RICHLAND, Wash. -- For the first time, researchers have found a particular kind of molecular switch in the food poisoning bacteria Salmonella Typhimurium under infection-like conditions. This switch, using a process called S-thiolation, appears to be used by the bacteria to respond to changes in the environment during infection and might protect it from harm, researchers report this week online in the Proceedings of the National Academy of Sciences Early Edition.
S-thiolation protects proteins from irreversible chemical changes when a cell is stressed. The newly discovered switch might regulate when or how proteins work while offering protection, providing researchers insight into Salmonella infection.
"We continue to recognize just how clever this bug is in adapting to its environment," said systems biologist Josh Adkins of the Department of Energy's Pacific Northwest National Laboratory. "During infection it lives in hostile environments, and so it can use multiple approaches to adjust its functions."
Salmonella Typhimurium causes food poisoning in people and can be fatal in the elderly or very young. Recent technological advances in the field known as proteomics are allowing researchers to explore how proteins, the workhorses of the cell, allow the bacteria to infect and cause illness. Most technologies that examine a cell's ensemble of proteins do so by chopping the proteins up. Adkins, lead author Charles Ansong and other colleagues wanted to look at whole proteins, which provides more information such as how proteins are regulated.
Cells regulate how proteins work in several ways. One of the most common adds molecular pieces that serve as gas pedals on proteins, turning them up or down in a grand orchestrated way. Proteomics methods that chop up proteins allow a researcher to determine that a particular protein was present, but not if it was actually functionin
|Contact: Mary Beckman|
DOE/Pacific Northwest National Laboratory