What is RNA interference (RNAi)?

What is RNA interference (RNAi)?

Introduction RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is a conserved biological response to double-stranded RNA that mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.

What causes interferon response in RNAi?

In mammalian cells long (>30nt) double-stranded RNAs usually cause Interferon response. A simplified model for the RNAi pathway is based on two steps, each involving ribonuclease enzyme.

What are the applications of RNAi in experiments and therapeutics?

RNAi in experiments and therapeutics: how it works. Consequently, RNAi is used in functional genomics (systematic analysis of loss-of-function phenotypes induced by RNAi triggers) and developing therapies for the treatment of viral infection, dominant disorders, neurological disorders, and many types of cancers…

What are the steps of RNAi pathway?

A simplified model for the RNAi pathway is based on two steps, each involving ribonuclease enzyme. In the first step, the trigger RNA (either dsRNA or miRNA primary transcript) is processed into an short, interfering RNA ( siRNA) by the RNase II enzymes Dicer and Drosha.

How does Exogenous dsRNA initiate RNAi?

Exogenous dsRNA initiates RNAi by activating the ribonuclease protein Dicer, which binds and cleaves double-stranded RNAs (dsRNAs) in plants, or short hairpin RNAs (shRNAs) in humans, to produce double-stranded fragments of 20–25 base pairs with a 2-nucleotide overhang at the 3′ end.

What is the difference between siRNA and gene silencing?

The siRNA is unwound during RISC assembly and the single-stranded RNA hybridizes with mRNA target. Gene silencing is a result of nucleolytic degradation of the targeted mRNA by the RNase H enzyme Argonaute (Slicer).