A novel apoptotic mode of action for a bacterial toxin

Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.

Although a wide range of bacterial effectors modulate apoptosis in host cells, none have been shown to act directly via the mitochondrion. In preliminary experiments we have shown that the Makes caterpillars floppy toxin (Mcf) appears to act by mimicking a BH3 domain only protein to promote apoptosis in both insect and mammalian cells. This is the first example of a BH3 domain containing protein that can promote apoptosis after topical application to cells. Here we will perform a series of experiments to prove that Mcf acts in a novel manner for a bacterial toxin. We will first purify enough Mcf for our studies and raise monoclonal antibodies specific to different domains of the protein. Second, we will investigate the functionality of the different domains using truncations of the protein and site directed mutagenesis of the BH3-like domain. Third, and finally, we will investigate where in the pathway Mcf acts by investigating its interaction with BcIX, over-expression of which appears to protect against Mcf mediated apoptosis. This work will not only describe the first BH3-like domain in prokaryotes but will also cast light on a protein which can be translocated across cell membranes.