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Grant, P. A. et al. Yeast Gcn5 functions in two multisubunit complexes to acetylate nucleosomal histones: characterization of an Ada complex and the SAGA (Spt/Ada) complex. Genes Dev. 11, 1640-1650

Department of Biochemistry and Molecular Biology and The Center for Gene Regulation, The Pennsylvania State University, University Park 16802-4500, USA.
Genes & Development (Impact Factor: 12.64). 08/1997; 11(13):1640-50. DOI: 10.1101/gad.11.13.1640
Source: PubMed

ABSTRACT The transcriptional adaptor protein Gcn5 has been identified as a nuclear histone acetyltransferase (HAT). Although recombinant yeast Gcn5 efficiently acetylates free histones, it fails to acetylate histones contained in nucleosomes, indicating that additional components are required for acetylation of chromosomal histones. We report here that Gcn5 functions as a catalytic subunit in two high-molecular-mass native HAT complexes, with apparent molecular masses of 0.8 and 1.8 megadalton (MD), respectively, which acetylate nucleosomal histones. Both the 0.8- and 1.8-MD Gcn5-containing complexes cofractionate with Ada2 and are lost in gcn5delta, ada2delta, or ada3delta yeast strains, illustrating that these HAT complexes are bona fide native Ada-transcriptional adaptor complexes. Importantly, the 1.8-MD adaptor/HAT complex also contains Spt gene products that are linked to TATA-binding protein (TBP) function. This complex is lost in spt20/ada5delta and spt7delta strains and Spt3, Spt7, Spt20/Ada5, Ada2, and Gcn5 all copurify with this nucleosomal HAT complex. Therefore, the 1.8-MD adaptor/HAT complex illustrates an interaction between Ada and Spt gene products and confirms the existence of a complex containing the TBP group of Spt proteins as demonstrated by genetic and biochemical studies. We have named this novel transcription regulatory complex SAGA (Spt-Ada-Gcn5-Acetyltransferase). The function of Gcn5 as a histone acetyltransferase within the Ada and SAGA adaptor complexes indicates the importance of histone acetylation during steps in transcription activation mediated by interactions with transcription activators and general transcription factors (i.e., TBP).

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    • "Some members additionally have an N-terminal PCAF homology domain for substrate selectivity (Xu et al., 1998) and a C-terminal bromodomain for binding acetylated lysine residues. As is the case with most HATs, GCN5 functions as the catalytic component in multi-subunit complexes SAGA, ADA and SLIK, playing important roles in transcriptional activation and various chromatin activities (Grant et al., 1997; Pray-Grant et al., 2002). GCN5 has been found to be involved in induction of stress-related genes for adaptation to environmental stress in yeasts (Xue-Franzen et al., 2013). "
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    ABSTRACT: Acetylation of histone lysine residues occurs in different organisms ranging from yeast to plants and mammals for the regulation of diverse cellular processes. With the identification of enzymes that create or reverse this modification, our understanding on histone acetylation has expanded at an amazing pace during the last two decades. In fungal pathogens of plants, however, the importance of such modification has only just begun to be appreciated in the recent years and there is a dearth of information on how histone acetylation is implicated in fungal pathogenesis. This review covers the current status of research related to histone acetylation in plant pathogenic fungi and considers relevant findings in the interaction between fungal pathogens and host plants. We first describe the families of histone acetyltransferases and deacetylases. Then we provide the cases where histone acetylation was investigated in the context of fungal pathogenesis. Finally, future directions and perspectives in epigenetics of fungal pathogenesis are discussed.
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    • "At first, transcription factors bind to the upstream activation sequences of the target gene, then recruit co-activators such as SAGA, SWI/SNF to facilitate TATAbinding protein (TBP), general transcription factors, RNA polII binding to promoter, and form pre-initiation complex . In Saccharomyces cerevisiae, the 1.8-MDa SAGA complex was originally purified on the basis of its ability to acetylate nucleosomal substrates in vitro (Grant et al., 1997), but it has subsequently been found to contain several different groups of proteins involved in transcription: adaptors (Ada proteins), spts (spt proteins), and TAFIIs "
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    ABSTRACT: Fusarium graminearum (teleomorph: Gibberella zeae), the dominant pathogen of Fusarium head blight (FHB) on wheat, can cause substantial economic loss. The Spt-Ada-Gcn5-acetyltransferase (SAGA) transcription coactivator plays multiple roles in regulating transcription because of the presence of functionally independent modules of subunits within the complex. The transcription factors spt3 and spt8 are components of the SAGA complex and they are important in yeasts and filamentous fungi including in F. graminearum. In this study, we identified Fgspt3 and Fgspt8, homologs of Saccharomyces cerevisiae spt3 and spt8, from F. graminearum using the BLASTP program. The aim of the present study was to investigate the functions of Fgspt3 and Fgspt8 in F. graminearum. The deletion mutants grew significantly slower than the wild-type parent and did not produce conidia. Expression of the sporulation-related gene FgFlbC and FgRen1 were significantly down-regulated in the mutants. The mutants exhibited no sexual reproduction on infected wheat kernels and a 90% decrease in virulence on wheat. Pigment formation was also greatly altered in the mutants. All of the defects were restored by genetic complementation of the mutant with wild-type Fgspt3 and Fgspt8 genes. Overall, Fgspt3 and Fgspt8 are essential genes in F. graminearum. This article is protected by copyright. All rights reserved.
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    • "Gcn5-containing complexes that have since been characterized as SAGA, a variant of the SAGA complex, named SLIK/SALSA, and ADA (Grant et al, 1997). All three complexes share the Gcn5/Ada2/Ada3 HAT module. "
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