Updated: 4/3/2020

RNA Processing

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
7
0
0
100%
0%
Evidence
1
0
0
100%
0%
Videos / Pods
2
Topic
Overview
  • Only in eukaryotes
    • pre-processed transcript = hnRNA
  • Process 
    • capping
      • 5' end
        • 7-methylguanosine cap
        • occurs before transcription has finished
        • functions to help in ribosomal binding
          • also protects against degradation
      • 3' end
        • polyadenylated (poly-A) tail
        • added by poly-A-polymerase
        • functions to protect from degradation
      • some viruses can steal host cell caps so that the viral mRNA gets translated
    • splicing 
      • process of intron removal 
      • mediated by the spliceosome composed of small nuclear ribonucleoproteins (snRNPs) 
        • lariat is formed
        • adjacent exons are attached
    • alternative splicing   
      • one hnRNA can be spliced differently to produce different protein products
      • this requires conserved sequences including
        • GU at the beginning of the intron
        • AG at the end of the intron
      • mutations that create new splice sites (AG) in the middle of the intron can lead to
        • abberant splicing that creates new nonfunctional proteins
        • longer proteins than the wildtype variant
  • Location
    • occurs in nucleus after transcription
    • only processed RNA is transported out of the nucleus
 

Please rate topic.

Average 4.8 of 4 Ratings

Questions (7)
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK

(M1.BC.15.72) Expression of an mRNA encoding for a soluble form of the Fas protein prevents a cell from undergoing programmed cell death. However, after inclusion of a certain exon, this same Fas pre-mRNA eventually leads to the translation of a protein that is membrane bound, subsequently promoting the cell to undergo apoptosis. Which of the following best explains this finding? Tested Concept

QID: 106503
1

Base excision repair

4%

(9/230)

2

Histone deacetylation

4%

(9/230)

3

DNA missense mutation

4%

(9/230)

4

Post-translational modifications

17%

(38/230)

5

Alternative splicing

70%

(162/230)

M 1 D

Select Answer to see Preferred Response

(M1.BC.15.1) Hepatocyte nuclear factor 4 alpha (HNF4a) is a transcription factor that is found in the liver, pancreas, kidney, and intestines. The gene is composed of 11 exons and depending on the tissue there are different isoforms of the protein being expressed. Which of the following is responsible for producing the different isoforms of HNF4a? Tested Concept

QID: 106969
1

Addition of 7-methylguanosine cap

0%

(0/23)

2

Addition of polyadenylated (poly-A) tail

4%

(1/23)

3

Alternative splicing

87%

(20/23)

4

Histone acetylation

9%

(2/23)

5

DNA methylation

0%

(0/23)

M 1 D

Select Answer to see Preferred Response

(M1.BC.14.24) A 30-year-old African American woman develops a facial rash in a "butterfly" pattern over her face and complains of feeling tired and achy in her joints. In the course of a full rheumatologic workup you note that she has anti-snRNP antibodies. Which of the following do snRNPs affect? Tested Concept

QID: 100089
1

Addition of the 5' 7-methylguanosine cap of mRNA

7%

(2/27)

2

Polyadenylation of the 3' end of mRNA

7%

(2/27)

3

Protection of mRNA from degradation

4%

(1/27)

4

Intron removal from the mRNA

70%

(19/27)

5

Transcription of mRNA

0%

(0/27)

M 1 C

Select Answer to see Preferred Response

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Evidence (2)
VIDEOS & PODCASTS (2)
EXPERT COMMENTS (18)
Private Note