Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Myosin V, The Molecular Motor, Moves in ’Monkey-Bar’ Motion

31.03.2003


Unique Hand-Over-Hand Rotation Transports Molecules Through Cells



Within every neuron is a vast protein trail system traversed by a small protein engine called Myosin V. The long-standing question of how this molecule moves may have finally been resolved by researchers from the University of Pennsylvania School of Medicine. Their findings, presented in this week’s issue of Nature, show how myosin V can move ’hand-over-hand’ on tracks, composed of a protein called actin, without completely letting go at any point. According to the researchers, myosin V offers a fascinating example of how cells convert chemical energy into motion, and may offer a natural example of molecular motors for the purposes of nanotechnology.

"There are a number of theories on how this molecule moves. What concerned me was how this little myosin motor can move along the track without letting go and floating off into the cytoplasm of the cell," said Yale E. Goldman, MD, PhD, professor in Penn’s Department of Physiology and director of the Pennsylvania Muscle Institute (PMI). "It turns out that myosin tilts as it steps along the actin track - one head attaches to the track and then the molecule rotates allowing the other head to attach - much like a child on a playground crosses the monkey-bars hand-over-hand."


Myosin V, which is also found in pigment cells, is a protein that consists of two heads attached to a long tail, which can bind to the motor’s molecular ’cargo.’ Myosin travels over long filaments of a protein called actin. This cytoskeletal network is a feature of all multicellular creatures, and it is used to transport molecules throughout a single cell. In humans, Griscelli disease, which is characterized by neurological deficits and a lack of pigment, stems from non-functioning myosin V.

Goldman and his colleagues were able to study the hand-over-hand motion of a single myosin motor in action thanks to an innovative microscopic technique created by Joseph N. Forkey, PhD, a post-doctoral researcher at Goldman’s PMI laboratory. The technique, called single-molecule fluorescence polarization, involved labeling myosin V with a fluorescent tag. The researchers then used a laser beam to hit the tag, creating an electromagnetic field that could resolve the angle at which the molecule tilts.

"Using single-molecule fluorescence polarization, we could detect the three-dimensional orientation of myosin V tilting back and forth between two well-defined angles as it teetered along," said Goldman.

Researchers contributing to this work include Margot E. Quinlan and M. Alexander Shaw of PMI and John E. T. Corrie of the National Institute for Medical Research in London, UK.

This research was supported by grants from the National Institutes of Health and the Medical Research Council.

Greg Lester | University of Pennsylvania Medic
Further information:
http://health.upenn.edu/News/News_Releases/mar03/myosinv.html
http://www.med.upenn.edu/

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>