Activator-Mediated Recruitment of the RNA Polymerase II Machinery Is the Predominant Mechanism for Transcriptional Activation in Yeast

Keaveney, Marie; Struhl, Kevin

doi:10.1016/s1097-2765(00)80091-x

Cited by 109 publications

(86 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…We have effectively ruled out this possibility by demonstrating that yeast cells carrying GAL4-TBP as the only source of TBP are phenotypically essentially wild type. Similarly, LexA-TBP was previously shown to complement tbp⌬ yeast (36). Second, it is possible that TBP is subject to negative regulation which is normally overcome by classical activation domains (28).…”

Section: Discussionmentioning

confidence: 93%

“…This may well account in part for the generally low transcription levels induced by artificially recruited TBP and also for part of its differential activity at different promoters (10,22,36,39,79). However, it does not readily explain the ability of RAP1 to synergize with GAL4-TBP at the modified HIS4 promoter of Fig.…”

Section: Discussionmentioning

confidence: 95%

“…Thus, our findings suggest that in spite of the histone acetyltransferase activity of yeast TAF II 130 (50), TFIID is considerably poorer at remodeling chromatin than are true activators. Previous studies have also reported variable transcriptional activation by artificially recruited TBP at different promoters in yeast, but chromatin structure has not generally been examined (10,22,36,39,79). Similarly, experiments done in mammalian cells have been performed with transiently transfected DNA, which is not incorporated into organized chromatin in the same fashion as genomic DNA (2,48,57,80).…”

Section: Discussionmentioning

confidence: 99%

“…Similarly, experiments done in mammalian cells have been performed with transiently transfected DNA, which is not incorporated into organized chromatin in the same fashion as genomic DNA (2,48,57,80). Interestingly, however, sufficient activation by artificially recruited TBP is seen at the HIS3 locus to allow growth in the presence of 3-aminotriazole (which requires HIS3 activation) (10,36,39), and this promoter contains a poly(dA-dT) sequence that creates an open chromatin structure (34).…”

Section: Discussionmentioning

confidence: 99%

See 3 more Smart Citations

Artificially Recruited TATA-Binding Protein Fails To Remodel Chromatin and Does Not Activate Three Promoters That Require Chromatin Remodeling

Ryan

Stafford

et al. 2000

Molecular and Cellular Biology

View full text Add to dashboard Cite

Transcriptional activators are believed to work in part by recruiting general transcription factors, such as TATA-binding protein (TBP) and the RNA polymerase II holoenzyme. Activation domains also contribute to remodeling of chromatin in vivo. To determine whether these two activities represent distinct functions of activation domains, we have examined transcriptional activation and chromatin remodeling accompanying artificial recruitment of TBP in yeast (Saccharomyces cerevisiae). We measured transcription of reporter genes with defined chromatin structure by artificial recruitment of TBP and found that a reporter gene whose TATA element was relatively accessible could be activated by artificially recruited TBP, whereas two promoters, GAL10 and CHA1, that have accessible activator binding sites, but nucleosomal TATA elements, could not. A third reporter gene containing the HIS4 promoter could be activated by GAL4-TBP only when a RAP1 binding site was present, although RAP1 alone could not activate the reporter, suggesting that RAP1 was needed to open the chromatin structure to allow activation. Consistent with this interpretation, artificially recruited TBP was unable to perturb nucleosome positioning via a nucleosomal binding site, in contrast to a true activator such as GAL4, or to perturb the TATA-containing nucleosome at the CHA1 promoter. Finally, we show that activation of the GAL10 promoter by GAL4, which requires chromatin remodeling, can occur even in swi gcn5 yeast, implying that remodeling pathways independent of GCN5, the SWI-SNF complex, and TFIID can operate during transcriptional activation in vivo.Transcriptional activators are thought to stimulate transcription of TATA-containing promoters in part by recruiting TFIID, a multiprotein complex consisting of the TATA-binding protein (TBP) and TBP-associated factors (TAFs), to the TATA box (25,60). Several in vitro and in vivo studies support this model. For example, transcription initiated at a mutated TATA element by induced synthesis of TBP with altered specificity was enhanced in both rate and extent in the presence of an activator that could bind upstream of the relevant promoter, consistent with activator-mediated recruitment (40). Recruitment has also been inferred from the results of "activator bypass" experiments in which artificial recruitment of TBP to promoter sites near the TATA element resulted in transcriptional activation, implying that TBP recruitment is a rate-limiting step in transcriptional activation in vivo (10,39,79). Most convincingly, chromatin immunoprecipitation experiments revealed TBP to be physically associated with promoters of numerous genes under activated, but not nonactivated, conditions, implying that recruitment accompanies activation (43,46).A potential obstacle to recruitment of TBP in vivo is posed by chromatin. Binding of TBP to nucleosomal TATA elements is greatly impeded in vitro (23, 32). Transcription is also strongly repressed by chromatin, but this repression can be largely alleviated by binding of act...

show abstract

Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Artificially Recruited TATA-Binding Protein Fails To Remodel Chromatin and Does Not Activate Three Promoters That Require Chromatin Remodeling

Ryan

Stafford

et al. 2000

Molecular and Cellular Biology

View full text Add to dashboard Cite

show abstract

“…A variety of lines of evidence indicate that activating regions such as those found in Gal4 work by recruiting the transcriptional machinery to DNA (5,(12)(13)(14). According to this idea, these activating regions merely have to perform a ''glue-like'' function, and in principle any of a variety of activatormachinery interactions could suffice for, or be involved in, activation.…”

mentioning

confidence: 99%

An artificial transcriptional activating region with unusual properties

Ansari

Ptashne

2000

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

We describe a series of transcriptional activators generated by adding amino acids (eight in one case, six in another) to fragments of the yeast Saccharomyces cerevisiae activator Gal4 that dimerize and bind DNA. One of the novel activating regions identified by this procedure is unusual, compared with previously characterized yeast activating regions, in the following ways: it works more strongly than does Gal4's natural activating region as assayed in yeast; it is devoid of acidic residues; and several lines of evidence suggest that it sees targets in the yeast transcriptional machinery at least partially distinct from those seen by Gal4's activating region.

show abstract

High levels of intracellular polyamines promote histone acetyltransferase activity resulting in chromatin hyperacetylation

Hobbs

Gilmour

2000

J. Cell. Biochem.

View full text Add to dashboard Cite

Polyamines stimulate expression of a variety of genes, including many implicated in cell proliferation. Indeed, aberrant expression of ornithine decarboxylase (ODC), a rate-limiting enzyme in polyamine biosynthesis, plays a causal role in tumorigenesis. Gene activity is influenced by dynamic changes in acetylation of nucleosomal histones. Although polyamines influence the histone acetyltransferase and deacetylase activities in cell-free systems, their ability to modulate these enzymes in live cells has never been established. To examine the effects of elevated intracellular levels of ODC and polyamines on gene transcription and histone acetylation, cells were infected with a retrovirus containing a cDNA for ODC. ODC overexpression potentiated the stimulatory effects of histone deacetylase inhibitors on reporter gene expression beyond that promoted by ODC or inhibitor treatment alone. Indeed, elevated intracellular levels of ODC promoted hyperacetylation of histones in several epidermal and fibroblast cell types. The ODC-mediated increase in acetylated histones was abrogated when cells were treated with alpha-difluoromethylornithine, a specific inhibitor of ODC activity, implying a distinct role for polyamines. Specifically, polyamines were found to enhance the action of histone acetyltransferases either directly or indirectly. Our studies document effects of elevated intracellular polyamine levels on histone acetylation in proliferating cells, suggesting a mechanism by which altered polyamine biosynthesis contributes to aberrant expression of genes, facilitating tumor growth. In addition, these studies may have implications for the development of drugs designed to regulate enzymes that modify the acetylation status of histones.

show abstract

Activator-Mediated Recruitment of the RNA Polymerase II Machinery Is the Predominant Mechanism for Transcriptional Activation in Yeast

Cited by 109 publications

References 48 publications

Artificially Recruited TATA-Binding Protein Fails To Remodel Chromatin and Does Not Activate Three Promoters That Require Chromatin Remodeling

Artificially Recruited TATA-Binding Protein Fails To Remodel Chromatin and Does Not Activate Three Promoters That Require Chromatin Remodeling

An artificial transcriptional activating region with unusual properties

High levels of intracellular polyamines promote histone acetyltransferase activity resulting in chromatin hyperacetylation

Contact Info

Product

Resources

About