scholarly journals ADA3: a gene, identified by resistance to GAL4-VP16, with properties similar to and different from those of ADA2.

1993 ◽  
Vol 13 (10) ◽  
pp. 5981-5989 ◽  
Author(s):  
B Piña ◽  
S Berger ◽  
G A Marcus ◽  
N Silverman ◽  
J Agapite ◽  
...  

We describe the isolation of a yeast gene, ADA3, mutations in which prevent the toxicity of GAL4-VP16 in vivo. Toxicity was previously proposed to be due to the trapping of general transcription factors required at RNA polymerase II promoters (S. L. Berger, B. Piña, N. Silverman, G. A. Marcus, J. Agapite, J. L. Regier, S. J. Triezenberg, and L. Guarente, Cell 70:251-265, 1992). trans activation by VP16 as well as the acidic activation domain of GCN4 is reduced in the mutant. Other activation domains, such as those of GAL4 and HAP4, are only slightly affected in the mutant. This spectrum is similar to that observed for mutants with lesions in ADA2, a gene proposed to encode a transcriptional adaptor. The ADA3 gene is not absolutely essential for cell growth, but gene disruption mutants grow slowly and are temperature sensitive. Strains doubly disrupted for ada2 and ada3 grow no more slowly than single mutants, providing further evidence that these genes function in the same pathway. Selection of initiation sites by the general transcriptional machinery in vitro is altered in the ada3 mutant, providing a clue that ADA3 could be a novel general transcription factor involved in the response to acidic activators.

1993 ◽  
Vol 13 (10) ◽  
pp. 5981-5989
Author(s):  
B Piña ◽  
S Berger ◽  
G A Marcus ◽  
N Silverman ◽  
J Agapite ◽  
...  

We describe the isolation of a yeast gene, ADA3, mutations in which prevent the toxicity of GAL4-VP16 in vivo. Toxicity was previously proposed to be due to the trapping of general transcription factors required at RNA polymerase II promoters (S. L. Berger, B. Piña, N. Silverman, G. A. Marcus, J. Agapite, J. L. Regier, S. J. Triezenberg, and L. Guarente, Cell 70:251-265, 1992). trans activation by VP16 as well as the acidic activation domain of GCN4 is reduced in the mutant. Other activation domains, such as those of GAL4 and HAP4, are only slightly affected in the mutant. This spectrum is similar to that observed for mutants with lesions in ADA2, a gene proposed to encode a transcriptional adaptor. The ADA3 gene is not absolutely essential for cell growth, but gene disruption mutants grow slowly and are temperature sensitive. Strains doubly disrupted for ada2 and ada3 grow no more slowly than single mutants, providing further evidence that these genes function in the same pathway. Selection of initiation sites by the general transcriptional machinery in vitro is altered in the ada3 mutant, providing a clue that ADA3 could be a novel general transcription factor involved in the response to acidic activators.


1997 ◽  
Vol 17 (8) ◽  
pp. 4622-4632 ◽  
Author(s):  
Y C Lee ◽  
S Min ◽  
B S Gim ◽  
Y J Kim

A temperature-sensitive mutation was obtained in Med6p, a component of the mediator complex from the yeast Saccharomyces cerevisiae. The mediator complex has been shown to enable transcriptional activation in vitro. This mutation in Med6p abolished activation of transcription from four of five inducible promoters tested in vivo. There was no effect, however, on uninduced transcription, transcription of constitutively expressed genes, or transcription by RNA polymerases I and III. Mediator-RNA polymerase II complex isolated from the mutant yeast strain was temperature sensitive for transcriptional activation in a reconstituted in vitro system due to a defect in initiation complex formation. A database search revealed the existence of MED6-related genes in humans and Caenorhabditis elegans, suggesting that the role of mediator in transcriptional activation is conserved throughout the evolution.


2004 ◽  
Vol 24 (16) ◽  
pp. 7043-7058 ◽  
Author(s):  
Célia Jeronimo ◽  
Marie-France Langelier ◽  
Mahel Zeghouf ◽  
Marilena Cojocaru ◽  
Dominique Bergeron ◽  
...  

ABSTRACT We have programmed human cells to express physiological levels of recombinant RNA polymerase II (RNAPII) subunits carrying tandem affinity purification (TAP) tags. Double-affinity chromatography allowed for the simple and efficient isolation of a complex containing all 12 RNAPII subunits, the general transcription factors TFIIB and TFIIF, the RNAPII phosphatase Fcp1, and a novel 153-kDa polypeptide of unknown function that we named RNAPII-associated protein 1 (RPAP1). The TAP-tagged RNAPII complex is functionally active both in vitro and in vivo. A role for RPAP1 in RNAPII transcription was established by shutting off the synthesis of Ydr527wp, a Saccharomyces cerevisiae protein homologous to RPAP1, and demonstrating that changes in global gene expression were similar to those caused by the loss of the yeast RNAPII subunit Rpb11. We also used TAP-tagged Rpb2 with mutations in fork loop 1 and switch 3, two structural elements located strategically within the active center, to start addressing the roles of these elements in the interaction of the enzyme with the template DNA during the transcription reaction.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Natalia Petrenko ◽  
Yi Jin ◽  
Liguo Dong ◽  
Koon Ho Wong ◽  
Kevin Struhl

Transcription by RNA polymerase II requires assembly of a preinitiation complex (PIC) composed of general transcription factors (GTFs) bound at the promoter. In vitro, some GTFs are essential for transcription, whereas others are not required under certain conditions. PICs are stable in the absence of nucleotide triphosphates, and subsets of GTFs can form partial PICs. By depleting individual GTFs in yeast cells, we show that all GTFs are essential for TBP binding and transcription, suggesting that partial PICs do not exist at appreciable levels in vivo. Depletion of FACT, a histone chaperone that travels with elongating Pol II, strongly reduces PIC formation and transcription. In contrast, TBP-associated factors (TAFs) contribute to transcription of most genes, but TAF-independent transcription occurs at substantial levels, preferentially at promoters containing TATA elements. PICs are absent in cells deprived of uracil, and presumably UTP, suggesting that transcriptionally inactive PICs are removed from promoters in vivo.


2001 ◽  
Vol 21 (4) ◽  
pp. 1145-1154 ◽  
Author(s):  
Mario Mencı́a ◽  
Kevin Struhl

ABSTRACT TFIID, a multiprotein complex comprising the TATA-binding protein (TBP) and TBP-associated factors (TAFs), associates specifically with core promoters and nucleates the assembly the RNA polymerase II transcription machinery. In yeast cells, TFIID is not generally required for transcription, although it plays an important role at many promoters. Understanding of the specific functions and physiological roles of individual TAFs within TFIID has been hampered by the fact that depletion or thermal inactivation of individual TAFs generally results in dissociation of the TFIID complex. We describe here C-terminally deleted derivatives of yeast TAF130 that assemble into normal TFIID complexes but are transcriptionally inactive in vivo. In vivo, these mutant TFIID complexes are dramatically reduced in their ability to associate with all promoters tested. In vitro, a TFIID complex containing a deleted form of TAF130 associates poorly with DNA, but it is unaffected for interacting with transcriptional activation domains. These results suggest that the C-terminal region of TAF130 is required for TFIID to associate with promoters.


2002 ◽  
Vol 22 (19) ◽  
pp. 6750-6758 ◽  
Author(s):  
Sheng Yao ◽  
Gregory Prelich

ABSTRACT Cyclin-dependent kinases (Cdks) were originally identified as regulators of eukaryotic cell cycle progression, but several Cdks were subsequently shown to perform important roles as transcriptional regulators. While the mechanisms regulating the Cdks involved in cell cycle progression are well documented, much less is known regarding how the Cdks that are involved in transcription are regulated. In Saccharomyces cerevisiae, Bur1 and Bur2 comprise a Cdk complex that is involved in transcriptional regulation, presumably mediated by its phosphorylation of the carboxy-terminal domain (CTD) of the largest subunit of RNA polymerase II. To investigate the regulation of Bur1 in vivo, we searched for high-copy-number suppressors of a bur1 temperature-sensitive mutation, identifying a single gene, CAK1. Cak1 is known to activate two other Cdks in yeast by phosphorylating a threonine within their conserved T-loop domains. Bur1 also has the conserved threonine within its T loop and is therefore a potential direct target of Cak1. Additional tests establish a direct functional interaction between Cak1 and the Bur1-Bur2 Cdk complex: Bur1 is phosphorylated in vivo, both the conserved Bur1 T-loop threonine and Cak1 are required for phosphorylation and Bur1 function in vivo, and recombinant Cak1 stimulates CTD kinase activity of the purified Bur1-Bur2 complex in vitro. Thus, both genetic and biochemical evidence demonstrate that Cak1 is a physiological regulator of the Bur1 kinase.


1995 ◽  
Vol 305 (3) ◽  
pp. 967-974 ◽  
Author(s):  
C C Franklin ◽  
A V McCulloch ◽  
A S Kraft

Transcriptional activator proteins interact with the general transcription factors TATA-binding protein (TBP), TFIIB and/or other TBP-associated factors (TAFs). Using affinity chromatography we demonstrate that members of the Jun family of transcriptional activators interact with both TBP and TFIIB in vitro. TBP binds to both the N-terminal activation domain and C-terminal bZIP regions of c-Jun, whereas TFIIB binds to only the c-Jun bZIP domain. This interaction requires the dimerization of the Jun protein. The ability of the N-terminal activation domains of c-Jun, JunB, JunD and v-Jun to interact with TBP in vitro correlates with their transcriptional activity in vivo. Domain mapping experiments indicate that c-Jun interacts with the conserved C-terminus of TBP. Studies using a set of TFIIB inframe deletion mutants demonstrate that C-terminal amino acids 178-201 and 238-316 play an important role in modulating the interaction between TFIIB and c-Jun. Although phosphorylation of the c-Jun N-terminal activation domain stimulates c-Jun transcriptional activity in vivo, it has no effect on the ability of c-Jun to interact with either TBP or TFIIB in vitro. These data suggest that the Jun family of activator proteins may activate transcription by interacting with the general transcription factors TBP and TFIIB.


2000 ◽  
Vol 20 (21) ◽  
pp. 8124-8133 ◽  
Author(s):  
Qian Tan ◽  
Xin Li ◽  
Parag P. Sadhale ◽  
Takenori Miyao ◽  
Nancy A. Woychik

ABSTRACT Using a high-copy-number suppressor screen to obtain clues about the role of the yeast RNA polymerase II subunit RPB4 in transcription, we identified three suppressors of the temperature sensitivity resulting from deletion of the RPB4 gene (ΔRPB4). One suppressor is Sro9p, a protein related to La protein, another is the nucleosporin Nsp1p, and the third is the RNA polymerase II subunit RPB7. Suppression by RPB7 was anticipated since its interaction with RPB4 is well established both in vitro and in vivo. We examined the effect of overexpression of each suppressor gene on transcription. Interestingly, suppression of the temperature-sensitive phenotype correlates with the correction of a characteristic transcription defect of this mutant: each suppressor restored the level of promoter-specific, basal transcription to wild-type levels. Examination of the effects of the suppressors on other in vivo transcription aberrations in ΔRPB4 cells revealed significant amelioration of defects in certain inducible genes in Sro9p and RPB7, but not in Nsp1p, suppressor cells. Analysis of mRNA levels demonstrated that overexpression of each of the three suppressors minimally doubled the mRNA levels during stationary phase. However, the elevated mRNA levels in Sro9p suppressor cells appear to result from a combination of enhanced transcription and message stability. Taken together, these results demonstrate that these three proteins influence transcription and implicate Sro9p in both transcription and posttranscription events.


2005 ◽  
Vol 83 (4) ◽  
pp. 497-504 ◽  
Author(s):  
Benoit Coulombe ◽  
Marie-France Langelier

High resolution X-ray crystal structures of multisubunit RNA polymerases (RNAP) have contributed to our understanding of transcriptional mechanisms. They also provided a powerful guide for the design of experiments aimed at further characterizing the molecular stages of the transcription reaction. Our laboratory used tandem-affinity peptide purification in native conditions to isolate human RNAP II variants that had site-specific mutations in structural elements located strategically within the enzyme's catalytic center. Both in vitro and in vivo analyses of these mutants revealed novel features of the catalytic mechanisms involving this enzyme.Key words: RNA polymerase II, transcriptional mechanisms, mutational analysis, mRNA synthesis.


2021 ◽  
Author(s):  
Li-Nan Wang ◽  
Xiang-Lei Peng ◽  
Min Xu ◽  
Yuan-Bo Zheng ◽  
Yue-Ying Jiao ◽  
...  

AbstractHuman respiratory syncytial virus (RSV) infection is the leading cause of lower respiratory tract illness (LRTI), and no vaccine against LRTI has proven to be safe and effective in infants. Our study assessed attenuated recombinant RSVs as vaccine candidates to prevent RSV infection in mice. The constructed recombinant plasmids harbored (5′ to 3′) a T7 promoter, hammerhead ribozyme, RSV Long strain antigenomic cDNA with cold-passaged (cp) mutations or cp combined with temperature-sensitive attenuated mutations from the A2 strain (A2cpts) or further combined with SH gene deletion (A2cptsΔSH), HDV ribozyme (δ), and a T7 terminator. These vectors were subsequently co-transfected with four helper plasmids encoding N, P, L, and M2-1 viral proteins into BHK/T7-9 cells, and the recovered viruses were then passaged in Vero cells. The rescued recombinant RSVs (rRSVs) were named rRSV-Long/A2cp, rRSV-Long/A2cpts, and rRSV-Long/A2cptsΔSH, respectively, and stably passaged in vitro, without reversion to wild type (wt) at sites containing introduced mutations or deletion. Although rRSV-Long/A2cpts and rRSV-Long/A2cptsΔSH displayed  temperature-sensitive (ts) phenotype in vitro and in vivo, all rRSVs were significantly attenuated in vivo. Furthermore, BALB/c mice immunized with rRSVs produced Th1-biased immune response, resisted wtRSV infection, and were free from enhanced respiratory disease. We showed that the combination of ΔSH with attenuation (att) mutations of cpts contributed to improving att phenotype, efficacy, and gene stability of rRSV. By successfully introducing att mutations and SH gene deletion into the RSV Long parent and producing three rRSV strains, we have laid an important foundation for the development of RSV live attenuated vaccines.


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