Describe and give an example (real or hypothetical) of each of...

Question

Describe and give an example (real or hypothetical) of each of the following: upstream activator sequence (UAS)

Accepted Answer

Hi, everyone. Welcome back. Here's our next question. Which of the following statements correctly pairs the role of the upstream activator sequence U A S with an example, choice A U A S elements are involved in the regulation of gene expression by binding to ribosomes to initiate translation. For example, G one U A S and yeast choice B U A S elements are responsible for splicing pre M R N A into mature M R N A. For example, C A MP response element C R E and mammals. Choice C U A S elements are involved in the regulation of gene expression by acting as binding sites for transcription factors. For example, lack operon U A S and bacteria. And finally, choice D U A S elements are involved in the post transcription of regulation of gene expression. For example, enhancer U A S Andrea. So we need to pair what the role is of the U A S and an example of this. So the U A S is upstream of the promoter in a team and it is a binding site or transcription factors that up regulate gene expression. So either causing it to be initiated or enhancing it causing it to increase. So that leads us to choice C which says U A S elements are involved in the regulation of gene expression by acting as binding sites for transcription factors. The example given is the lac operon U A S and bacteria. And this is an example of this happening when glucose is absent, that results in an increase in the amount of C A MP in A cell. C A MP binds to the protein cap and this C A MP cap complex binds to the cap binding site which is an upstream activator sequence because once it binds to the cap binding site that enhances the transcription of the lack genes. And it does that by causing the R N A polymer to bind more tightly to the promoter, causing a greater amount of gene transcription. So that is a correct example. Let's just look at our other answer choices to understand why they're incorrect choice. A correctly says that they're involved in the regulation of gene expression. But it says by binding to ribosomes to initiate translation. But this is not correct because they help to initiate transcription, not translation. So that's why choice A is not correct choice. B says they're responsible for splicing pre M R N A into mature M R N A. Well, this is not correct. That's the spliceosome, which is a large R N A protein complex that is responsible for that splicing. Not upstream activator elements. So that's why choice B is incorrect. And finally, choice D says they're involved in post transcription of regulation of gene expression. That would be things like splicing out introns, adding a poly, a tail, adding a five prime cap and that is not the role of upstream activator sequences. So that's why choice D is not correct. So again, which of the following statements correctly pairs the role of the upstream activator sequence. With an example, choice C U A S elements are involved in the regulation of gene expression by acting as binding sites for transcription factors. For example, lack opera on U A S in bacteria. See you in the next video.

Describe and give an example (real or hypothetical) of each of the following: upstream activator sequence (UAS)

Key Concepts

Upstream Activator Sequence (UAS)

Transcription Factors

Gene Regulation

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