SUMO-1 modification of PIASy, an E3 ligase, is necessary for PIASy-dependent activation of Tcf-4

Mol Cell Biol. 2005 May;25(9):3506-18. doi: 10.1128/MCB.25.9.3506-3518.2005.

Abstract

We have previously shown that modification of Tcf-4, a transcription factor in the Wnt pathway, with SUMO by PIASy, a SUMO E3 ligase, enhances its transcriptional activity. Since PIASy itself was also modified with SUMO-1, we studied the role of sumoylation of PIASy in the regulation of Tcf-4. Lys(35) was found to be a sumoylation site of PIASy. PIASy(K35R), in which Lys(35) was mutated to Arg, did not enhance sumoylation of Tcf-4, although this PIASy mutant did not lose the ligase activity of sumoylation for other proteins. Wild-type PIASy and PIASy(K35R) showed a distinct distribution in the nucleus, although both were colocalized with Tcf-4. Promyelocytic leukemia protein, which is involved in transcriptional regulation, was associated with PIASy(K35R) more frequently than wild-type PIASy in the nucleus. PIASy(K35R) could not stimulate the transcriptional activity of Tcf-4 under the conditions in which wild-type PIASy enhanced it. Conjugation of SUMO-1 to the amino terminus of PIASy(K35R) neither enhanced sumoylation of Tcf-4 nor stimulated the transcriptional activity of Tcf-4. These results suggest that sumoylation of Lys(35) in PIASy determines the nuclear localization of PIASy and that it is necessary for PIASy-dependent sumoylation and transcriptional activation of Tcf-4.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution / genetics
  • Animals
  • Arginine / metabolism
  • Cell Line
  • Cell Nucleus / chemistry
  • DNA-Binding Proteins / analysis
  • DNA-Binding Proteins / metabolism*
  • Humans
  • Intracellular Signaling Peptides and Proteins / analysis
  • Intracellular Signaling Peptides and Proteins / genetics
  • Intracellular Signaling Peptides and Proteins / metabolism*
  • Lysine / metabolism
  • Mutation / genetics
  • Neoplasm Proteins / metabolism
  • Nuclear Proteins / analysis
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Poly-ADP-Ribose Binding Proteins
  • Promyelocytic Leukemia Protein
  • Protein Inhibitors of Activated STAT
  • Recombinant Fusion Proteins / metabolism
  • SUMO-1 Protein / physiology*
  • TCF Transcription Factors
  • Transcription Factor 7-Like 2 Protein
  • Transcription Factors / analysis
  • Transcription Factors / metabolism*
  • Transcription, Genetic / genetics
  • Transcription, Genetic / physiology
  • Tumor Suppressor Proteins
  • Ubiquitin-Protein Ligases / physiology*

Substances

  • DNA-Binding Proteins
  • Intracellular Signaling Peptides and Proteins
  • Neoplasm Proteins
  • Nuclear Proteins
  • PIAS4 protein, human
  • Poly-ADP-Ribose Binding Proteins
  • Promyelocytic Leukemia Protein
  • Protein Inhibitors of Activated STAT
  • Recombinant Fusion Proteins
  • SUMO-1 Protein
  • TCF Transcription Factors
  • TCF7L2 protein, human
  • Transcription Factor 7-Like 2 Protein
  • Transcription Factors
  • Tumor Suppressor Proteins
  • PML protein, human
  • Arginine
  • Ubiquitin-Protein Ligases
  • Lysine