Upstream activating sequence: Difference between revisions

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An '''upstream activation sequence''' (UAS) is a [[Cis-regulatory element|cis-acting regulatory sequence]]. It is distinct from the [[promotor (biology)|promoter]] and increases the [[Transcription (genetics)|expression]] of a neighbouring [[gene]]. Due to its essential role in activating transcription, the upstream activating sequence is often considered to be analogous to the function of the enhancer in multicellular eukaryotes.<ref>{{cite journal|last1=Webster|first1=Nocholas|last2=Jin|first2=Jia Rui|last3=Green|first3=Stephen|last4=Hollis|first4=Melvyn|last5=Chambon|first5=Pierre|title=The Yeast UAS{{sub|G}} is a transciptional enhancer in human hela cells in the presence of the GAL4 trans-activator|journal=Cell|date=29 January 1988|volume=52|issue=2|pages=169-178}}</ref>

Its property to bind the GAL4 protein is utilised in the [[GAL4/UAS system|GAL4/UAS technique]] for controlled gene misexpression in Drosophila. In this technique, four related binding sites between the GAL10 and GAL1 loci in ''Saccharomyces cerevisiae'' serve as an Upstream Activating Sequences (UAS) element through GAL4 binding.<ref>{{cite journal|last1=Duffy|first1=Joseph B.|title=GAL4 system in Drosophilia: A Fly Geneticist's Swiss Army Knife|journal=Genesis|date=2002|volume=34|issue=1-2|pages=1-15}}</ref>

==Instances==

Several studies have been conducted with ''Saccharomyces cerevisiae'' to explore the exact function of upstream activation sequences, often focusing on the GAL1-GAL10 intergenic region [https://www.wikigenes.org/e/gene/e/852307.html]. One such study explored the galactose-responsive upstream activation sequence (UAS{{sub|G}}),looking at the influence of proximity to this UAS for nucleosome positioning. The role of specific regions of UAS{{sub|G}} was analyzed by inserting oligonucleotides with different binding properties, leading to the successful identification of a region responsible for the creation of an ordered array.<ref>{{cite journal|last1=Fedor|first1=Martha J.|last2=Lue|first2=Neal F.|last3=Kornberg|first3=Roger D.|title=Statistical positioning of nucleosomes by specific protein-binding to an upstream activating sequence in yeast|journal=Journal of Molecular Biology|date=5 November 1988|volume=204|issue=1|pages=109-127}}</ref> Another study looked at the effect of inserting the UAS{{sub|G}} into the promoter region of the glyceraldehyde-3-phosphate dehydrogenase gene (GPD). When compared to the native GPD promoter, the transcriptional activity remained equivalently enhanced under induced conditions.<ref>{{cite journal|last1=Bitter|first1=Grant A.|last2=Egan|first2=Kevin M.|title=Expression of interferon-gamma from hybrid yeast GPD promoters containing upsream regulatory sequences from the GAL1-GAL10 intergenic region|journal=Gene|date=30 September 1988|volume=69|issue=2|pages=193-207}}</ref>

===GAL1-GAL10===

It has been shown to be involved in five of the seven genes which are glucose repressed. These genes were repressed in yeast ([[Saccharomyces cerevisiae]]) eventually after growing for hours in YPD (Yeast peptone dextrose) media. After using up glucose for fermentation, these genes get activated for aerobic respiration.

Several studies have been conducted with ''Saccharomyces cerevisiae'' to explore the exact function of upstream activation sequences, often focusing on the GAL1-GAL10 intergenic region [https://www.wikigenes.org/e/gene/e/852307.html]. Its property to bind the GAL4 protein is utilised in the [[GAL4/UAS system|GAL4/UAS technique]] for controlled gene misexpression in Drosophila. In this technique, four related binding sites between the GAL10 and GAL1 loci in ''Saccharomyces cerevisiae'' serve as an Upstream Activating Sequences (UAS) element through GAL4 binding.<ref>{{cite journal|last1=Duffy|first1=Joseph B.|title=GAL4 system in Drosophilia: A Fly Geneticist's Swiss Army Knife|journal=Genesis|date=2002|volume=34|issue=1-2|pages=1-15}}</ref>.

Several studies have been conducted with ''Saccharomyces cerevisiae'' to explore the exact function of upstream activation sequences, often focusing on the GAL1-GAL10 intergenic region [https://www.wikigenes.org/e/gene/e/852307.html]. One such study explored the galactose-responsive upstream activation sequence (UAS{{sub|G}}),looking at the influence of proximity to this UAS for nucleosome positioning. The role of specific regions of UAS{{sub|G}} was analyzed by inserting oligonucleotides with different binding properties, leading to the successful identification of a region responsible for the creation of an ordered array.<ref>{{cite journal|last1=Fedor|first1=Martha J.|last2=Lue|first2=Neal F.|last3=Kornberg|first3=Roger D.|title=Statistical positioning of nucleosomes by specific protein-binding to an upstream activating sequence in yeast|journal=Journal of Molecular Biology|date=5 November 1988|volume=204|issue=1|pages=109-127}}</ref> Another study looked at the effect of inserting the UAS{{sub|G}} into the promoter region of the glyceraldehyde-3-phosphate dehydrogenase gene (GPD). When compared to the native GPD promoter, the transcriptional activity remained equivalently enhanced under induced conditions.<ref>{{cite journal|last1=Bitter|first1=Grant A.|last2=Egan|first2=Kevin M.|title=Expression of interferon-gamma from hybrid yeast GPD promoters containing upsream regulatory sequences from the GAL1-GAL10 intergenic region|journal=Gene|date=30 September 1988|volume=69|issue=2|pages=193-207}}</ref>

Another study looked at the effect of inserting the UAS{{sub|G}} into the promoter region of the glyceraldehyde-3-phosphate dehydrogenase gene (GPD). When compared to the native GPD promoter, the transcriptional activity remained equivalently enhanced under induced conditions.<ref>{{cite journal|last1=Bitter|first1=Grant A.|last2=Egan|first2=Kevin M.|title=Expression of interferon-gamma from hybrid yeast GPD promoters containing upsream regulatory sequences from the GAL1-GAL10 intergenic region|journal=Gene|date=30 September 1988|volume=69|issue=2|pages=193-207}}</ref>

==References==