Spliceosome

Question 1

When were intron discovered?

Answer 1

1970s

Question 2

What are introns

Answer 2

Interveneing sequences

Question 3

What are exons

Answer 3

Expressed sequences/Coding sequences

Question 4

What does splicing require a lot of?

Answer 4

Hydrolysis of a large quantity of ATP

Question 5

What does snRNPs stand for?

Answer 5

Small nuclar RiboNucleoProtein

Question 6

Give an example of another cellular RNP

Answer 6

The ribosomal subunits

Question 7

Where does the biogenisis of spliceosomal snRNPs take place?

Answer 7

In distinct subcellular compartments

Question 8

Define the biogenisis of spliceosomal snRNPs

Answer 8

the assembly of stable, but inactive, pre-RNPs that require maturation at locations that are distinct from their sites of function

Question 9

Define the biogenisis of spliceosomal snRNPs

Answer 9

the assembly of stable, but inactive, pre-RNPs that require maturation at locations that are distinct from their sites of function

Question 10

What are ribonucleoprotein?

Answer 10

a complex of ribonucleic acid and RNA-binding protein

Question 11

What is ribonucleic acid

Answer 11

RNA, a polymeric moleucle using the nitrogenous bases of guanine, uracil, adenine, and cytosine, denoted by the letters G, U, A, and C

Question 12

What are snRNAs?

Answer 12

abundant, non-coding, non-polyadenylated transcripts

Question 13

Where do snRNAs carry out their function?

Answer 13

Nuceloplasm

Question 14

What is the nuceloplasm?

Answer 14

the type of protoplasm that makes up the cell nucleus, the most prominent organelle of the eukaryotic cell. It is enclosed by the nuclear envelope, also known as the nuclear membrane

Question 15

What two basises are snRNAs be divided into?

Answer 15

Common sequence features and protein cofactors

Question 16

What are the two major classes of snRNAs?

Answer 16

Sm and Sm-like

Question 17

What are the seven Sm class of spliceosomal snRNAs?

Answer 17

U1, U2, U4, U4atac, U5, U11 and U12

Question 18

What are the two Sm-like snRNAs?

Answer 18

U6 and U6atac

Question 19

Why is are the classes called Sm?

Answer 19

They contain the Sm motif

Question 20

What does the Sm motif composed of?

Answer 20

two conserved regions, termed Sm1 and Sm2, which are separated by a non-conserved linker region

Question 21

What is a common feature of snRNA genes and protein-coding genes?

Answer 21

They both have elements that control transcriptin and RNA processing in the same relative position

Question 22

Is the transcription and processing of snRNA the same as mRNA?

Answer 22

No, they are coupled by a cellular system that is parallel to but distinct from each other

Question 23

What promotors are Sm class snRNAs transcribed from?

Answer 23

RNA polymerase II (pol II)

Question 24

What do pol II promotors contain?

Answer 24

proximal and distal sequence elements similar to the TATA box and enhancer sequences, respectively, of protein-coding genes

Question 25

What does the initiation of transcription of snRNA require?

Answer 25

binding of a pentameric factor called the snRNA-activating protein complex (SNAPc)

Question 26

What is required for the maturation of the snRNA 3’ end?

Answer 26

a large, multi-subunit factor called the Integrator complex

Question 27

Have they found an answer to pol II snRNA gene transcription termination?

Answer 27

No

Question 28

Where do Sm class snRNPs primarily function?

Answer 28

In the nucleus

Question 29

Why might precurson snRNPs undergo remodelling outside the place where they function?

Answer 29

This might be a mechanism for quality control, ensuring that partially assembled RNPs would not come into contact with their substrates.

Question 30

Give examples of five RNAs

Answer 30

rRNA, tRNA, mRNA, miRNA and SRP RNA

Question 31

How do appropriate transport receptors bind to RNAs?

Answer 31

They recognize specifc sequences and/or strutures on the RNA