A human SPT3-TAFII31-GCN5-L acetylase complex distinct from transcription factor IID.
In yeast, SPT3 is a component of the multiprotein SPT-ADA-GCN5 acetyltransferase (SAGA) complex that integrates proteins with transcription coactivator/adaptor functions (ADAs and GCN5), histone acetyltransferase activity (GCN5), and core promoter-selective functions (SPTs) involving interactions with the TATA-binding protein (TBP). In particular, yeast SPT3 has been shown to interact directly with TBP. Here we report the molecular cloning of a cDNA encoding a human homologue of yeast SPT3. Amino acid sequence comparisons between human SPT3 (hSPT3) and its counterparts in different yeast species reveal three highly conserved domains, with the most conserved 92-amino acid N-terminal domain being 25% identical with human TAFII18. Despite the significant sequence similarity with TAFII18, native hSPT3 is not a bona fide TAFII because it is not associated in vivo either with human TBP/TFIID or with a TFIID-related TBP-free TAFII complex. However, we present evidence that hSPT3 is associated in vivo with TAFII31 and the recently described longer form of human GCN5 (hGCN5-L) in a novel human complex that has histone acetyltransferase activity. We propose that the human SPT3-TAFII31-GCN5-L acetyltransferase (STAGA) complex is a likely homologue of the yeast SAGA complex.
Martinez
E
E
Laboratory of Biochemistry and Molecular Biology, The Rockefeller University, New York, New York 10021, USA.
Kundu
T K
TK
Fu
J
J
Roeder
R G
RG
D000123:Acetyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D018797:Cell Cycle Proteins; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D051548:Histone Acetyltransferases; D006801:Humans; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D035381:TATA-Binding Protein Associated Factors; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D035362:Transcription Factor TFIID; D014157:Transcription Factors / Q000378:metabolism*; D019473:Transcription Factors, TFII / Q000378:metabolism*; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor
D000123:Acetyltransferases; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D051548:Histone Acetyltransferases; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D035381:TATA-Binding Protein Associated Factors; D015534:Trans-Activators; D035362:Transcription Factor TFIID; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D050880:p300-CBP Transcription Factors; D000099224:p300-CBP-Associated Factor; C115819:SUPT3H protein, human; C106849:TAF9 protein, human; C501179:KAT2A protein, human