Lecture 22-RNA Interference

What does eyeless protein do?

Coordinates the formation of eyes

What does white protein do?

Contributes to eye pigmentation

What is hybridization

The process of combining two complementary single-stranded DNA or RNA molecules and allowing them to form a single double-stranded molecule through base pairing.

Does does RNA hybridization allow for the detection of mRNA molecules?

1. Design oligonucleotides complimentary to RNA molecule.

2. The oligonucleotide hybridizes to complementary RNA and fluoresces.

What was the first organism that RNA knockdown was studied on?

C.elegans

Does the injection of double-stranded or antisense RNA have a strong effect?

Double-stranded RNA

What does the injection of dsRNA do?

1. Inhibits the synthesis of specific proteins.

2. Promotes mRNA degradation

RNA interference (RNAi) is a mechanism of ___.

Gene regulation

What does Dicer do?

Cleaves the dsRNA into small fragments (of approximately 23 nucleotide pairs) called small interfering RNAs (siRNAs).

After siRNAs are produced, what happens?

siRNAs bind to Argonaute and other components of the RISC complex.

What does RISC stand for?

RNA-induced silencing complex

What is the RISC complex made of?

Ribonucleic acid, RNA-binding proteins, and Argonaute.

Explain how RNAi works?

1. Long double-stranded RNA (dsRNA) is cleaved into small interfering RNA (siRNA) by the enzyme Dicer.

2. The siRNA joins the RNA-induced silencing complex (RISC)

3. Argonaute2 (AGO2) cleaves the sense strand of RNA.

4. The RISC-siRNA complex binds and degrades the complementary mRNA

5. The activated RISC-siRNA complex can then be reused.

In what organisms is RNAi used in?

Plants, worms, and insects against viruses and jumping genes

Double-stranded RNA can be introduced experimentally to ____.

silence genes of interest

What is a short hairpin RNA (shRNA)?

An artificial RNA molecule with a hairpin turn that mimics a dsRNA molecule.

RNAi allows removal of specific proteins in cells and tissues without affecting the ___.

genome

An RNAi screen in cells is used to identify ___ proteins.

cell morphology