ProjectApoptotic foci: composition, structure and dynamics

Basic data

Apoptotic foci: composition, structure and dynamics
01/04/2019 to 29/02/2024
Abstract / short description:
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
organelle biology and trafficking
cell death including senescene and autophagy
Macromolecular complexes incl. interactions involving nucleic acids, proteins, lipids, carbohydrates
Molecular biophysics (e.g. single-molecule approaches, bioenergetics, fluorescence)

Involved staff


Garcia Sáez, Ana Jesús
Faculty of Science
University of Tübingen
Interfaculty Institute of Biochemistry (IFIB)
Interfaculty Institutes

Local organizational units

Interfaculty Institute of Biochemistry (IFIB)
Interfaculty Institutes
University of Tübingen



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