This evolutionary slight-of-hand sheds new insights into the lethal tricks of Salmonella, which kills more than 2 million people a year.
"In evolutionary terms, this hijacking of cellular machinery to diversify the function of a bacterial protein is mind boggling,'' said Jorge Galan, senior author of the paper and the Lucille P. Markey Professor of Microbial Pathogenesis and Cell Biology and chair of microbial pathogenesis at Yale.
Salmonella causes disease when it takes control of cells lining the intestinal track using its own specialized "nano-syringe" called a type III secretion system. Using this structure, Salmonella injects bacterial proteins that mimic proteins of the host cell and help the pathogen avoid destruction.
The Yale study describes the crucial role a bacterial protein called SopB plays in both Salmonella's forced entry into the cell and its subsequent internal camouflage act. First, SopB works within the external membrane of the cell, called the plasma membrane, to coax the cell into taking in the pathogen, which is then encapsulated within a tiny bubble-like compartment called a vesicle.
SopB's second trick helps prevent the vesicle from being sucked into the lyosome, the organelle within the cell that degrades proteins. In order to accomplish this, SopB must move from the plasma membrane of the cell to the membrane of the internal vesicle containing the pathogen. The Yale group found that Salmonella coaxes the cell to "mark" the SopB protein with a tag called ubiquitin. Addition of this tag makes the bacterial protein recognizable to the cellular machinery that normally moves proteins from the plasma membranes to internal vesicles.
"These studies provide a unique insight into the mechanisms by which this important pathogen causes disease," Galan said. "In addition, this finding may point to a novel paradigm that may be applicable to other important pathogens."
Other Yale authors of the paper are Jayesh C. Patel, Karsten Hueffer, and Tukiet T. Lam.
The study was funded by a grant from the National Institute of Allergy and Infectious Diseases of the National Institutes of Health
Bill Hathaway | EurekAlert!
Further reports about: > Salmonella > Salmonella enterica > SopB > bacterial protein > cell death > cellular machinery > hijack cellular functions > hijacking of cellular machinery > microbial pathogenesis > nano-syringe > plasma membrane > tiny bubble-like compartment > type III secretion system > vesicle
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences