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

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:

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

More articles from Life Sciences:

nachricht International team discovers novel Alzheimer's disease risk gene among Icelanders
24.10.2016 | Baylor College of Medicine

nachricht New bacteria groups, and stunning diversity, discovered underground
24.10.2016 | DOE/Lawrence Berkeley National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

New method increases energy density in lithium batteries

24.10.2016 | Power and Electrical Engineering

International team discovers novel Alzheimer's disease risk gene among Icelanders

24.10.2016 | Life Sciences

New bacteria groups, and stunning diversity, discovered underground

24.10.2016 | Life Sciences

More VideoLinks >>>