Laty Cahoon, PhD, assistant professor of biological sciences, Kenneth P. Dietrich School of Arts and Sciences, will deliver her lecture, “Lysosomal Quality Control in Health and Disease,” today from noon-1 p.m. via Zoom.

Listeria monocytogenes is a bacterium that lives in many natural environments like soil and water. However, when L. monocytogenes bacteria contaminate food, the bacteria can be a deadly pathogen for vulnerable populations, like pregnant women, newborns and immunocompromised individuals.

During infection, L. monocytogenes secretes virulence factors that enhance its ability to invade and spread through host cells. Its primary virulence factor, a pore-forming protein called listeriolysin O (LLO), helps the bacteria escape phagosomal lysis by perforating the host cell's vacuolar membrane. However, for secreted virulence factors like LLO to work, they must become active in the space between the bacterial cell membrane and cell wall. Since proteins need to fold into their functional conformations to become active, chaperone proteins often assist in this process. L. monocytogenes produces a chaperone protein, PrsA2, that is crucial for LLO activation—but that activation mechanism is largely unknown.

In her talk, Cahoon will discuss her discovery that PrsA2 interacts with and folds LLO and protects it from denaturation. Additionally, she will share her team’s identification of the molecular features that allow PrsA2 to interact with LLO. These discoveries reveal a new way to mitigate LLO-dependent membrane damage to host cells.

Speaker

Laty Cahoon, PhD

Assistant Professor of Biological Sciences, Dietrich School of Arts and Sciences

Topic

Gram-Positive Secretion: Don’t Leave the Cell Without a Chaperone!