ch. 15

Which DNA sequence would also work in place of the following bi-directional enhancer?

5' GTTC 3'

3' CAAG 5'

A) 5' GAAC 3'

3' CTTG 5

Select all structural motifs that promote protein dimerization.

Leucine zipper

Helix-loop-helix

Which of the following is a region in DNA that binds to a steroid receptor?

GRE

A mutation in which of the following would result in little or no effect on the expression of a

gene regulated by a CRE?

Glucocorticoid receptor

What activates CREB?

Phosphorylation

What would be the result of a mutation in Hsp90 that prevented its binding to the glucocorticoid

receptor?

Expression of the regulated genes would become constitutive

What general transcription factor is most often affected by regulatory transcription factors?

TFIID

Which of the following recognizes response elements, control elements, and regulatory

elements?

Regulatory transcription factors

cAMP is known as a second messenger since the pathway is first activated by a extracellular

signaling molecule.

True

Which one of the following directly interacts with the DNA as a transcriptional regulator?

CREB protein dimer

Histone acetyltransferases are directly involved in which of the following?

Chemical modification of histones

CpG islands are associated with which of the following?

DNA methylation

Genomic imprinting is a result of ________.

DNA methylation

Transcription factors are proteins that influence the ability of the RNA polymerase to

transcribe a gene.

True

Activator proteins bind to silencer sequences and repressor proteins bind to enhancer

sequences.

False

If a portion of a transcription factor's domain is the same in a variety of organisms, it is called

a motif.

True

A heterodimer occurs when two identical transcription factors interact on a sequence of DNA.

False

A repressor protein would enhance the ability of TFIID to bind to the TATA box of the

promoter.

False

Steroid hormones are an example of an effector which regulates regulatory transcription factor

activity

True

Prior to hormone binding, receptors for steroid hormones are usually found in the nucleus of

the cell.

False

DNA that contains actively transcribed genes would most likely contain chromatin in the

closed configuration.

False

Nucleosome location may be changed by a process called ATP-dependent chromatin

remodeling.

True

DNA methylation usually activates gene expression.

False

Housekeeping genes are unmethylated and active in most cells.

True

For which of the following histones has variant forms not yet been identified?

H4

In ChIP-Seq, the DNA fragments to be sequenced are around 150 bp in length. What does this

size of DNA represent?

B) The amount of DNA wrapped around a nucleosome

A particular cell contains all of the standard histones but lacks several histone variants. Which

of the following MAY be true of this cell?

D) The cell will express different sets of genes than other cells in the same organism.

Which of the following might complicate the interpretation of ChIP-Seq data?

Because histones can be moved around or ejected from the chromatin, DNA that is only

sometimes wrapped around a histone might not be sequenced.

A particular gene has a mutation in its NFR that causes it to bind abnormally tightly to

histones. What effect would you expect this mutation has on the expression of this gene?

The expression of the gene would be abnormally low or absent

Which DNA sequence important for gene expression is usually contained within the NFR?

Core promoter

What might happen if the insulator between two genes is missing?

Transcription factors influencing one gene's expression may abnormally influence a

neighboring gene's expression.

Which of the following is the most likely location of an insulator sequence?

Between two genes

Which of the following is a major finding from the ENCODE project?

More than 80% of the human genome sequence is linked to a biological function.

A transactivation domain is an example of a motif found in transcription factors

False

Methylation of DNA bases is one way that regulatory transcription factors may influence gene

expression.

False

The activity of some transcription factors can be regulated by covalent modifications.

True

When a glucocorticoid hormone binds to the glucocorticoid receptor, HSP90 is released.

True

Insulators exert their effects on gene expression through histone acetyltransferase, histone

deacetylase, and RNA polymerase.

False

In the presence of abundant iron in the cell, the iron binds IRP. The complex is then released

from IREs leading to

an increase in ferritin mRNA translation and a decrease in transferrin receptor mRNA stability.