TGF-β-Induced Phosphorylation of Usp9X Stabilizes Ankyrin-G and Regulates Dendritic Spine Development and Maintenance

Cell Rep. 2020 May 26;31(8):107685. doi: 10.1016/j.celrep.2020.107685.


Signaling by the cytokine transforming growth factor β (TGF-β) has been implicated in a multitude of biological functions; however, TGF-β signaling, particularly in the CNS, remains largely unexplored. ANK3 variants (encoding ankyrin-G) are associated with bipolar disorder, intellectual disability, and autism spectrum disorder, while mutations in USP9X, which encodes a deubiquitinase, are associated with X-linked intellectual disability and autism in humans. Here, we show that TGF-β signaling promotes Usp9X phosphorylation, which enhances its interaction with ankyrin-G and stabilizes ankyrin-G in spines, leading to spine enlargement. Using in situ proximity ligation combined with structured illumination superresolution microscopy, we characterize the postsynaptic spatial organization of phosphorylation-dependent regulation of Usp9X/ankyrin-G interactions in dendrites and its quantitative relationship with spine morphology and number. These data reveal a cytokine-mediated mechanism regulating protein stability in spines and suggest a role for deubiquitination and TGF-β signaling in neurodevelopmental disorder pathogenesis and treatment.

Keywords: TGF-β; Usp9X; ankyrin-G; proximity ligation assay; structured illumination microscopy.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Ankyrins / metabolism*
  • Dendritic Spines / metabolism*
  • Humans
  • Phosphorylation
  • Transforming Growth Factor beta / metabolism*
  • Ubiquitin Thiolesterase / metabolism*


  • Ankyrins
  • Transforming Growth Factor beta
  • USP9X protein, human
  • Ubiquitin Thiolesterase