Domains involved in ETO and human N-CoR interaction and ETO transcription repression.
The (8;21) translocation between the AML1 and ETO genes is seen in approximately 12-15% of all acute myeloid leukemia (AML) and is a frequently observed nonrandom genetic alteration associated with AML. The ETO moiety was shown to interact with the nuclear receptor co-repressor (N-CoR) complex, which includes mSin3A and the histone deacetylase, HDAC1. Repression of AML1-responsive hematopoietic genes by AML1-ETO and the N-CoR complex may play a mechanistic role in t(8;21) leukemogenesis. In order to characterize the interaction between ETO and N-CoR, mutants of either protein were constructed and tested for binding in both yeast two-hybrid and immunoprecipitation assays. We found that two domains of human N-CoR, amino acid residues 988-1126 and 1551-1803, were necessary for interaction with ETO. Previously, we and other investigators had reported that two unusual zinc finger motifs at the C-terminus of ETO mediated binding to N-CoR. Here, using mammalian two-hybrid assays, we found that transcription repression by ETO was substantially decreased when either zinc finger motif of ETO is deleted or mutated. In addition, we identified a second transcription repression domain located between residues 275 and 487. Characterization of the ETO interaction domains within human N-CoR and of the transcription domains of ETO is a first step in designing targeted molecular therapy for t(8;21) AML.
Wang
Jianxiang
J
State Key Laboratory of Experimental Hematology, Institute of Hematology, Chinese Academy of Medical Sciences, Peking Union Medical College, 288 Nanjing Road, Tianjin, PR China.
Wang
Min
M
Liu
Johnson M
JM
D000208:Acute Disease; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D006801:Humans; D007951:Leukemia, Myeloid / Q000503:physiopathology*; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D056971:Nuclear Receptor Co-Repressor 1; D015514:Oncogene Proteins, Fusion / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010449:Peptide Mapping; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection; D020798:Two-Hybrid System Techniques; D016335:Zinc Fingers
C539127:NCOR1 protein, human; D009687:Nuclear Proteins; D056971:Nuclear Receptor Co-Repressor 1; D015514:Oncogene Proteins, Fusion; D012097:Repressor Proteins; D014157:Transcription Factors