Sophie Schminke

Insertion of Salmonellas integral membrane effector proteins SseF and SseG into host cell membranes

The pathogen Salmonella Typhimurium invades and replicates inside eukaryotic cells through injection of virulent effector proteins into its host cell via type III secretion system (T3SS)-1 and T3SS-2. Among the T3SS-2 injected effectors are the integral membrane proteins SseF and SseG (SseFG). Both proteins possess two transmembrane segments (TMSs). After their injection into the hosts cytosol, SseFG need to integrate into the membranes of the host through an unknown mechanism.

To unravel the membrane insertion mechanisms of SseFG into the host cell membranes, I first want to compare the correct localization of SseFG after T3SS-2 injection vs. in-host-translation. In order to achieve this goal, I will apply fluorescent live cell microscopy, subcellular fractionation and proteomics.

In addition, I will investigate the possible protein-protein interaction necessary for SseFG membrane insertion, applying in vivo proximity biotinylation using the biotin ligase TurboID. Finally, I aim to dissect the intrinsic features of SseFG for membrane targeting and insertion by replacing their TMSs or generating serial deletions of the TMSs.