Exam 11: Transcription in Eukaryotes

What is the key property of DNase I that makes it useful for determining whether chromatin is in a closed (tightly condensed) or open (loosely packed) configuration?

The unwinding of DNA during the initiation of transcription is mediated by The helicase activity of

The basic leucine zipper (bZIP) motif has all of the following characteristics, except:

What roles are histone acetyltransferases (HATs), histone deacetylases (HDACs), histone methyltransferases (HMTs) thought to play in activation and repression of transcription?

RNA polymerase II is only responsive to the presence of transcriptional activators in the presence of which protein complex?

What types of proteins bind to promoter-proximal elements?

TAFs and TBP are together known as

Explain why transcription factors are called "modular" proteins. How is this exploited in a yeast two-hybrid assay?

Compare and contrast the structure and function of six post-translational modifications of histone N-terminal tails.

You have discovered a novel factor that you think is involved in facilitating transcription through nucleosome arrays. You propose that the factor displaces a histone dimer from the core octamer, leaving a core hexamer on the DNA. Design an experiment to test your hypothesis and show sample positive results.

Describe a common motif found in transactivation domains.

Nuclear import and export of proteins

A long-range regulatory element that marks the border between regions of heterochromatin and euchromatin is called a(n)

Explain how the disease Greig cephalopolysyndactyly syndrome is related to the zinc-finger DNA binding domain.

You are studying a new class of eukaryotic promoters recognized by a novel RNA polymerase. You discover two general transcription factors that are required for transcription of these promoters. You suspect that one has helicase activity and that the other is required to recruit the helicase and the RNA polymerase to the promoter. Describe experiments you would perform to test your hypothesis. Provide sample results of your experiments.

Diagram the key steps in the regulated nuclear import of NF- $\kappa$ B.

What does "Sonic the Hedgehog" have to do with zinc fingers?

Steroid hormones, such as glucocorticoids, bind to receptors inside the cell. The hormone-receptor complex is transported into the nucleus, where it can directly affect gene expression. To get from the location where the receptor binds the hormone to its site of action:

Discuss how Ran functions as a "molecular switch" in both nuclear import and export.

Describe a model for transcriptional regulation by matrix attachment regions (MARs).