Ch. 3 pt 2

Question 1

An example of alternative RNA splicing for tumors is _______, which makes a big difference in protein function

Answer 1

Bcl-x

Question 2

What is the difference between Bcl-XL and Bcl-XS?

Answer 2

Bcl-XL inhibits apoptosis
Bcl-XS promotes apoptosis

Question 3

drosophila gene _______ contains 24 exons with multiple splice site possibilities

Answer 3

dscam1
- differential splicing allows neurons to have unique identity

Question 4

A single base-pair change at the 5’-end of exon 2 in the human _______ gene prevents splicing and generates nonfunctional mRNA

Answer 4

beta-globin

Question 5

Mutation in ______ gene causes severe and life-threatening anemia

Answer 5

beta-globin

Question 6

a mutation in the _______ gene causes skipping an intron and leads to a form of muscular dystrophy

Answer 6

dystrophin

Question 7

mutations in the _______ gene have produced family members with extreme muscle formation

Answer 7

myostatin

Question 8

The longer an mRNA persists in the cytoplasm, the more it can be translated. This depends largely on what?

Answer 8

the length of its poly-A tail
- can also be affected by proteins

Question 9

_______ is an example of a protein that can increase the half-life of casein mRNA during lactation

Answer 9

prolactin

Question 10

prolactin is an example of a protein that can increase the half-life of _______ during lactation

Answer 10

casein mRNA

Question 11

_______ typically produce and store large quantities of mRNA’s in a dormant state. When are they translated?

Answer 11

Oocytes (unfertilized eggs)
- arent translated till after fertilization

Question 12

In oocytes, mRNA regulation is _______, preventing translation until a proper signal is received

Answer 12

negative

Question 13

In amphibians, _______ protein binds to the 5’ cap and 3’ poly-A tail creating a configuration that prevents translation

Answer 13

maskin

Question 14

Explain the 2 steps maskin takes to prevent translation of an mRNA

Answer 14

1) maskin binds to CPEB, which attaches to 3’UTR
2) maskin binds to eIF4E factor attached to 5’cap

Question 15

What does CPEB stand for?

Answer 15

cytoplasmic polyadenylation element-binding protein

Question 16

Explain the 5 steps to initiate a maskin dormant mRNA

Answer 16

1) progesterone activates kinase that phosphorylates CPEB
2) CPEB binds to CPSF
3) CPSF stimulates poly-A-pol
4) PABP binds to the extended tail
5) stablizes interaction between eIF4E and eIF4G (ribosome assembly)

Question 17

It has long been assumed that ribosomes do not show favoritism for some mRNAs. This is NOT reality. What is an example?

Answer 17

Rpl38 ribosome that translates HOX genes

Question 18

_______ are short antisense RNA molecules that are complimentary to small regions of other mRNA’s

Answer 18

miRNA’s

Question 19

What is an example of miRNA’s in C.elegans?

Answer 19

lin-4 miRNA binding to lin-14 RNA inhibiting synthesis of LIN-14

Question 20

_______: the process by which miRNAs inhibit expression of specific genes by degrading or binding to their mRNA’s

Answer 20

RNA interference

Question 21

What is the process of RNA interference?

Answer 21

1) miRNA ds loops are processed by Drosha and Dicer to make ss miRNA
2) ss miRNA are packaged into RNA-inducing silencing complexes (RISC)
3) silencing, aided by argonaute, occurs

Question 22

1) miRNA ds loops are processed by _______ and _______ to make ss miRNA
2) ss miRNA are packaged into _______
3) silencing, aided by _______ occurs

Answer 22

1) Drosha, Dicer
2) RNA-induced silencer complexes
3) argonaute

Question 23

_______ family proteins are particularly important to the activity of RISC

Answer 23

argonaute

Question 24

What are the 2 major outcomes of RNA interference?

Answer 24

1) translational repression
2) mRNA destruction

Question 25

by physically moving mRNA’s around not only can the timing of translation be controlled, but the _______ can also be specified

Answer 25

location

Question 26

What are the 3 different mechanisms for moving mRNA around the cell?

Answer 26

1) diffusion and anchoring
2) localized protection
3) active transport along the cytoskeleton using microtubules

Question 27

The mechanisms for moving mRNA are most often accomplished through interactions with their _______

Answer 27

3’-UTR’s

Question 28

ATPase motor proteins:
- _______ (- ends of microtubules)
- _______ (+ ends of microtubules)

Answer 28

dynein
kinesin

Question 29

make sure to review tools for developmental biologists:
mRNA, proteins, and protein function

Answer 29

STUDY
- SNOW DROP