Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

A New Way of Looking at Molecular Motors

10.02.2006


An innovative method of categorizing myosin—one of three molecular “motors” that produce movement within the cells of the body—has dramatically increased the amount of information available about these essential proteins. The studies lay the groundwork for development of treatments for conditions ranging from certain kinds of blindness and kidney disease to neurodegenerative disorders and parasitic diseases such as malaria.



All complex organisms use myosin and its relatives, kinesin and dynein, to move substances around inside cells and to help cells move from one place to the other. Myosins also help parasites enter and infect hosts. Defects in the motors play a role in a variety of human and animal disorders, including retinitis pigmentosa (which causes blindness), polycystic kidney disease, brain development defects, neurodegenerative diseases, muscular dystrophy, skin pigmentation problems, and genetic hearing loss.

Researchers led by Dominique Soldati, a Howard Hughes Medical Institute (HHMI) international research scholar at the University of Geneva in Switzerland, have developed a new system of classifying myosins. Up to now, researchers have only studied approximately 130 myosins at a time. The new system includes 250 myosins and increases the number of myosin subclasses from 18 to 24, enabling researchers to better understand each myosin’s function.


“Myosins that belong to the same class work in similar ways but can have very different functions,” explained Soldati. “We will have to discover the myosins’ functions one by one, and the better we understand how they are related, the faster that will occur.”

The new classification system also describes common evolutionary links between subclasses and protein components within myosins themselves. It includes myosins from insects, algae, parasites, and animals that have not been studied before.

The work will appear in the Proceedings of the National Academy of Sciences, with advance online publication February 6, 2006. Bernardo Foth, a postdoctoral fellow in Soldati’s laboratory, is the first author.

Soldati and Foth became interested in myosins after they discovered that the molecular motors enabled toxoplasmosis and malaria parasites to force their way into human cells.

The researchers say that although their research is theoretical and a long way from clinical applications, the new classification system will help other researchers address important biomedical puzzles more precisely.

“We hope our work will help scientists ask the right questions and perform the right kind of experiments on myosins,” Foth said. “In the long term, that could lead to new drug targets being discovered more quickly."

Molecular motors run on tracks, like trains, using chemical reactions that involve the chemical compound adenosine triphosphate (ATP) for fuel. Myosin runs on the filaments of actin, a protein found in muscle cells, but kinesins and dyneins use microtubules, which are hollow protein structures inside the cell, as their track.

Movement is created several ways. Biological cargo is transported within cells by single motors that run backward and forward, the way a person moves hand over hand along a rope. Making muscles contract involves a large number of motors that work very fast in neatly arranged teams, quickly letting go of the track once they have completed their “power stroke.”

Most molecular motors have a head, a neck (which powers movement), and a tail. Myosins usually look like two-headed snakes, kinesins like hairpins with a head at each end, and dyneins like three-headed flowers with one stem. Soldati and Foth have confirmed that the motor neck and tail evolved together. That finding helped them define some of their new categories.

Organisms employ all three types of motors at the same time, but in different proportions. For example, yeast uses six kinesins, five myosins, and one dynein while mammals have genes for more than 40 kinesins, 40 myosins and more than a dozen dyneins.

Genetic and acquired defects in the motors cause disease by preventing developing cells from migrating to their necessary destinations before birth or by preventing parts of the body, such as sperm tails or the tiny hairs that keep mucus flowing in the lungs, from moving when they are supposed to. The motors in parasitic organisms contribute to disease by enabling the parasites to break through biological barriers within the human body and actively invade cells.

So far, molecular motors have been found in all organisms but bacteria, red algae, and the parasite Giardia. The new myosin classification system should help cell biologists, biochemists, biophysicists, parasitologists, and medical researchers make advances in a wide variety of fields, from veterinary medicine to tropical diseases.

Foth and Soldati’s research was funded by the European Molecular Biology Organization as well as HHMI.

Cindy Fox Aisen | EurekAlert!
Further information:
http://www.hhmi.org

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>