Protein Synthesis: Viruses and Cancer

Question 1

what % of genetic disorders are from a stop codon

Answer 1

1/3

Question 2

Which EIF recognizes the cap and initiates translation?

Answer 2

EIF4E

Question 3

what does EIF4A?

Answer 3

helicase unwinds

Question 4

what does EIF3 do?

Answer 4

brings in ribosomal subunit!

Question 5

What needs to be prebound to ribosome before translation can occur?

Answer 5

eif2, trna, GTP

Question 6

what does phosphorylation of eif2’s alpha subunit do?

Answer 6

increases its affinity by a lot for binding gtp-ase EIF2B so it cant recycle gdp>gtp and protein synth is inhibited

Question 7

What are 4 EIF2a kinases that inhibit translation via phosphorylated EIF2a?

Answer 7

HCR( regulates hemoglobin production RBCs)

PKR (viral dsrna activates immune response/interferons)

GCN2 (histidine regulated - detects lvl of nutrition and if it’s low, it shuts off protein synthesis

PERK (within ER, detects stress)

Question 8

what does phosphatase GADD34 do?

Answer 8

dephosphorylates eIF2 to turn translation back on

Question 9

what do interferons stimulate?

Answer 9

PKR to inhibit translation in response to PKR sensing dsdna

Question 10

how do smart viruses evade pkr?

Answer 10

either by masking dsdna or by making decoy dsdna that binds to PKR and inhibits it, thus allowing PS to continue

Question 11

how does Flu evade?

Answer 11

ns1 protein helps mask drsna