Navigation Links
Molecular steps involved in the creation of gene-silencing microRNAs identified

First discovered only a few brief years ago, microRNAs are small, remarkably powerful molecules that appear to play a pivotal role in gene silencing, one of the body's main strategies for regulating its genome. A scant 22 nucleotides in length, miRNAs appear to work by binding to and somehow interfering with messenger RNA, itself responsible for translating genes into proteins.

But how do miRNAs arise? And what can we learn about their biological function from their origins? In a study published last year in Nature, researchers at The Wistar Institute identified a two-protein complex, called the microprocessor complex, which controls the earliest steps in the creation of miRNAs in the cell nucleus.

Now, in a new study published online by Nature today, the Wistar group has identified a three-protein complex that picks up the process in the cell cytoplasm and carries it through to the maturation of the finished miRNAs.

Taken together, the two Nature studies trace the generation of miRNAs from the genes that give rise to long primary RNA molecules through to the mature miRNAs that target messenger RNA. Significantly, the research also shows that the finished miRNAs are associated with a protein called Argonaute 2, known to be involved in inactivating messenger RNA.

"In this study, we were able to link processing of the miRNAs directly through to the molecules responsible for silencing genes," says Ramin Shiekhattar, Ph.D., an associate professor at Wistar and senior author on both Nature studies. "The miRNAs provide specificity for those molecules, which do the actual work of gene silencing."

Intriguingly, the research also links the process of creating miRNAs with aspects of the HIV life cycle and with tumor suppression. The study identifies three proteins that work together in the cytoplasm to create finished miRNAs. Individually, each of the proteins was known previously, but their joint role in producing miRNAs is newly deline ated here. Equally as important, however, is the fact that while two of the proteins had been associated with miRNAs in earlier work, the third protein, TRBP, had not been. And TRBP is clearly a protein of interest to scientists.

"TRBP was first observed as a protein that binds to HIV during transcription of the virus," says Shiekhattar. "The tantalizing implication is that the RNA interference pathway may play a significant role in HIV replication. TRBP has also been identified as a tumor suppressor, which suggests still other connections to be explored."

The lead authors on the Nature study are Thimmaiah Chendrimada, Richard I. Gregory, and Easwari Kumaraswamy, with each contributing equally to the work. The remaining co-authors are Jessica Norman, Neil Cooch, and Wistar professor Kazuko Nishikura, Ph.D. Corresponding author Shiekhattar is an associate professor in two programs at Wistar, the gene expression and regulation program and molecular and cellular oncogenesis program. Support for the research was provided by the National Institutes of Health, the American Cancer Society, and the Jane Coffin Child Memorial Fund for Medical Research.


'"/>

Source:The Wistar Institute


Related biology news :

1. Molecular biology fills gaps in knowledge of bat evolution
2. Molecular machine may lead to new drugs to combat human diseases
3. Molecular Motors Cooperate In Moving Cellular Cargo, Study Shows
4. Molecular models advance the fight against malaria
5. Molecular fossils uncover link between viruses and the immune system
6. Molecular thermometers on skin cells detect heat and camphor
7. Molecular messengers perform a crucial role in the ability of injured nerve cells to heal themselves
8. Molecular miners find pain relief drugs from the sea
9. Molecular mechanism of feather formation found
10. Molecular trigger for Huntingtons disease found
11. Molecular Partners Required For Appropriate Neuronal Gene Repression
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:3/30/2017)... March 30, 2017  On April 6-7, 2017, Sequencing.com ... Genome hackathon at Microsoft,s headquarters in ... will focus on developing health and wellness apps that ... Hack the Genome is the first hackathon for ... world,s largest companies in the genomics, tech and health ...
(Date:3/29/2017)... -- higi, the health IT company that operates the largest ... , today announced a Series B investment from BlueCross ... new investment and acquisition accelerates higi,s strategy to create ... health activities through the collection and workflow integration of ... and secures data today on behalf of over 36 ...
(Date:3/24/2017)... 2017 The Controller General of Immigration from Maldives ... Algeen have received the prestigious international IAIR Award for the most ... Reading ... Maldives ... Abdulla Algeen (small picture on the right) have received the IAIR award ...
Breaking Biology News(10 mins):
(Date:8/15/2017)... 15, 2017 After spending the past two years building ... data collection, GeneFo now offers this platform to healthcare stakeholders (hospitals, ... support, adherence, and data collection vis a vis their members, under ... successful launch of this offer. ... GeneFo ...
(Date:8/15/2017)... , ... August 15, 2017 , ... ... family of 6” modular downlights designed to stay tightly sealed and perform efficiently ... where damp and wet location listings just aren't enough, such as: hospitals; behavioral ...
(Date:8/14/2017)... ... 2017 , ... Opal Kelly, a leading producer of powerful ... the release of SYZYGY™, a new open standard for connecting high-performance peripherals to ... low cost, low pin-count, high-performance connectivity solution between FPGAs and single-purpose hardware peripherals. ...
(Date:8/11/2017)... ... August 11, 2017 , ... “There ... particular, more natural alternatives to synthetic ingredients,” said Matt Hundt, President of Third ... the established manufacturing presence and know-how of Biorigin will allow us to bring ...
Breaking Biology Technology: