scholarly journals The SANT Domain of Ada2 Is Required for Normal Acetylation of Histones by the Yeast SAGA Complex

2002 ◽  
Vol 277 (10) ◽  
pp. 8178-8186 ◽  
Author(s):  
David E. Sterner ◽  
Xun Wang ◽  
Melissa H. Bloom ◽  
Gabriel M. Simon ◽  
Shelley L. Berger
Keyword(s):  
Saga Complex ◽  
Sant Domain

scholarly journals Host Cell Factor and an Uncharacterized SANT Domain Protein Are Stable Components of ATAC, a Novel dAda2A/dGcn5-Containing Histone Acetyltransferase Complex in Drosophila

2006 ◽  
Vol 26 (3) ◽  
pp. 871-882 ◽  
Author(s):  
Sebastián Guelman ◽  
Tamaki Suganuma ◽  
Laurence Florens ◽  
Selene K. Swanson ◽  
Cheri L. Kiesecker ◽  
...  
Keyword(s):  
Host Cell ◽  
Mammalian Cells ◽  
Histone Acetyltransferase ◽  
Affinity Purification ◽  
Saga Complex ◽  
Host Cell Factor ◽  
Biochemical Fractionation ◽  
Sant Domain ◽  
Domain Protein ◽  
Insight Into

ABSTRACT Gcn5 is a conserved histone acetyltransferase (HAT) found in a number of multisubunit complexes from Saccharomyces cerevisiae, mammals, and flies. We previously identified Drosophila melanogaster homologues of the yeast proteins Ada2, Ada3, Spt3, and Tra1 and showed that they associate with dGcn5 to form at least two distinct HAT complexes. There are two different Ada2 homologues in Drosophila named dAda2A and dAda2B. dAda2B functions within the Drosophila version of the SAGA complex (dSAGA). To gain insight into dAda2A function, we sought to identify novel components of the complex containing this protein, ATAC (Ada two A containing) complex. Affinity purification and mass spectrometry revealed that, in addition to dAda3 and dGcn5, host cell factor (dHCF) and a novel SANT domain protein, named Atac1 (ATAC component 1), copurify with this complex. Coimmunoprecipitation experiments confirmed that these proteins associate with dGcn5 and dAda2A, but not with dSAGA-specific components such as dAda2B and dSpt3. Biochemical fractionation revealed that ATAC has an apparent molecular mass of 700 kDa and contains dAda2A, dGcn5, dAda3, dHCF, and Atac1 as stable subunits. Thus, ATAC represents a novel histone acetyltransferase complex that is distinct from previously purified Gcn5/Pcaf-containing complexes from yeast and mammalian cells.

scholarly journals A Novel Human Ada2 Homologue Functions with Gcn5 or Brg1 To Coactivate Transcription

2003 ◽  
Vol 23 (19) ◽  
pp. 6944-6957 ◽  
Author(s):  
Nickolai A. Barlev ◽  
Alexander V. Emelyanov ◽  
Paola Castagnino ◽  
Philip Zegerman ◽  
Andrew J. Bannister ◽  
...  
Keyword(s):  
Histone Acetylation ◽  
Chromatin Remodeling ◽  
Adaptor Protein ◽  
Saga Complex ◽  
Yeast Two Hybrid ◽  
Functional Assays ◽  
Two Hybrid ◽  
Histone Acetyltransferase Activity

ABSTRACT In yeast, the transcriptional adaptor yeast Ada2 (yAda2) is a part of the multicomponent SAGA complex, which possesses histone acetyltransferase activity through action of the yGcn5 catalytic enzyme. yAda2, among several SAGA proteins, serves to recruit SAGA to genes via interactions with promoter-bound transcription factors. Here we report identification of a new human Ada2 homologue, hAda2β. Ada2β differs both biochemically and functionally from the previously characterized hAda2α, which is a stable component of the human PCAF (human Gcn5 homologue) acetylase complex. Ada2β, relative to Ada2α, interacted selectively, although not stably, with the Gcn5-containing histone acetylation complex TFTC/STAGA. In addition, Ada2β interacted with Baf57 (a component of the human Swi/Snf complex) in a yeast two-hybrid screen and associated with human Swi/Snf in vitro. In functional assays, hAda2β (but not Ada2α), working in concert with Gcn5 (but not PCAF) or Brg1 (the catalytic component of hSwi/Snf complex), increased transcription via the B-cell-specific transcription factor Pax5/BSAP. These findings support the view that Gcn5 and PCAF have distinct roles in vivo and suggest a new mechanism of coactivator function, in which a single adaptor protein (Ada2β) can coordinate targeting of both histone acetylation and chromatin remodeling activities.

scholarly journals Activation Domain-Specific and General Transcription Stimulation by Native Histone Acetyltransferase Complexes

1999 ◽  
Vol 19 (1) ◽  
pp. 855-863 ◽  
Author(s):  
Keiko Ikeda ◽  
David J. Steger ◽  
Anton Eberharter ◽  
Jerry L. Workman
Keyword(s):  
Histone Acetyltransferase ◽  
Regulation Of Transcription ◽  
Dependent Manner ◽  
Saga Complex ◽  
Histone H4 ◽  
Activation Domain ◽  
Activation Domains ◽  
Nucleosomal Array ◽  
Histone H4 Acetylation

ABSTRACT Recent progress in identifying the catalytic subunits of histone acetyltransferase (HAT) complexes has implicated histone acetylation in the regulation of transcription. Here, we have analyzed the function of two native yeast HAT complexes, SAGA (Spt-Ada-Gcn5 Acetyltransferase) and NuA4 (nucleosome acetyltransferase of H4), in activating transcription from preassembled nucleosomal array templates in vitro. Each complex was tested for the ability to enhance transcription driven by GAL4 derivatives containing either acidic, glutamine-rich, or proline-rich activation domains. On nucleosomal array templates, the SAGA complex selectively stimulates transcription driven by the VP16 acidic activation domain in an acetyl coenzyme A-dependent manner. In contrast, the NuA4 complex facilitates transcription mediated by any of the activation domains tested if allowed to preacetylate the nucleosomal template, indicating a general stimulatory effect of histone H4 acetylation. However, when the extent of acetylation by NuA4 is limited, the complex also preferentially stimulates VP16-driven transcription. SAGA and NuA4 interact directly with the VP16 activation domain but not with a glutamine-rich or proline-rich activation domain. These data suggest that recruitment of the SAGA and NuA4 HAT complexes by the VP16 activation domain contributes to HAT-dependent activation. In addition, extensive H4/H2B acetylation by NuA4 leads to a general activation of transcription, which is independent of activator-NuA4 interactions.

scholarly journals Functional Organization of the Yeast SAGA Complex: Distinct Components Involved in Structural Integrity, Nucleosome Acetylation, and TATA-Binding Protein Interaction

1999 ◽  
Vol 19 (1) ◽  
pp. 86-98 ◽  
Author(s):  
David E. Sterner ◽  
Patrick A. Grant ◽  
Shannon M. Roberts ◽  
Laura J. Duggan ◽  
Rimma Belotserkovskaya ◽  
...  
Keyword(s):  
Histone Acetylation ◽  
Structural Integrity ◽  
Functional Organization ◽  
Binding Protein ◽  
Tata Binding Protein ◽  
Saga Complex ◽  
Specific Domain ◽  
Nucleosomal Histone

ABSTRACT SAGA, a recently described protein complex in Saccharomyces cerevisiae, is important for transcription in vivo and possesses histone acetylation function. Here we report both biochemical and genetic analyses of members of three classes of transcription regulatory factors contained within the SAGA complex. We demonstrate a correlation between the phenotypic severity of SAGA mutants and SAGA structural integrity. Specifically, null mutations in the Gcn5/Ada2/Ada3 or Spt3/Spt8 classes cause moderate phenotypes and subtle structural alterations, while mutations in a third subgroup, Spt7/Spt20, as well as Ada1, disrupt the complex and cause severe phenotypes. Interestingly, double mutants (gcn5Δ spt3Δand gcn5Δ spt8Δ) causing loss of a member of each of the moderate classes have severe phenotypes, similar tospt7Δ, spt20Δ, or ada1Δmutants. In addition, we have investigated biochemical functions suggested by the moderate phenotypic classes and find that first, normal nucleosomal acetylation by SAGA requires a specific domain of Gcn5, termed the bromodomain. Deletion of this domain also causes specific transcriptional defects at the HIS3 promoter in vivo. Second, SAGA interacts with TBP, the TATA-binding protein, and this interaction requires Spt8 in vitro. Overall, our data demonstrate that SAGA harbors multiple, distinct transcription-related functions, including direct TBP interaction and nucleosomal histone acetylation. Loss of either of these causes slight impairment in vivo, but loss of both is highly detrimental to growth and transcription.

scholarly journals Sgf29 binds histone H3K4me2/3 and is required for SAGA complex recruitment and histone H3 acetylation

2011 ◽  
Vol 30 (14) ◽  
pp. 2829-2842 ◽  
Author(s):  
Chuanbing Bian ◽  
Chao Xu ◽  
Jianbin Ruan ◽  
Kenneth K Lee ◽  
Tara L Burke ◽  
...  
Keyword(s):  
Histone H3 ◽  
Saga Complex ◽  
Histone H3 Acetylation ◽  
H3 Acetylation

scholarly journals DOT1L Complex Regulates Transcriptional Initiation 1 in Human Cells

2020 ◽  
Author(s):  
Ming Yu ◽  
Robert Roeder ◽  
Aiwei Wu ◽  
Junhong Zhi ◽  
Tian Tian ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Elongation Factor ◽  
Elongation Rate ◽  
Human Cells ◽  
Mixed Lineage Leukemia ◽  
Transcriptional Elongation ◽  
Saga Complex ◽  
Transcriptional Initiation ◽  
Pol Ii ◽  
General Transcription Factors

DOT1L, the only H3K79 methyltransferase in human cells and a homolog of the yeast Dot1, normally forms a complex with AF10, AF17 and ENL/AF9, is dysregulated in most of the cases of mixed lineage leukemia (MLL) and is believed to regulate transcriptional elongation without much evidence. Here we show that DOT1L depletion reduced the global occupancy without affecting the traveling ratio or the elongation rate of Pol II, suggesting it not a major elongation factor. An examination of general transcription factors binding revealed globally reduced TBP and TFIIA occupancies near promoters after DOT1L loss, pointing to a role in transcriptional initiation. Proteomic studies uncovered that DOT1L regulates transcriptional initiation likely by facilitating the recruitment of TFIID. Moreover, ENL, a DOT1L complex subunit with a known role in DOT1L recruitment, also regulates transcriptional initiation. Furthermore, DOT1L stimulates H2B monoubiquitination by limiting the recruitment of human SAGA complex, and the connection between Dot1/DOT1L and SAGA complex is conserved between yeast and human. These results advanced current understanding of roles of DOT1L complex in transcriptional regulation and MLL.

scholarly journals The STAGA Subunit ADA2b Is an Important Regulator of Human GCN5 Catalysis

2008 ◽  
Vol 29 (1) ◽  
pp. 266-280 ◽  
Author(s):  
Armin M. Gamper ◽  
Jaehoon Kim ◽  
Robert G. Roeder
Keyword(s):  
Saga Complex ◽  
Histone Tails ◽  
Functional Roles ◽  
Enzymatic Function ◽  
Core Histones ◽  
Human Proteins ◽  
Important Regulator ◽  
And Function

ABSTRACT Human STAGA is a multisubunit transcriptional coactivator containing the histone acetyltransferase GCN5L. Previous studies of the related yeast SAGA complex have shown that the yeast Gcn5, Ada2, and Ada3 components form a heterotrimer that is important for the enzymatic function of SAGA. Here, we report that ADA2a and ADA2b, two human homologues of yeast Ada2, each have the ability to form a heterotrimer with ADA3 and GCN5L but that only the ADA2b homologue is found in STAGA. By comparing the patterns of acetylation of several substrates, we found context-dependent requirements for ADA2b and ADA3 for the efficient acetylation of histone tails by GCN5. With human proteins, unlike yeast proteins, the acetylation of free core histones by GCN5 is unaffected by ADA2b or ADA3. In contrast, the acetylation of mononucleosomal substrates by GCN5 is enhanced by ADA2b, with no significant additional effect of ADA3, and the efficient acetylation of nucleosomal arrays (chromatin) by GCN5 requires both ADA2b and ADA3. Thus, ADA2b and ADA3 appear to act at two different levels of histone organization within chromatin to facilitate GCN5 function. Interestingly, although ADA2a forms a complex(es) with GCN5 and ADA3 both in vitro and in vivo, ADA2a-containing complexes are unable to acetylate nucleosomal H3. We have also shown the preferential recruitment of ADA2b, relative to ADA2a, to p53-dependent genes. This finding indicates that the previously demonstrated presence and function of GCN5 on these promoters reflect the action of STAGA and that the ADA2a and ADA2b paralogues have nonredundant functional roles.

scholarly journals Deletion ofADA2Increases Antifungal Drug Susceptibility and Virulence inCandida glabrata

2018 ◽  
Vol 62 (3) ◽  
Author(s):  
Shang-Jie Yu ◽  
Ya-Lin Chang ◽  
Ying-Lien Chen
Keyword(s):  
Cell Wall ◽  
Systemic Infection ◽  
Drug Tolerance ◽  
Drug Susceptibility ◽  
Antifungal Drugs ◽  
Antifungal Drug ◽  
Saga Complex ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Downstream Target

ABSTRACTCandida glabrata, the second most frequent cause of candidiasis afterCandida albicans, is an emerging human fungal pathogen that is intrinsically drug tolerant. Currently, studies ofC. glabratagenes involved in drug tolerance are limited. Ada2, a component serving as a transcription adaptor of the Spt-Ada-Gcn5 acetyltransferase (SAGA) complex, is required for antifungal drug tolerance and virulence inC. albicans. However, its roles inC. glabrataremain elusive. In this study, we found thatada2mutants demonstrated severe growth defects at 40°C but only mild defects at 37°C or 25°C. In addition,C. glabrata ada2mutants exhibited pleiotropic phenotypes, including susceptibility to three classes of antifungal drugs (i.e., azoles, echinocandins, and polyenes) and cell wall-perturbing agents but resistance to the endoplasmic reticulum stressor tunicamycin. According to RNA sequence analysis, the expression of 43 genes was downregulated and the expression of 442 genes was upregulated in theada2mutant compared to their expression in the wild type.C. glabrata ADA2, along with its downstream targetERG6, controls antifungal drug tolerance and cell wall integrity. Surprisingly,ada2mutants were hypervirulent in a murine model of systemic infection, possibly due to the upregulation of multiple adhesin-like genes, increased agar invasion, and overstimulation of murine tumor necrosis factor alpha production.

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