The Small Ubiquitin-like Modifier-1 (SUMO-1) Consensus Sequence Mediates Ubc9 Binding and is Essential for SUMO-1 Modification

Deborah A. Sampson, Min Wang, Michael J. Matunis

Research output: Contribution to journalArticle

Abstract

SUMO-1 is an ubiquitin-related protein that is covalently conjugated to a diverse assortment of proteins. The consequences of SUMO-1 modification include the regulation of protein-protein interactions, protein-DNA interactions, and protein subcellular localization. At present, very little is understood about the specific mechanisms that govern the recognition of proteins as substrates for SUMO-1 modification. However, many of the proteins that are modified by SUMO-1 interact directly with the SUMO-1 conjugating enzyme, Ubc9. These interactions suggest that Ubc9 binding may play an important role in substrate recognition as well as in substrate modification. The SUMO-1 consensus sequence (SUMO-1-CS) is a motif of conserved residues surrounding the modified lysine residue of most SUMO-1 substrates. This motif conforms to the sequence "ΨKXE," where Ψ is a large hydrophobic residue, K is the lysine to which SUMO-1 is conjugated, X is any amino acid, and E is glutamic acid. In this study, we demonstrate that the SUMO-1-CS is a major determinant of Ubc9 binding and SUMO-1 modification. Mutating residues in the SUMO-1-CS abolishes both Ubc9 binding and substrate modification. These findings have important implications for how SUMO-1 substrates are recognized and for how SUMO-1 is ultimately transferred to specific lysine residues on these substrates.

Original languageEnglish (US)
Pages (from-to)21664-21669
Number of pages6
JournalJournal of Biological Chemistry
Volume276
Issue number24
DOIs
StatePublished - Jun 15 2001
Externally publishedYes

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ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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