TATA-binding Protein and the Gal4 Transactivator Do Not Bind to Promoters Cooperatively

Xie, Yueqing; Sun, Liping; Kodadek, Thomas

doi:10.1074/jbc.m007019200

Cited by 9 publications

(4 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have shown that Tbp1 is not an essential target of Gal4p. Our in i o results are consistent with previous results obtained in itro [39][40][41]. Transcriptional activators work by raising the concentration of one or several limiting components for the transcription process.…”

Section: Discussionsupporting

confidence: 92%

The TATA-binding protein is not an essential target of the transcriptional activators Gal4p and Gcn4p in Saccharomyces cerevisiae

Bongards

Chew

Lehming

2003

Biochemical Journal

View full text Add to dashboard Cite

According to the recruitment model, transcriptional activators work by increasing the local concentration of one or several limiting factors for the transcription process at the target promoter. The TATA-binding protein Tbp1 has been considered as a likely candidate for such a limiting factor. We have used a series of Gal4p and Tbp1 mutants to correlate the in vivo interaction between the two proteins with the strength of activation. We find a clear correlation between activation strength and in vivo interaction for the series of Gal4p mutants. Consistently, the weaker activator Gcn4p does not interact with Tbp1. However, a corresponding analysis of the series of Tbp1 mutants revealed that Tbp1 is not an essential target of the acidic activators Gal4p and Gcn4p. Furthermore, detailed analysis of a Tbp1 mutant deficient for transcriptional activation by Gal4p revealed that the mutant is defective in interactions with five other proteins involved in the process of transcription.

show abstract

Section: Discussionsupporting

confidence: 92%

The TATA-binding protein is not an essential target of the transcriptional activators Gal4p and Gcn4p in Saccharomyces cerevisiae

Bongards

Chew

Lehming

2003

Biochemical Journal

View full text Add to dashboard Cite

show abstract

“…However, the Gal4 transactivator and TBP did not bind cooperatively to target promoters (42). This may indicate that recruitment of TFIID is not the primary activation mechanism of the Gal4 protein (42).…”

Section: Fig 7 Functional Interactions Between Rf2a and Mutants Andmentioning

confidence: 89%

Functional Analysis of RF2a, a Rice Transcription Factor

Dai

Petruccelli

Ordiz

et al. 2003

Journal of Biological Chemistry

View full text Add to dashboard Cite

RF2a is a bZIP transcription factor that regulates expression of the promoter of rice tungro bacilliform badnavirus. RF2a is predicted to include three domains that contribute to its function. The results of transient assays with mutants of RF2a from which one or more domains were removed demonstrated that the acidic domain was essential for the activation of gene expression, although the proline-rich and glutamine-rich domains each played a role in this function. Studies using fusion proteins of different functional domains of RF2a with the 2C7 synthetic zinc finger DNA-binding domain showed that the acidic region is a relatively strong activation domain, the function of which is dependent on the context in which the domain is placed. Data from transgenic plants further supported the conclusion that the acidic domain was important for maintaining the biological function of RF2a. The severe stunting symptoms of rice tungro disease are caused by infection of rice tungro bacilliform virus (RTBV), 1 a double-stranded DNA badnavirus. Understanding the transcriptional regulation of RTBV is an important factor to elucidate the basis of the disease. RTBV carries a single, vascular tissue-specific promoter with several defined DNA cis-elements (1-4). Box II, one of the DNA cis-elements in the promoter, is essential for phloem-specific expression of the promoter (3, 4).A bZIP type rice host transcription factor, RF2a, was identified by its interaction with Box II (5). Furthermore, overexpression of RF2a in transgenic plants is sufficient to activate expression of RTBV promoter in other than vascular tissues (6).Temporal and spatial regulation of gene expression relies largely on the function of gene-specific transcription factors and is achieved by the activity of multiple proteins that bind to regulatory elements and with other proteins to alter basal rates of transcription initiation and/or elongation (7-9). A typical gene-specific eukaryotic transcription factor includes a DNAbinding domain and one or more domains that influence the activation or repression of transcription through interactions with general transcription factors, co-factors, chromatin remodeling complexes, and components of RNA polymerase II holoenzyme, among others (7, 10 -13). Transacting domains are often characterized as having a high content of specific amino acids, including domains rich in the acidic amino acids, proline or glutamine (14 -16). Acidic domains have been reported to possess activation functions that include interactions with TATA-binding proteins (TBP) (13, 17), TBP-associated factors (TAFs) (18), TFIIA (19), TFIIB (20, 21), other general transcription complexes (13,22), and co-factors (12). Proline-rich and glutamine-rich domains typically act through interactions with TBP, TAFs, and other co-factors (14). Although proline-rich and glutamine-rich domains act as activation domains in most of the cases, they can also function as repression domains (23,24). RF2a contains three putative transacting domains, namely proline-rich and ac...

show abstract

“…However, other studies suggest that recruitment in its simplest form cannot fully and always account for transcrip-tional activation. For example, recent findings suggest that Gal4 and TBP do not bind cooperatively to either the AdMLP or a promoter containing a nonconsensus TATA box (97). Additionally, Gal4-VP16 fails to stimulate the levels of TBP bound to the TATA box in multiple reports (56,62,98).…”

Section: Discussionmentioning

confidence: 99%

“…For example, recent findings suggest that Gal4 and TBP do not bind cooperatively to either the AdMLP or a promoter containing a nonconsensus TATA box (97). Additionally, Gal4-VP16 fails to stimulate the levels of TBP bound to the TATA box in multiple reports (56,62,98).…”

Section: Activators Increase Transcription From Specific Promotersmentioning

confidence: 99%

Gal4-VP16 and Gal4-AH Increase the Orientational and Axial Specificity of TATA Box Recognition by TATA Box Binding Protein

Kays

Schepartz

2002

Biochemistry

View full text Add to dashboard Cite

Previous work has shown that binding of the TATA box binding protein (TBP) to the TATA box is a rate-limiting step during preinitiation complex (PIC) formation. Although the transcription of eukaryotic genes normally proceeds in one direction, studies in solution have shown that TBP lacks the information necessary to orient itself on the TATA box. Instead, yeast TBP binds TATA-containing promoters in two orientations that are related by a 180°rotation about TBP's pseudo-2-fold symmetry axis. Recruitment of PIC components by gene-specific activators is considered a primary mechanism of transcriptional enhancement. Here we ask whether activators might function, at least in part, by increasing the fraction of PICs assembled with TBP bound in the orientation necessary for transcription. We use DNA affinity cleavage and a TBP-phenanthroline-copper conjugate to monitor the orientation of TBP in the presence of the well-studied activators Gal4-VP16 and Gal4-AH. In the absence of a transcriptional activator, only 51% of the TBP‚TATA box complexes were bound in the orientation necessary for the initiation of transcription. However, in the presence of saturating Gal4-VP16, 87% of the TBP bound to the TATA box was oriented correctly at equilibrium. This increase in orientational specificity corresponds to a free energy difference (∆∆G obs ) of 1.1 kcal·mol -1 and was accompanied by a dramatic increase in axial specificity, reminiscent of the effects of transcription factors TFIIB and TFIIA reported previously. Gal4-AH also enhanced the orientational and axial specificity of the TBP‚TATA complex, although to a lesser extent. We suggest that these effects on specificity represent a variation of recruitment, since they require direct interactions between the activator and a PIC component but only increase the effective concentration of the correctly oriented PIC component. These findings add to increasing evidence that recruitment may encompass a broad range of mechanisms.The rate of transcription of any single eukaryotic gene is controlled at multiple steps, including the initiation of transcription (1-3). Preinitiation complex (PIC) 1 formation, the first step in transcription initiation, is an essential control point in the transcription of protein-encoding genes by RNA polymerase II (pol II). The PIC consists of several basal transcription factors (TF) including TFIIA, TFIID, TFIIB, TFIIE, TFIIF, and TFIIH, as well as Srb and Med factors and pol II (4-7). Pol II itself does not contain the information required to identify the promoter of a gene. As a result, pol II must be placed correctly at the start site by other proteins within the PIC. Two pathways have been described by which the PIC assembles and pol II is placed correctly on the promoter. One pathway involves a stepwise assembly of basal transcription factors that begins with the binding of TFIID (5,8). An alternative pathway involves the binding of a holoenzyme composed of pol II and various basal, Srb, and Med factors (9-13). In either case, TFIID is w...

show abstract

TATA-binding Protein and the Gal4 Transactivator Do Not Bind to Promoters Cooperatively

Cited by 9 publications

References 47 publications

The TATA-binding protein is not an essential target of the transcriptional activators Gal4p and Gcn4p in Saccharomyces cerevisiae

The TATA-binding protein is not an essential target of the transcriptional activators Gal4p and Gcn4p in Saccharomyces cerevisiae

Functional Analysis of RF2a, a Rice Transcription Factor

Gal4-VP16 and Gal4-AH Increase the Orientational and Axial Specificity of TATA Box Recognition by TATA Box Binding Protein

Contact Info

Product

Resources

About