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Identifying Protein-protein Interaction Sites Using Peptide Arrays
Published on: November 18, 2014
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Structural and functional characterization of Pin1BP1: A novel Pin1-interacting protein regulating apoptosis
Wen-Der Lin1, Yu-Cheng Lee2, Hui-Chuan Cheng1
1Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
International Journal of Biological Macromolecules
|June 28, 2025
Summary
We discovered Pin1BP1, a protein that interacts with Pin1, promoting apoptosis and potentially serving as a cancer biomarker. Its interaction with Pin1 enhances stability and apoptotic function, offering therapeutic possibilities.
Area of Science:
- Molecular Biology
- Cell Biology
- Biochemistry
Background:
- Pin1 (Peptidyl-prolyl cis-trans isomerase) regulates cell cycle and apoptosis by isomerizing phosphorylated serine/threonine-proline bonds.
- Understanding Pin1-regulated pathways is crucial for cell cycle and apoptosis research.
Purpose of the Study:
- To identify and characterize Pin1BP1, a novel binding partner of Pin1.
- To elucidate the role of Pin1BP1 in apoptosis and its implications in cancer biology.
Main Methods:
- Yeast two-hybrid screening to identify Pin1BP1.
- RT-PCR for expression analysis.
- Immunocytochemistry for localization.
- Co-immunoprecipitation and GST pull-down assays for interaction studies.
- Peptide array and AlphaFold3 for structural analysis.
- Functional studies in HeLa cells and Kaplan-Meier analysis for cancer prognosis.
Main Results:
- Pin1BP1 was identified as a Pin1-interacting protein, ubiquitously expressed and localized in the nucleus.
- Pin1 directly binds Pin1BP1 in a phosphorylation-independent manner, stabilizing Pin1BP1.
- Pin1BP1 overexpression induces apoptosis, with its stability and activity enhanced by Pin1 interaction.
- Low Pin1BP1 expression correlates with poor breast cancer prognosis.
Conclusions:
- Pin1BP1 plays a significant role in inducing apoptosis.
- Pin1BP1 is a potential biomarker and therapeutic target in cancer, particularly breast cancer.
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