Exam 11: Transcription in Eukaryotes

Transcription of protein-coding genes in eukaryotes is carried out by

A team of molecular biologists has made transgenic mice using a viral promoter and a cDNA coding for a human protein called p45. In most of the transgenic mice, they observe position-dependent expression of the human gene. They seek your advice. Suggest regulatory regions that you could link to the promoter- p45 DNA construct that might confer position-independent expression. Explain your choice of regulatory regions.

Describe two models for translocation of cargo through the nuclear pore complex.

Compare and contrast the key characteristics of proximal promoter elements, enhancers, and locus control regions.

Assume that you are studying a transcription factor (TF). You have constructed a plasmid vector for expression of GFP-tagged TF. You discover that TF is sometimes in the nucleus and sometimes in the cytoplasm. Describe a possible mechanism for its cytoplasmic retention and subsequent signal-mediated import. Design an experiment to test your hypothesis and provide sample results.

You have purified a transcription factor that has a leucine-rich region. You perform an electrophoretic mobility shift assay (EMSA) using a double-stranded oligonucleotide that you know from other studies contains the site recognized by this transcription factor in vivo. However, the transcription factor does not bind to the labeled oligonucleotide in your EMSA. Provide an explanation for this result.

You have made a transgenic mouse using a cDNA coding for a human protein under control of a heterologous promoter. In most of the transgenic mice, you observe position-dependent expression of the human protein. Define the term "position-dependent" and give examples of regulatory regions that you could link to the promoter-human cDNA construct that might confer position-independent expression. Explain your choice of regulatory regions.

Reinitiation of transcription requires

Which assay would allow you to determine whether two transcription factors with nearby binding sites in a promoter sequence bind to the sequence synergistically?

Diagram the key steps in the regulated nuclear import of the glucocorticoid receptor (GR).

RanGAP stimulates the conversion of

During nuclear transport, RanGTP

Chromatin remodeling by the SWR1 family results in:

Small eukaryotic proteins that are known to add specificity to polymerase-dependent RNA synthesis are known as