• Home
  • Textbooks
  • Molecular Biology
  • Other RNA Processing Events and Post-Transcriptional Control of Gene Expression

Molecular Biology

Robert F. Weaver

Chapter 16

Other RNA Processing Events and Post-Transcriptional Control of Gene Expression - all with Video Answers

Educators

Chapter Questions

05:43

Problem 1

Draw the structure of a mammalian $\mathrm{rRNA}$ precursor, showing the locations of all three mature rRNAs.

Rabeya Zahid
Rabeya Zahid
Numerade Educator
02:13

Problem 1

Why can dicer dsRNA never completely block RNAi?

Hast Aggarwal
Hast Aggarwal
Numerade Educator
02:12

Problem 2

What is the function of RNase P? What is unusual about this enzyme (at least the bacterial and eukaryotic nuclear forms of the enzyme)?

Shazia Naz
Shazia Naz
Numerade Educator
02:07

Problem 2

Prediet the effects of the following mutativus on the abundance of the TfR mRNA. That is, would the mutations result in a constitutively low or high level of the TfR mRNA regardless of iron concentration, or would they have no effect on the mRNA level?
a. A mutation that blocks the production of aconitase.
b. A mutation that prevents aconitase from binding iron.
c. A mutation that prevents aconitase from binding to the IREs.

Rabeya Zahid
Rabeya Zahid
Numerade Educator
00:25

Problem 3

Discuss the conflicting evidence about the effect of lin-4 miRNA on expression of the lin-14 gene in C. elegans.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator

Problem 3

Illustrate the difference between cis- and trans-splicing.

Check back soon!

Problem 4

Describe and give the results of an experiment that shows that a $Y$-shaped intermediate exists in the splicing of a trypanosome pre-mRNA. Show how this result is compatible with trans-splicing, but not with cis-splicing.

Check back soon!
01:23

Problem 5

Describe what we mean by RNA editing. What is a cryptogene?

Rabeya Zahid
Rabeya Zahid
Numerade Educator

Problem 6

Describe and give the results of an experiment that shows that editing of kinetoplast mRNA goes in the $3^{\prime} \rightarrow 5^{\prime}$ direction.

Check back soon!
00:47

Problem 7

Draw a diagram of a model of RNA editing that fits the data at hand. What enzymes are involved?

Mikayla Stephens
Mikayla Stephens
Numerade Educator
01:40

Problem 8

Present direct evidence for guide RNAs.

Joanna Quigley
Joanna Quigley
Numerade Educator
02:51

Problem 9

Outline the evidence that shows that editing of the mouse GluR-B transcript by ADAR2 is essential, and that this transcript is the only critical target of ADAR2.

James Kiss
James Kiss
Numerade Educator

Problem 10

Describe and give the results of an experiment that shows that prolactin controls the casein gene primarily at the post-transcriptional level.

Check back soon!
02:59

Problem 11

What two proteins are most directly involved in iron homeostasis in mammalian cells? How do their levels respond to changes in iron concentration?

Mikayla Stephens
Mikayla Stephens
Numerade Educator
00:37

Problem 12

How do we know that a protein binds to the iron response elements (IREs) of the TfR mRNA?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator

Problem 13

Describe and give the results of an experiment that shows that one kind of mutation in the TfR IRE region results in an iron-unresponsive and stable $\mathrm{mRNA}$, and another kind of mutation results in an iron-unresponsive and unstable mRNA. Interpret these results in terms of the rapid turnover determinant and interaction with IRE-binding protein(s).

Check back soon!

Problem 14

Present a model for the involvement of aconitase in determining the stability of TfR mRNA.

Check back soon!
02:13

Problem 15

What evidence suggests that RNA interference depends on mRNA degradation?

Hast Aggarwal
Hast Aggarwal
Numerade Educator
02:26

Problem 16

Present a model for the mechanism of RNA interference.

Dennis Howard
Dennis Howard
Numerade Educator
02:51

Problem 17

Describe and give the results of an experiment that shows that Argonaute 2 has slicer activity.

James Kiss
James Kiss
Numerade Educator
02:51

Problem 18

What roles do R2D2 and Ago2 play in formation of the RISC? What happens if R2D2 is absent?

James Kiss
James Kiss
Numerade Educator
02:05

Problem 19

Diagram the ping-pong mechanism whereby piRNAs are thought to amplify themselves and inactivate transposons at the same time.

Rabeya Zahid
Rabeya Zahid
Numerade Educator
02:51

Problem 20

Present a model for the involvement of the RNAi machinery in heterochromatization in fission yeast. How would this model have to be modified to describe the situation in mammals?

James Kiss
James Kiss
Numerade Educator
00:45

Problem 21

Present a model for gene silencing and heterochromatization in flowering plants. In what major ways does this differ from the model in fission yeast?

Mikayla Stephens
Mikayla Stephens
Numerade Educator
00:30

Problem 22

What is the evidence for the importance of non-siRNA transcripts in gene silencing in fission yeast and in flowering plants?

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
04:17

Problem 23

Chromatin targets for heterochromatization in dividing cells must be transcribed in order to be silenced. How is this problem resolved in fission yeast and in flowering plants?

Eric Goldman
Eric Goldman
Numerade Educator
00:45

Problem 24

Describe and give the results of experiments showing: (1) that a mammalian gene can be silenced by a mechanism involving an siRNA directed at the gene's control region; and (2) that DNA methylation is involved in the silencing.

Mikayla Stephens
Mikayla Stephens
Numerade Educator
01:25

Problem 25

Outline the processes by which siRNAs and miRNAs are produced. List the key players in these processes. Be sure to include two different ways to produce pre-miRNAs.

Josee Pacheco
Josee Pacheco
Numerade Educator
00:22

Problem 26

How can siRNAs that target the promoter region of a gene be made? Present evidence to support your hypothesis.

Joanna Quigley
Joanna Quigley
Numerade Educator
00:56

Problem 27

Compare and contrast the typical actions of siRNAs and miRNAs in animals.

Joanna Quigley
Joanna Quigley
Numerade Educator
00:37

Problem 28

MicroRNAs in animals typically base-pair imperfectly to their targets in the $3^{\prime}$-UTRs of mRNAs. How does their activity change if they base-pair perfectly, or near-perfectly? Present evidence.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator
02:51

Problem 29

Describe an example in which an miRNA activates translation of a gene. How was this activation assayed? Present evidence that base-pairing between this miRNA and the mRNA's ARE is important in activation.

James Kiss
James Kiss
Numerade Educator
04:18

Problem 30

Describe and present the results of an experiment that shows that the protein GW182 can reduce translation of an $\mathrm{mRNA}$ in P-bodies. Include a description of how the protein can be physically tethered to the mRNA. How much of the loss of protein product is due to mRNA destruction, and how much is due to translation repression? How can these two effects be experimentally separated?

Sana Riaz
Sana Riaz
Numerade Educator
00:45

Problem 31

Describe and give the results of experiments that show that: (a) translation of an mRNA is repressed by an miRNA in P-bodies.
(b) this repression can be overcome in stressed cells.
(c) an $\mathrm{m} R N A$-binding protein is also required for relief of repression.
(d) relief of repression is accompanied by the translocation of the mRNA from P-bodies to polysomes.

Sam Limsuwannarot
Sam Limsuwannarot
Numerade Educator