A Chain of Events: Regulating Target Proteins by SUMO Polymers

Trends Biochem Sci. 2021 Feb;46(2):113-123. doi: 10.1016/j.tibs.2020.09.002. Epub 2020 Sep 29.


Small ubiquitin-like modifiers (SUMOs) regulate virtually all nuclear processes. The fate of the target protein is determined by the architecture of the attached SUMO protein, which can be of polymeric nature. Here, we highlight the multifunctional aspects of dynamic signal transduction by SUMO polymers. The SUMO-targeted ubiquitin ligases (STUbLs) RING-finger protein 4 (RNF4) and RNF111 recognize SUMO polymers in a chain-architecture-dependent manner, leading to the formation of hybrid chains, which could enable proteasomal destruction of proteins. Recent publications have highlighted essential roles for SUMO chain disassembly by the mammalian SUMO proteases SENP6 and SENP7 and the yeast SUMO protease Ulp2. SENP6 is particularly important for centromere assembly. These recent findings demonstrate the diversity of SUMO polymer signal transduction for proteolytic and nonproteolytic purposes.

Keywords: SUMO; SUMO-specific protease; SUMO-targeted ubiquitin ligase; chains; small ubiquitin-like modifier; ubiquitin.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Polymers*
  • SUMO-1 Protein
  • Small Ubiquitin-Related Modifier Proteins*
  • Ubiquitin
  • Ubiquitin-Protein Ligases


  • Polymers
  • SUMO-1 Protein
  • Small Ubiquitin-Related Modifier Proteins
  • Ubiquitin
  • Ubiquitin-Protein Ligases