Navigation Links
Killing the messenger RNA -- But which one?

Tiny molecules called microRNAs, only 19 to 21 nucleotides in length, are able to effectively silence sometimes large sets of genes. They do this by specifically binding to and neutralizing another form of RNA called messenger RNA, responsible for conveying the information from genes to the cellular machinery that uses that information to create proteins, the building blocks of the body. Several hundred species of microRNAs have been identified to date, and increasingly they are being seen as vitally important players in regulating the genome.

Now, a new study led by researchers at The Wistar Institute shows that these microRNAs can undergo a kind of molecular editing with significant physiological consequences. A single substitution in their sequence can redirect these microRNAs to target and silence entirely different sets of genes from their unedited counterparts. Further, errors in the editing can lead to serious health problems. The team’s findings appear in the February 23 issue of Science.

"What we found was that, in certain cases, edited versions of these microRNAs are being produced that differ from the unedited versions by only a single nucleotide change," says Kazuko Nishikura, Ph.D., a professor in the Gene Expression and Regulation Program at Wistar and senior author on the study. "These edited microRNAs are not encoded in the DNA, which means that at least two versions can being produced by one gene. This was not anticipated ?it was something really new.

"Looking more closely, we realized that the substitution we’d identified occurred in a particularly critical region of the molecule, the first 7 or 8 nucleotides ?out of a total of only 19 or 21 ?that define the molecule’s target specificity. This suggested that the change might well redirect these edited microRNAs to silence entirely different sets of genes from the unedited versions."

Using bioinformatics tools to compare the unedited and edited versions of only o ne species of microRNA against data banks of known gene sequences, the scientists identified two different groups of about 80 genes each likely to be targeted by the two versions of the molecule. They then selected three genes from each group for a closer look, testing to see whether their expression was in fact altered, up or down, by the microRNAs. It was.

Then they chose one potentially affected gene at random to explore the ramifications of microRNA editing in depth. As it turned out, the gene they selected, known as PRPS1, codes for an essential enzyme involved in synthesizing uric acid. If levels of the enzyme are poorly regulated, a number of health problems can arise. For example, too-high levels of the enzyme can cause uric acid levels to rise in the blood, triggering painful episodes of gout. Similarly, in the brain, excess uric acid can damage sensory neurons and cause deafness.

Working with a strain of transgenic mice unable to perform RNA editing and normal control mice, the researchers found that a complete lack of the edited version of the microRNA in question had the effect of driving production of the PRPS1 enzyme to about double its normal levels. This, in turn, drove levels of uric acid up to about two times what they should be.

"This confirmed that our original computer prediction of differential targeting by unedited and edited microRNAs of different sets of genes is likely to be correct," Nishikura says. "And in at least the case of the one gene we investigated, this differential has physiological consequences seen in the elevated uric acid levels."

Given the fact that the PRPS1 gene was randomly selected for investigation by the researchers, the findings suggest that a number of other as-yet unidentified disorders may also have their roots in this newly identified microRNA editing process.
'"/>

Source:The Wistar Institute


Related biology news :

1. Duke Experiments Boost Radiations Cancer-Killing Effects
2. Killing brain tumors from within: A Trojan horse approach
3. Molecular messengers perform a crucial role in the ability of injured nerve cells to heal themselves
4. Second messenger NAADP shows fast, dose-related impact on satiety cycle
5. Notorious cancer gene may work by destroying messenger
6. Identification of specific genes predicts which patients will respond to Hepatitis C treatment
7. Overbearing colored light may reveal a second mechanism by which birds interpret magnetic signals
8. Bacteria which sense the Earths magnetic field
9. Researchers discover which organs in Antarctic fish produce antifreeze
10. First-ever genomic test predicts which lung cancer patients need chemotherapy to live
11. Researchers discover key mechanism by which lethal viruses Ebola and Marburg cause disease

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/22/2016)... , March 22, 2016 ... report "Electronic Sensors Market for Consumer Industry by Type ... Others), Application (Communication & IT, Entertainment, Home ... Global Forecast to 2022", published by MarketsandMarkets, ... expected to reach USD 26.76 Billion by ...
(Date:3/17/2016)... March 17, 2016 ABI Research, the ... the global biometrics market will reach more than ... increase from 2015. Consumer electronics, particularly smartphones, continue ... sensors anticipated to reach two billion shipments by ... Dimitrios Pavlakis , Research Analyst at ABI Research. ...
(Date:3/14/2016)... HANOVER , Allemagne, March 14, 2016 /PRNewswire/ ... http://www.apimages.com ) - --> - ... ) - --> ... les solutions biométriques, fournit de nouveaux lecteurs d,empreintes ... lecteur LF10 de DERMALOG sera utilisé pour produire ...
Breaking Biology News(10 mins):
(Date:5/24/2016)... ... 2016 , ... Last week, Callan Capital, an integrated wealth management firm specializing ... of San Diego Life Science event at the Estancia La Jolla Resort and Spa. ... with speakers Dr. Rich Heyman, former CEO of Aragon and Seragon, and Faheem Hasnain, ...
(Date:5/23/2016)... ... 23, 2016 , ... The need for blood donations in South Texas and across the nation ... Blood & Tissue Center, blood donations are on the decline. In fact, donations across the ... 21 percent in South Texas in the last four years alone. , There is no ...
(Date:5/23/2016)... , May 23, 2016 Zimmer Biomet Holdings, ... healthcare, today announced that its Board of Directors has approved ... the second quarter of 2016. The cash ... about July 29, 2016 to stockholders of record as of ... of dividends are subject to approval of the Board of ...
(Date:5/23/2016)... LONDON , May 23, 2016 ... Efficiency by 40% - Frontage Implement a Single Platform ... Quality, Compliance and Traceability Within the Bioanalytical lab Frontage ... the United States and China ... across its laboratory facilities. In addition to serving as the global ...
Breaking Biology Technology: