Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers at the RUB and from Taiwan discover energy supply for protein secretion

10.05.2012
Out of the cell

Journal of Biological Chemistry: mechanism of bacterial transport system published

In order to interact with the environment, bacteria secrete a whole arsenal of proteins. Researchers have now found how one of the transportation systems used for this purpose – the type VI secretion system – works for the single-celled organism Agrobacterium tumefaciens. They have identified the relevant transport proteins and their energy suppliers.


Export mechanism: To get to the outside, Hcp has to get past two cell membranes. This is only possible if it forms a complex with the two membrane proteins TssM (grey) and TssL (white). The energy for the export is produced by the interaction of TssM with the energy storage molecule ATP. Figure: modified from the Journal of Biological Chemistry

With colleagues at the Academia Sinica in Taiwan, RUB biologist Prof. Dr. Franz Narberhaus describes the findings in the Journal of Biological Chemistry. “The proteins involved also occur in other secretion apparatuses” explains Narberhaus from the Department of Microbial Biology. “Therefore, the results contribute to the general understanding of the system.”

Protein arsenal for many purposes

Bacteria use secreted proteins to make nutrients available, to fend off competitors and to infect human, animal or plant host cells. “Agrobacterium tumefaciens is a fascinating bacterium. It can genetically modify plants and stimulate tumour formation”, says Narberhaus. Five bacterial secretion systems have been known for a long time. The type VI system was only discovered a few years ago. Among other things, it transports the protein Hcp through two membranes into the environment – for what purpose is, as yet, unclear. The question of how the export of Hcp is driven was also unanswered. This is precisely what the German-Taiwanese team has now revealed.

Membrane protein TssM: the driver of the protein export

Narberhaus and his colleagues have shown that two proteins in the cell membrane of the bacteria, called TssL and TssM, are responsible for the export of Hcp. The molecule ATP, a cellular energy store, serves as fuel for the transport process. The membrane protein TssM binds the energy supplier ATP, thereby changing its own structure and splitting the ATP. The energy thus released allows the associated membrane protein TssL to bind its cargo (Hcp) so that a tripartite complex of TssM, TssL and Hcp is formed. Hcp only passes from the bacterial cell into the environment when this complex forms.

Successful cooperation between Bochum und Taiwan

“Large membrane proteins such as TssM are difficult to study biochemically. Our colleagues in Taiwan have done a great job” Prof. Narberhaus explains. “It will now be particularly interesting to explore the biological significance of the system.” The analyses of ATP splitting, also called hydrolysis, were established in Prof. Narberhaus’s laboratory by the doctoral student Lay-Sun Ma during a research visit. “Because of the participation in the Collaborative Research Centre SFB 642 ‘GTP- and ATP-dependent membrane processes’, we are able to offer ideal conditions for working with ATP-dependent proteins” the RUB-biologist explains. This is the second time that the DAAD has funded the cooperation between the laboratories of Franz Narberhaus and Erh-Min Lai. The successful cooperation is also to continue in the future. “It is bound to last for many years”, the Bochum researcher is convinced. The next exchange of doctoral students is planned for autumn.

Bibliographic record

L.-S. Ma, F. Narberhaus, E.-M. Lai (2012): IcmF family protein TssM exhibits ATPase activity and energizes type VI secretion, Journal of Biological Chemistry, doi: 10.1074/jbc.M111.301630

Further information

Prof. Dr. Franz Narberhaus, Department of Microbial Biology, Faculty of Biology and Biotechnology at the Ruhr-Universität, 44780 Bochum, Germany, Tel. +49/234/32-23100

franz.narberhaus@rub.de

Click for more

Microbial biology at the RUB
http://www.ruhr-uni-bochum.de/mikrobiologie/index_en.html
Editor: Dr. Julia Weiler

Dr. Josef König | idw
Further information:
http://www.ruhr-uni-bochum.de/
http://www.ruhr-uni-bochum.de/mikrobiologie/index_en.html

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

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,...

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

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>