Lecture 5 - Regulation of Gene Expression

Question 1

Alternative promoter use and regulation of the NF-kB pathway are forms of what type of genetic regulation?

Answer 1

Transcriptional regulation

Question 2

Use of alternative promoters allows for:

Answer 2

different isoforms of a particular protein

Question 3

What type of regulation involves controlling the access of RNA polymerase to the gene?

Answer 3

Transcriptional control

Question 4

There is a strong ________ correlation between DNA methylation and chromatin accessibility.

Answer 4

Inverse

Question 5

What type of regulation involves control at the level of alternative splicing or polyadenylation?

Answer 5

Post-transcriptional control

Question 6

Alternative splicing and polyadenylation are types of ______.

Answer 6

RNA processing

Question 7

What type of regulation involves control at the level of mRNA transport and mRNA stability?

Answer 7

Post-transcriptional control

Question 8

What two classes of elements are involved in transcriptional control?

Answer 8

1. cis-acting elements

2. activator or repressor proteins

Question 9

What element(s) function to bind DNA and/or interact with transcription proteins?

Answer 9

Activator or repressor proteins

Question 10

DNA sequence elements adjacent to or within the gene are called: _______

Answer 10

cis-acting elements

Question 11

Imprinted genes are an example of what type of transcriptional regulation?

Answer 11

DNA methylation

Question 12

Covalent modification of histones (such as acetylation and methylation) may regulate a gene by producing changes in: __________

Answer 12

local chromatin structure

Question 13

What are two examples of covalent modifications of histones?

Answer 13

Acetylation

Methylation

Question 14

Binding a regulatory protein to ______ elements of the DNA may either activate or repress transcription.

Answer 14

cis-acting elements

Question 15

Many promoters lack a TATA box and use _________ instead.

Answer 15

initiator (INR) element - note: this is functionally analogous. The core promoter of individual genes need not contain all elements of a promoter region.

Question 16

Eukaryotic promoters contain conversed sites that are bound by: _____.

Answer 16

Ubiquitous transcription factors

Question 17

What is one example of a promoter with a variety of sequence elements recognized by ubiquitous and tissue-specific transcription factors?

Answer 17

Human insulin gene promoter

Question 18

The _________ gene is often regulated by alternative promoter use, so that alternative promoters can generate tissue-specific isoforms.

Answer 18

Dystrophin gene

Question 19

What form of post-transcriptional regulation determines whether an antibody molecule is secreted or remains membrane-bound/?

Answer 19

Regulation of the site of RNA cleavage and poly-A addition

Question 20

What allows for the cleavage of membrane bound OR secreted forms of immunoglobulin?

Answer 20

Alternative polyadenylation

Question 21

Is a-tropomyosin made in striated muscle different from that made from the same gene in smooth muscle? How does this occur?

Answer 21

It is different because of alternative splicing - the primary transcript can be spliced in different ways to produce distinct mRNAs, which then give rise to different proteins.

Question 22

Regulation of ferritin heavy chain and transferrin receptor production by iron is what form of post-transcriptional control?

Answer 22

Control of mRNA translation and stability.

Question 23

Processing of human apolipoprotein B rRMA in the intestine is an example of tissue-specific __________.

Answer 23

RNA editing (a form of post-transcriptional control)

Question 24

MicroRNAs are very small and regulate gene expression by what type of mechanism?

Answer 24

An antisense mechanism

Question 25

RNAi is an important form of gene expression regulation that utilizes ___________ RNAs.

Answer 25

antisense

Question 26

_______ are encoded by noncoding regions of the genome as well as by introns of protein coding genes.

Answer 26

MiRNAs

Question 27

In RNA interference, the target mRNAs can either be degraded or their translation inhibited based on what?

Answer 27

Their degree of mismatch between the miRNA and mRNA

Question 28

The degree of mismatch between the miRNA and the mRNA during RNAi can determine whether a target mRNA is ________ or _________

Answer 28

degraded or translation inhibited

Question 29

A single mRNA can be regulated by __________; a single miRNA can regulate ________.

Answer 29

A single mRNA can be regulated by multiple miRNAs; a single miRNA can regulate multiple mRNAs.

Question 30

MiRNA expression profiles have been shown to be significantly altered in:

Answer 30

a variety of human diseases, including cancers. They can potentially be used for early diagnosis and prognosis of disease.

Question 31

Iron levels in the body stimulate production of ferritin protein without a corresponding increase in the levels of mRNA. Which of the following best describes this phenomenon? A. RNA editing B. Alternative splicing C. Translational regulation D. Ubiquitination

Answer 31

C.

Question 32

a-tropomyosin regulates contraction in muscle cells. The primary transcript can be spliced in different ways to produce distinct mRNAs, which then give rise to variant proteins - for example, in striated vs. smooth muscle cells. Which of the following best describes this phenomenon? ``` A. RNA editing B. Alternative splicing C. Translational regulation D. Ubiquitination E. Alternative polyadenylation ```

Answer 32

B.

Question 33

In unstimulated B lymphocytes, an intron sequence near the 3' end is removed to provide an mRNA that codes for membrane-bound antibody molecule. After antigen stimulation, however, the RNA transcript is cleaved upstream from the intron's 3' splice site. Some of the intron sequence remains as a coding sequence in the short transcript and the antibody molecule is secreted. Which of the following best describes this phenomenon? ``` A. RNA editing B. Alternative splicing C. Translational regulation D. Ubiquitination E. Alternative polyadenylation ```

Answer 33

E.

Question 34

In the liver, a codon CAA of the APOB mRNA specifies glutamine but is replaced by U in the intestine to make stop codon UAA. Which of the following best describes this phenomenon? ``` A. RNA editing B. Alternative splicing C. Translational regulation D. Ubiquitination E. Alternative polyadenylation ```

Answer 34

A.