MYC interacts with the human STAGA coactivator complex via multivalent contacts with the GCN5 and TRRAP subunits.
MYC is an oncogenic DNA-binding transcription activator of many genes and is often upregulated in human cancers. MYC has an N-terminal transcription activation domain (TAD) that is also required for cell transformation. Various MYC TAD-interacting coactivators have been identified, including the transcription/transformation-associated protein (TRRAP), a subunit of different histone acetyltransferase (HAT) complexes such as the human "SPT3-TAF9-GCN5 Acetyltransferase" (STAGA) complex involved in MYC transactivation of the TERT gene. However, it remains unclear whether TRRAP and/or other subunits are directly contacted by MYC within these macromolecular complexes. Here, we characterize the interactions of MYC TAD with the STAGA complex. By protein crosslinking we identify both TRRAP and the GCN5 acetyltransferase as MYC TAD-interacting subunits within native STAGA. We show that purified GCN5 binds to an N-terminal sub-domain of MYC TAD (residues 21-108) and that the interaction of GCN5 and STAGA with this sub-domain is dependent on two related sequence motifs: M2 within the conserved MYC homology box I (MBI), and M3 located between residues 100-106. Interestingly, specific substitutions within the M2/3 motifs that only moderately reduce the intracellular MYC-STAGA interaction and do not influence dimerization of MYC with its DNA-binding partner MAX, strongly inhibit MYC acetylation by GCN5 and reduce MYC binding and transactivation of the GCN5-dependent TERT promoter in vivo. Hence, we propose that MYC associates with STAGA through extended interactions of the TAD with both TRRAP and GCN5 and that the TAD-GCN5 interaction is important for MYC acetylation and MYC binding to certain chromatin loci.
Department of Biochemistry, University of California Riverside, 900 University Ave., Riverside, CA 92521, USA.
Na
N
Zhang
Department of Biochemistry, University of California Riverside, 900 University Ave., Riverside, CA 92521, USA.
Wataru
W
Ichikawa
Department of Biochemistry, University of California Riverside, 900 University Ave., Riverside, CA 92521, USA.
Francesco
F
Faiola
Department of Biochemistry, University of California Riverside, 900 University Ave., Riverside, CA 92521, USA.
Szu-Ying
SY
Lo
Department of Biochemistry, University of California Riverside, 900 University Ave., Riverside, CA 92521, USA.
Xiaohui
X
Liu
Department of Biochemistry, University of California Riverside, 900 University Ave., Riverside, CA 92521, USA. Electronic address: ernest.martinez@ucr.edu.
Ernest
E
Martinez
D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D002460:Cell Line; D045744:Cell Line, Tumor; D002843:Chromatin / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism*; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D035362:Transcription Factor TFIID / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D015533:Transcriptional Activation; D050880:p300-CBP Transcription Factors / Q000235:genetics / Q000378:metabolism*; D000099224:p300-CBP-Associated Factor
D000123:Acetyltransferases; D048868:Adaptor Proteins, Signal Transducing; D002843:Chromatin; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D021122:Protein Subunits; D016271:Proto-Oncogene Proteins c-myc; D035381:TATA-Binding Protein Associated Factors; D015534:Trans-Activators; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor; C115819:SUPT3H protein, human; C106849:TAF9 protein, human; C113829:transformation-transcription domain-associated protein
Chromatin; Coactivator; Histone acetyltransferase complex; MYC oncoprotein; Protein–protein interaction; Transcription