UCSF

Pathogenic bacteria rely on a myriad of survival mechanisms to successfully establish their infection niche. This includes methods of immune evasion, nutrient switching, and environmental adaptation. In Listeria monocytogenes, the causative agent of listeriosis, environmental adaptation is regulated by a macromolecular machine known as the stressosome. The stressosome is a megadalton cytosolic protein complex that geometrically takes on a pseudo-icosahedron. Comprised primarily of multiple copies of three proteins RsbR, RsbS and a kinase RsbT, the stressosome is responsible for sensing changes in pH, salt, ethanol, and light. Stressosome activation and assembly are tightly linked to phosphorylation state; however, we have limited information about how phosphorylation impacts the stressosome structurally. Here in Chapter 1, I will provide a brief introduction into my PhD project, in Chapter 2, I will present my findings on the role of phosphorylation in stressosome assembly, and finally in Chapter 3, I will share preliminary work on stressosome assembly related to a phosphatase, RsbX.