Peptides Targeting the IF1-ATP Synthase Complex Modulate the Permeability Transition Pore in Cancer HeLa Cells

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• The mitochondrial protein IF1 is upregulated in numerous tumors.
• IF1 acts as a pro-oncogenic protein by interacting with ATP synthase and inhibiting apoptosis.
• The precise molecular nature of the IF1-Oligomycin Sensitivity Conferring Protein (OSCP) interaction and its therapeutic potential are under investigation.

Purpose of the Study:

• To investigate the IF1-OSCP interaction as a potential target for novel anti-cancer therapeutic interventions.
• To generate and characterize mitochondria-targeting peptides designed to displace IF1 from OSCP.

Main Methods:

• Generation of mitochondria-targeting peptides.
• Immunoprecipitation to confirm IF1 displacement from ATP synthase.
• Nuclear Magnetic Resonance (NMR) spectroscopy to identify peptides binding to OSCP.
• In situ treatment of HeLa cells with peptide derivatives.

Main Results:

• A selective peptide successfully displaced IF1 from ATP synthase.
• NMR identified a peptide with affinity for the OSCP N-terminal region, overlapping the IF1 binding site.
• Peptide treatment in IF1-silenced HeLa cells inhibited mitochondrial permeability transition without affecting respiration.
• A third peptide counteracted the anti-apoptotic role of IF1.

Conclusions:

• The IF1-OSCP interaction plays a crucial role in inhibiting apoptosis in cancer cells.
• Targeting the IF1-OSCP interaction with specific peptides can disrupt this pro-oncogenic pathway.
• OSCP represents a promising target for developing novel anti-cancer therapies.