Prof. Dr. Dr. Klaus Aktories studied pharmacy and medicine in Frankfurt and remained there to earn his doctorate in medicine in 1977. He then relocated to the University of Heidelberg, first earning his PhD in natu- ral sciences and then com- pleting his habilitation at the Faculty of Theoretical Medicine in 1983. After several years working at various positions in Mainz, Gießen, and Essen, he accepted a post as profes- sor of pharmacology and toxicology at Saarland Uni- versity in Homburg in 1991. Aktories has researched and taught at the University of Freiburg since 1995. He is director of Department I at the Institute of Experi- mental and Clinical Pharma- cology and Toxicology and a member of the Freiburg Cluster of Excellence BIOSS Centre for Biological Signal- ling Studies. His research group is studying the effects of bacterial toxins and the possibilities of using them to develop pharmacological agents. Photo: BIOSS Dr. Carsten Schwan stud- ied biology at the Univer- sity of Freiburg. In 2007 he completed his studies with a diplom degree and began work on his disser- tation in the department led by Prof. Dr. Dr. Klaus Aktories at the Institute of Experimental and Clinical Pharmacology and Toxicol- ogy. He submitted his dissertation, titled The Effect of Bacterial Toxins on the Cytoskeleton, in 2010. He then accepted a postdoctoral position in Aktories’ research group. His main research inter- ests are the cytoskeleton and inquiry into the role bacterial toxins play in the interaction with their hosts. Photo: private Further Reading Guttenberg, G./Hornei, S./Jank, T./Schwan, C./Lü, W./Einsle, O./Papatheodorou, P./ Aktories, K. (2012): Molecular characteristics of Clostridium perfringens TpeL toxin and consequences of mono-O-GlcNAcylation of Ras in living cells. In: Journal of Biological Chemistry 287/30, pp. 24929–24940. Papatheodorou, P./Carette, J. E./Bell, G. W./ Schwan,C./Guttenberg,G./Brummelkamp,T. R./ Aktories, K. (2011): Lipolysis-stimulated lipo- protein receptor (LSR) is the host receptor for the binary toxin Clostridium difficile transfer ase (CDT). In: Proceedings of the National Academy of Sciences of the United States of America 108/39, pp. 16422–16427. “The bacterium creates its own little niche and makes itself right at home” its effects. Aktories and his research group are looking for a way to introduce it into cancer cells without infecting healthy cells. They have decided to enlist the help of immunotoxins, an artificial protein they already have experience with. Immunotoxins identify cancer cells by way of special markings, so-called tumor markers. They can then introduce toxins like TpeL into these cells. “A single molecule per cell could al ready be sufficient,” says Aktories. TpeL would jump from Ras to Ras and switch them off, one after the other. This is the plan. But first Aktories still has to test whether TpeL knocks out the mutated Ras protein as effectively as its natural counterpart. As for CDT, the question is currently what prop erties its receptor LSR has and what happens in detail when CDT attacks the cytoskeleton. The researcher also speaks enthusiastically about other bacterial toxins – ones that cause nerves to grow or live in a symbiotic relationship with parasitic worms that derive nourishment from them. “We are studying a whole lot of other toxins,” says Klaus Aktories. “They are so inter esting that one could write a whole series of articles about them.” 38