Excessive tubulin polyglutamylation causes neurodegeneration and perturbs neuronal transport

EMBO J. 2018 Dec 3;37(23):e100440. doi: 10.15252/embj.2018100440. Epub 2018 Nov 12.


Posttranslational modifications of tubulin are emerging regulators of microtubule functions. We have shown earlier that upregulated polyglutamylation is linked to rapid degeneration of Purkinje cells in mice with a mutation in the deglutamylating enzyme CCP1. How polyglutamylation leads to degeneration, whether it affects multiple neuron types, or which physiological processes it regulates in healthy neurons has remained unknown. Here, we demonstrate that excessive polyglutamylation induces neurodegeneration in a cell-autonomous manner and can occur in many parts of the central nervous system. Degeneration of selected neurons in CCP1-deficient mice can be fully rescued by simultaneous knockout of the counteracting polyglutamylase TTLL1. Excessive polyglutamylation reduces the efficiency of neuronal transport in cultured hippocampal neurons, suggesting that impaired cargo transport plays an important role in the observed degenerative phenotypes. We thus establish polyglutamylation as a cell-autonomous mechanism for neurodegeneration that might be therapeutically accessible through manipulation of the enzymes that control this posttranslational modification.

Keywords: axonal transport; neurodegeneration; tubulin code; tubulin polyglutamylation; tubulin posttranslational modifications.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Transport, Active / genetics
  • Mice
  • Mice, Knockout
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Neurodegenerative Diseases / genetics
  • Neurodegenerative Diseases / metabolism*
  • Neurodegenerative Diseases / pathology
  • Peptide Synthases / genetics
  • Peptide Synthases / metabolism
  • Peptides / genetics
  • Peptides / metabolism*
  • Protein Processing, Post-Translational*
  • Purkinje Cells / metabolism*
  • Purkinje Cells / pathology
  • Tubulin / genetics
  • Tubulin / metabolism*


  • Ccdc115 protein, mouse
  • Nerve Tissue Proteins
  • Peptides
  • Tubulin
  • polyglutamine
  • Peptide Synthases
  • tubulin polyglutamylase