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Chapter category: Chaperones

Hop: An Hsp70/Hsp90 Co-Chaperone That Functions within and beyond Hsp70/Hsp90 Protein Folding Pathways

This chapter appears in the following book:

Networking of Chaperones
by Co-Chaperones

Edited by: Gregory L. Blatch
ISBN: 978-0-387-49308-4
» Get more information about this book at landesbioscience.com «

Chapter authors:
Sheril Daniel, Csaba Söti, Peter Csermely, Graeme Bradley and Gregory L Blatch


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Molecular chaperones and their co-chapterones are crucial for the facilitation of efficient protein folding, and prevention of denaturation and aggregation of nascent polypeptides. Hsp70/Hsp90 organizing protein (Hop), a co-chapterone of the two major molecular chaperones, heat shock protein 70 (Hsp70) and heat shock protein 90 (Hsp90), facilitates their interaction by acting as an adaptor between the two chaperones, so that substrate is efficiently transferred from Hsp70 to Hsp90. Although initial studies reported its scaffolding properties to be its primary function, recent findings suggest an additional modulatory effect of Hop on the activities of Hsp70 and Hsp90. In addition, a more diverse role of Hop, involving structurally and functionally unrelated biomolecules and complexes, is currently being revealed. This review focuses on the integratory and modulatory effects of Hop on the Hsp70 and Hsp90 protein folding pathways, and puts forward evidence and theories regarding its multifaceted roles within various biological systems.

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Additional chapters from this book:

The Chaperone and Co-Chaperone Activities of Cdc37 during Protein Kinase Maturation

Avrom J. Caplan

Eukaryotic protein kinases fold in the cytosol in association with the Hsp90 molecular chaperone machine. This machine comprises a large number of chaperones and co-chaperones, among them Cdc37,...

Hop: An Hsp70/Hsp90 Co-Chaperone That Functions within and beyond Hsp70/Hsp90 Protein Folding Pathways

Sheril Daniel, Csaba Söti, Peter Csermely, Graeme Bradley and Gregory L Blatch

Molecular chaperones and their co-chapterones are crucial for the facilitation of efficient protein folding, and prevention of denaturation and aggregation of nascent polypeptides. Hsp70/Hsp90 o...

The Roles of GroES As a Co-Chaperone for GroEL

Han Liu and Peter A Lund

GroES works with the essential chaperone GroEL to mediate the folding of certain proteins from an unfolded or partially folded state. These two proteins form the only essential chaperone machine...

The Role of Hsp70 and Its Co-Chaperones in Protein Misfolding, Aggregation and Disease

Jacqueline van der Spuy, Michael E. Cheetham and J. Paul Chapple

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Hsp70 molecular chaperones hydrolyze and re-bind ATP concomitant with the binding and release of aggregation-prone protein substrates. As a result, Hsp70s can enhance protein folding and degradation...


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