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

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.

1999 ◽  
Vol 19 (9) ◽  
pp. 5952-5959 ◽  
Author(s):  
Annika E. Wallberg ◽  
Kristen E. Neely ◽  
Jan-Åke Gustafsson ◽  
Jerry L. Workman ◽  
Anthony P. H. Wright ◽  
...  

ABSTRACT Previous studies have shown that the Ada adapter proteins are important for glucocorticoid receptor (GR)-mediated gene activation in yeast. The N-terminal transactivation domain of GR, τ1, is dependent upon Ada2, Ada3, and Gcn5 for transactivation in vitro and in vivo. Using in vitro techniques, we demonstrate that the GR-τ1 interacts directly with the native Ada containing histone acetyltransferase (HAT) complex SAGA but not the related Ada complex. Mutations in τ1 that reduce τ1 transactivation activity in vivo lead to a reduced binding of τ1 to the SAGA complex and conversely, mutations increasing the transactivation activity of τ1 lead to an increased binding of τ1 to SAGA. In addition, the Ada-independent NuA4 HAT complex also interacts with τ1. GAL4-τ1-driven transcription from chromatin templates is stimulated by SAGA and NuA4 in an acetyl coenzyme A-dependent manner. Low-activity τ1 mutants reduce SAGA- and NuA4-stimulated transcription while high-activity τ1 mutants increase transcriptional activation, specifically from chromatin templates. Our results demonstrate that the targeting of native HAT complexes by the GR-τ1 activation domain mediates transcriptional stimulation from chromatin templates.


2005 ◽  
Vol 25 (21) ◽  
pp. 9175-9188 ◽  
Author(s):  
Edwin R. Smith ◽  
Christelle Cayrou ◽  
Rong Huang ◽  
William S. Lane ◽  
Jacques Côté ◽  
...  

ABSTRACT We describe a stable, multisubunit human histone acetyltransferase complex (hMSL) that contains homologs of the Drosophila dosage compensation proteins MOF, MSL1, MSL2, and MSL3. This complex shows strong specificity for histone H4 lysine 16 in chromatin in vitro, and RNA interference-mediated knockdown experiments reveal that it is responsible for the majority of H4 acetylation at lysine 16 in the cell. We also find that hMOF is a component of additional complexes, forming associations with host cell factor 1 and a protein distantly related to MSL1 (hMSL1v1). We find two versions of hMSL3 in the hMSL complex that differ by the presence of the chromodomain. Lastly, we find that reduction in the levels of hMSLs and acetylation of H4 at lysine 16 are correlated with reduced transcription of some genes and with a G2/M cell cycle arrest. This is of particular interest given the recent correlation of global loss of acetylation of lysine 16 in histone H4 with tumorigenesis.


2007 ◽  
Vol 28 (1) ◽  
pp. 140-153 ◽  
Author(s):  
Masayoshi Iizuka ◽  
Olga F. Sarmento ◽  
Takao Sekiya ◽  
Heidi Scrable ◽  
C. David Allis ◽  
...  

ABSTRACT Hbo1 is a histone acetyltransferase (HAT) that is required for global histone H4 acetylation, steroid-dependent transcription, and chromatin loading of MCM2-7 during DNA replication licensing. It is the catalytic subunit of protein complexes that include ING and JADE proteins, growth regulatory factors and candidate tumor suppressors. These complexes are thought to act via tumor suppressor p53, but the molecular mechanisms and links between stress signaling and chromatin, are currently unknown. Here, we show that p53 physically interacts with Hbo1 and negatively regulates its HAT activity in vitro and in cells. Two physiological stresses that stabilize p53, hyperosmotic shock and DNA replication fork arrest, also inhibit Hbo1 HAT activity in a p53-dependent manner. Hyperosmotic stress during G1 phase specifically inhibits the loading of the MCM2-7 complex, providing an example of the chromatin output of this pathway. These results reveal a direct regulatory connection between p53-responsive stress signaling and Hbo1-dependent chromatin pathways.


2019 ◽  
Vol 21 (1) ◽  
pp. 173
Author(s):  
Linhong Zhao ◽  
Min Li ◽  
Tao Wei ◽  
Chang Feng ◽  
Tingting Wu ◽  
...  

Both OGT1 (O-linked β-N-acetylglucosamine (O-GlcNAc) transferase isoform 1) and NSL3 (nonspecific lethal protein 3) are crucial components of the MOF (males absent on the first)/NSL histone acetyltransferase complex. We previously described how global histone H4 acetylation levels were modulated by OGT1/O-GlcNAcylation-mediated NSL3 stability. However, the specific modification site of NSL3 and its molecular mechanism of protein stability remain unknown. Here, we present evidence from biochemical experiments arguing that O-GlcNAcylation of NSL3 at Thr755 is tightly associated with holoenzyme activity of the MOF/NSL complex. Using in vitro O-GlcNAc-transferase assays combined with mass spectrometry, we suppose that the residue Thr755 on NSL3 C-terminus is the major site O-GlcNAc-modified by OGT1. Importantly, O-GlcNAcylation of this site is involved in the regulation of the ubiquitin-degradation of NSL3, because this site mutation (T755A) promotes the ubiquitin-mediated degradation of NSL3. Further in-depth research found that ubiquitin conjugating enzyme E2 S (UBE2S) accelerated the degradation of NSL3 via direct binding to it. Interestingly, OGT1 and UBE2S competitively bind to NSL3, suggesting the coordination of OGT1–UBE2S in regulating NSL3 stability. Furthermore, O-GlcNAcylation of NSL3 Thr755 site regulates the histone H4 acetylation levels at lysine 5, 8, and 16, suggesting that the O-GlcNAcylation of NSL3 at Thr755 is required for maintaining the integrity and holoenzyme activity of the MOF/NSL complex. In colony formation assays, we found that the integrity of the complex impacts the proliferation of the lung carcinoma type II epithelium-like A549 cells. Taken together, our results provide new insight into the elucidation of the molecular mechanism of the MOF/NSL complex.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sara Busacca ◽  
Qi Zhang ◽  
Annabel Sharkey ◽  
Alan G. Dawson ◽  
David A. Moore ◽  
...  

AbstractWe hypothesized that small molecule transcriptional perturbation could be harnessed to target a cellular dependency involving protein arginine methyltransferase 5 (PRMT5) in the context of methylthioadenosine phosphorylase (MTAP) deletion, seen frequently in malignant pleural mesothelioma (MPM). Here we show, that MTAP deletion is negatively prognostic in MPM. In vitro, the off-patent antibiotic Quinacrine efficiently suppressed PRMT5 transcription, causing chromatin remodelling with reduced global histone H4 symmetrical demethylation. Quinacrine phenocopied PRMT5 RNA interference and small molecule PRMT5 inhibition, reducing clonogenicity in an MTAP-dependent manner. This activity required a functional PRMT5 methyltransferase as MTAP negative cells were rescued by exogenous wild type PRMT5, but not a PRMT5E444Q methyltransferase-dead mutant. We identified c-jun as an essential PRMT5 transcription factor and a probable target for Quinacrine. Our results therefore suggest that small molecule-based transcriptional perturbation of PRMT5 can leverage a mutation-selective vulnerability, that is therapeutically tractable, and has relevance to 9p21 deleted cancers including MPM.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii19-ii19
Author(s):  
Anca Mihalas ◽  
Heather Feldman ◽  
Anoop Patel ◽  
Patrick Paddison

Abstract Current standard of care therapy for glioblastoma (GBM) includes cytoreduction followed by ablative therapies that target rapidly dividing cell types. However, the presence of quiescent-like/G0 states, therefore, represents a natural reservoir of tumor cells that are resistant to current treatments. Quiescence or G0 phase is a reversible state of “stasis” cells enter in response to developmental or environmental cues. To gain insight into how glioblastoma cells might regulate G0-like states, we performed a genome-wide CRISPR-Cas9 screen in patient-derived GBM stem-like cells (GSCs) harboring a G0-reporter to identify genes that when inhibited trap GSCs in G0-like states. Among the top screen hits were members of the Tip60/KAT5 histone acetyltransferase complex, which targets both histones (e.g., H4) and non-histone proteins for acetylation. NuA4 functions as a transcriptional activator, whose activities are coordinated with MYC in certain contexts, and also participates in DNA double-strand break repair by facilitating chromatin opening. However, currently little is known about the roles for NuA4 complex in GBM biology. Through modeling KAT5 function in GSC in vitro cultures and in vivo tumors, we find that KAT5 inhibition causes cells to arrest in a G0-like state with high p27 levels, G1-phase DNA content, low protein synthesis rates, low rRNA rates, lower metabolic rate, suppression of cell cycle gene expression, and low histone H4 acetylation. Interestingly, partial inhibition of KAT5 activity slows highly aggressive tumor growth, while increasing p27hi H4-aclow populations. Remarkably, we that low grade gliomas have significantly higher H4-aclow subpopulations and generally lower H4-ac levels than aggressive grade IV tumors. Taken together, our results suggest that NuA4/KAT5 activity may play a key role in quiescence ingress/egress in glioma and that targeting its activity in high grade tumors may effectively “down grade” them, thus, increase patient survival.


1990 ◽  
Vol 10 (10) ◽  
pp. 5532-5535 ◽  
Author(s):  
C Abate ◽  
D Luk ◽  
E Gagne ◽  
R G Roeder ◽  
T Curran

The products of c-fos and c-jun (Fos and Jun) function in gene regulation by interacting with the AP-1 binding site. Here we have examined the contribution of Fos and Jun toward transcriptional activity by using Fos and Jun polypeptides purified from Escherichia coli. Fos contained a transcriptional activation domain as well as a region which exerted a negative influence on transcriptional activity in vitro. Moreover, distinct activation domains in both Fos and Jun functioned cooperatively in transcriptional stimulation. Thus, regulation of gene expression by Fos and Jun results from an integration of several functional domains in a bimolecular complex.


1994 ◽  
Vol 14 (9) ◽  
pp. 6056-6067
Author(s):  
M Tanaka ◽  
W Herr

The POU domain activator Oct-2 contains an N-terminal glutamine-rich transcriptional activation domain. An 18-amino-acid segment (Q18III) from this region reconstituted a fully functional activation domain when tandemly reiterated and fused to either the Oct-2 or GAL4 DNA-binding domain. A minimal transcriptional activation domain likely requires three tandem Q18III segments, because one or two tandem Q18III segments displayed little activity, whereas three to five tandem segments were active and displayed increasing activity with increasing copy number. As with natural Oct-2 activation domains, in our assay a reiterated activation domain required a second homologous or heterologous activation domain to stimulate transcription effectively when fused to the Oct-2 POU domain. These results suggest that there are different levels of synergy within and among activation domains. Analysis of reiterated activation domains containing mutated Q18III segments revealed that leucines and glutamines, but not serines or threonines, are critical for activity in vivo. Curiously, several reiterated activation domains that were inactive in vivo were active in vitro, suggesting that there are significant functional differences in our in vivo and in vitro assays. Reiteration of a second 18-amino-acid segment from the Oct-2 glutamine-rich activation domain (Q18II) was also active, but its activity was DNA-binding domain specific, because it was active when fused to the GAL4 than to the Oct-2 DNA-binding domain. The ability of separate short peptide segments derived from a single transcriptional activation domain to activate transcription after tandem reiteration emphasizes the flexible and modular nature of a transcriptional activation domain.


2011 ◽  
Vol 18 (5) ◽  
pp. 243-252 ◽  
Author(s):  
Federica Franciosi ◽  
Valentina Lodde ◽  
Ghylène Goudet ◽  
Guy Duchamp ◽  
Stefan Deleuze ◽  
...  

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Yao Liang ◽  
Yuanyuan Su ◽  
Chenzhong Xu ◽  
Na Zhang ◽  
Doudou Liu ◽  
...  

Abstract The histone acetyltransferase (HAT) KAT7/HBO1/MYST2 plays a crucial role in the pre-replication complex (pre-RC) formation, DNA replication and cell proliferation via acetylation of histone H4 and H3. In a search for protein kinase D1 (PKD1)-interacting proteins, we have identified KAT7 as a potential PKD1 substrate. We show that PKD1 directly interacts and phosphorylates KAT7 at Thr97 and Thr331 in vitro and in vivo. PKD1-mediated phosphorylation of KAT7 enhances its expression levels and stability by reducing its ubiquitination-mediated degradation. Significantly, the phospho-defective mutant KAT7-Thr97/331A attenuates histone H4 acetylation levels, MCM2/6 loading on the chromatin, DNA replication and cell proliferation. Similarly, PKD1 knockdown decreases, whereas the constitutive active mutant PKD1-CA increases histone H4 acetylation levels and MCM2/6 loading on the chromatin. Overall, these results suggest that PKD1-mediated phosphorylation of KAT7 may be required for pre-RC formation and DNA replication.


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