DSS1/Sem1, a Multifunctional and Intrinsically Disordered Protein

Trends Biochem Sci. 2016 May;41(5):446-459. doi: 10.1016/j.tibs.2016.02.004. Epub 2016 Mar 1.


DSS1/Sem1 is a versatile intrinsically disordered protein. Besides being a bona fide subunit of the 26S proteasome, DSS1 associates with other protein complexes, including BRCA2-RPA, involved in homologous recombination; the Csn12-Thp3 complex, involved in RNA splicing; the integrator, involved in transcription; and the TREX-2 complex, involved in nuclear export of mRNA and transcription elongation. As a subunit of the proteasome, DSS1 functions both in complex assembly and possibly as a ubiquitin receptor. Here, we summarise structural and functional aspects of DSS1/Sem1 with particular emphasis on its multifunctional and disordered properties. We suggest that DSS1/Sem1 can act as a polyanionic adhesive to prevent nonproductive interactions during construction of protein assemblies, uniquely employing different structures when associating with the diverse multisubunit complexes.

Keywords: DNA repair; PCI domain; intrinsically disordered proteins; mRNA export; proteasome; protein degradation.

Publication types

  • Review

MeSH terms

  • Active Transport, Cell Nucleus
  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism
  • Humans
  • Intrinsically Disordered Proteins / chemistry*
  • Intrinsically Disordered Proteins / genetics
  • Intrinsically Disordered Proteins / metabolism
  • Mice
  • Proteasome Endopeptidase Complex / chemistry*
  • Proteasome Endopeptidase Complex / genetics
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Binding
  • Protein Conformation, alpha-Helical
  • Protein Conformation, beta-Strand
  • Protein Interaction Domains and Motifs
  • RNA Splicing
  • RNA, Messenger / chemistry*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Ubiquitin / chemistry*
  • Ubiquitin / genetics
  • Ubiquitin / metabolism


  • Intrinsically Disordered Proteins
  • RNA, Messenger
  • SEM1 protein, human
  • Ubiquitin
  • Proteasome Endopeptidase Complex
  • ATP dependent 26S protease