Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Within a cell, actin keeps things moving

21.12.2009
University of Oregon-made technique is putting new light on machinery driving intracellular transport

Using new technology developed in his University of Oregon lab, chemist Andrew H. Marcus and his doctoral student Eric N. Senning have captured what they describe as well-orchestrated, actin-driven, mitochondrial movement within a single cell.

That movement -- documented in a paper appearing online the week of Dec. 14-18 ahead of regular publication in the Proceedings of the National Academy of Sciences -- appears to be coordinated by mitochondria's recruitment of actin-related proteins that rapidly assemble into extended fractal-like structures in a molecular chemical reaction known as polymerization. The coordinated movement of mitochondria is important for reproduction of identical daughter cells, and the sorting of mitochondrial DNA into the spinoff cells.

The research was done with a molecular fluorescence technology called Fourier imaging correlation spectroscopy that allows researchers using focused laser beams to see, measure and map the intermittent movement of mitochondria at micron scales. Marcus will discuss the technology, developed with funding from the National Institutes of Health and National Science Foundation, at the 2010 annual meeting of the American Physical Society in Portland, Ore., in March. It also was detailed in a paper published online in October by the journal Annual Reviews of Physical Chemistry.

In their project published by PNAS -- funded by the NIH -- Senning and Marcus looked at actin's behavior using inhibitory agents to monitor mitochondrial activity in Saccharomyces cerevisiae, a species of budding yeast often used in research. They also introduced two defective forms of the protein. Their technique included the use of hormones to trick a yeast cell into thinking it was about to mate, so that it stops dividing and sits and fluctuates -- much like a car in idle. From this state, the images are drawn.

The picture that emerged, Marcus said, was that actin is drawn to the surfaces of mitochondria to regulate the polymerization machinery so that it operates in an efficient, organized manner. The findings, the researchers wrote, lend support to an existing model in which non-equilibrium forces are directly coupled to mitochondrial membrane surfaces. In effect, the findings support the idea that despite the cramped quarters of molecules in densely packed cells, intracellular transport is accomplished by coordinating the movements of a multi-faceted machine, rather than resulting from random (Brownian) movements of material based on what obstacles will allow.

The quest for understanding the machinery is more than just biological, where this research provides insight into how the cell moves its mitochondria into the daughter cells, Marcus said. The knowledge could become useful in the production of nanotechnology devices.

"A central question in modeling cell transport is whether the cytoplasm may be viewed as a simple extension of a complex fluid at equilibrium or if non-equilibrium effects dominate the motions of intracellular species," he said. "If somebody wants to design a micron-scale machine or make a self-replicating device, one would have to have these physical principles in place. One would need to have a motor in place and know how much force the motor needs to apply, either cooperatively or individually with other components."

Marcus is a member of the UO's Oregon Center for Optics, and an associate member of the Institute of Molecular Biology and the Materials Science Institute.

About the University of Oregon

The University of Oregon is a world-class teaching and research institution and Oregon's flagship public university. The UO is a member of the Association of American Universities (AAU), an organization made up of the 62 leading public and private research institutions in the United States and Canada. The UO is one of only two AAU members in the Pacific Northwest.

Source: Andrew H. Marcus, associate professor of chemistry, 541-346-4809, ahmarcus@uoregon.edu

Jim Barlow | EurekAlert!
Further information:
http://www.uoregon.edu

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 >>>