Please help 1. Imagine you have been given the task of designing an interfering
ID: 54699 • Letter: P
Question
Please help
1. Imagine you have been given the task of designing an interfering RNA that is intended to reduce the level of protein production from Gene A. Gene A’s genomic structure is shown below:
promoter = nucleotides 1-100
exon 1 = nucleotides 101-200
intron 1 = nucleotides 201-300
exon 2 = nucleotides 301-400
intron 2 = nucleotides 401-500
exon 3 = nucleotides 501-600
Imagine you have designed three interfering RNAs:
1. iRNA1 has a sequence that is identical to nucleotides 175-225 in Gene A’s sequence (except there are Us in the RNA sequence where there are Ts in the DNA sequence)
2. iRNA2 has a sequence that is identical to nucleotides 325-375 in Gene A’s sequence (except there are Us in the RNA sequence where there are Ts in the DNA sequence)
3. iRNA3 has a sequence that is identical to nucleotides 175-200 in Gene A’s sequence joined with nucleotides 301-325 (except there are Us in the RNA sequence where there are Ts in the DNA sequence)
Question: You already know that interfering RNAs can work through several different mechanisms. Imagine that both iRNAs are properly designed, and both will bind to complementary sequences in both DNA and RNA if they find any. Please describe the similarities and differences in the mechanisms you expect these iRNAs to be able to work through. Include mention of whether you think each iRNA will work at low concentration (3-4 molecules per cell) as well as high concentration (3,000-4,000 molecules per cell).
Explanation / Answer
iRNA 1 having sequence in the region of 175 -225 acts as RITS - RNA induced transcriptional silencer and inhibits transcription and forms heterochromatin.
iRNA 2 having sequence in the region of 325 to 375 also have the same function of iRNA 1 given. It acts on processed mRNA and inhibits translation.
iRNA3- having sequence in 301 to 325 inhibits by RISC- where the inhibits further translation of mRNA. It binds to processed mRNA of the gene.
The iRNA 1 is more effective and can act on low to high copy numbers.