Navigation Links
Little but lethal -- small RNAs coordinate bacterial attack on epithelial cells
Date:1/13/2014

Two small RNAs (sRNAs) working in concert enable the deadly enterohemorrhagic Escherichia coli (EHEC) 0157:H7 to attach to and initiate infection in epithelial cells that line the digestive tract, according to a study published in mBio, the online open-access journal of the American Society for Microbiology.

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 cole Polytechnique Fdrale 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.


'/>"/>

Contact: Jim Sliwa
jsliwa@asmusa.org
202-942-9297
American Society for Microbiology
Source:Eurekalert

Related biology news :

1. Young tropical forests contribute little to biodiversity conservation
2. Targeted culling of deer controls disease with little effect on hunting
3. Beyond the little blue pill: scientists develop compound that may treat priapism
4. Little changes -- large effects
5. Genetic secrets of the worlds toughest little bird
6. Solitary lemurs avoid danger with a little help from the neighbors
7. Climate change may have little impact on tropical lizards
8. AACR news: Little molecule makes big difference in bladder cancer metastasis
9. Cell therapy a little more concrete thanks to VIB research
10. Little did we know about beetle diversity: Astonishing 138 new species in a single genus
11. NTU researchers study little mighty creature for scientific breakthrough
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/11/2017)... PALM BEACH GARDENS, Fla. , April 11, ... biometric identity management and secure authentication solutions, today ... million contract by Intelligence Advanced Research Projects Activity ... technologies for IARPA,s Thor program. "Innovation ... the onset and IARPA,s Thor program will allow ...
(Date:4/5/2017)... SEATTLE , April 5, 2017  The Allen ... the Allen Cell Explorer: a one-of-a-kind portal and dynamic ... large-scale 3D imaging data, the first application of deep ... edited human stem cell lines and a growing suite ... the platform for these and future publicly available resources ...
(Date:3/30/2017)... ANGELES , March 30, 2017  On April ... Hack the Genome hackathon at Microsoft,s ... exciting two-day competition will focus on developing health and ... Hack the Genome is the ... been tremendous. The world,s largest companies in the genomics, ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... October 12, 2017 , ... They call ... complex biological network, a depiction of a system of linkages and connections so ... PhD, associate professor of computer science at Worcester Polytechnic Institute (WPI) and director ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... the pharmaceutical and biotechnology industries to improve patient outcomes and quality of life, ... in analytical testing are being attributed to new regulatory requirements for all new ...
(Date:10/11/2017)... ... October 11, 2017 , ... ComplianceOnline’s Medical Device Summit ... 7th and 8th June 2018 in San Francisco, CA. The Summit brings together current ... several distinguished CEOs, board directors and government officials from around the world to address ...
(Date:10/11/2017)... ... October 11, 2017 , ... A ... pregnancy rates in frozen and fresh in vitro fertilization (IVF) transfer ... age to IVF success. , After comparing the results from the fresh and ...
Breaking Biology Technology: