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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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TL;DR: It is demonstrated that three homologous DNA sequences originally reported to be present in the inducer-responsive UASI are in fact three exchangeable elements (UASI-A, UAS I-B, and UASi-C), which are required for maximal levels of induction.
Abstract: Arginase (CAR1) gene expression in Saccharomyces cerevisiae is induced by arginine. The 5' regulatory region of CAR1 contains four separable regulatory elements--two inducer-independent upstream activation sequences (UASs) (UASC1 and UASC2), an inducer-dependent UAS (UASI), and an upstream repression sequence (URS1) which negatively regulates CAR1 and many other yeast genes. Here we demonstrate that three homologous DNA sequences originally reported to be present in the inducer-responsive UASI are in fact three exchangeable elements (UASI-A, UASI-B, and UASI-C). Although two of these elements, either the same or different ones, are required for transcriptional activation to occur, all three are required for maximal levels of induction. The elements operate in all orientations relative to one another and to the TATA sequence. All three UASI elements bind protein(s); protein binding does not require arginine or overproduction of any of the putative arginine pathway regulatory proteins. The UASI-protein complex was also observed even when extracts were derived from arg80/argRI or arg81/argRII deletion mutants. Similar sequences situated upstream of ARG5,6 and ARG3 and reported to negatively regulate their expression are able to functionally substitute for the CAR1 UASI elements and mediate reporter gene expression.

11 citations

Journal ArticleDOI
01 May 1991-Virology
TL;DR: The upstream element was necessary for efficient expression of the pseudorabies virus immediate-early gene and increased somewhat the efficiency of the herpes simplex virus thymidine kinase promoter.

11 citations

Journal ArticleDOI
TL;DR: It is shown that the ovine S GLT1 promoter fragment can drive the transcription of a reporter gene when transfected into the epithelial cell lines STC-1 and LLC-PK1, which endogenously express SGLT1.

11 citations

Journal ArticleDOI
TL;DR: The nif promoters are representative of a new class of promoter, the members of which lack the consensus sequences normally found in prokaryotic promoters.
Abstract: Seventeen genes specifically required for nitrogen fixation are clustered on the chromosome of Klebsiella pneumoniae and form a complex regulon that is organized into eight transcriptional units. The nif promoters are representative of a new class of promoter, the members of which lack the consensus sequences normally found in prokaryotic promoters. nif gene transcription is positively controlled and requires: (1) the ntrA gene product, which replaces the rpoD-encoded sigma subunit of RNA polymerase to allow recognition of nif promoter sequences; and (2) the product of either the nitrogen regulation gene ntrC or the specific nif regulatory gene, nifA, which are both transcriptional activators. Most nif promoters require an upstream activator sequence (UAS) for nifA-mediated activation. The UAS acts independently of orientation and can function when placed 2 kilobases upstream from the transcription start site. Current evidence suggests that activation requires an interaction between proteins bound at the UAS and at the downstream nif promoter consensus, possibly via a loop in the DNA structure. Transcription of nif is modulated by the ntrB and nifL gene products. Both proteins can `sense' environmental changes: ntrB prevents activation by ntrC in response to excess nitrogen whereas nifL prevents activation by nifA in response to fixed nitrogen and oxygen. The C-terminal end of ntrB shows clear homology at the amino acid level with a number of diverse control proteins involved in regulation or sensory transduction. Each member of this family interacts with another protein component showing homology to the N-terminal sequence of ntrC, but not to nifA. The significance of these protein homologies is discussed.

11 citations

Journal ArticleDOI
TL;DR: The various regulatory stimuli affecting expression of fdhF in E. coli have their target at the upstream regulatory sequence, i.e. anaerobic induction with formate and repression by oxygen and nitrate.
Abstract: Summary Hybrid 5′ regulatory regions were constructed in which the upstream activator sequence (UAS) and promoter of various nif genes were exchanged with the upstream regulatory sequence (URS) of the fdhF gene from Escherichia coli. They were analysed for their regulatory response under different growth conditions with the aid of fdhF′-′lacZ or nif′-′lacZ fusions. Placement of the UAS from the Bradyrhizobium japonicum nifH gene in front of the spacer (DNA region between URS and promoter) plus promoter from fdhF renders fdhF expression activatable by the Klebsiella pneumoniae NIFA protein, both under aerobic and anaerobic conditions. This excludes the possibility that the spacer of the fdhF 5’flanking region contains a site recognized by a putative oxygen- or nitrate-responsive repressor. There was also considerable activation by NIFA of fdhF expression in a construct lacking the nifH UAS but containing the fdhF spacer plus promoter. Further experimental evidence suggests that this reflects a direct interaction between NIFA and RNA polymerase at the nfrA-dependent promoter. A second set of hybrid constructs in which the URS from fdhF (E. coli) was placed In front of the nifD spacer plus promoter from B. Japonicum or in front of the K. pneumoniae nifH, nifU, nifB spacers and promoters, delivered inactive constructs in the case of the nifD, nifU and nifB genes. However, a nifH′-′lacZ fusion preceded by its own spacer and promoter plus the foreign fdhF URS displayed all the regulatory characteristics of fdhF expression, i.e. anaerobic induction with formate and repression by oxygen and nitrate. Although it is not known why only one out of the four nif promoters could be activated by the fdhF URS, this result nevertheless demonstrates that the various regulatory stimuli affecting expression of fdhF in E. coli have their target at the upstream regulatory sequence.

11 citations


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