Secreted effector protein SseI
Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)
Effector proteins function to alter host cell physiology and promote bacterial survival in host tissues. This protein is required to maintain a long-term chronic systemic infection in mice. It inhibits normal cell migration of primary macrophages and dendritic cells, by a mechanism that involves interaction with the host factor IQGAP1, an important regulator of the cytoskeleton and cell migration. Also accelerates the systemic spread of infection from the gastrointestinal tract to the bloodstream, probably by interacting with host TRIP6.