Gene Silencing Flashcards
What is RNA interfernece?
Accurate and potent gene silencing method that silences RNA by breaking it down or stopping translation
dsRNA
What are the types of siRNAs?
What causes RNAi?
siRNA
What does RNAi do?
Promote the degredation of mRNA
Where does dsRNA eom from?
What is DiceR?
Processes dsRNA and converts to smaller dsRNA molecules
What is the short dsRNA called?
siRNA which has 21-23 nucleotides with 3’ two nucleotide overhang
When siRNA interacts with dicer what does it activate?
RISC which cleaves the passenger strand of the siRNA while the guide strand remaines associate with the RISC
What does the guide strand do?
Activate the RIS to target its target mRNA for cleavage by AGO2
What genes does the guide strand bind to?
Only binds to strands that is fully complementary to it siRNA causing specific gene silencing
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The RISC and AGO complex join together and use the siRNA strand to?
Bind to the complimentary mRNA for cleavage
What can the argonaute protein do when bound to the complimentary strand?
Recruit accerssory factors to regulate the target sequence in other ways
What is miRNA?
Class of moleucles that negatively regulate gene expression
What is the difference between miRNA and sirna?
the sequence does not need to be fully complimentary to the compared strand
What transports the miRNA out of the nucleus and into the cytoplasm?
exportin5
What does DICER do?
Cleaves the ends of the miRNA and siRNA making it compatible with the RIS-AGO enzyme
What is a difference between miRNA and SiRNA in terms of the risc-ago2 complex?
What causes the discarding of the miRNA strand/
The passenger strand is unwound from the miRNA duplex leading to it being discarded
What is the major difference between siRNA and miRNA?
What is the benefit of the miRNA and mRNA recognition?
One miRNA strand can recognize an array of mRNAs and hence miRNA has the charactertistics of having multiple target
What is the benefit of RNAi therapeutics?
Review the next chart
What are the limitations of RNAi?
Vulnerable to serum nucleases, degraded rapidly, short half-life, poor stability.
What is the role of delivering RNAi?
Facilitate the cellular uptake of siRNA and miRNA to their target sites, protext the nucleic acids from premature nuclease degredation
What are some delivery systems for RNAi?
Viral vectors, polymer based and lipid based systems
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What does crispr components make up?
Guide RNAs, cas9, DNA templates
What is the BCL11A gene?
This repressed the fetal hemoglobin expression hence, by turning this off we can start producing fetal hemoglobin again and fix sickle cell anemia
