What is RNA interferance?

Question

What is RNA interferance?

Answer 1

RNA interference is a natural genetic mechanism present in most plants and animals. Its function is to protect the cellular machinery from invasion and exploitation by viruses and other foreign genetic material. RNA interference can silence specific genes, making it a valuable research tool in biotechnology research and even next-generation medical therapies. For instance, if we could use RNA interference to silence the genes responsible for a slow metabolism, we could allow people to lose weight without forcing them to go on a diet or fighting against their natural dietary tendencies.

Recall that viruses reproduce by inserting their genetic material into the genome of a host, reprogramming it to pump out copies of the virus. After a few hundred viruses are produced by the genetic machinery of the cell, it bursts, releasing more virions which go on to infect other cells. The main point of RNA interference is to suppress certain sections of the genome so that viruses cannot exploit it to produce copies.

Most organisms have a genome that produces messenger RNA which goes on to instruct the cell’s protein-producing machinery to create various proteins. RNA interference consists of special segments of RNA, called small interfering RNA strands (siRNA) which have nucleotide sequences complementary to the targeted RNA strand. These complementary strands serve as a targeting mechanism which guides proteins to the mRNA of choice, dicing the long double-stranded RNA molecules into fragments which cannot be translated into proteins. In this way, specific genes can be silenced.

Today, the use of RNA interference for biotechnological and therapeutic purposes is a hot research area. RNA interference used to selectively suppress desired genes is a form of genetic engineering. Imagine curing or making progress towards a cure for AIDS, hepatitis, and the flu – all through selectively suppressing the expression of viral genomes. Fully utilizing RNA interference, we might be able to create cotton seeds without poison — they possess great amounts of protein but natural cotton seeds are poisonous — tobacco without carcinogens, and plants with extreme resistance to crop-destroying viruses. RNA interference is a valuable method in the biotechnological toolbox which will continue ushering in the biotech revolution for the 21st century.

Answer 2

Actually lusciouslollipops is partly correct....she forgot to mention ALSO

that 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, transgene silencing, and quelling. Only after these apparently-unrelated processes were fully understood did it become clear that they all described the RNAi phenomenon. RNAi has also been confused with antisense suppression of gene expression, which does not act catalytically to degrade mRNA, but instead involves single-stranded RNA fragments physically binding to mRNA and blocking protein translation. 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,[3] which they published in 1998.[4]

Answer 3

RNA interference (RNAi) is a mechanism that inhibits gene expression at the stage of translation or by hindering the transcription of specific genes. RNAi targets include RNA from viruses and transposons (significant for some forms of innate immune response), and also plays a role in regulating development and genome maintenance. Small interfering RNA strands (siRNA) are key to the RNAi process, and have complementary nucleotide sequences to the targeted RNA strand. Specific RNAi pathway proteins are guided by the siRNA to the targeted messenger RNA (mRNA), where they "cleave" the target, breaking it down into smaller portions that can no longer be translated into protein. A type of RNA transcribed from the genome itself, microRNA (miRNA), works in the same way.[2]

The RNAi pathway is initiated by the enzyme dicer, which cleaves long, dsRNA molecules into short fragments of 20–25 base pairs. One of the two strands of each fragment, known as the guide strand, is then incorporated into the RNA-induced silencing complex (RISC) and pairs with complementary sequences. The most well-studied outcome of this recognition event is post-transcriptional gene silencing. This occurs when the guide strand specifically pairs with an mRNA molecule and induces the degradation by argonaute, the catalytic component of the RISC complex. Another outcome is epigenetic changes to a gene – histone modification and DNA methylation – affecting the degree the gene is transcribed.