Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Missing protein in Fragile X Syndrome is key to transporting signals within neurons

10.06.2008
Fragile X syndrome (FXS) robs the brain of a protein that plays a major role in the way neurons communicate and that is essential for brain development, learning and memory.

A team of scientists has discovered new information about how FXS interferes with signaling between the nucleus of neurons and the synapse, the outer reaches of the neuron where two neurons communicate via chemical and electrical signals. The discovery should help lead the way to the development of new treatments for FXS, the most common form of inherited mental retardation and also a genetic contributor to some types of autism and epilepsy.

The research will be published in the June 10 issue of Developmental Cell. The team was led by Gary J. Bassell, professor of cell biology and neurology at Emory University School of Medicine and Robert H. Singer, PhD, professor of anatomy & structural biology at the Albert Einstein College of Medicine. First author was Jason B. Dictenberg of Hunter College, City University of New York and Albert Einstein College of Medicine.

Translation of an organism's genetic information begins in the nucleus of a cell, where the DNA sequence (gene) is copied into an mRNA molecule, then exported into the cell's cytoplasm and translated into protein molecules.

... more about:
»FMRP »FXS »Neuron »Nucleus »Protein »RNA »Synapse »dendrites »mRNA

FXS is caused by the silencing of a single gene, which normally would encode for the expression of the fragile x mental retardation protein (FMRP)--an mRNA (messenger RNA) binding protein. mRNA binding proteins are known to be key regulators of gene expression because they act as master regulators of other mRNAs and broadly influence how proteins are synthesized from mRNAs.

The precise functions for FMRP have been unclear, but scientists recently have learned that FMRP is able to bind and regulate several mRNAs that are present at synapses in the brain. Each mRNA molecule can be translated many times at the synapse, producing many copies of the encoded protein and providing an efficient way for a neuron to supply its synapse with essential proteins needed for communication. Since mRNAs can be turned on or off, each synapse can decide for itself whether or not new proteins are needed to promote signaling. Proper signaling at synapses is essential for the complex wiring of connections that must occur during brain development and during learning and memory. In FXS, there are defects in both the structure and signaling at synapses, due to the lack of FMRP regulation of mRNAs at synapses. Until now, a major unanswered question has been how FMRP and its bound mRNAs are delivered to axons and dendrites Ð the tentacle-like projections of neurons-- and to the synapses at their outer extremities.

"A major challenge for the field of neuroscience has been to understand how a selective group of mRNAs can be transported long distances from the nucleus, where the RNA is made, to reach the synapses, where this select group of mRNAs can be translated into the protein molecules that are needed to enable signaling," says Bassell. "This mechanism of mRNA transport into axons and dendrites and its translation at synapses is critical for synapse signaling during learning, memory and cognition."

Bassell and his Emory colleagues have developed high resolution microscopic imaging tools to visualize FMRP in live neurons, allowing them to track the movements of FMRP and associated mRNA molecules along dendrites, using cultured neurons isolated from the hippocampus of mouse embryos.

The researchers discovered that FMRP binds to a molecular motor, which allows it to carry its bound mRNAs in the form of particles out into the dendrites.

"FMRP seems to be quite a clever protein that acts like a postal carrier to deliver messages to the synapse, enabling and sustaining their continued signaling," says Bassell.

In a mouse model of FXS, the investigators discovered that mRNAs are not motored into dendrites in response to synaptic signaling and thus cannot allow for local protein synthesis at synapses needed to sustain the synaptic signaling between nerve cells. In essence, the ability of the nerve cell to communicate from the nucleus to the synapse is lost in fragile X.

The researchers also were able to identify the select group of mRNAs that the neuron ships into dendrites via FMRP. Knowing which molecules within the FMRP pathway function at synapses should facilitate the development of new treatment strategies and drug interventions for FXS.

Holly Korschun | EurekAlert!
Further information:
http://www.emory.edu

Further reports about: FMRP FXS Neuron Nucleus Protein RNA Synapse dendrites mRNA

More articles from Life Sciences:

nachricht Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>