Project description
Role of apoptotic foci in mitochondrial outer membrane permeabilisation
Apoptotic cell death regulation is essential for development, immune function and tissue homeostasis. Mitochondrial outer membrane permeabilisation (MOMP) is central for apoptosis execution, and understanding the mechanisms mediating MOMP is crucial for the potential clinical application of apoptosis. Recent studies from the host laboratory found that Bax and Bak protein dimers assemble at specific apoptotic foci to mediate MOMP. The EU-funded APOSITE project will investigate the composition, dynamics and structure of apoptotic foci to elucidate their integral role in apoptosis regulation. Researchers will capitalise on their expertise in cell death and advanced imaging technologies. The multidisciplinary approach promises to solve the question of how Bax and Bak mediate MOMP and to help develop apoptosis modulators for medical applications.
Objective
Apoptotic cell death is essential for development, immune function or tissue homeostasis, and it is often deregulated in disease. Mitochondrial outer membrane permeabilization (MOMP) is central for apoptosis execution and plays a key role in its inflammatory outcome. Knowing the architecture of the macromolecular machineries mediating MOMP is crucial for understanding their function and for the clinical use of apoptosis.
Our recent work reveals that Bax and Bak dimers form distinct line, arc and ring assemblies at specific apoptotic foci to mediate MOMP. However, the molecular structure and mechanisms controlling the spatiotemporal formation and range of action of the apoptotic foci are missing. To address this fundamental gap in our knowledge, we aim to unravel the composition, dynamics and structure of apoptotic foci and to understand how they are integrated to orchestrate function. We will reach this goal by building on our expertise in cell death and cutting-edge imaging and by developing a new analytical pipeline to:
1) Identify the composition of apoptotic foci using in situ proximity-dependent labeling and extraction of near-native Bax/Bak membrane complexes coupled to mass spectrometry.
2) Define their contribution to apoptosis and its immunogenicity and establish their assembly dynamics to correlate it with apoptosis progression by live cell imaging.
3) Determine the stoichiometry and structural organization of the apoptotic foci by combining single molecule fluorescence and advanced electron microscopies.
This multidisciplinary approach offers high chances to solve the long-standing question of how Bax and Bak mediate MOMP. APOSITE will provide textbook knowledge of the mitochondrial contribution to cell death and inflammation. The implementation of this new analytical framework will open novel research avenues in membrane and organelle biology. Ultimately, understanding of Bax and Bak structure/function will help develop apoptosis modulators for medicine.
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Programme(s)
Funding Scheme
ERC-COG - Consolidator GrantHost institution
50931 Koln
Germany