Fusicoccin-A Targets Cancerous Inhibitor of Protein Phosphatase 2A by Stabilizing a C-Terminal Interaction with...

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an oncoprotein overexpressed in various cancers.
• CIP2A stabilizes oncoproteins like cMYC by preventing dephosphorylation by protein phosphatase 2A.

Purpose of the Study:

• To identify new interaction partners of CIP2A.
• To investigate the potential of targeting the CIP2A/14-3-3 interaction for cancer therapy.

Main Methods:

• Phosphorylation analysis of CIP2A's C-terminus.
• Co-immunoprecipitation to identify protein interactions.
• Treatment with protein-protein interaction stabilizer fusicoccin-A (FC-A).
• Assessment of CIP2A and 14-3-3 association in triple-negative breast cancer (TNBC) cells.

Main Results:

• Phosphorylation of Ser904 in CIP2A creates a binding site for 14-3-3.
• 14-3-3 is identified as a novel interaction partner of CIP2A.
• Fusicoccin-A enhances Ser904 phosphorylation and the association between CIP2A and 14-3-3 in TNBC cells.
• The composite interface between 14-3-3 and CIP2A's C-terminus is targeted by FC-A.

Conclusions:

• The interaction between CIP2A and 14-3-3 is a druggable target.
• Fusicoccin-A modulates this interaction, offering a potential therapeutic strategy for cancers overexpressing CIP2A.