title: ETO, a target of t(8;21) in acute leukemia, makes distinct contacts with multiple histone deacetylases and binds mSin3A through its oligomerization domain.
abstract: t(8;21) and t(16;21) create two fusion proteins, AML-1-ETO and AML-1-MTG16, respectively, which fuse the AML-1 DNA binding domain to putative transcriptional corepressors, ETO and MTG16. Here, we show that distinct domains of ETO contact the mSin3A and N-CoR corepressors and define two binding sites within ETO for each of these corepressors. In addition, of eight histone deacetylases (HDACs) tested, only the class I HDACs HDAC-1, HDAC-2, and HDAC-3 bind ETO. However, these HDACs bind ETO through different domains. We also show that the murine homologue of MTG16, ETO-2, is also a transcriptional corepressor that works through a similar but distinct mechanism. Like ETO, ETO-2 interacts with N-CoR, but ETO-2 fails to bind mSin3A. Furthermore, ETO-2 binds HDAC-1, HDAC-2, and HDAC-3 but also interacts with HDAC-6 and HDAC-8. In addition, we show that expression of AML-1-ETO causes disruption of the cell cycle in the G(1) phase. Disruption of the cell cycle required the ability of AML-1-ETO to repress transcription because a mutant of AML-1-ETO, Delta469, which removes the majority of the corepressor binding sites, had no phenotype. Moreover, treatment of AML-1-ETO-expressing cells with trichostatin A, an HDAC inhibitor, restored cell cycle control. Thus, AML-1-ETO makes distinct contacts with multiple HDACs and an HDAC inhibitor biologically inactivates this fusion protein.
authors.affiliation: Department of Biochemistry, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Amann
authors.forename: J
authors.initials: J
authors.lastname: Nip
authors.forename: D K
authors.initials: DK
authors.lastname: Strom
authors.forename: B
authors.initials: B
authors.lastname: Lutterbach
authors.forename: H
authors.initials: H
authors.lastname: Harada
authors.forename: N
authors.initials: N
authors.lastname: Lenny
authors.forename: J R
authors.initials: JR
authors.lastname: Downing
authors.forename: S
authors.initials: S
authors.lastname: Meyers
authors.forename: S W
authors.initials: SW
authors.lastname: Hiebert
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000378:metabolism*; D006877:Hydroxamic Acids / Q000494:pharmacology; D015479:Leukemia, Myelomonocytic, Acute / Q000235:genetics*; D051379:Mice; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism / Q000502:physiology; D056971:Nuclear Receptor Co-Repressor 1; D015514:Oncogene Proteins, Fusion / Q000037:antagonists & inhibitors / Q000502:physiology*; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins; D000075142:RUNX1 Translocation Partner 1 Protein; D012097:Repressor Proteins / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D056264:Sin3 Histone Deacetylase and Corepressor Complex; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism* / Q000502:physiology*; D014158:Transcription, Genetic; D014178:Translocation, Genetic
chemical_list: C107844:AML1-ETO fusion protein, human; C117411:Cbfa2t3 protein, mouse; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; C539127:NCOR1 protein, human; C539128:Ncor1 protein, mouse; D009687:Nuclear Proteins; D056971:Nuclear Receptor Co-Repressor 1; D015514:Oncogene Proteins, Fusion; D011518:Proto-Oncogene Proteins; D000075142:RUNX1 Translocation Partner 1 Protein; C082222:RUNX1T1 protein, human; D012097:Repressor Proteins; C099683:SIN3A transcription factor; D014157:Transcription Factors; C012589:trichostatin A; D006655:Histone Deacetylases; D056264:Sin3 Histone Deacetylase and Corepressor Complex