Modulation of ETS-1 transcriptional activity by huUBC9, a ubiquitin-conjugating enzyme.
Ets transcription factors have Ets DNA binding domains, that have a winged helix-turn-helix structure. ETS-1, the founding member of the family, is regulated by the Ras and Ca2+ signaling pathways and is implicated in various physiological processes leading to cell growth, differentiation and apoptosis. We have identified ETS-1 interacting factors with a yeast two-hybrid screen. The majority of the positive clones turned out to encode the human homologue of the yeast ubiquitin-conjugating enzymes UBC9 and Hus5. In two different yeast assays, ETS-1 interacted with huUBC9. In an in vitro GST 'pull-down' assay, ETS-1 and several other Ets family members complexed with huUBC9. Interestingly, in mammalian cells, coexpression of huUBC9 resulted in a substantial increase in the transcriptional activity of ETS-1. Coexpressed huUBC9 did not affect the ETS-1 protein level, and moreover, a point mutation at Cys93, an amino acid known to be essential for ubiquitination, did not abolish the stimulation of the ETS-1 transcriptional activity. Our results indicate that the modulation of ETS-1 activity by huUBC9 results from processes other than ubiquitination and ETS-1 stabilization.
Hahn
S L
SL
Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS-INSERM-ULP, Illkirch, France.
Wasylyk
B
B
Criqui-Filipe
P
P
Criqui
P
P
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D006801:Humans; D008025:Ligases / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins / Q000737:chemistry / Q000378:metabolism*; D050783:Proto-Oncogene Proteins c-ets; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic; D044763:Ubiquitin-Conjugating Enzymes; D000098843:Ubiquitin-Conjugating Enzyme UBC9
C494041:ETS1 protein, human; D050784:Proto-Oncogene Protein c-ets-1; D011518:Proto-Oncogene Proteins; D050783:Proto-Oncogene Proteins c-ets; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D044763:Ubiquitin-Conjugating Enzymes; D011505:Protein-Tyrosine Kinases; D008025:Ligases; D000098843:Ubiquitin-Conjugating Enzyme UBC9