scholarly journals Adenovirus 5 E2 transcription unit: an E1A-inducible promoter with an essential element that functions independently of position or orientation.

1984 ◽  
Vol 4 (5) ◽  
pp. 875-882 ◽  
Author(s):  
M J Imperiale ◽  
J R Nevins
Keyword(s):  
Transcription Initiation ◽  
Essential Element ◽  
Inducible Promoter ◽  
Initiation Site ◽  
Transcription Unit ◽  
Upstream Sequence ◽  
Wild Type ◽  
Promoter Sequences ◽  
Adenovirus 5 ◽  
Wild Type Promoter

Utilizing deletion mutants of a plasmid containing the adenovirus E2 gene, an E1A-inducible transcription unit, we determined the promoter sequences required for full expression in transient transfection assays. Wild-type expression was obtained from plasmids containing only 79 nucleotides of upstream sequence relative to the transcription initiation site. Removal of an additional nine nucleotides lowered expression 10-fold, and deletion to -59 resulted in near total loss of transcription. Wild-type levels of expression were restored to a -28 deletion mutant by insertion of the sequence from -21 to -262 from the wild-type promoter at the -28 position, in either orientation, even though when inserted in the opposite orientation the relevant sequences were ca. 270 nucleotides upstream from their normal position. Finally, this sequence could be placed at a distance of 4,000 nucleotides from the E2 cap site and still retain near total function. Thus, the E2 promoter element can function independent of orientation and position, properties characteristic of enhancer elements.

Adenovirus 5 E2 transcription unit: an E1A-inducible promoter with an essential element that functions independently of position or orientation

1984 ◽  
Vol 4 (5) ◽  
pp. 875-882
Author(s):  
M J Imperiale ◽  
J R Nevins
Keyword(s):  
Transcription Initiation ◽  
Essential Element ◽  
Inducible Promoter ◽  
Initiation Site ◽  
Transcription Unit ◽  
Upstream Sequence ◽  
Wild Type ◽  
Promoter Sequences ◽  
Adenovirus 5 ◽  
Wild Type Promoter

Utilizing deletion mutants of a plasmid containing the adenovirus E2 gene, an E1A-inducible transcription unit, we determined the promoter sequences required for full expression in transient transfection assays. Wild-type expression was obtained from plasmids containing only 79 nucleotides of upstream sequence relative to the transcription initiation site. Removal of an additional nine nucleotides lowered expression 10-fold, and deletion to -59 resulted in near total loss of transcription. Wild-type levels of expression were restored to a -28 deletion mutant by insertion of the sequence from -21 to -262 from the wild-type promoter at the -28 position, in either orientation, even though when inserted in the opposite orientation the relevant sequences were ca. 270 nucleotides upstream from their normal position. Finally, this sequence could be placed at a distance of 4,000 nucleotides from the E2 cap site and still retain near total function. Thus, the E2 promoter element can function independent of orientation and position, properties characteristic of enhancer elements.

scholarly journals Core Promoter-Dependent TFIIB Conformation and a Role for TFIIB Conformation in Transcription Start Site Selection

2002 ◽  
Vol 22 (19) ◽  
pp. 6697-6705 ◽  
Author(s):  
Jennifer A. Fairley ◽  
Rachel Evans ◽  
Nicola A. Hawkes ◽  
Stefan G. E. Roberts
Keyword(s):  
Transcription Start Site ◽  
Site Selection ◽  
Transcription Initiation ◽  
Core Promoter ◽  
Initiation Site ◽  
Start Site ◽  
Wild Type ◽  
Transcription Start ◽  
General Transcription Factor ◽  
Selection Of

ABSTRACT The general transcription factor TFIIB plays a central role in the selection of the transcription initiation site. The mechanisms involved are not clear, however. In this study, we analyze core promoter features that are responsible for the susceptibility to mutations in TFIIB and cause a shift in the transcription start site. We show that TFIIB can modulate both the 5′ and 3′ parameters of transcription start site selection in a manner dependent upon the sequence of the initiator. Mutations in TFIIB that cause aberrant transcription start site selection concentrate in a region that plays a pivotal role in modulating TFIIB conformation. Using epitope-specific antibody probes, we show that a TFIIB mutant that causes aberrant transcription start site selection assembles at the promoter in a conformation different from that for wild-type TFIIB. In addition, we uncover a core promoter-dependent effect on TFIIB conformation and provide evidence for novel sequence-specific TFIIB promoter contacts.

scholarly journals Identification of a Previously Unrecognized Promoter That Drives Expression of the UXP Transcription Unit in the Human Adenovirus Type 5 Genome

2010 ◽  
Vol 84 (21) ◽  
pp. 11470-11478 ◽  
Author(s):  
Baoling Ying ◽  
Ann E. Tollefson ◽  
William S. M. Wold
Keyword(s):  
Transcription Initiation ◽  
Promoter Activity ◽  
Mrna Level ◽  
A549 Cells ◽  
Initiation Site ◽  
Transcription Unit ◽  
Transcription Initiation Site ◽  
Luciferase Reporter ◽  
Rnase Protection ◽  
Ccaat Box

ABSTRACT We previously identified an adenovirus (Ad) protein named U exon protein (UXP) encoded by a leftward-strand (l-strand) transcription unit. Here we identify and characterize the UXP promoter. Primer extension and RNase protection assays mapped the transcription initiation site at 32 nucleotides upstream of the UXP gene initiation codon. A series of viral mutants with mutations at two putative inverted CCAAT (I-CCAAT) boxes and two E2F sites were generated. With mutants lacking the proximal I-CCAAT box, the UXP mRNA level decreased significantly to 30% of the Ad type 5 (Ad5) mRNA level as measured by quantitative reverse transcription-PCR. Decreased UXP was also observed by immunoblotting and immunofluorescence. UXP mRNA and protein levels were similar to those of Ad5 for mutants lacking the distal I-CCAAT box or both putative E2F sites. Ad DNA levels were similar in mutant- and wild-type Ad5-infected cells during the late stage of infection, strongly suggesting that the decreased UXP mRNA and protein from mutants lacking the proximal I-CCAAT box was due to decreased promoter activity. Electrophoretic mobility shift assays (EMSA) indicated that a cellular factor binds specifically to the proximal I-CCAAT box of the UXP promoter. An in vitro luciferase reporter assay demonstrated that basal promoter activity lies between bp −158 and +30 of the transcription initiation site. No E1A-mediated promoter transactivation was observed in 293 cells compared with A549 cells. Thus, we propose that there is a previously unidentified Ad5 promoter that drives expression of the UXP transcription unit. This promoter is embedded within the gene for fiber, and it contains a proximal I-CCAAT box critical for UXP mRNA transcription.

scholarly journals Control of Adenovirus Early Gene Expression during the Late Phase of Infection

1998 ◽  
Vol 72 (5) ◽  
pp. 4049-4056 ◽  
Author(s):  
Shawn P. Fessler ◽  
C. S. H. Young
Keyword(s):  
Gene Expression ◽  
Dna Replication ◽  
Transcription Initiation ◽  
Late Phase ◽  
Transcription Unit ◽  
Early Gene ◽  
Wild Type ◽  
Mrna Accumulation ◽  
Early Gene Expression ◽  
Late Protein

ABSTRACT The adenovirus gene regulatory program occurs in two distinct phases, as defined by the onset of DNA replication. During the early phase, the E1A, E1B, E2, E3, and E4 genes are maximally expressed, while the major late promoter (MLP) is minimally expressed and transcription is attenuated. After the onset of DNA replication, the IVa2 and pIX genes are expressed at high levels, transcription from the MLP is unattenuated and fully activated, and early gene expression is repressed. Although the cis elements andtrans-acting factors responsible for the late-phase activation of the MLP have been identified and characterized and the role of DNA replication in activation has been established, the mechanism(s) underlying the commensurate decrease in early gene expression has yet to be elucidated. The results of this study demonstrate that this decrease depends on a fully functional MLP. Specifically, virus mutants with severely deficient transcription from the MLP exhibit a marked increase in expression of the E1A, E1B, and E2 early genes. These increases were observed at the level of transcription initiation, mRNA accumulation, and protein production. In addition, expression from the late gene pIX, which is not contained within the major late transcription unit (MLTU), is also markedly increased. To begin the analysis of the mechanisms underlying these late-phase effects, mixed-infection experiments with mutant and wild-type viruses were performed. The results show that the effects on early gene expression, as measured both at the protein and RNA levels, are mediated in trans and not in cis. These observations are consistent either with a model in which one or more late protein products encoded by the MLTU acts as a repressor of early gene expression or with one in which the wild-type MLP competes with early promoters for limiting transcription factors.

scholarly journals Alternatively Initiated Gene 50/RTA Transcripts Expressed during Murine and Human Gammaherpesvirus Reactivation from Latency

2008 ◽  
Vol 83 (1) ◽  
pp. 314-328 ◽  
Author(s):  
Kathleen S. Gray ◽  
Robert D. Allen ◽  
Michael L. Farrell ◽  
J. Craig Forrest ◽  
Samuel H. Speck
Keyword(s):  
B Cell ◽  
Cell Lines ◽  
Transcription Initiation ◽  
Initiation Site ◽  
Transcription Initiation Site ◽  
Raw 264.7 ◽  
Virus Reactivation ◽  
Wild Type ◽  
Latently Infected ◽  
Distal Gene

ABSTRACT In the process of characterizing the requirements for expression of the essential immediate-early transcriptional activator (RTA) encoded by gene 50 of murine gammaherpesvirus 68 (MHV68), a recombinant virus was generated in which the known gene 50 promoter was deleted (G50pKO). Surprisingly, the G50pKO mutant retained the ability to replicate in permissive murine fibroblasts, albeit with slower kinetics than wild-type MHV68. 5′-rapid amplification of cDNA ends analyses of RNA prepared from G50pKO-infected fibroblasts revealed a novel upstream transcription initiation site, which was also utilized during wild-type MHV68 infection of permissive cells. Furthermore, the region upstream of the distal gene 50/RTA transcription initiation site exhibited promoter activity in both permissive NIH 3T12 fibroblasts as well as in the murine macrophage cell line RAW 264.7. In addition, in RAW 264.7 cells the activity of the distal gene 50/RTA promoter was strongly upregulated (>20-fold) by treatment of the cells with lipopolysaccharide. Reverse transcriptase PCR analyses of RNA prepared from Kaposi's sarcoma-associated herpesvirus- and Epstein-Barr virus-infected B-cell lines, following induction of virus reactivation, also revealed the presence of gene 50/RTA transcripts initiating upstream of the known transcription initiation site. The latter argues that alternative initiation of gene 50/RTA transcription is a strategy conserved among murine and human gammaherpesviruses. Infection of mice with the MHV68 G50pKO demonstrated the ability of this mutant virus to establish latency in the spleen and peritoneal exudate cells (PECs). However, the G50pKO mutant was unable to reactivate from latently infected splenocytes and also exhibited a significant reactivation defect from latently infected PECs, arguing in favor of a model where the proximal gene 50/RTA promoter plays a critical role in virus reactivation from latency, particularly from B cells. Finally, analyses of viral genome methylation in the regions upstream of the proximal and distal gene 50/RTA transcription initiation sites revealed that the distal promoter is partially methylated in vivo and heavily methylated in MHV68 latently infected B-cell lines, suggesting that DNA methylation may serve to silence the activity of this promoter during virus latency.

E1a transactivation of the human HSP70 promoter is mediated through the basal transcriptional complex

1989 ◽  
Vol 9 (6) ◽  
pp. 2574-2587
Author(s):  
G T Williams ◽  
T K McClanahan ◽  
R I Morimoto
Keyword(s):  
Transcription Initiation ◽  
Promoter Sequence ◽  
Initiation Site ◽  
Transcription Unit ◽  
Hsp70 Promoter ◽  
Basal Transcription ◽  
Induced Expression ◽  
Transcriptional Complex ◽  
Simplex Virus ◽  
Human Hsp70

We have examined the promoter sequence requirements for E1a transactivation of the human HSP70 gene by using a transient cotransfection assay. A 5' deletion study has defined a basal transcription unit extending to -74 relative to the transcription initiation site which was fully E1a responsive. Further deletion, abolishing a CCAAT element at -67, drastically reduced basal and E1a-induced expression. A linker-scanner analysis has identified four functional elements within the basal transcription unit which may interact with CTF, SP1, TFIID, and an ATF/AP1-like factor. Sequences between -100 and -188 can partially compensate for mutations in these elements. No mutation specifically abolished E1a inducibility. Any reduction in absolute E1a-induced levels was accompanied by a corresponding reduction in absolute basal levels, thereby maintaining a constant relative fold induction. We conclude that E1a transactivation of the human HSP70 promoter does not require any single basal transcription element. We also examined an HSP70 promoter fragment, containing the CCAAT element at -67 and the purine-rich element at -54, out of its normal context by fusing it upstream of a transcriptionally inactive herpes simplex virus thymidine kinase deletion construct containing only the TATA box. The resulting chimeric promoter was fully E1a responsive. Mutagenesis of this promoter fusion demonstrated that the CCAAT element was essential for detectable basal and E1a-induced expression. Mutations in the purine-rich element resulted in an approximately 10-fold elevation in basal levels and rendered the promoter nonresponsive to E1a.

scholarly journals Genetic evidence for promoter competition in Saccharomyces cerevisiae.

1988 ◽  
Vol 8 (11) ◽  
pp. 4608-4615 ◽  
Author(s):  
J E Hirschman ◽  
K J Durbin ◽  
F Winston
Keyword(s):  
Transcription Initiation ◽  
Initiation Site ◽  
Base Change ◽  
Wild Type ◽  
Base Pairs ◽  
Cis Acting ◽  
Initiation Of Transcription ◽  
In Trans ◽  
Tata Sequence ◽  
Transcription Signals

The his4-912 delta mutation is an insertion of the long terminal repeat (delta) of the yeast retrotransposon Ty into the HIS4 promoter region, such that the delta is 97 base pairs upstream of the HIS4 transcription initiation site. Strains carrying the his4-912 delta allele are His- at 23 degrees C; this phenotype can be reversed either by growth at 37 degrees C or by mutations in trans-acting SPT genes. Under conditions in which his4-912 delta confers a His- phenotype. HIS4 transcription initiates at the delta initiation site, rather than at the HIS4 initiation site, producing a longer, nonfunctional transcript. Under conditions in which the strain is His+, transcription initiates at the wild-type HIS4 initiation site. To understand how transcription is balanced between the delta and HIS4 promoters, we have selected for cis-acting suppressors of his4-912 delta. Two classes defined by six independent mutations restore synthesis of a functional HIS4 transcript. The first class is an A-to-G base change 1 base upstream of the proposed delta TATA sequence. These mutants do not synthesize the delta-initiated transcript; instead, they synthesize only the wild-type HIS4 transcript. The second class of mutations alters base pairs surrounding the functional HIS4 TATA sequence. The two strongest His+ mutants of this class synthesize the wild-type HIS4 transcript at levels consistent with their His+ phenotype. Surprisingly, these two mutants also have a reduced level of the delta-initiated transcript relative to the his4-912 delta parent. Analysis of these mutants indicates that the level of transcription from one promoter can affect the level of transcription from the other promoter and suggests that delta and HIS4 transcription signals compete for initiation of transcription from each site.

scholarly journals E1a transactivation of the human HSP70 promoter is mediated through the basal transcriptional complex.

1989 ◽  
Vol 9 (6) ◽  
pp. 2574-2587 ◽  
Author(s):  
G T Williams ◽  
T K McClanahan ◽  
R I Morimoto
Keyword(s):  
Transcription Initiation ◽  
Promoter Sequence ◽  
Initiation Site ◽  
Transcription Unit ◽  
Hsp70 Promoter ◽  
Basal Transcription ◽  
Induced Expression ◽  
Transcriptional Complex ◽  
Simplex Virus ◽  
Human Hsp70

We have examined the promoter sequence requirements for E1a transactivation of the human HSP70 gene by using a transient cotransfection assay. A 5' deletion study has defined a basal transcription unit extending to -74 relative to the transcription initiation site which was fully E1a responsive. Further deletion, abolishing a CCAAT element at -67, drastically reduced basal and E1a-induced expression. A linker-scanner analysis has identified four functional elements within the basal transcription unit which may interact with CTF, SP1, TFIID, and an ATF/AP1-like factor. Sequences between -100 and -188 can partially compensate for mutations in these elements. No mutation specifically abolished E1a inducibility. Any reduction in absolute E1a-induced levels was accompanied by a corresponding reduction in absolute basal levels, thereby maintaining a constant relative fold induction. We conclude that E1a transactivation of the human HSP70 promoter does not require any single basal transcription element. We also examined an HSP70 promoter fragment, containing the CCAAT element at -67 and the purine-rich element at -54, out of its normal context by fusing it upstream of a transcriptionally inactive herpes simplex virus thymidine kinase deletion construct containing only the TATA box. The resulting chimeric promoter was fully E1a responsive. Mutagenesis of this promoter fusion demonstrated that the CCAAT element was essential for detectable basal and E1a-induced expression. Mutations in the purine-rich element resulted in an approximately 10-fold elevation in basal levels and rendered the promoter nonresponsive to E1a.

scholarly journals Multiple Alignment of Promoter Sequences from the Arabidopsis thaliana L. Genome

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 135
Author(s):  
Eugene V. Korotkov ◽  
Yulia M. Suvorova ◽  
Dmitrii O. Kostenko ◽  
Maria A. Korotkova
Keyword(s):  
Arabidopsis Thaliana ◽  
Dna Sequences ◽  
Transcription Initiation ◽  
Initiation Site ◽  
Multiple Alignment ◽  
Multiple Sequence ◽  
Promoter Sequences ◽  
Alignment Algorithms ◽  
Artificial Dna ◽  
Arabidopsis Thaliana Genome

In this study, we developed a new mathematical method for performing multiple alignment of highly divergent sequences (MAHDS), i.e., sequences that have on average more than 2.5 substitutions per position (x). We generated sets of artificial DNA sequences with x ranging from 0 to 4.4 and applied MAHDS as well as currently used multiple sequence alignment algorithms, including ClustalW, MAFFT, T-Coffee, Kalign, and Muscle to these sets. The results indicated that most of the existing methods could produce statistically significant alignments only for the sets with x < 2.5, whereas MAHDS could operate on sequences with x = 4.4. We also used MAHDS to analyze a set of promoter sequences from the Arabidopsis thaliana genome and discovered many conserved regions upstream of the transcription initiation site (from −499 to +1 bp); a part of the downstream region (from +1 to +70 bp) also significantly contributed to the obtained alignments. The possibilities of applying the newly developed method for the identification of promoter sequences in any genome are discussed. A server for multiple alignment of nucleotide sequences has been created.

scholarly journals The Cyclic AMP Receptor Protein Is Dependent on GcvA for Regulation of the gcv Operon

1999 ◽  
Vol 181 (6) ◽  
pp. 1912-1919 ◽  
Author(s):  
Laura D. Wonderling ◽  
George V. Stauffer
Keyword(s):  
Cyclic Amp ◽  
Transcription Initiation ◽  
Mutational Analysis ◽  
Initiation Site ◽  
Receptor Protein ◽  
Single Mutation ◽  
Wild Type ◽  
Double Deletion ◽  
Footprint Analysis ◽  
Camp Receptor

ABSTRACT The Escherichia coli gcv operon is transcriptionally regulated by the GcvA, GcvR, Lrp, and PurR proteins. In this study, the cyclic AMP (cAMP) receptor protein (CRP) is shown to be involved in positive regulation of the gcv operon. A crpdeletion reduced expression of a gcvT-lacZ fusion almost fourfold in glucose minimal (GM) medium. The phenotype was complemented by both the wild-type crp gene and four crpalleles that encode proteins with amino acid substitutions in known activating regions of CRP. A cyaA deletion also resulted in a fourfold decrease in gcvT-lacZ expression, and wild-type expression was restored by the addition of cAMP to the growth medium. AcyaA crp double deletion resulted in levels ofgcvT-lacZ expression identical to those observed with either single mutation, showing that CRP and cAMP regulate through the same mechanism. Growth in GM medium plus cAMP or glycerol minimal medium did not result in a significant increase ingcvT-lacZ expression. Thus, the level of cAMP present in GM medium appears to be sufficient for regulation by CRP. DNase I footprint analysis showed that CRP binds and protects two sites centered at bp −313 (site 1) and bp −140 (site 2) relative to the transcription initiation site, but a mutational analysis demonstrated that only site 1 is required for CRP-mediated regulation ofgcvT-lacZ expression. Expression of thegcvT-lacZ fusion in a crp gcvA double mutant suggested that CRP’s role is dependent on the GcvA protein.

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