Ruth Kluck-Projects

Ruth Kluck-Projects



Understanding mitochondrial pore formation during apoptotic cell death

A key event in apoptotic cell death is the oligomerisation of the Bak and Bax proteins to form pores in mitochondria, although how they form pores is still unclear.

We recently found that cells lacking the putative trafficking protein PACS1 are resistant to apoptosis due to unusual complexes of Bak and Bax (Brasacchio et al, accepted, Cell Death Differ). We are thus characterising the unusual Bak and Bax complexes in PACS1-knockdown cells to understand this new means of resistance.

Elucidating how homodimers of Bak and of Bax form the apoptotic pore

As the formation of Bak and Bax homo-oligomers strongly correlates with their ability to perforate mitochondria, defining how Bak and Bax dimers self-associate and interact with the membrane will reveal how they trigger apoptosis.

Our recent data indicate that dimers do not interact by distinct protein-protein interface, but form disordered clusters to generate pores (Uren et al, BIORXIV/2016/059899). A range of biochemical approaches will examine further how the outer membrane is involved in oligomerisation of dimers.

Determining how Mcl-1 sequestration of Bak contributes to resistance during anti-cancer treatment

Inhibition of apoptosis by prosurvival Bcl-2 proteins contributes to oncogenesis and to resistance to cancer treatments.

In particular, Mcl-1 causes resistance to a range of anti-cancer therapies. Mcl-1 acts by sequestering the BH3-only proteins (Mode 1), but may also sequester activated Bak and Bax (Mode 2), depending on cell context.

We aim to understand the protein interactions involved in Mode 2 in mitochondrial assays and in cells.

Developing intracellular antibodies to trigger apoptotic cell death

We recently found that certain antibodies to the Bak protein can trigger its activation leading to mitochondrial pore formation and cell death (Iyer et al, Nat Commun 2016 7:11734). Antibodies to Bax can block its function.

To investigate if intracellular antibodies can be developed as novel anti-cancer agents, this project will electroporate, inject or express different antibodies to Bak and Bax into cancer cell lines and test for induction of cell death.