RNA interference
hideRNA interference (RNAi) is a system within living cells that helps to control which genes are active and how active they are. Two types of small RNA molecules – microRNA (miRNA) and small interfering RNA (siRNA) – are central to RNA interference. RNAs are the direct products of genes, and these small RNAs can bind to specific other RNAs and either increase or decrease their activity, for example by preventing a messenger RNA from producing a protein. RNA interference has an important role in defending cells against parasitic genes – viruses and transposons – but also in directing development as well as gene expression in general.
The RNAi pathway is found in many eukaryotes including animals and is initiated by the enzyme Dicer, which cleaves long double-stranded RNA (dsRNA) molecules into short fragments of ~20 nucleotides. One of the two strands of each fragment, known as the guide strand, is then incorporated into the RNA-induced silencing complex (RISC). The most well-studied outcome is post-transcriptional gene silencing, which occurs when the guide strand base pairs with a complementary sequence of a messenger RNA molecule and induces cleavage by Argonaute, the catalytic component of the RISC complex. This process is known to spread systemically throughout the organism despite initially limited molar concentrations of siRNA.
The selective and robust effect of RNAi on gene expression makes it a valuable research tool, both in cell culture and in living organisms because synthetic dsRNA introduced into cells can induce suppression of specific genes of interest. RNAi may also be used for large-scale screens that systematically shut down each gene in the cell, which can help identify the components necessary for a particular cellular process or an event such as cell division. Exploitation of the pathway is also a promising tool in biotechnology and medicine.
Historically, RNA interference was known by other names, including post transcriptional gene silencing, and quelling. Only after these apparently unrelated processes were fully understood did it become clear that they all described the RNAi phenomenon. In 2006, Andrew Fire and Craig C. Mello shared the Nobel Prize in Physiology or Medicine for their work on RNA interference in the nematode worm C. elegans, which they published in 1998.
For more information about RNA interference, read the full article at
Wikipedia.
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News tagged with rna interference
Explained: RNA interference
Nov 12, 2009 |
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Every high school biology student learns the basics of how genes are expressed: DNA, the cell’s master information keeper, is copied into messenger RNA, which carries protein-building instructions to the ribosome, ...
Scientists Plot Genetic Ploy Against Grain Pest
Nov 03, 2009 |
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(PhysOrg.com) -- Aided by a genomic map of the red flour beetle, Tribolium castaneum, Agricultural Research Service (ARS) and university scientists are plotting a kind of genetic sabotage on the pest’s basic ...
Using RNAi-based technique, scientists find new tumor suppressor genes in lymphoma
Oct 13, 2009 |
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Researchers from Cold Spring Harbor Laboratory (CSHL) have uncovered a large, new cache of genes that act as built-in barriers against cancer. Known as tumor suppressors, the newly identified genes and the insight that they ...
Researchers discover RNA repair system in bacteria
Oct 12, 2009 |
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In new papers appearing this month in Science and the Proceedings of the National Academy of Sciences, University of Illinois biochemistry professor Raven H. Huang and his colleagues describe the first RNA repair system to be ...
Research points to potential chink in cancer's armor
Oct 06, 2009 |
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Scientists at the University of York have identified and successfully silenced a gene that appears essential to cancer cell survival.
Researchers identify gene that regulates breast cancer metastasis
Oct 05, 2009 |
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Researchers at The Wistar Institute have identified a key gene (KLF17) involved in the spread of breast cancer throughout the body. They also demonstrated that expression of KLF17 together with another gene (Id1) known to ...
'Hedgehog' pathway may hold key to anti-cancer therapy
Aug 26, 2009 |
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Scientists in Switzerland have discovered a way to block the growth of human colon cancer cells, preventing the disease from reaching advanced stages and the development of liver metastases. The research, published today ...
One step closer to turning off cancer genes with gene-silencing
Jun 04, 2009 |
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(PhysOrg.com) -- Researchers at The University of Queensland have developed a way to deliver drugs which can specifically shut down cancer-causing genes in tumour cells while sparing normal healthy tissues.
Hitting cancer where it hurts
May 28, 2009 |
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Two studies in the May 29th issue of Cell, a Cell Press publication, have taken advantage of new technological advances to search for and find previously unknown weaknesses in a hard to treat form of cancer. The discoveries lend n ...
Cancer cells need normal, nonmutated genes to survive
May 28, 2009 |
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Corrupt lifestyles and vices go hand in hand; each feeds the other. But even the worst miscreant needs customary societal amenities to get by. It's the same with cancer cells. While they rely on vices in the form of genetic ...
UCSF creates fast, affordable tool for finding gene 'on-off' switches
May 19, 2009 |
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UCSF scientists have created a method of quickly identifying large numbers of the genetic material known as short hairpin RNA — also called shRNA - that turns genes on and off.
Nanotechnology holds promise for STD drug delivery
Nanotechnology / Nanomaterials
May 03, 2009 |
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Yale researchers describe a breakthrough in safe and effective administration of potential antiviral drugs — small interfering RNA (siRNA) molecules that silence genes — the first step in development of a ...
Researchers report oral delivery system for RNAi therapeutics
Apr 29, 2009 |
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Researchers at the University of Massachusetts Medical School (UMMS) report today on a novel approach to the delivery of small bits of genetic material in order to silence genes using "RNA interference"—and in the process, ...
Scientists identify host factors critical to dengue virus infection
Apr 22, 2009 |
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By painstakingly silencing genes one at a time, scientists at Duke University Medical Center have identified dozens of proteins the dengue fever virus depends upon to grow and spread among mosquitoes and humans.
New therapeutic strategy could target toxic protein in most patients with Huntington's disease
Apr 09, 2009 |
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Howard Hughes Medical Institute researchers have designed tiny RNA molecules that shut off the gene that causes Huntington's disease without damaging that gene's healthy counterpart, which maintains the health and vitality ...
