Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New insight into fragile X syndrome: Scientists identify possible link to RNAi

01.10.2002


Two independent research groups, led by Drs. Haruhiko Siomi (Institute for Genome Research, University of Tokushima, Japan) and Gregory Hannon (Cold Spring Harbor Laboratory, USA) have discovered that the Drosophila version of the human fragile X mental retardation protein associates with components of the RNAi pathway, suggesting that the molecular mechanism underlying fragile X syndrome may involve an RNAi-related process.



"It has been our feeling since we became involved in the field several years ago that only through an understanding of the mechanism of RNAi would we be able to understand the biological implications of this process," states Dr. Hannon.

Fragile X syndrome is the most common form of hereditary mental retardation, affecting 1 in 4000 males and 1 in 8000 females. Fragile X syndrome is the result of a genetic mutation at one end of the fragile X mental retardation 1 gene (FMR1) that causes the abnormal inactivation of the gene. It is known that the protein encoded by FMR1 -- the so-called fragile X mental retardation protein (FMRP) -- binds to RNA and is thought to regulate the expression of specific genes during neural development, but the mode of FMRP action in cells is yet to be defined.


This work provides some important clues.

Using Drosophila as a model organism, Drs. Siomi and Hannon and colleagues found that FMRP associates with RNAi-related cellular machinery. RNAi-induced gene silencing depends upon the introduction of double-stranded RNA, which is processed by Dicer enzymes into short pieces of double-stranded RNA. These short interfering RNAs, or siRNAs as they are known, are incorporated into an RNAi-induced silencing complex (RISC), which uses them as a guide to target and destroy complementary mRNAs, and thereby prevent synthesis of the encoded protein.

Both teams of researchers identified an association between FMRP, short double-stranded RNAs, and a previously identified subunit of RISC (a protein called AGO2); Dr. Siomi and colleagues also found that FMRP associates with the Dicer processing enzyme. These finding suggest that FMRP may function in an RNAi-related process to regulate the expression of its target genes at the level of translation (protein synthesis).

Further delineation of both the identity of FMRP target genes and how changes in their expression patterns can alter the neural landscape in such a way as to result in mental retardation are needed, but as Dr. Siomi explains, "the link between the fragile X syndrome as a phenotype and a possible role for defects in an RNAi-related apparatus through loss of the FMR1 protein will likely open up an entirely new field of molecular human genetics: defects in an RNAi-related apparatus that cause disease."

Heather Cosel | EurekAlert!
Further information:
http://www.cshl.org/

More articles from Life Sciences:

nachricht Show me your leaves - Health check for urban trees
12.12.2017 | Gesellschaft für Ökologie e.V.

nachricht Liver Cancer: Lipid Synthesis Promotes Tumor Formation
12.12.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Long-lived storage of a photonic qubit for worldwide teleportation

12.12.2017 | Physics and Astronomy

Multi-year submarine-canyon study challenges textbook theories about turbidity currents

12.12.2017 | Earth Sciences

Electromagnetic water cloak eliminates drag and wake

12.12.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>