Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers shake up scientific theory on motor protein

09.02.2009
An international team of scientists led by the University of Leeds has shed new light on the little-understood motor protein called dynein, thought to be involved in progressive neurological disorders such as motor neurone disease.

Researchers from the University's Astbury Centre for Structural Molecular Biology and from the University of Tokyo have for the first time identified key elements of dynein's structure, and the winch-like mechanism by which it moves.

The research – funded by the Biotechnology and Biological Sciences Research Council and the Wellcome Trust – is published in the latest issue of Cell.

Dynein is the largest, but least understood of the three families of motor proteins, yet it is responsible for many key processes, such as powering the movement of sperm and eggs, and helping cells divide. It is also responsible for transporting molecular cargo within cells such as motor neurones, the nerve cells that supply all voluntary muscle activity.

Lead researcher, Dr Stan Burgess from the University of Leeds' Faculty of Biological Sciences, says: "Motor neurones have a very complex transportation system. While the nuclei of motor neurones lie within the spinal cord, they have branches that can run the entire length of a limb, say from the spine to the big toe. This branch is like a highway for molecular motors such as dynein. If there's a disruption to the traffic, it can lead to cell death and eventually to muscular weakness, characterised in diseases such as motor neurone disease."

Measuring only 50 nanometers, dynein can carry its cargo up to a metre in humans - the equivalent of humans walking about forty thousand kilometres. Dynein is poorly understood, partly because it is difficult to engineer for experimental studies and because the usual techniques for determining the structure of a molecule – X-ray crystallography and nuclear magnetic resonance spectroscopy (NMR) - have been unsuccessful.

The Leeds team worked with synthetic dynein engineered by their Japanese colleagues which contained fluorescent marker proteins at key points within the motor. Using an electron microscope, they were able to plot the positions of the marker proteins both with and without ATP, the 'fuel' that drives the motor.

Dr Burgess says: "Dynein, like all proteins, is a long linear molecule folded up into a complicated three-dimensional structure. While we can't solve the atomic structure using electron-microscopy, our research has enabled us to map key points in the chain and see which parts of it move."

Co-researcher Anthony Roberts, says: "Seeing the molecule change shape with ATP gives us clues to its motor mechanism that we will follow up in future work."

The Japanese scientists also removed the ends of the dynein molecule to expose the core, and imaging at Leeds showed that – contrary to the accepted model – the core of dynein is similar to other ring-shaped molecular machines in the cell, with which dynein shares distant evolutionary links.

"There has been disagreement over the structure of dynein within the scientific community, and both elements of our research – identifying the moving parts and revealing the structure of the core – has meant we can correct some of the mistaken ideas," says Dr Burgess. "Hopefully this will enable future research on this very important protein to move forward much faster."

The researchers from Leeds and Tokyo have already joined forces with colleagues in Ljubljana, Slovenia, to secure a grant of US$1.2 million from the prestigious Human Frontier Science Program (HFSP) to continue their research on dynein. Their bid was ranked first among 18 awards made from 600 original applications from around the world.

Headed by Dr Burgess, the international team will build on their latest findings and their expertise in engineering and imaging dynein. They aim to study the structure of two-headed dynein walking along its microtubule track using electron microscopy. Colleagues in Tokyo will measure the force it exerts as it walks as well as its step size and speed. The team in Slovenia will then combine all the new data into a computer model to simulate the movement of the protein.

"By examining the structure and mechanism of dynein while it's moving, we hope to learn more about how the protein works in the cell, so we can better understand what happens when it goes wrong," says Dr Burgess.

Jo Kelly | EurekAlert!
Further information:
http://www.leeds.ac.uk

More articles from Life Sciences:

nachricht Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz

nachricht Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>