Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How enzymes communicate

19.05.2017

Freiburg scientists explain the cell mechanism that transforms electrical signals into chemical ones

The enzymes nitric oxide (NO) synthase (NOS1) and protein kinase C (PKC) play an important role in a variety of signal transfer processes in neurons of the brain, as well as in many cell types of other organs.


Electro-chemical coupling through protein super complexes: The calcium channel (Cav2) delivers calcium ions (Ca2+) that activate the enzyme NO synthase (NOS) for generation of the messenger NO. Source: Bernd Fakler

Together with Prof. Dr. Bernd Fakler at the Institute of Physiology at the University of Freiburg, the scientists Dr. Cristina Constantin and Dr. Catrin Müller have shown for the first time that enzymes can be activated under physiological conditions through sole electrical stimulation of the cell membrane.

Protein super complexes that rapidly transform electrical signals at the cell membrane into chemical signal processes inside the cell emerge through direct structural interaction of both enzymes with voltage-gated calcium channels. The researchers have presented their work in the current issue of the scientific journal Proceedings of the National Academy of Sciences (PNAS).

The Fakler group has previously shown that both calcium-dependent enzymes NOS1 and PKC are components of the protein nano-environment of certain voltage-gated calcium channels (Cav2-channels) in the brain. As yet, however, it was not know how these enzymes communicate with the calcium channels.

The research group has now found that both enzymes are integrated into protein super complex with Cav2 channels. Within such Cav2-NOS1/PKC complexes NOS1 or PKC are anchored at the cytoplasmic side of the cell membrane and are placed at in the immediate vicinity of the channel pore.

Upon excitation of the cell membrane, the Cav2 channels open and deliver calcium ions to the cell cytoplasm, where they bind to both enzymes. Calcium binding activates the enzymes, which subsequently produce the diffusible second messengers NO or phosphorylate cytoplasmic target proteins.

Due to the proximity between channel and enzyme, electrical stimulations of less than a millisecond duration are required for effective electro-chemical coupling. The latter becomes maximal when the cell, instead of being stimulated by individual impulses, fires action potentials with a frequency of one hertz or more.

The Cav2-enzyme super complexes not only guarantee an ultrafast and reliable electro-chemical coupling. They also ensure that signal transduction remains locally restricted, that is, within an area less than a few nanometers around the Cav2 channels. This local restriction guarantees that the enzymes only initiate specific cellular processes, while other calcium signalling pathways, including cell death, are prevented.

In addition, the researchers’ experiments highlighted the physiological mechanism for activation of NOS1 and PKC thus presenting an alternative to the widely used synthetic activators, such as NO donors or diacylglycerols.

Bernd Fakler is the director of Department II of the Institute of Physiology and area coordinator of the Cluster of Excellence BIOSS Centre for Biological Signalling Studies at the University of Freiburg.

Originalpublikation:
Constantin, C.E., Müller, C.S., Leitner, M., Bildl, W., Schulte, U., Oliver, D., and Fakler, B. (2017). Identification of Cav2-PKC and Cav2-NOS1 complexes as entities for ultrafast electro-mechanical coupling. Proc Natl Acad Sci USA (in press).

Contact:
Prof. Dr. Bernd Fakler
Institute of Physiology, Faculty of Medicine / BIOSS Centre for Biological Signalling Studies
University of Freiburg
Tel.: 0761/203-5175
E-Mail: bernd.fakler@physiologie.uni-freiburg.de

Weitere Informationen:

https://www.pr.uni-freiburg.de/pm-en/2017/how-enzymes-communicate?set_language=e...

Rudolf-Werner Dreier | Albert-Ludwigs-Universität Freiburg im Breisgau

More articles from Life Sciences:

nachricht Meadows beat out shrubs when it comes to storing carbon
23.11.2017 | Norwegian University of Science and Technology

nachricht Migrating Cells: Folds in the cell membrane supply material for necessary blebs
23.11.2017 | Westfälische Wilhelms-Universität Münster

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

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....

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

Underwater acoustic localization of marine mammals and vehicles

23.11.2017 | Information Technology

Enhancing the quantum sensing capabilities of diamond

23.11.2017 | Physics and Astronomy

Meadows beat out shrubs when it comes to storing carbon

23.11.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>