Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Small RNA as Modular Kit

16.11.2010
Even pathogenic bacteria can suffer from stress – when they are attacked by the immune system of their host, for instance. How salmonella bacteria react to such stress conditions is described by Würzburg infection biologists in the scientific journal PNAS.

Salmonella is a type of bacteria that can cause severe diarrhea in humans. On entering the digestive tract, these bacteria will not proliferate unchallenged: The immune system attacks the intruders – with peptides, for instance. These peptides are small proteins, which tear holes in the envelope of the bacteria.

The salmonella react immediately to such envelope damage: Among other things, they produce a small RNA molecule (RybB-sRNA), which promptly prevents the synthesis of about ten proteins in the bacterial cell. All of the proteins in question fulfill biological functions on the envelope of the bacteria.

A reasonable mechanism: "In this way, the salmonella bacteria quickly help themselves. Since the outer membrane is full of holes, the proteins would not be able to persist there and fulfill their function," explains Kai Papenfort of the Institute for Molecular Infection Biology at the University of Würzburg. Thus, the small RNA molecule avoids a waste of protein resources.

RNA start region binds precursors for proteins

But how does the small RNA manage to regulate the production of multiple proteins all at the same time? An answer to this question is given by the Würzburg researchers in the current issue of the scientific journal PNAS: "The start region of the sRNA molecule binds the transcripts, which are a kind of precursor for all these proteins," says Professor Jörg Vogel, the head of the institute. "As soon as this happens, the protein production stops." To prove this, the researchers transferred this start region to other RNA molecules. As a result, the modified molecules also brought the production of the ten proteins to a halt.

Without change in the evolution of the bacteria

With this research, the Würzburg scientists have shown for the first time: Even small RNA molecules possess clearly defined regions to which a regulatory function can be attributed. Previously, this was known to be true only for proteins, but not for "simpler" molecules such as RNA. "RNA also consists of functional units, which can be newly arranged on the basis of a modular design principle," explains Professor Vogel.

Furthermore, the regulatory region represents an RNA section, which has not changed in the evolution of the bacteria. This means: "This RNA is present not only in salmonella, but also in many other pathogenic bacteria and it always has the same function," explains Kai Papenfort.

A molecular structure, which has not undergone any evolutionary change – this suggests that it must be essential. It may be a factor, which is indispensable to the bacteria for the infection process and could play a role in triggering the disease. To clarify whether this is the case is the next objective of the Würzburg researchers. Ultimately, the start region of RybB-sRNA might even become a starting point for new drugs.

Basic research on small RNA

The team of Professor Jörg Vogel conducts basic research on small RNA molecules, the chains of which consist of about 100 components (small RNA, short: sRNA). This particular type of RNA regulates life processes in bacteria and more highly developed cells. Besides salmonella, the Würzburger scientists also used helicobacter as a model organism – a bacterium, which can cause stomach cancer.

"Evidence for an autonomous 5‘ target recognition domain in an Hfq-associated small RNA", Kai Papenfort, Marie Bouvier, Franziska Mika, Cynthia M. Sharma, and Jörg Vogel; PNAS, published online on 8 November 2010, doi 10.1073/pnas.1009784107

Contact person

Dr. Kai Papenfort, Institute for Molecular Infection Biology at the University of Würzburg, T +49 (0)931 31-81230, kai.papenfort@uni-wuerzburg.de

Robert Emmerich | idw
Further information:
http://www.uni-wuerzburg.de

More articles from Life Sciences:

nachricht Discovery of a Key Regulatory Gene in Cardiac Valve Formation
24.05.2017 | Universität Basel

nachricht Carcinogenic soot particles from GDI engines
24.05.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Physicists discover mechanism behind granular capillary effect

24.05.2017 | Physics and Astronomy

Measured for the first time: Direction of light waves changed by quantum effect

24.05.2017 | Physics and Astronomy

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>