Gram-negative bacteria such as EHEC enter their prey and deploy syringe-like weapons called type III secretion systems (T3SS) that inject proteins into the epithelial cells to promote reorganization of the the cytoskeleton into pedestals that act as docking stations for the bacteria to adhere to the cells.
Both pedestal and T3SS formation demand rapid activation and precise coordination of a large number of bacterial genes co-opted from a pathogenicity island called the locus of enterocytes effacement (LEE) which Charley Gruber, Vanessa Sperandio and their colleagues at the University of Texas Southwestern Medical School in Dallas recently discovered is orchestrated by two sRNAs known as GlmY and GlmZ.
"Our data reveal two previously unknown mechanisms of actions for these sRNAs," Sperandio says. "Working together GlmY and GlmZ cleave the transcript between espJ and espFu genes enabling translation of EspFu, a protein important for efficient mammalian-cell invasion, and also destabilize the LEE 4 and 5 transcripts thus fine tuning LEE gene expression."
"Destabilization of LEE is especially important for two reasons first, it permits the differential expression of various genes encoded within the same cluster and second, it ensures that the bacteria are forming optimal pedestal levels on epithelial cells during infection," according to Sperandio. Thus, these researchers propose that these sRNAs are responsible for the dynamic rewiring of the bacterial complex machineries that enable infection.
"This is a very important contribution to the field particularly because it shows that things are more complicated than they initially appeared," comments Petr G. Leiman at École Polytechnique Fédérale de Lausanne in Switzerland. "Studies involving sRNA are tricky and require many controls which this paper appears to present in full, thus making the Sperandio team's work very significant."
"The horizontal acquisitions of pathogenicity islands [such as LEE] with their added virulence genes enable bacteria to exploit additional niches and new hosts," explains Sperandio. "Our results suggest that the interplay between ancient and recent evolutionary acquisitions shaped the EHEC we're dealing with today," Gruber adds. However, the evolution is ongoing and as the Red Queen in Alice in Wonderland so famously said, we have to race ahead just to keep up.
mBio® is an open access online journal published by the American Society for Microbiology to make microbiology research broadly accessible. The focus of the journal is on rapid publication of cutting-edge research spanning the entire spectrum of microbiology and related fields. It can be found online at http://mbio.asm.org.
The American Society for Microbiology is the largest single life science society, composed of over 39,000 scientists and health professionals. ASM's mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.
Jim Sliwa | EurekAlert!
New Model of T Cell Activation
27.05.2016 | Albert-Ludwigs-Universität Freiburg im Breisgau
Fungi – a promising source of chemical diversity
27.05.2016 | Leibniz-Institut für Naturstoff-Forschung und Infektionsbiologie - Hans-Knöll-Institut (HKI)
A biological and energy-efficient process, developed and patented by the University of Innsbruck, converts nitrogen compounds in wastewater treatment facilities into harmless atmospheric nitrogen gas. This innovative technology is now being refined and marketed jointly with the United States’ DC Water and Sewer Authority (DC Water). The largest DEMON®-system in a wastewater treatment plant is currently being built in Washington, DC.
The DEMON®-system was developed and patented by the University of Innsbruck 11 years ago. Today this successful technology has been implemented in about 70...
Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.
The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...
In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.
In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...
Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices
Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.
When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene
In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...
24.05.2016 | Event News
20.05.2016 | Event News
19.05.2016 | Event News
27.05.2016 | Awards Funding
27.05.2016 | Life Sciences
27.05.2016 | Life Sciences