Analysis of SUMO1-conjugation at synapses

Elife. 2017 Jun 9;6:e26338. doi: 10.7554/eLife.26338.

Abstract

SUMO1-conjugation of proteins at neuronal synapses is considered to be a major post-translational regulatory process in nerve cell and synapse function, but the published evidence for SUMO1-conjugation at synapses is contradictory. We employed multiple genetic mouse models for stringently controlled biochemical and immunostaining analyses of synaptic SUMO1-conjugation. By using a knock-in reporter mouse line expressing tagged SUMO1, we could not detect SUMO1-conjugation of seven previously proposed synaptic SUMO1-targets in the brain. Further, immunostaining of cultured neurons from wild-type and SUMO1 knock-out mice showed that anti-SUMO1 immunolabelling at synapses is non-specific. Our findings indicate that SUMO1-conjugation of synaptic proteins does not occur or is extremely rare and hence not detectable using current methodology. Based on our data, we discuss a set of experimental strategies and minimal consensus criteria for the validation of SUMOylation that can be applied to any SUMOylation substrate and SUMO isoform.

Keywords: SUMO1 knock-in; SUMO1 knock-out; SUMOylation; Synapse; mouse; neuroscience.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Gene Knock-In Techniques
  • Gene Knockout Techniques
  • Mice
  • SUMO-1 Protein / genetics
  • SUMO-1 Protein / metabolism*
  • Staining and Labeling
  • Sumoylation*
  • Synapses / metabolism*

Substances

  • SUMO-1 Protein

Grant support

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.