ATAC-king the complexity of SAGA during evolution

Molecular Cancer Research, Netherlands Proteomics Center, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands.
Genes & development (Impact Factor: 10.8). 03/2012; 26(6):527-41. DOI: 10.1101/gad.184705.111
Source: PubMed


The yeast SAGA (Spt-Ada-Gcn5-acetyltransferase) coactivator complex exerts functions in gene expression, including activator interaction, histone acetylation, histone deubiquitination, mRNA export, chromatin recognition, and regulation of the basal transcription machinery. These diverse functions involve distinct modules within this multiprotein complex. It has now become clear that yeast SAGA has diverged during metazoan evolution into two related complexes, SAGA and ATAC, which exist in two flavors in vertebrates. The compositions of metazoan ATAC and SAGA complexes have been characterized, and functional analyses indicate that these complexes have important but distinct roles in transcription, histone modification, signaling pathways, and cell cycle regulation.

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Available from: Wwm Pim Pijnappel, Nov 15, 2014
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    • "TAFs are also present in the Spt-Ada-Gcn5 histone acetyltransferase (SAGA HAT) complex[15]. In mammalian cells, TAF10 is present in TFIID and SAGA-type complexes16171819. SAGA complexes contain the GCN5 HAT enzyme, as well as SPT, TRRAP, and ADA proteins. "

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    • "TFIID and SAGA (Spt–Ada–Gcn5–acetyltransferase) interact with the promoter and participate in the recruitment of the pre-initiation complex (PIC). SAGA specifically activates gene transcription in response to environmental stress [11-13]. After SAGA or TFIID binding to the promoter, several transcription factors are recruited to form the PIC. "
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    • "This association is functionally required for acetylation at various residues of histones H3 and H4 (notably K14/K27 and K8/K12, respectively ) on their promoter region and for their efficient induction by light (Benhamed et al., 2006). GCN5 is part of the SAGA complex in yeast, a transcriptional co-activator that promotes gene expression at a post-initiation step (Weake and Workman, 2008; Spedale et al., 2012), a function that seems to be conserved in Arabidopsis (Vlachonasios et al., 2003; Servet et al., 2010). At least two HDACs counterbalance acetylation levels on histone H3 and H4 on light-regulated genes, HISTONE DEACETYLASE 1/19 (HD1/HDA19) and HDA15, in addition to HDA6 that impacts light-triggered heterochromatin dynamics. "
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