Ciliopathy patient variants reveal organelle-specific functions for TUBB4B in axonemal microtubules

Science. 2024 Apr 26;384(6694):eadf5489. doi: 10.1126/science.adf5489. Epub 2024 Apr 26.


Tubulin, one of the most abundant cytoskeletal building blocks, has numerous isotypes in metazoans encoded by different conserved genes. Whether these distinct isotypes form cell type- and context-specific microtubule structures is poorly understood. Based on a cohort of 12 patients with primary ciliary dyskinesia as well as mouse mutants, we identified and characterized variants in the TUBB4B isotype that specifically perturbed centriole and cilium biogenesis. Distinct TUBB4B variants differentially affected microtubule dynamics and cilia formation in a dominant-negative manner. Structure-function studies revealed that different TUBB4B variants disrupted distinct tubulin interfaces, thereby enabling stratification of patients into three classes of ciliopathic diseases. These findings show that specific tubulin isotypes have distinct and nonredundant subcellular functions and establish a link between tubulinopathies and ciliopathies.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Axoneme* / metabolism
  • Centrioles* / metabolism
  • Cilia* / metabolism
  • Ciliary Motility Disorders* / genetics
  • Ciliary Motility Disorders* / metabolism
  • Female
  • Humans
  • Male
  • Mice
  • Mice, Knockout
  • Mutation
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Tubulin* / genetics
  • Tubulin* / metabolism


  • Protein Isoforms
  • Tubulin
  • TUBB4B protein, human