Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineered coral pigment helps scientists to observe protein movement with super-resolution

28.07.2010
Scientists in Southampton, UK, and Ulm and Karlsruhe in Germany have shown that a variant form of a fluorescent protein (FP) originally isolated from a reef coral has excellent properties as a marker protein for super-resolution microscopy in live cells. Their findings have been published online by Nature Methods and will appear in print in the upcoming August issue of that journal.

Fluorescent proteins produced by a range of marine animals glow with a rainbow of colours, adding to the visual spectacle of coral reefs. Over recent years, molecular biologists have isolated a number of FPs and their genes, and used them to create genetically engineered variant FPs with particular light-emission characteristics.

“Fluorescent pigments from corals and related animals have proved to be invaluable lead structures to produce advanced markers for biomedical research,” said Dr Jörg Wiedenmann of the University of Southampton’s School of Ocean and Earth Science (SOES) based at the National Oceanography Centre, Southampton: “They enable a plethora of exciting experiments, including non-invasive study of dynamical processes within live cells,”

Photoactivatable FPs (PA-FPs)can, as their name suggests, be switched on by light. When light of a particular wavelength is shone upon them they start to glow, emitting light of characteristic hue.

Wiedenmann and his collaborators previously described EosFP, a PA-FP from the reef-building coral Lobophyllia. Genetic engineering yielded the variant IrisFP with dual photoactivation capacity. In one mode it is irreversibly ‘photo-converted’ from a green- to a red-emitting form under violet light. In a second mode, these two light-emitting forms can be switched on and off more or less at will using light of different wavelengths (‘photo-switching’).

For use in cell biology experiments, PA-FPs are genetically fused to proteins of interest, and expressed in live cells. Small regions of the cell are then illuminated with laser light of specific wavelength, causing the marker proteins to emit light at another wavelength. This allows dynamical cell processes to be visualised and studied under the microscope.

In the native state, four molecules of IrisFP join together to form a tetramer, creating problems for fusion-protein applications. To get round this, the researchers have now modified the protein by introducing four mutations. This makes individual IrisFP molecules (monomers) more stable, reducing their tendency for form tetramers.

“The monomeric variant, mIrisFP, maintains dual photoactivation capacity and has excellent properties as a genetically encoded fluorescent marker protein,” explained Wiedenmann.

To test the usefulness of mIrisFP, the researchers genetically fused it with a number of other proteins within cultured cells. These included transcription factors, which regulate the expression of genes within the cell nucleus, and constituent proteins of the cell skeleton (‘cytoskeleton’). In all cases, the fusion proteins functioned normally.

Further experiments demonstrated that mIrisFP fusion proteins could, as hoped, be used to study dynamical processes within live cells with a spatial resolution beyond the limits of conventional light microscopy. Specifically, the researchers successfully combined so-called pulse-chase experiments with photoactivation localisation microscopy (PALM) imaging to follow the movement of fluorescently marked fusion proteins over time and at very high spatial resolution.

“The dual photoactivation capability and the monomeric nature of mIrisFP should allow cell biologists to perform a wider range of experiments than possible using only conventional PA-FPs,” said Wiedenmann.

“Marine animals such as corals and anemones are not only beautiful and important for ecosystem functioning, but also as source of fluorescent proteins of enormous value to biomedical research,” he added.

The research was supported supported by the Deutsche Forschungsgemeinschaft and the State of Baden-Württemberg through the Center for Functional Nanostructures, by Deutsche Forschungsgemeinschaft grant NI 291/9, Landesstiftung Baden-Württemberg and Fonds der Chemischen Industrie.

The researchers are Jochen Fuchs, Susan Boehme,Per Niklas Hedde and Ulrich Nienhaus(Karlsruhe Institute of Technology),Franz Oswald(University of Ulm), Maike Krause (Institute of Biophysics, Ulm), and Jörg Wiedenmann(SOES).

Publication:

Fuchs, J., Boehme, S., Oswald, F., Hedde, P. N., Krause, M., Wiedenmann, J. & Nienhaus, G. U. A photoactivatable marker protein for pulse-chase imaging with superresolution. Nature Methods (Published online: 4 July 2010). | doi:10.1038/nmeth.1477

http://www.nature.com/nmeth/journal/vaop/ncurrent/abs/nmeth.1477.html

The Coral Reef Laboratory at the National Oceanography Centre, Southampton: http://www.noc.soton.ac.uk/corals/

Dr. Rory Howlett | EurekAlert!
Further information:
http://www.noc.soton.ac.uk
http://noc.ac.uk/news/engineered-coral-pigment-helps-scientists-observe-protein-movement-super-resolution

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 >>>