Invited Speaker

Prenylome And Lipid Modifications
Kirill Alexandrov, Sergei Mureev, Oleksiy Kovtun, Uyen T.T. Nguyen
Australia

Protein prenylation is a widespread phenomenon in eukaryotic cells that affects many important signaling molecules. We present the structure-guided design of engineered protein prenyltransferases and their universal synthetic substrate, biotin-geranyl pyrophosphate. These novel tools allowed us to detect femtomolar amounts of prenylatable proteins in cells and organs and identify their cognate protein prenyltransferases. Using this approach we analyzed the in vivo effects of protein prenyltransferase inhibitors that are currently being clinically tested for anticancer therapies and demonstrate that while some of the inhibitors displayed the expected activities, others lacked in vivo activity or targeted a broader spectrum of prenyltransferases than previously believed. To quantitate the in vivo effect of the prenylation inhibitors, we profiled biotin-geranyl-tagged RabGTPases across the proteome by mass spectrometry. We also demonstrate that sites of active vesicular transport carry most of the RabGTPases. This approach for the first time enables a quantitative proteome-wide analysis of the regulation of protein prenylation and its modulation by therapeutic agents