Channel forming proteins called porins are found in large quantities in the outer membrane of Gram-negative bacteria, along with phospholipids, lipopolysaccharides, lipoproteins and other integralmembrane proteins. A specific Porin from Neisserial species, PorB, is highly abundant and usuallyfacilitates the uptake of small nutrient molecules, however it is also associated with pathogenesis.Structurally, PorB can be charactersied as a 16 stranded beta-barrel protein that forms trimers. It alsoshares several features with the mitochondrial voltage-dependent anion channel (VDAC), which issuggested to play a role in host cell apoptosis. An interaction between the two proteins has also beensuggested to occur during Neisserial pathogenesis.During infection PorB localises to host mitochondria, however the molecular mechanisms of thetranslocation events from the bacteria and into host cells is not understood..We have established a controllable expression system for the synthesis of PorB in host cells. With thissystem, in combination with infection assays with Neisseria gonorrhoeae secreted protein extracts,

we will study the targeting and the impact of PorB on host cell mitochondrial function and overall cell viability.