Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Newly identified cell explosions involved in bacterial secretion and adherence

14.04.2016

Researchers have been unclear on how bacteria form and release certain extracellular components involved in cell adhesion and multicellular structures that also contribute to antibiotic resistance. However, a recent study from a multinational team of researchers identified a previously unknown phenomenon, explosive cell lysis, as crucial in the production of membrane vesicles and biofilm formation. The study was reported in Nature Communications.

Membrane vesicles are tiny spheres that develop from bacterial membranes and contain a mixture of proteins, DNA, and RNA. They are important for the virulence of the bacterium--its ability to cause disease--as they play vital roles in invasion, secretion, and signaling.


Bacteria cells change from a rod-like to spherical shape before exploding controlled by the Lys enzyme. Cell membrane fragments curl up to form vesicles and extracellular DNA are released, which can interact with other cells.

Credit: University of Tsukuba

They also contribute to the formation of biofilms, the slimy three-dimensional structures that form when bacteria adhere to moist surfaces such as teeth or wounds. Extracellular (e)DNA is a key structural organization of biofilms, yet it was not known how certain structural proteins or eDNA are released.

To answer this, the researchers used live cell microscopy of the pathogenic bacterium Pseudomonas aeruginosa to reveal that cells quickly changed from rod- to round-shaped, and explode. "Cells lose their structural integrity in 5-10 seconds," corresponding author Cynthia Whitchurch of the University of Technology Sydney explains, "and the explosion releases cellular content including eDNA, proteins, and membrane fragments into the surrounding environment."

Using super-resolution microscopy to follow the explosions, they found a surprising observation described by first author Lynne Turnbull: "We observed that membrane fragments produced by exploding bacteria curled up to form membrane vesicles that captured eDNA and other cellular components released by the explosion."

Co-corresponding and co-first author Masanori Toyofuku of the University of Tsukuba and University of Zurich explains that, "this was completely unexpected as until now bacterial membrane vesicles were thought to form from membranous protrusions at the cell surface."

The team found that the explosions are caused by an enzyme (Lys) used by bacteria-infecting viruses (phages) and phage-like elements to disrupt the cell wall of their hosts. Using a mutant bacterial strain incapable of producing Lys, they discovered that the enzyme was needed to produce eDNA and membrane vesicles.

Through a range of experiments, the team also demonstrated that exposure of cells to different forms of stress, such as antibiotics or DNA damaging agents, stimulated expression of the gene encoding Lys and induced explosive cell lysis. "This shows that the bacterial 'SOS' response triggers explosive cell lysis in response to unfavorable environmental conditions," co-corresponding author Leo Eberl of the University of Zurich says.

This mechanism may enable bacteria to release important cellular factors for use by bacterial communities as public goods, and knowledge of its control could be used to interfere with biofilm formation of pathogenic bacteria.

Media Contact

Masataka Watanabe
kohositu@un.tsukuba.ac.jp
81-298-532-039

Masataka Watanabe | EurekAlert!

Further reports about: DNA bacteria biofilm formation enzyme explosions fragments proteins structural integrity vesicles

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
21.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

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...

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

Nagoya physicists resolve long-standing mystery of structure-less transition

21.08.2017 | Materials Sciences

Chronic stress induces fatal organ dysfunctions via a new neural circuit

21.08.2017 | Health and Medicine

Scientists from the MSU studied new liquid-crystalline photochrom

21.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>