Splicesosomes and Splicing

Question 1

What are the 4 patterns of alternative splicing?

Answer 1

1. Optional Exon splicing
2. Optional Intron splicing
3. Mutually exclusive exons
4. Internal splice sites

Question 2

How does intron ambiguity contribute to alternative splicing?

Answer 2

The splicesosome is unable to distinguish between two or more alternative splice sites because different isoforms include or exclude different exons and introns.

Question 3

What is the consequence of negative regulation of splicing?

Answer 3

A repressor binds and blocks splicing at a particular site, only exposing weak splicing sites.

Question 4

What is the consequence of positive regulation of splicing?

Answer 4

An activator directs splicing at over looked sites to suppress a competing site.

Question 5

What does normal splicing result in?

Answer 5

Wild type protein

Question 6

What does exon skipping result in?

Answer 6

Protein with an in frame deletion

Question 7

What does alternative 5’ splicing result in?

Answer 7

A protein with an alternate amino acid sequence

Question 8

What does alternative 3’ splicing result in?

Answer 8

A protein with an out-of-frame deletion

Question 9

What does intron retention result in?

Answer 9

A protein with an insertion.