Format

Send to

Choose Destination
Mol Cell. 2010 Apr 9;38(1):89-100. doi: 10.1016/j.molcel.2010.03.010.

The conformational dynamics of the mitochondrial Hsp70 chaperone.

Author information

1
Institute for Physiological Chemistry, LMU M√ľnchen, 81377 Munich, Germany.

Abstract

Heat shock proteins 70 (Hsp70) represent a ubiquitous and conserved family of molecular chaperones involved in a plethora of cellular processes. The dynamics of their ATP hydrolysis-driven and cochaperone-regulated conformational cycle are poorly understood. We used fluorescence spectroscopy to analyze, in real time and at single-molecule resolution, the effects of nucleotides and cochaperones on the conformation of Ssc1, a mitochondrial member of the family. We report that the conformation of its ADP state is unexpectedly heterogeneous, in contrast to a uniform ATP state. Substrates are actively involved in determining the conformation of Ssc1. The J protein Mdj1 does not interact transiently with the chaperone, as generally believed, but rather is released slowly upon ATP hydrolysis. Analysis of the major bacterial Hsp70 revealed important differences between highly homologous members of the family, possibly explaining tuning of Hsp70 chaperones to meet specific functions in different organisms and cellular compartments.

PMID:
20385092
DOI:
10.1016/j.molcel.2010.03.010
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center