Exam 17: Transcriptional Regulation in Eukaryotes

The GAL gene system in yeast is used to metabolize galactose.In the presence of galactose,the GAL genes are expressed; however,in the absence of galactose,the GAL genes are repressed.A yeast mutant is discovered that continuously expresses the GAL genes in the presence or absence of galactose.Which GAL gene is likely mutated?

The human metallothionein IIA gene hMTIIA)is transcriptionally regulated through the interplay of regulatory elements and transcription factors.What is the function of this gene,and how is it regulated by environmental circumstances?

Explain why a transcription factor must have at least two functional domains.

UASs upstream activating sequences)are DNase hypersensitive.This means that__________ .

Two modular elements that appear as consensus sequences upstream from RNA polymerase II transcription start sites are__________ .

Enhancers are said to be cis- acting.What is meant by cis- acting,and what are enhancers?

Describe the ENCODE project and list five of their findings.

Some diseases are linked to the under or over expression of specific genes.A particular cancer is characterized by the overexpression of a gene.Do you predict the histones associated with this gene to be acetylated? Describe why this would lead to increased gene expression and how histone acetyl transfer HAT)and histone deacetylase HDAC)could be involved.

Describe the difference between a focused promoter and a dispersed promoter.

Approximately 5% of the cytosine residues are methylated in the genome of any given eukaryote.In what way is DNA methylation related to genetic regulation?

Explain five ways that eukaryotic gene regulation is more complex than bacterial gene regulation?

The nuclear regions that contain RNA polymerase and transcription regulatory molecules that help compartmentalize eukaryotic regulation are called__________ .

In a particular organism,there are two similar genes called YFG1 and YFG2.YFG1 is expressed in the liver and not in the pancreas,and YFG2 is expressed in the pancreas but not the liver.Neither YFG1 nor YFG2 is expressed in the heart.Based on these observations,which of the following is most true?

Describe how the presence or absence of nucleosomes influences gene transcription.

A regulatory sequence of DNA that is 10,000 base pairs away from the gene it regulates is mutated.The result is that the gene being regulated is now expressed at a higher rate compared to when this regulatory sequence was not mutated.What would this sequence of DNA best be called?

Transcription factors are important molecules that regulate gene activity in eukaryotes.What are the two general classes of transcription factors that exist in eukaryotes? Describe where they bind and what their effects are.

What is meant by the term helix- turn- helix HTH ?

In what way 5'- azacytidine is used experimentally)in the treatment of sickle- cell anemia?

Describe three characteristics of enhancers and silencers.