Ubiquitination of the Dishevelled DIX domain blocks its head-to-tail polymerization

Nat Commun. 2015 Apr 24;6:6718. doi: 10.1038/ncomms7718.

Abstract

Dishevelled relays Wnt signals from the plasma membrane to different cytoplasmic effectors. Its signalling activity depends on its DIX domain, which undergoes head-to-tail polymerization to assemble signalosomes. The DIX domain is ubiquitinated in vivo at multiple lysines, which can be antagonized by various deubiquitinases (DUBs) including the CYLD tumour suppressor that attenuates Wnt signalling. Here, we generate milligram quantities of pure human Dvl2 DIX domain mono-ubiquitinated at two lysines (K54 and K58) by genetically encoded orthogonal protection with activated ligation (GOPAL), to investigate their effect on DIX polymerization. We show that the ubiquitination of DIX at K54 blocks its polymerization in solution, whereas DIX58-Ub remains oligomerization-competent. DUB profiling identified 28 DUBs that cleave DIX-ubiquitin conjugates, half of which prefer, or are specific for, DIX54-Ub, including Cezanne and CYLD. These DUBs thus have the potential to promote Dvl polymerization and signalosome formation, rather than antagonize it as previously thought for CYLD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Amino Acid Motifs
  • Chromatography, Liquid
  • Dishevelled Proteins
  • Escherichia coli
  • Humans
  • Lysine / metabolism*
  • Mass Spectrometry
  • Organisms, Genetically Modified
  • Phosphoproteins / metabolism*
  • Polymerization*
  • Spectrometry, Mass, Electrospray Ionization
  • Tandem Mass Spectrometry
  • Tumor Suppressor Proteins
  • Ubiquitination*
  • Wnt Signaling Pathway*

Substances

  • Adaptor Proteins, Signal Transducing
  • DVL2 protein, human
  • Dishevelled Proteins
  • Phosphoproteins
  • Tumor Suppressor Proteins
  • Lysine