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Hsp70 Chaperones

  1. Elizabeth A Craig1,
  2. Jaroslaw Marszalek2

Published Online: 15 MAR 2011

DOI: 10.1002/9780470015902.a0023188

eLS

eLS

How to Cite

Craig, E. A. and Marszalek, J. 2011. Hsp70 Chaperones. eLS. .

Author Information

  1. 1

    University of Wisconsin, Madison, Wisconsin, USA

  2. 2

    University of Gdansk, Gdansk, Poland

Publication History

  1. Published Online: 15 MAR 2011

Abstract

Via their interaction with client proteins, Hsp70 molecular chaperone machines function in a variety of cellular processes, including protein folding, translocation of proteins across membranes and assembly/disassembly of protein complexes. Such machines are composed of a core Hsp70, as well as a J-protein and a nucleotide exchange factor as co-chaperones. These co-factors regulate the cycle of adenosine triphosphate (ATP) hydrolysis and nucleotide exchange, which is critical for Hsp70's interaction with client proteins. Cellular compartments often contain multiple Hsp70s, J-proteins and nucleotide exchange factors. The capabilities of Hsp70s to carry out diverse cellular functions can result from either specialisation of an Hsp70 or by interaction of a multifunctional Hsp70 with a suite of J-protein co-chaperones. The well-studied Hsp70 systems of mitochondria provide an example of such modes of diversification and specialisation of Hsp70 machinery, which are applicable to other cellular compartments.

Key Concepts:

  • Fundamental biochemical properties of different Hsp70 systems are very similar, yet very adaptable.

  • Diversification of Hsp70 function is often due to multiple J-protein partners.

  • Although most Hsp70s bind a broad array of peptide sequences, some have become specialised and have a very restricted binding specificity.

Keywords:

  • molecular chaperone;
  • Hsp70;
  • J-protein;
  • Hsp40;
  • mitochondria;
  • mitochondrial DNA;
  • protein folding;
  • protein import;
  • iron–sulphur biogenesis;
  • protein evolution