Vest 1

Question 1

The process of removing intron sequences from pre-mRNA and joining exon sequences is called __________.

Answer 1

Splicing

Question 2

The __________ structure is added to the 5’ end of a pre-mRNA during transcription to protect it from degradation.

Answer 2

7-methyl G cap

Question 3

The __________ at the 3’ end of a mRNA molecule facilitates translation.

Answer 3

poly(A) tail

Question 4

__________ are a class of non-coding sequences that are removed from pre-mRNA during splicing.

Answer 4

Introns

Question 5

The __________ is a large ribonucleoprotein complex that catalyzes the splicing of pre-mRNA.

Answer 5

Spliceosome

Question 6

__________ are a family of small nuclear ribonucleoprotein particles that are essential components of the spliceosome.

Answer 6

snRNPs

Question 7

The __________ is a sequence element, typically AAUAAA, found near the 3’ end of pre-mRNA that signals where the poly(A) tail should be added.

Answer 7

Polyadenylation signal (PAS)

Question 8

__________ is a type of alternative RNA processing that allows a single gene to code for multiple protein isoforms by including or excluding different exons in the mature mRNA.

Answer 8

Alternative splicing

Question 9

__________ RNA splicing occurs without the need for any protein enzymes.

Answer 9

Self-splicing

Question 10

List three functions of the 5’ cap:

Answer 10

• Protects pre-mRNA and mRNA from degradation by 5’ exonucleases
• Enhances splicing of the 5’ most exon
• Necessary for targeting mRNAs for export to the cytoplasm through the nuclear pores

Question 11

__________ RNA methylation is a common internal modification to RNA that can influence stability, splicing, and translation of RNA.

Answer 11

N6-methyladenosine (m6A)

Question 12

__________ are a newly discovered class of non-coding RNAs that form covalently closed loop structures and have been implicated in a variety of cellular processes.

Answer 12

Circular RNAs (circRNAs)

Question 13

Three primary functions of circRNAs are:

Answer 13

• miRNA sponges – regulate translation and expression
• Protein sponges – regulate transcription and alternative splicing
• Encode novel proteins using alternative translation initiation mechanisms – IRES and m6A residues

Question 14

The __________ of the RNA polymerase II plays a crucial role in coordinating the different steps of pre-mRNA processing, including capping, splicing, and polyadenylation.

Answer 14

carboxy-terminal domain (CTD)

Question 15

The phosphorylation state of __________ on the CTD of RNA polymerase II is associated with the recruitment of capping enzymes.

Answer 15

Serine 5

Question 16

The presence of both __________ and __________ on the CTD of RNA polymerase II is associated with the recruitment of splicing proteins.

Answer 16

Phospho-Ser 5, Ser 2

Question 17

__________ of the CTD of RNA polymerase II leads to the recruitment of cleavage and polyadenylation factors.

Answer 17

Phosphorylation of Serine 2

Question 18

__________ is the process of adding a poly(A) tail to the 3’ end of an RNA molecule.

Answer 18

Polyadenylation

Question 19

The 5’ splice site is typically characterized by the consensus sequence __________.

Answer 19

GU A/G AGU

Question 20

The 3’ splice site is typically characterized by the consensus sequence __________.

Answer 20

CAGG

Question 21

The __________ is an adenine nucleotide located 18-40 nucleotides upstream of the 3’ splice site that plays a crucial role in the splicing reaction.

Answer 21

Branch point

Question 22

The __________ is a pyrimidine-rich sequence located upstream of the 3’ splice site.

Answer 22

Polypyrimidine tract

Question 23

The __________ binds to the 5’ splice site of pre-mRNA.

Answer 23

U1 snRNP

Question 24

The __________ binds to the branch point of the pre-mRNA.

Answer 24

U2 snRNP

Question 25

The __________ plays a crucial role in holding the 5' and 3' exons in close proximity during splicing.

Answer 25

U5 snRNP

Question 26

__________ and __________ interact near the branch point during the splicing reaction.

Answer 26

U4-U6 snRNPs

Question 27

The __________ binds to the polypyrimidine tract and helps recruit the U2 snRNP to the branch point.

Answer 27

U2AF (U2 associated factor)

Question 28

In addition to the five main snRNPs, there are over __________ other proteins that can contribute to the spliceosome.

Answer 28

24

Question 29

The 5’ end of the intron base pairs with the __________ during splicing.

Answer 29

U6 snRNP

Question 30

The __________ binds to the AG dinucleotide at the 3' splice site.

Answer 30

U2AF-35

Question 31

__________ refers to the skipping of an exon during the splicing process, leading to its exclusion from the mature mRNA.

Answer 31

Exon skipping

Question 32

__________ splicing refers to the process where exons are included in the mature mRNA in the order in which they appear in the gene.

Answer 32

Default sequential

Question 33

Alternative splicing can occur if something disrupts __________.

Answer 33

default sequential splicing

Question 34

The protein __________ can act as a major deciding factor that influences alternative splicing.

Answer 34

RBM25

Question 35

__________ elements within RNA are recognized by activator proteins, which commonly belong to the SR (serine-arginine rich) family of proteins.

Answer 35

Enhancer

Question 36

__________ elements within RNA are bound by repressor proteins, often part of the hnRNP (heterogenous nuclear ribonucleoprotein) protein family.

Answer 36

Silencer

Question 37

__________ enhance the binding of the spliceosome to regulated splice sites.

Answer 37

Activators

Question 38

__________ inhibit the binding or function of spliceosomal components.

Answer 38

Repressors

Question 39

__________ are sequences within exons that promote splicing.

Answer 39

ESEs (exonic splicing enhancers)

Question 40

__________ are sequences within introns that inhibit splicing.

Answer 40

ISSs (intronic splicing silencers)

Question 41

__________ are sequences within introns that enhance splicing.

Answer 41

ISEs (intronic splicing enhancers)

Question 42

The __________ binds to the AAUAAA sequence of the PAS.

Answer 42

Cleavage and Polyadenylation Specificity Factor (CPSF)

Question 43

The __________ binds to the GU-rich or U-rich downstream element of the pre-mRNA.

Answer 43

Cleavage Stimulatory Factor (CSTF)

Question 44

__________ adds adenine residues to the 3' end of the pre-mRNA.

Answer 44

Poly-A polymerase (PAP)

Question 45

The __________ binds to the poly(A) tail.

Answer 45

Nuclear Poly-A binding protein (PABPN1)

Question 46

The __________ is responsible for cleaving the pre-mRNA downstream of the PAS.

Answer 46

Endonuclease activity of CPSF2

Question 47

__________ and __________ are exonucleases that degrade the 5' end of the cleaved RNA.

Answer 47

XRN2, RAT1

Question 48

__________ polyadenylation involves the regular dissociation of PAP, allowing only a few adenine residues to be added at a time.

Answer 48

Distributive

Question 49

__________ polyadenylation occurs when PABPN1 binds to short poly(A) sequences, stabilizing the binding of PAP and leading to the addition of adenine residues without PAP dissociation.

Answer 49

Processive

Question 50

Approximately __________ of mammalian mRNAs contain more than one PAS.

Answer 50

75%

Question 51

What are the four splicing sequences?

Answer 51

The four splicing sequences are: 5' splice site, 3' splice site, polypyrimidine tract, and branch point.