Molbiol 2011-12-eukaryotic gene-expression

Notes de l'éditeur

1. Questives What form of transcriptional regulation is used in eukaryotic cells? What problem does RNA polymerase encounter when attempting to gain access to a eukaryotic promoter? What does Dnase I do to isolated chromatin? When the DNA fragments from Dnase I treatment of chromatin are visualized by agarose gele electrophoresis, what is seen? Why is a ladder produced? What does the size of the bands reflect? Would you expect to see this pattern in all DNA? Which part of a transcriptionally active gene would you expect to lose the ladder? So what does Dnase hypersensitivity reflect? What happens to histone H1 during transcription of a gene? How does methylation of cytosine in CpG islands affect transcription? Is there a drug that can affect methylation? What are two domains of histones? How does acetylation of histones affect Nucleosome assembly? Nucleosome structure? Transcription? Where is a TATA box located? What distinguishes an enhancer from a promoter? What are 3 classes of eukaryotic transcription factors? What do basal transcription factors do? What does a DNA binding transactivator do? What DNA sequence does it bind? What protein(s) does it interact with? What do coactivators do? What are three ways in which a repressor interacts with an inducer in eukaryotes? Give an example of a DNA binding transactivator that binds to hormones? What three domains are necessary for a Ligand binding/DNA binding transactivator to work? What type of control is exerted over the GAL genes of yeast? Why are these genes coordinately controlled? How does the induction/repression system in GAL work? What is the function of Gal4p? Gal3p Gal80 What is SP1? What does it bind? What is CFT1? What does it bind?
2. Quiztiff What two types of hormone receptors are there? Where are diffusible receptors located prior to binding hormone? What happens on binding hormone? What type of transcription factor is a diffusible receptor? Name a few steroid hormones. How does a steroid reach its target tissue? Why do some require carriers? How do they cross the membrane barrier of a cell? Draw a typical steroid hormone receptor Which region is most variable in sequence? What is the defect in testicular feminization? What is the difference between cis and trans elements? What is the HRE? What modification of a transcription factor commonly affects its activity? What advantage does translational regulation of gene expression through sequestration of an mRNA confer on gene expression as opposed to regulation at the level of transcriptional initiation? What are three mechanisms of translational repression in eukaryotes? In what cell does eIF2 inhibition act to interfere with globin synthesis? What protein regulates this translational repression? What structure does EIF4G bind and what does this result in? How does maskin interfere with this interaction? What three gene families are responsible for fly development? Where are Maternal effect genes active? What doe maternal effect genes establish? What do segmentation genes do? What do homeotic genes do? In what structure is polarity established? What is the main difference between the effect of gap genes and pair rule genes? A segment originally destined to give rise to a haltere in a fly has given rise to a set of wings. Which gene has been mutated? What type of gene is antennaepedia? What creates polarity? How is the initial gradient within an egg established? What does the gradient consist of? How does bicoid regulate caudal? How does bicoid regulate hunchback? What does hunchback do? What is the result of a mutation in bicoid? What type of gene is fushi tarazu? What does fushi tarazu do?