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Updated: Aug 17, 2025

In Situ Monitoring of Transiently Formed Molecular Chaperone Assemblies in Bacteria, Yeast, and Human Cells
Published on: September 2, 2019
J-Domain Proteins Orchestrate the Multifunctionality of Hsp70s in Mitochondria: Insights from Mechanistic and
Jaroslaw Marszalek1, Elizabeth A Craig2, Bartlomiej Tomiczek3
1Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Gdansk, Poland. jaroslaw.marszalek@ug.edu.pl.
Abstract:
Mitochondrial J-domain protein (JDP) co-chaperones orchestrate the function of their Hsp70 chaperone partner(s) in critical organellar processes that are essential for cell function. These include folding, refolding, and import of mitochondrial proteins, maintenance of mitochondrial DNA, and biogenesis of iron-sulfur cluster(s) (FeS), prosthetic groups needed for function of mitochondrial and cytosolic proteins. Consistent with the organelle's endosymbiotic origin, mitochondrial Hsp70 and the JDPs' functioning in protein folding and FeS biogenesis clearly descended from bacteria, while the origin of the JDP involved in protein import is less evident. Regardless of their origin, all mitochondrial JDP/Hsp70 systems evolved unique features that allowed them to perform mitochondria-specific functions. Their modes of functional diversification and specialization illustrate the versatility of JDP/Hsp70 systems and inform our understanding of system functioning in other cellular compartments.
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