Identification of a new promoter upstream of the murine dihydrofolate reductase gene

1989 ◽  
Vol 9 (10) ◽  
pp. 4568-4570
Author(s):  
L J Schilling ◽  
P J Farnham
Keyword(s):  
Dihydrofolate Reductase ◽  
Transcription Initiation ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Deletion Mapping ◽  
Reductase Gene ◽  
Bona Fide ◽  
Translational Start

In vitro reactions identified a transcription initiation site located 740 nucleotides upstream of the dihydrofolate reductase translational start. Transcription from this site proceeded in the direction opposite to that of dihydrofolate reductase mRNA. Deletion mapping indicated that this new promoter can be separated from the dihydrofolate reductase promoter and that separation increased transcription at -740. Transcripts that initiate at -740 were also detected in cellular RNA, indicating that this is a bona fide transcription initiation site in vivo.

scholarly journals Identification of a new promoter upstream of the murine dihydrofolate reductase gene.

1989 ◽  
Vol 9 (10) ◽  
pp. 4568-4570 ◽  
Author(s):  
L J Schilling ◽  
P J Farnham
Keyword(s):  
Dihydrofolate Reductase ◽  
Transcription Initiation ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Deletion Mapping ◽  
Reductase Gene ◽  
Bona Fide ◽  
Translational Start

In vitro reactions identified a transcription initiation site located 740 nucleotides upstream of the dihydrofolate reductase translational start. Transcription from this site proceeded in the direction opposite to that of dihydrofolate reductase mRNA. Deletion mapping indicated that this new promoter can be separated from the dihydrofolate reductase promoter and that separation increased transcription at -740. Transcripts that initiate at -740 were also detected in cellular RNA, indicating that this is a bona fide transcription initiation site in vivo.

scholarly journals Transcriptional initiation is controlled by upstream GC-box interactions in a TATAA-less promoter.

1990 ◽  
Vol 10 (12) ◽  
pp. 6632-6641 ◽  
Author(s):  
M C Blake ◽  
R C Jambou ◽  
A G Swick ◽  
J W Kahn ◽  
J C Azizkhan
Keyword(s):  
Dihydrofolate Reductase ◽  
Gene Promoter ◽  
In Vitro Transcription ◽  
Initiation Site ◽  
Start Site ◽  
Transcriptional Initiation ◽  
Reductase Gene ◽  
Gc Box

Numerous genes contain TATAA-less promoters, and the control of transcriptional initiation in this important promoter class is not understood. We have determined that protein-DNA interactions at three of the four proximal GC box sequence elements in one such promoter, that of the hamster dihydrofolate reductase gene, control initiation and relative use of the major and minor start sites. Our results indicate that although the GC boxes are apparently equivalent with respect to factor binding, they are not equivalent with respect to function. At least two properly positioned GC boxes were required for initiation of transcription. Abolishment of DNA-protein interaction by site-specific mutation of the most proximal GC box (box I) resulted in a fivefold decrease in transcription from the major initiation site and a threefold increase in heterogeneous transcripts initiating from the vicinity of the minor start site in vitro and in vivo. Mutations that separately abolished interactions at GC boxes II and III while leaving GC box I intact affected the relative utilization of both the major and minor initiation sites as well as transcriptional efficiency of the promoter template in in vitro transcription and transient expression assays. Interaction at GC box IV when the three proximal boxes were in a wild-type configuration had no effect on transcription of the dihydrofolate reductase gene promoter. Thus, GC box interactions not only are required for efficient transcription but also regulate start site utilization in this TATAA-less promoter.

scholarly journals Transcriptional initiation is controlled by upstream GC-box interactions in a TATAA-less promoter

1990 ◽  
Vol 10 (12) ◽  
pp. 6632-6641
Author(s):  
M C Blake ◽  
R C Jambou ◽  
A G Swick ◽  
J W Kahn ◽  
J C Azizkhan
Keyword(s):  
Dihydrofolate Reductase ◽  
Gene Promoter ◽  
In Vitro Transcription ◽  
Initiation Site ◽  
Start Site ◽  
Transcriptional Initiation ◽  
Reductase Gene ◽  
Gc Box

Numerous genes contain TATAA-less promoters, and the control of transcriptional initiation in this important promoter class is not understood. We have determined that protein-DNA interactions at three of the four proximal GC box sequence elements in one such promoter, that of the hamster dihydrofolate reductase gene, control initiation and relative use of the major and minor start sites. Our results indicate that although the GC boxes are apparently equivalent with respect to factor binding, they are not equivalent with respect to function. At least two properly positioned GC boxes were required for initiation of transcription. Abolishment of DNA-protein interaction by site-specific mutation of the most proximal GC box (box I) resulted in a fivefold decrease in transcription from the major initiation site and a threefold increase in heterogeneous transcripts initiating from the vicinity of the minor start site in vitro and in vivo. Mutations that separately abolished interactions at GC boxes II and III while leaving GC box I intact affected the relative utilization of both the major and minor initiation sites as well as transcriptional efficiency of the promoter template in in vitro transcription and transient expression assays. Interaction at GC box IV when the three proximal boxes were in a wild-type configuration had no effect on transcription of the dihydrofolate reductase gene promoter. Thus, GC box interactions not only are required for efficient transcription but also regulate start site utilization in this TATAA-less promoter.

scholarly journals Cellular factor YY1 downregulates the human papillomavirus 16 E6/E7 promoter, P97, in vivo and in vitro from a negative element overlapping the transcription-initiation site

2009 ◽  
Vol 90 (10) ◽  
pp. 2402-2412 ◽  
Author(s):  
Michael J. Lace ◽  
Yasushi Yamakawa ◽  
Masato Ushikai ◽  
James R. Anson ◽  
Thomas H. Haugen ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Transcription Initiation ◽  
Regulatory Region ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Wild Type ◽  
Hpv 16 ◽  
Human Papillomavirus 16

Cellular factors that bind to cis sequences in the human papillomavirus 16 (HPV-16) upstream regulatory region (URR) positively and negatively regulate the viral E6 and E7 oncogene promoter, P97. DNase I footprinting has revealed the binding of cellular proteins to two previously undetected cis elements overlapping and 3′ of the transcription-initiation site of the P97 promoter. Mutations within homologous motifs found in both of these cis elements abolished their negative function in vivo and the binding of the same cellular complex in vitro. This factor was identified as YY1 by complex mobility and binding specificity in comparison with vaccinia virus-expressed, purified recombinant YY1 protein and by antigenic reactivity with YY1 antisera. Cis mutations in the ‘initiator’ YY1 site activated the P97 promoter in vivo and in vitro. P97 was also activated threefold in vitro by depletion of endogenous YY1 with wild-type, but not mutant, YY1 oligonucleotides from the IgH kappa E3′ enhancer. Furthermore, increasing concentrations of exogenous, purified recombinant YY1 repressed wild-type P97 transcript levels by up to threefold, but did not influence the P97 promoter mutated in the ‘initiator’ YY1 site. Thus, the promoter-proximal YY1 site was not necessary for correct transcription initiation at the P97 promoter, but was found to be required for downregulation of P97 transcription in vivo and in vitro. In contrast to other viral and cellular promoters, where YY1 is thought to function as a positive transcription-‘initiator’ factor, HPV-16 P97 transcription is downregulated by YY1 from a critical motif overlapping the transcription start site.

scholarly journals Molecular Basis of In Vivo Resistance to Sulfadoxine-Pyrimethamine in African Adult Patients Infected withPlasmodium falciparum Malaria Parasites

1998 ◽  
Vol 42 (7) ◽  
pp. 1811-1814 ◽  
Author(s):  
Leonardo K. Basco ◽  
Rachida Tahar ◽  
Pascal Ringwald
Keyword(s):  
Dihydrofolate Reductase ◽  
Point Mutations ◽  
Gene Mutations ◽  
Adult Patients ◽  
Wild Type ◽  
Dihydropteroate Synthase ◽  
Reductase Gene ◽  
Parasite Populations

ABSTRACT In vitro sulfadoxine and pyrimethamine resistance has been associated with point mutations in the dihydropteroate synthase and dihydrofolate reductase domains, respectively, but the in vivo relevance of these point mutations has not been well established. To analyze the correlation between genotype and phenotype, 10 Cameroonian adult patients were treated with sulfadoxine-pyrimethamine and followed up for 28 days. After losses to follow-up (n = 1) or elimination of DNA samples due to mixed parasite populations with pyrimethamine-sensitive and pyrimethamine-resistant profiles (n = 3), parasite genomic DNA from day 0 blood samples of six patients were analyzed by DNA sequencing. Three patients who were cured had isolates characterized by a wild-type or mutant dihydrofolate reductase gene (with one or two mutations) and a wild-type dihydropteroate synthase gene. Three other patients who failed to respond to sulfadoxine-pyrimethamine treatment carried isolates with triple dihydrofolate reductase gene mutations and either a wild-type or a mutant dihydropteroate synthase gene. Three dihydrofolate reductase gene codons (51, 59, and 108) may be reliable genetic markers that can accurately predict the clinical outcome of sulfadoxine-pyrimethamine treatment in Africa.

Analysis of Saccharomyces cerevisiae his3 transcription in vitro: biochemical support for multiple mechanisms of transcription

1990 ◽  
Vol 10 (6) ◽  
pp. 2832-2839
Author(s):  
A S Ponticelli ◽  
K Struhl
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Initiation Site ◽  
Activator Proteins ◽  
Nuclear Extracts ◽  
Transcription In Vitro

The promoter region of the Saccharomyces cerevisiae his3 gene contains two TATA elements, TC and TR, that direct transcription initiation to two sites designated +1 and +13. On the basis of differences between their nucleotide sequences and their responsiveness to upstream promoter elements, it has previously been proposed that TC and TR promote transcription by different molecular mechanisms. To begin a study of his3 transcription in vitro, we used S. cerevisiae nuclear extracts together with various DNA templates and transcriptional activator proteins that have been characterized in vivo. We demonstrated accurate transcription initiation in vitro at the sites used in vivo, transcriptional activation by GCN4, and activation by a GAL4 derivative on various gal-his3 hybrid promoters. In all cases, transcription stimulation was dependent on the presence of an acidic activation region in the activator protein. In addition, analysis of promoters containing a variety of TR derivatives indicated that the level of transcription in vitro was directly related to the level achieved in vivo. The results demonstrated that the in vitro system accurately reproduced all known aspects of in vivo his3 transcription that depend on the TR element. However, in striking contrast to his3 transcription in vivo, transcription in vitro yielded approximately 20 times more of the +13 transcript than the +1 transcript. This result was not due to inability of the +1 initiation site to be efficiently utilized in vitro, but rather it reflects the lack of TC function in vitro. The results support the idea that TC and TR mediate transcription from the wild-type promoter by distinct mechanisms.

scholarly journals Transcription of Drosophila Troponin I Gene Is Regulated by Two Conserved, Functionally Identical, Synergistic Elements

2004 ◽  
Vol 15 (3) ◽  
pp. 1185-1196 ◽  
Author(s):  
María-Cruz Marín ◽  
José-Rodrigo Rodríguez ◽  
Alberto Ferrús
Keyword(s):  
Transcription Initiation ◽  
Troponin I ◽  
Regulatory Element ◽  
Expression Patterns ◽  
In Silico Analysis ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Upstream Regulatory Element ◽  
Transgenic Lines

The Drosophila wings-up A gene encodes Troponin I. Two regions, located upstream of the transcription initiation site (upstream regulatory element) and in the first intron (intron regulatory element), regulate gene expression in specific developmental and muscle type domains. Based on LacZ reporter expression in transgenic lines, upstream regulatory element and intron regulatory element yield identical expression patterns. Both elements are required for full expression levels in vivo as indicated by quantitative reverse transcription-polymerase chain reaction assays. Three myocyte enhancer factor-2 binding sites have been functionally characterized in each regulatory element. Using exon specific probes, we show that transvection is based on transcriptional changes in the homologous chromosome and that Zeste and Suppressor of Zeste 3 gene products act as repressors for wings-up A. Critical regions for transvection and for Zeste effects are defined near the transcription initiation site. After in silico analysis in insects (Anopheles and Drosophila pseudoobscura) and vertebrates (Ratus and Coturnix), the regulatory organization of Drosophila seems to be conserved. Troponin I (TnI) is expressed before muscle progenitors begin to fuse, and sarcomere morphogenesis is affected by TnI depletion as Z discs fail to form, revealing a novel developmental role for the protein or its transcripts. Also, abnormal stoichiometry among TnI isoforms, rather than their absolute levels, seems to cause the functional muscle defects.

scholarly journals Interactions of the Antizyme AtoC with Regulatory Elements of the Escherichia coli atoDAEB Operon

2007 ◽  
Vol 189 (17) ◽  
pp. 6324-6332 ◽  
Author(s):  
Meropi K. Matta ◽  
Efthimia E. Lioliou ◽  
Cynthia H. Panagiotidis ◽  
Dimitrios A. Kyriakidis ◽  
Christos A. Panagiotidis
Keyword(s):  
Escherichia Coli ◽  
Transcription Initiation ◽  
Response Regulator ◽  
Regulatory Elements ◽  
Initiation Site ◽  
Integration Host Factor ◽  
Chemical Mutagenesis ◽  
Dual Function

ABSTRACT AtoC has a dual function as both an antizyme, the posttranslational inhibitor of polyamine biosynthetic enzymes, and the transcriptional regulator of genes involved in short-chain fatty acid catabolism (the atoDAEB operon). We have previously shown that AtoC is the response regulator of the AtoS-AtoC two-component signal transduction system that activates atoDAEB when Escherichia coli is exposed to acetoacetate. Here, we show that the same cis elements control both promoter inducibility and AtoC binding. Chromatin immunoprecipitation experiments confirmed the acetoacetate-inducible binding of AtoC to the predicted DNA region in vivo. DNase I protection footprinting analysis revealed that AtoC binds two 20-bp stretches, constituting an inverted palindrome, that are located at −146 to −107 relative to the transcription initiation site. Analyses of promoter mutants obtained by in vitro chemical mutagenesis of the atoDAEB promoter verified both the importance of AtoC binding for the inducibility of the promoter by acetoacetate and the σ54 dependence of atoDAEB expression. The integration host factor was also identified as a critical component of the AtoC-mediated induction of atoDAEB.

scholarly journals In vitro transcription and delimitation of promoter elements of the murine dihydrofolate reductase gene.

1986 ◽  
Vol 6 (7) ◽  
pp. 2392-2401 ◽  
Author(s):  
P J Farnham ◽  
R T Schimke
Keyword(s):  
Dihydrofolate Reductase ◽  
In Vitro Transcription ◽  
S Phase ◽  
Specific Factor ◽  
Or Efficiency ◽  
Transcription System ◽  
Nuclear Extracts ◽  
Reductase Gene

We have developed an in vitro transcription system for the murine dihydrofolate reductase gene. Although transcription in vitro from a linearized template was initiated at the same start sites as in vivo, the correct ratios were more closely approximated when a supercoiled template was used. In addition, whereas the dihydrofolate reductase promoter functions bidirectionally in vivo, the initiation signals directed unidirectional transcription in this in vitro system. The dihydrofolate reductase gene does not have a typical TATA box, but has four GGGCGG hexanucleotides within 300 base pairs 5' of the AUG codon. Deletion analysis suggested that, although sequences surrounding each of the GC boxes could specify initiation approximately 40 to 50 nucleotides downstream, three of the four GC boxes could be removed without changing the accuracy or efficiency of initiation at the major in vivo site. The dihydrofolate reductase promoter initiated transcription very rapidly in vitro, with transcripts visible by 1 min and almost maximal by 2 min at 30 degrees C with no preincubation. Nuclear extracts prepared from cells blocked in the S phase by aphidicolin or from adenovirus-infected cells at 16 h postinfection had enhanced dihydrofolate reductase transcriptional activity. This increased in vitro transcription mimicked the increase in dihydrofolate reductase mRNA seen in S-phase cells and suggested the presence of a cell-cycle-specific factor(s) which stimulated transcription from the dihydrofolate reductase gene.

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