The native structure of the Trichonympha centriole cartwheel reveals a zigzag stacking pattern.

Authors

Carlee M Rowsell, Shintaroh Kubo, Asuva Arin, Thibault Legal, Molly Yining Yu, Khanh Huy Bui

Published in

Proceedings of the National Academy of Sciences of the United States of America. Volume 123. Issue 37. Pages e2612170123. Sep 15, 2026. Epub Sep 08, 2026.

Abstract

Centrioles are essential cellular organelles with complex architectures. Their earliest assembly intermediate-the cartwheel-has a ninefold symmetry established by Spindle assembly abnormal protein 6 (SAS-6). Using cryoelectron tomography and subtomogram averaging, we resolved the native structure of the SAS-6 rings within the cartwheel of the exceptionally long Trichonympha proximal centriole, identifying a 16-nm axial periodicity was formed by stacked rings of V-shaped SAS-6 tetramers, which comprise the fundamental unit of the cartwheel central hub. Within these stacked rings, SAS-6 N-terminal head domains adopted a zigzag stacking pattern. Additionally, our improved resolution provides insights into the function of the previously observed cartwheel inner density, nine asymmetric densities that bridge adjacent tetramers, potentially imparting polarity and enhancing structural stability. Molecular dynamics simulations indicate increased rigidity in intertetramer interactions, supporting efficient ring formation and revealing how cartwheel architecture and polarity are established and stabilized.

PMID:
42709820
Bibliographic data and abstract were imported from PubMed on 09 Sep 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.