Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Small signaling molecule gives green light for cell division

07.05.2015

Generating offspring is the evolutionary goal of all living organisms. The multiplication of individual cells is coordinated by the cell cycle. For the discovery of how this process is regulated in eukaryotes the Noble Prize was awarded in 2001.

The team of Prof. Urs Jenal at the Biozentrum of the University of Basel has now identified the central switch for reproduction in bacteria. While cell cycle progression in eukaryotes is regulated by small proteins called cyclins, in bacteria this role is adopted by a small signaling molecule, c-di-GMP. In the current issue of «Nature» the scientists describe the molecular details of this process.


Enzymes producing the small signalling molecule c-di-GMP (yellow) control Caulobacter cell cycle.

University of Basel, Biozentrum

Though very tiny, the molecule is vital for the survival of almost all bacteria. This signaling messenger – called c-di-GMP – controls behavioral processes in bacteria. For instance, it ensures that bacteria join together to form biofilms, which can cause chronic infections in humans.

The scientists working with Prof. Urs Jenal at the Biozentrum of the University of Basel have now demonstrated that c-di-GMP also plays a decisive role in bacterial reproduction. They discovered that oscillating levels of the messenger subsequently influence the activity of key regulatory proteins, thereby controlling cell cycle progression and proliferation of bacteria.

Signaling molecule sets traffic lights at check points

How do cells multiply? When cells divide, two daughter cells arise from one mother cell. Before this, however, the cell must go through several phases from growth, to the replication of its genetic information and finally to cell division.

This process is known as the cell cycle. In their study on the model bacterium Caulobacter crescentus the infection biologists show for the first time, that the signaling messenger c-di-GMP controls the cell cycle in a similar way as a traffic light works. In the absence of c-di-GMP in the cell, the light shows red.

This indicates that the cell will have to remain in the first phase of the cell cycle. If the c-di-GMP level increases, the light switches to green and the cell enters the next phase. The scientists have investigated what exactly occurs on the molecular level.

c-di-GMP controls an enzyme with two modes of action

The role of this traffic light is played by an enzyme that works in two different ways. “When c-di-GMP is lacking, it blocks the process which leads to replication of the genetic material,” explains Jenal. “However, as soon as c-di-GMP is produced, it binds to the enzyme, thus altering its structure and mode of action. Subsequently, this blockade is lifted and the bacterial chromosomes can be copied.”

This step marks the entry into the next phase of the cell cycle. The varying spatial distribution of the signaling molecule in the dividing mother cell also plays an important role in the behavior of the progeny.

Pathogens use the same signaling network

It is the first time that the researchers have been able to establish a direct connection between the two major regulatory networks of bacterial cells, – the small messenger and important regulatory enzymes called kinases. The insights gained provide an important basis for elucidating the much more complicated c-di-GMP networks of pathogens.

The signaling molecule is involved in virulence, persistence mechanisms and antibiotic resistance of pathogens. For instance, dangerous pathogens causing cholera or pneumonia use c-di-GMP signaling to survive in their human host. As a next step, the researchers want to figure out, whether this molecule acts in these pathogens in the same way as in the model bacterium C. crescentus.

Original paper

Lori C, Ozaki S, Steiner S, Böhm R, Abel S, Dubey BN, Schirmer T, Hiller S, and Jenal U.
Cyclic di-GMP acts as a cell cycle oscillator to drive chromosome replication. Nature; published online 6th May 2015.

Further informations

Prof. Urs Jenal, Biozentrum University of Basel, Tel: +41 61 267 21 35,
E-Mail: urs.jenal@unibas.ch

Weitere Informationen:

http://www.nature.com/nature/journal/vaop/ncurrent/full/nature14473.html - Original paper

Christoph Dieffenbacher | Universität Basel
Further information:
http://www.unibas.ch

More articles from Life Sciences:

nachricht Zap! Graphene is bad news for bacteria
23.05.2017 | Rice University

nachricht Discovery of an alga's 'dictionary of genes' could lead to advances in biofuels, medicine
23.05.2017 | University of California - Los Angeles

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

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...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

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

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

 
Latest News

Scientists propose synestia, a new type of planetary object

23.05.2017 | Physics and Astronomy

Zap! Graphene is bad news for bacteria

23.05.2017 | Life Sciences

Medical gamma-ray camera is now palm-sized

23.05.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>