Molecular dissection of ceramide-induced apoptosis: a bottom-up approach

• Applicant: Professor Dr. Joost Holthuis
• Subject Area: Biophysics ; Biochemistry
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 448344643

Ceramides are central intermediates of sphingolipid metabolism that can activate a variety of tumor suppressive cellular programs, including cell cycle arrest, senescence and apoptosis. Consequently, the potential of ceramide-based therapeutics in the treatment of cancer has become a major focus of interest. While a growing body of evidence indicates that ceramides can act directly on mitochondria to trigger apoptotic cell death, molecular details of the underlying mechanism are scarce. Combining a computational approach with functional studies in cancer cells, we recently identified the voltage-dependent anion channel VDAC2 as a direct effector of ceramide-mediated apoptosis. Our data support a sophisticated molecular framework in which ceramides serve as critical modulators of VDAC-based platforms to control mitochondrial recruitment of core apoptotic machinery. In this project, we propose a bottom-up strategy to validate fundamental aspects of this model. Coarse-grain molecular dynamics simulations will be combined with TIRF spectroscopy and single molecule imaging approaches in polymer-supported membranes to directly assess the influence of ceramides on the formation of pro- and anti-apoptotic VDAC-protein assemblies. The acquired knowledge will be used to reconstitute ceramide-induced apoptotic pore formation in vitro. Our efforts will provide an invaluable guide for unravelling the mechanism by which ceramides exert their tumor suppressor activities in vivo.

• DFG Programme: Research Grants