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Updated: Jul 10, 2026

In Vitro SUMOylation Assay to Study SUMO E3 Ligase Activity
Published on: January 29, 2018
Pc2 and SUMOylation
1Center for Cell Signaling and Department of Biochemistry and Molecular Genetics, University of Virginia, 800577 HSC, Charlottesville, VA 22908, USA. dw2p@virginia.edu
Abstract:
Polycomb proteins are key regulators of transcription in metazoan organisms. Recent work has shed light on the nature of the polycomb protein complexes in flies and mammalian cells. Multiple enzymatic activities have been shown to associate with polycomb complexes, including histone methyltransferase, histone deacetylase and ubiquitination activities, which are primarily directed towards the modification of chromatin structure. In addition to these chromatin-based functions, other potential roles for polycomb proteins exist. Here, we present a comparison of vertebrate Pc2 (polycomb 2 protein) homologues, and review the known functions of the mammalian Pc2 focusing on its role as a SUMO (small ubiquitin-related modifier) E3 ligase. Pc2 is an E3 for several SUMO substrates, but still appears to have a more limited repertoire than other SUMO E3s, perhaps due to its association with polycomb complexes. One possibility is that Pc2 represents a relatively specialized polycomb protein, which has additional functions to those associated with other mammalian Pc (polycomb protein) paralogues.
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