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Upstream activating sequence

About: Upstream activating sequence is a research topic. Over the lifetime, 1633 publications have been published within this topic receiving 100112 citations.


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Journal ArticleDOI
26 Dec 1986-Cell
TL;DR: It is shown that, in addition to its termination function, this same sequence motif acts as an upstream element of the adjacent promoter and appears to contribute to the long-term stability of the transcription complex.

111 citations

Journal ArticleDOI
TL;DR: Findings indicate that Nrg1 acts as a DNA-binding repressor and mediates glucose repression of the STA1 gene expression by recruiting the Ssn6-Tup1 complex.
Abstract: Expression of genes encoding starch-degrading enzymes is regulated by glucose repression in the yeast Saccharomyces cerevisiae. We have identified a transcriptional repressor, Nrg1, in a genetic screen designed to reveal negative factors involved in the expression of STA1, which encodes a glucoamylase. The NRG1 gene encodes a 25-kDa C2H2 zinc finger protein which specifically binds to two regions in the upstream activation sequence of the STA1 gene, as judged by gel retardation and DNase I footprinting analyses. Disruption of the NRG1 gene causes a fivefold increase in the level of the STA1 transcript in the presence of glucose. The expression of NRG1 itself is inhibited in the absence of glucose. DNA-bound LexA-Nrg1 represses transcription of a target gene 10.7-fold in a glucose-dependent manner, and this repression is abolished in both ssn6 and tup1 mutants. Two-hybrid and glutathione S-transferase pull-down experiments show an interaction of Nrg1 with Ssn6 both in vivo and in vitro. These findings indicate that Nrg1 acts as a DNA-binding repressor and mediates glucose repression of the STA1 gene expression by recruiting the Ssn6-Tup1 complex.

111 citations

Journal ArticleDOI
TL;DR: It is proposed that two short sequence elements just upstream of initiation sites form at least a portion of the sequence requirements for a maize mitochondrial promoter, suggesting that posttranscriptional processes are important in the modulation of mRNA abundance.
Abstract: Lysed maize mitochondria synthesize RNA in the presence of radioactive nucleoside triphosphates, and this assay was utilized to compare the rates of transcription of seven genes. The rates of incorporation varied over a 14-fold range, with the following rank order: 18S rRNA greater than 26S rRNA greater than atp1 greater than atp6 greater than atp9 greater than cob greater than cox3. The products of run-on transcription hybridized specifically to known transcribed regions and selectively to the antisense DNA strand; thus, the isolated run-on transcription system appears to be an accurate representation of endogenous transcription. Although there were small differences in gene copy abundance, these differences cannot account for the differences in apparent transcription rates; we conclude that promoter strength is the main determinant. Among the protein coding genes, incorporation was greatest for atp1. The most active transcription initiation site of this gene was characterized by hybridization with in vitro-capped RNA and by primer extension analyses. The DNA sequences at this and other transcription initiation sites that we have previously mapped were analyzed with respect to the apparent promoter strengths. We propose that two short sequence elements just upstream of initiation sites form at least a portion of the sequence requirements for a maize mitochondrial promoter. In addition to modulation at the level of transcription, steady-state abundance of protein-coding mRNAs varied over a 20-fold range and did not correlate with transcriptional activity. These observations suggest that posttranscriptional processes are important in the modulation of mRNA abundance.

111 citations

Journal ArticleDOI
TL;DR: Variations in the structure of a core promoter might alter the rate-limiting step for transcription initiation and thereby alter the potential modes of transcriptional regulation, without severely changing the pathway used to assemble a functional preinitiation complex.
Abstract: Promoters containing Sp1 binding sites and an initiator element but lacking a TATA box direct high levels of accurate transcription initiation by using a mechanism that requires the TATA-binding protein (TBP). We have begun to address the role of TBP during transcription from Sp1-initiator promoters by varying the nucleotide sequence between -14 and -33 relative to the start site. With each of several promoters containing different upstream sequences, we detected accurate transcription both in vitro and in vivo, but the promoter strengths varied widely, particularly with the in vitro assay. The variable promoter activities correlated with, but were not proportional to, the abilities of the upstream sequences to function as TATA boxes, as assessed by multiple criteria. These results confirm that accurate transcription can proceed in the presence of an initiator, regardless of the sequence present in the -30 region. However, the results reveal a role for this upstream region, most consistent with a model in which initiator-mediated transcription requires binding of TBP to the upstream DNA in the absence of a specific recognition sequence. Moreover, in vivo it appears that the promoter strength is modulated less severely by altering the -30 sequence, consistent with a previous suggestion that TBP is not rate limiting in vivo for TATA-less promoters. Taken together, these results suggest that variations in the structure of a core promoter might alter the rate-limiting step for transcription initiation and thereby alter the potential modes of transcriptional regulation, without severely changing the pathway used to assemble a functional preinitiation complex.

110 citations

Journal ArticleDOI
TL;DR: A hybrid protein containing TBP of the yeast Saccharomyces cerevisiae fused to the DNA-binding domain of GAL4 can interact with the TATA element and direct high levels of transcription, indicating that binding of TBP to promoters in S. Cerevisiae is a major rate-limiting step accelerated by upstream activator proteins.
Abstract: The binding of TATA-binding protein (TBP) to the TATA element is the first step in the initiation of RNA polymerase II transcription from many promoters in vitro. It has been proposed that upstream activator proteins stimulate transcription by recruiting TBP to the promoter, thus facilitating the assembly of a transcription complex. However, the role of activator proteins acting at this step to stimulate transcription in vivo remains largely speculative. To test whether recruitment of TBP to the promoter is sufficient for transcriptional activation in vivo, we constructed a hybrid protein containing TBP of the yeast Saccharomyces cerevisiae fused to the DNA-binding domain of GAL4. Our results show that TBP recruited by the GAL4 DNA-binding domain to promoters bearing a GAL4-binding site can interact with the TATA element and direct high levels of transcription. This finding indicates that binding of TBP to promoters in S. cerevisiae is a major rate-limiting step accelerated by upstream activator proteins.

110 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20232
20223
20218
20206
20196
20186