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
In living color: Brightly-colored bacteria could be used to 'grow' paints and coatings
20.02.2018 | University of Cambridge
Computers aid discovery of new, inexpensive material to make LEDs with high color quality
20.02.2018 | University of California - San Diego
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.
But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.
The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...
Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters
Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
20.02.2018 | Life Sciences
20.02.2018 | Life Sciences
20.02.2018 | Physics and Astronomy