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 NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

nachricht Pollen taxi for bacteria
18.07.2018 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>