When dangerous toxins teach fundamental biology

Exploring the mechanics of anthrax infection, scientists at EPFL have discovered two proteins that are involved in controlling the levels of cholesterol in the membrane of our cells. "What our work shows is how a complex in the center of the cell, the ER-Golgi interaction region, controls plasma membrane cholesterol, which is essential for many cellular functions, if not essential for multicellular life," says Professor Gisou van der Goot at EPFL's School of Life Sciences. Her group, working with the group of Giovanni D'Angelo at EPFL, have published a study uncovering how pathogens exploit a key cellular process to intoxicate cells. Since pathogens have evolved to hijack many of their hosts' cellular processes, studying host-pathogen interactions help us better understand fundamental biological processes. Here, the scientists found that the interaction between two key organelles in the cell, the endoplasmic reticulum and the Golgi apparatus, is essential to control which lipids are at the cell membrane. Both organelles play essential roles in synthesizing new proteins and their transport within the cell. The researchers set out to find which proteins are important for the toxin from the anthrax bacterium Bacillus anthracis to enter the cell. To do this, they screened a library of 1500 genes that are normally involved in organizing the cell's organelles as well as its membrane. Anthrax infection and ER-Golgi contact sites