RNA interference
Molecular Biology · Biotechnology
Say it: ar-en-AY in-tur-FEER-uns
RNA interference is a natural process in which small RNA molecules guide the destruction or blocking of matching messenger RNAs, silencing specific genes.
Also: RNAi
Definition
What is RNA interference?
RNA interference (RNAi) is a gene-silencing mechanism found in plants, animals and fungi, triggered by double-stranded RNA. An enzyme called Dicer chops the double-stranded RNA into small interfering RNAs (siRNAs) about 21 to 23 nucleotides long. One strand of each siRNA is loaded into the RNA-induced silencing complex (RISC), which uses it as a guide to find messenger RNAs with a matching sequence. When the match is exact, an Argonaute protein in RISC cuts the mRNA, so the protein it encodes is no longer made.
Cells use RNAi to fight viruses and to keep transposons quiet, and the closely related microRNA pathway regulates many of the cell's own genes. Andrew Fire and Craig Mello described the mechanism in 1998, after finding that double-stranded RNA injected into the worm Caenorhabditis elegans silenced the matching gene far more strongly than either single strand. They were awarded a Nobel Prize for the work in 2006.
RNAi soon became a standard laboratory tool: by adding a synthetic siRNA, or a gene that makes a short hairpin RNA, researchers can knock down almost any gene and see what changes. Since 2018, siRNA drugs have been approved for several diseases, including hereditary transthyretin amyloidosis, where they cut production of a harmful liver protein.
Word parts
Where does the term “RNA interference” come from?
- interfere
- to strike against each otherOld French s'entreferir, from Latin inter (between) and ferire (to strike)
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Terms that go with it
- MicroRNAA microRNA is a short RNA, about 22 nucleotides long, that does not code for protein but silences genes by pairing with their messenger RNAs.
- Messenger RNAMessenger RNA is the RNA copy of a gene that carries protein-building instructions from DNA to the ribosomes, where it is read in three-base codons.
- Gene expressionGene expression is the use of a gene's information to make a working product, usually a protein or a functional RNA molecule.
- TransposonA transposon is a DNA sequence that can move from one place in a genome to another, in some cases leaving a copy behind as it goes.
- AmyloidosisAmyloidosis is a group of diseases in which misfolded proteins clump into insoluble amyloid fibrils that build up in organs and disrupt how they work.
- CRISPRCRISPR is a genome-editing technology, adapted from a bacterial defense system, that uses a guide RNA to direct an enzyme such as Cas9 to cut DNA.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- The Nobel Prize in Physiology or Medicine 2006: Press release
- NCBI MeSH: RNA Interference
- Agrawal et al. (2003), RNA Interference: Biology, Mechanism, and Applications, Microbiology and Molecular Biology Reviews
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