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 Multi-institutional collaboration uncovers how molecular machines assemble
02.12.2016 | Salk Institute

nachricht Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>