Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Head in a Cage

11.06.2013
Fatty acid composition of diacylglycerols determines local signaling patterns

In the human body, lipids do not only serve as energy stores and structural elements, but they are also important signaling molecules. Disruptions of lipid signal transmission seem to be involved in diseases such as atherosclerosis and diabetes, as well as inflammation and pain.



In the journal Angewandte Chemie, researchers from Heidelberg have now reported on photoactivatable lipids that can be used to manipulate signaling processes in cells with both spatial and time resolution.

To communicate with each other and react to external stimuli, cells need signal-transmission mechanisms. The signal cascades involved are very complex and vary greatly from one cell type to the next. For example, one type of cascade involves the activation of phospholipase C, which then splits a membrane building block into inositol trisphosphate and the lipid diacylglycerol (DAG). These in turn serve as secondary messengers within the cell.

DAG anchors the enzyme protein kinase C (PKC) to the cell membrane and activates it. In addition, DAG can open certain calcium channels in the cell membrane, allowing calcium ions to flow into the cell. This stimulates further steps of the network and hence eventually trigger physiological responses, such as changes in gene expression.

Lipids as secondary messengers have received relatively little attention from researchers. Lipids consist of a head group and a “tail” made of a hydrocarbon chain that can vary greatly with regard to its length and the number, distribution, and arrangement of its double bonds. Previous investigations did not differentiate the effects of the different tails, only those of the heads.

Carsten Schultz and a team from the European Molecular Biology Laboratory (EMBL) in Heidelberg have now taken on this challenge. They synthesized DAG lipids with a variety of tails and locked their glycerol heads into “cages” – molecules attached so as to block and deactivate the head group.

The cages are designed with a built-in “break-away” point that breaks open upon irradiation with light to release the DAG. These types of photoactivatable molecules make it possible to deliver biologically active signal molecules at a specific time and place with subcellular resolution.

Through these experiments, the researchers were able to demonstrate that the activation of PKC is locally limited by DAG, whereas the elevation of internal calcium ion concentration through activation of calcium channels affects the entire cell. Surprisingly, these effects seem to be dependent on the fatty acid composition of the lipid. One of the DAG variants thus induced fewer, shorter, and weaker elevations of the calcium level, while another caused stronger, long-lasting calcium signals. A third had no significant influence on the intracellular calcium concentration.

“If this variability concerning the fatty acid composition should influence the control of cellular processes in most lipids, a completely new level of complexity has to be considered in cell biology”, says Schultz. “Furthermore, our results demonstrate that cells can respond to a given spatially confined signal both with a local and a global response pattern. Local signaling is particularly important in polarized and migrating cells, where different signals are needed at opposite ends of the cell.”

About the Author
Dr Carsten Schultz is an interdisciplinary team leader and Senior Scientist at the European Molecular Biology Laboratory (EMBL) in Heidelberg. His main research fields include the manipulation and visualization of intracellular signal transduction networks by using chemical biology, as well as the development of fluorescent detection systems, for example in applications concerning chronic lung disorders within the framework of the German Center for Lung Research (DZL) in Heidelberg.
Author: Carsten Schultz, European Molecular Biology Laboratory, Heidelberg (Germany), http://www.embl.de/research/units/cbb/schultz/members/index.php?s_personId=CP-60002438
Title: The Fatty Acid Composition of Diacylglycerols Determines Local Signaling Patterns

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201301716

Carsten Schultz | Angewandte Chemie
Further information:
http://pressroom.angewandte.org

More articles from Life Sciences:

nachricht The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie

nachricht How protein islands form
15.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

New thruster design increases efficiency for future spaceflight

16.08.2017 | Physics and Astronomy

Transporting spin: A graphene and boron nitride heterostructure creates large spin signals

16.08.2017 | Materials Sciences

A new method for the 3-D printing of living tissues

16.08.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>