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06:51
Studies of Chaperone-Cochaperone Interactions using Homogenous Bead-Based Assay
Published on: July 21, 2021
Co-chaperone FKBP38 promotes HERG trafficking
Valerie E Walker1, Roxana Atanasiu, Hung Lam
1Department of Physiology, McGill University, Montreal, Quebec H3G 1Y6, Canada.
The Journal of Biological Chemistry
|June 16, 2007
Summary
FKBP38 acts as a co-chaperone for the HERG potassium channel, crucial for its trafficking and maturation. This finding sheds light on Long QT Syndrome pathways and potential therapeutic targets.
Area of Science:
- Cardiology
- Molecular Biology
- Genetics
Background:
- Long QT Syndrome (LQTS) is a cardiac disorder causing arrhythmias, syncope, and sudden death.
- LQTS is often linked to mutations in the HERG gene (KCNH2), affecting potassium channel function.
Purpose of the Study:
- To identify proteins interacting with HERG to understand its maturation and trafficking.
- To investigate the role of identified proteins in HERG channel function and LQTS.
Main Methods:
- Proteomics screen using myc-tagged HERG in cardiac (HL-1) and non-cardiac (HEK 293) cell lines.
- Immunoprecipitation and co-localization studies to validate protein interactions.
- Small interfering RNA (siRNA) knockdown and overexpression experiments to assess functional impact.
Main Results:
- Identified cytosolic chaperones (Hsc70, Hsp90) and membrane proteins (calnexin, FKBP38) interacting with HERG.
- Confirmed FKBP38 interaction and co-localization with HERG.
- Demonstrated that FKBP38 knockdown impairs HERG trafficking, while its overexpression rescues a trafficking-deficient HERG mutant.
Conclusions:
- FKBP38 functions as a co-chaperone for HERG, facilitating its trafficking via the Hsc70/Hsp90 system.
- FKBP38 plays a role in the proper trafficking of both wild-type and mutant HERG channels.
- Findings provide insights into LQTS pathogenesis and potential therapeutic strategies targeting HERG trafficking.
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