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Updated: Jun 30, 2025
00:08
In Situ Monitoring of Transiently Formed Molecular Chaperone Assemblies in Bacteria, Yeast, and Human Cells
Published on: September 2, 2019
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A unique chaperoning mechanism in class A JDPs recognizes and stabilizes mutant p53
Guy Zoltsman1, Thi Lieu Dang2, Miriam Kuchersky1
1Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 761000, Israel.
Molecular Cell
|March 20, 2024
Summary
Molecular chaperones called J-domain proteins (JDPs) use a unique β-hairpin site to detect early protein misfolding. This mechanism sequesters damaged proteins, potentially promoting cancer by stabilizing p53 mutants.
Area of Science:
- Molecular biology
- Protein folding and chaperones
- Cancer biology
Background:
- J-domain proteins (JDPs) are molecular chaperones crucial for Hsp70 targeting and chaperone function specificity.
- JDP malfunction is linked to various human diseases.
- Understanding how chaperones recognize misfolded proteins is vital.
Purpose of the Study:
- To uncover the mechanism by which human class A JDPs recognize misfolded protein clients.
- To investigate the role of a newly identified β-hairpin site in this recognition process.
- To explore the implications of this mechanism in cancer progression and therapeutic targeting.
Main Methods:
- Identification and characterization of a novel β-hairpin site in class A JDPs.
- Analysis of chaperone-client interactions, focusing on early misfolding events.
- Investigation of JDPs' role in sequestering misfolding-prone proteins and their interaction with p53 mutants.
- Functional assessment of the β-hairpin site by its removal and evaluation of chaperoning activities.
Main Results:
- Class A JDPs utilize a β-hairpin site to detect subtle changes in protein dynamics during initial misfolding stages.
- JDPs sequester misfolding-prone proteins into oligomeric assemblies, preventing aggregation.
- Class A JDPs bind and protect destabilized p53 mutants from Hsp70-mediated degradation, promoting cancer progression.
- Abrogation of the β-hairpin site eliminates this protective activity against p53 mutants while minimally impacting other chaperoning functions.
Conclusions:
- Human class A JDPs possess a unique β-hairpin mediated mechanism for recognizing early-stage misfolded proteins.
- This mechanism contributes to cancer progression by stabilizing oncoproteins like p53 mutants.
- The class A JDP β-hairpin represents a specific and promising target for novel cancer therapeutics.
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