Cellular and Molecular Life Sciences

, Volume 62, Issue 6, pp 670-684

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Hsp70 chaperones: Cellular functions and molecular mechanism

  • M. P. MayerAffiliated withZentrum für Molekulare Biologie (ZMBH), Universität Heidelberg Email author 
  • , B. BukauAffiliated withZentrum für Molekulare Biologie (ZMBH), Universität Heidelberg


Hsp70 proteins are central components of the cellular network of molecular chaperones and folding catalysts. They assist a large variety of protein folding processes in the cell by transient association of their substrate binding domain with short hydrophobic peptide segments within their substrate proteins. The substrate binding and release cycle is driven by the switching of Hsp70 between the low-affinity ATP bound state and the high-affinity ADP bound state. Thus, ATP binding and hydrolysis are essential in vitro and in vivo for the chaperone activity of Hsp70 proteins. This ATPase cycle is controlled by co-chaperones of the family of J-domain proteins, which target Hsp70s to their substrates, and by nucleotide exchange factors, which determine the lifetime of the Hsp70-substrate complex. Additional co-chaperones fine-tune this chaperone cycle. For specific tasks the Hsp70 cycle is coupled to the action of other chaperones, such as Hsp90 and Hsp100.

Key words.

Hsp70 DnaK DnaJ heat shock proteins chaperones protein folding quality control