona Institute of Science and Technology
María Gili: The Barcelona Institute of Science and Technology
Silvia Speroni: The Barcelona Institute of Science and Technology
Raquel García-Castellanos: The Barcelona Institute of Science and Technology
Michel O. Steinmetz: Paul Scherrer Institut
Thomas Surrey: The Barcelona Institute of Science and Technology

Nature Communications, 2025, vol. 16, issue 1, 1-17

Abstract: Abstract A critical feature of microtubules is their GTP cap, a stabilizing GTP-tubulin rich region at growing microtubule ends. Microtubules polymerized in the presence of GTP analogs or from GTP hydrolysis-deficient tubulin mutants have been used as GTP-cap mimics for structural and biochemical studies. However, these analogs and mutants generate microtubules with diverse biochemical properties and lattice structures, leaving it unclear what is the most faithful GTP mimic and hence the structure of the GTP cap. Here, we generate a hydrolysis-deficient human tubulin mutant, αE254Q, with the smallest possible modification. We show that αE254Q-microtubules are stable, but still exhibit mild mutation-induced growth abnormalities. However, mixing two GTP hydrolysis-deficient tubulin mutants, αE254Q and αE254N, at an optimized ratio eliminates growth and lattice abnormalities, indicating that these ‘mosaic microtubules’ are faithful GTP cap mimics. Their cryo-electron microscopy structure reveals that longitudinal lattice expansion, but not protofilament twist, is the primary structural feature distinguishing the GTP-tubulin containing cap from the GDP-tubulin containing microtubule shaft. However, alterations in protofilament twist may be transiently needed to allow lattice compaction and GTP hydrolysis. Together, our results provide insights into the structural origin of GTP cap stability, the pathway of GTP hydrolysis and hence microtubule dynamic instability.

Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41467-025-57555-6 Abstract (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:natcom:v:16:y:2025:i:1:d:10.1038_s41467-025-57555-6

Ordering information: This journal article can be ordered from
https://www.nature.com/ncomms/

DOI: 10.1038/s41467-025-57555-6

Access Statistics for this article

Nature Communications is currently edited by Nathalie Le Bot, Enda Bergin and Fiona Gillespie

More articles in Nature Communications from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().