TraPPs - Tracking of Phosphoinositide Pools - Key Signalling Components in Cell Migration and Polarisation

• Applicant: Professor Dr. Carsten Schultz
• Subject Area: Cell Biology
• Term: from 2009 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 128165748

Membrane dynamics modulate cell polarity, vesicular trafficking, migration, growth, proliferation, differentiation, and more. Of all membrane lipids, phosphoinositides play a central role in these processes (Wymann & Marone 2005 Curr Opin Cell Biol; Lindmo & Stenmark 2006 J Cell Sci; Simonsen & Stenmark 2007 Nat Chem Biol). Although a role for the prominent 3-phosphorylated phosphoinositides such as PtdIns(3,4,5)P3 and PtdIns(3)P has been highlighted in physiology and disease (Wymann et al. 2003 TiPS), dynamics and localization of these lipids are still poorly understood. TraPPs will provide a dynamic and refined view of phosphoinositide flux, and required lipid modifying enzymes, e.g. PI3Ks, lipases, and lipid phosphatases. Lipid-modifying enzymes will be targeted dynamically to distinct cellular locations, and lipid-interacting proteins shall be manipulated to display their free or lipid-bound state. Finally, the activity state of phospholipid-modifying enzymes will be imaged by the formation of enzyme-substrate complexes in living cells (Yudushkin et al., 2007, Science). Activation of lipid modifying enzymes will be linked to localized upstream signalling and specific cell responses. Cellular, genetic fly and mouse models will be used to validate the uncovered molecular mechanisms. This work provides the basis for a broader systems biology approach of lipid signaling, and will elucidate dynamic cellular processes relevant to cancer and inflammation.

• DFG Programme: Research Grants