Immunity system complexity: bacterial molecular attacks (Introduction)

by David Turell , Tuesday, December 12, 2023, 18:42 (137 days ago) @ David Turell

new research on bacterial mechanisms in disease:

https://phys.org/news/2023-12-scientists-bacteria-protein-cells-infection.html

"Scientists discover how bacteria build protein signals in cells during infection

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"A study published today in the journal Molecular Cell describes how the protein ubiquitin is modified during bacterial infection.

"The study details the steps taken to create a form of the protein known as lysine 6 polyubiquitin, where a long chain of ubiquitin molecules are linked through the amino acid lysine. This form of ubiquitin helps cells communicate by sending a molecular message—communication that remains poorly understood.

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"...the details of how lysine 6 polyubiquitin is formed or how it is involved in disease aren't yet clear.

"To explore this, OHSU scientists focused on illness-causing bacteria and how they manipulate lysine 6 polyubiquitin during infection. Researchers isolated enzymes used by E. coli and Salmonella to cause food poisoning and other illnesses, and observed how the enzymes interacted with ubiquitin.

"The team learned that one particular enzyme was central to building up lysine 6 polyubiquitin. (my bold)

"In earlier, related research that was published in January, the same scientists found that a different enzyme from a different illness-causing bacteria, Legionella pneumophila—which causes a type of pneumonia called Legionnaires' disease—actively breaks apart the same molecule during infection.

"This means different enzymes have different impacts on the same lysine 6 polyubiquitin during infection.

"'Knowing how lysine 6 polyubiquitin is regulated is an important first step," said the study's senior researcher, Jonathan Pruneda, Ph.D., an assistant professor of molecular microbiology and immunology at the OHSU School of Medicine. "We'll use this knowledge as a foundation for future research, including exploring how bacteria take advantage of ubiquitin while infecting cells.'"

Comment: research at this molecular level allows scientists to develop counteracting drugs. As usual, I must call attention to a complex enzyme in action. These are giant, very complex molecules to promote specific molecular reactions. Such molecules require design, not Darwinian chance mutations.