SUMO-1 conjugation in vivo requires both a consensus modification motif and nuclear targeting

J Biol Chem. 2001 Apr 20;276(16):12654-9. doi: 10.1074/jbc.M009476200. Epub 2000 Dec 21.


SUMO-1 is a small ubiquitin-related modifier that is covalently linked to many cellular protein targets. Proteins modified by SUMO-1 and the SUMO-1-activating and -conjugating enzymes are located predominantly in the nucleus. Here we define a transferable sequence containing the PsiKXE motif, where Psi represents a large hydrophobic amino acid, that confers the ability to be SUMO-1-modified on proteins to which it is linked. Whereas addition of short sequences from p53 and IkappaBalpha, containing the PsiKXE motif, to a carrier protein is sufficient for modification in vitro, modification in vivo requires the additional presence of a nuclear localization signal. Thus, protein substrates must be targeted to the nucleus to undergo SUMO-1 conjugation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism
  • Cell Nucleus / metabolism*
  • Consensus Sequence
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / metabolism*
  • GTPase-Activating Proteins / chemistry
  • GTPase-Activating Proteins / metabolism
  • HeLa Cells
  • Humans
  • I-kappa B Proteins*
  • NF-KappaB Inhibitor alpha
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • SUMO-1 Protein
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transfection
  • Tumor Suppressor Protein p53 / chemistry
  • Tumor Suppressor Protein p53 / metabolism*
  • Ubiquitins / chemistry
  • Ubiquitins / genetics
  • Ubiquitins / metabolism*


  • Carrier Proteins
  • DNA-Binding Proteins
  • GTPase-Activating Proteins
  • I-kappa B Proteins
  • NFKBIA protein, human
  • RANGAP1 protein, human
  • Recombinant Fusion Proteins
  • SUMO-1 Protein
  • Tumor Suppressor Protein p53
  • Ubiquitins
  • NF-KappaB Inhibitor alpha