Gerd John Prehna

B.S., University of Rochester
A Structural Basis for Host Cytoskeletal Disruption and Virulence by Yersinia Protein Kinase A
presented by C. Erec Stebbins

Nearly 200 million people are estimated to have died in the plague epidemics that ravaged the ancient world. The plague bacterium is able to inject into human cells a number of bacterial protein toxins and is key to disease in this organism. Gerd Prehna came to my lab in 2003, and chose to study one such toxin from the plague, called YpkA. However, despite the fact that this protein had been studied for nearly 15 years, when Gerd began work on it, almost nothing was known about how it functioned. The best minds and hands in bacterial pathogenesis had failed even to make the protein in a form stable in solution. But Gerd was very much up to the task. He was able to solubilize, crystallize and determine the structure of YpkA bound to its human protein target at the molecular level using x-ray crystallography.
What he saw revealed that this protein possessed an unexpected mimicry of a class of human proteins that regulate cell shape, and this was exciting because a key element of the plague’s effect on us is to wreak havoc on the shape of our immune cells. To test this idea, he was led to examine the biochemistry of this protein and study its effects on cultured cells. He was able to show that this function of the protein is critical for virulence in animals, thus directly connecting his molecular hypothesis to disease.
In September 2006, he was first author on a paper published in the journal Cell presenting these fascinating results. Gerd accomplished what others have not been able to do for nearly 15 years, and did so spectacularly. For these outstanding accomplishments, I am proud to be able to stand here before his family and friends, and the Rockefeller community and its honored guests, to present Gerd Prehna for the degree of doctor of philosophy.