The BioGRID | PUBLICATION VIEW

	Jan (2008); 0:
Hsp110 is a nucleotide-activated exchange factor for Hsp70-
Andreasson C, Fiaux J, Rampelt H, Mayer MP, Bukau B
Zentrum fur Molekulare Biologie der Universitat Heidelberg -ZMBH-, University of Heidelberg, Heidelberg, BWu D-69120-
Abstract: Hsp110 proteins constitute a subfamily of the Hsp70 chaperones and are potent nucleotide exchange factors -NEFs- for canonical Hsp70s of the eukaryotic cytosol- Here, we show that the NEF activity of the yeast Hsp110 homologue, Sse1, itself is controlled by nucleotide- Nucleotide binding results in formation of a stabilized conformation of Sse1 that is required for association with the yeast Hsp70, Ssa1- The interaction triggers release of bound ADP from Ssa1, but nucleotide persists bound to Sse1 in the complex- Surprisingly, removal of this nucleotide does not affect the integrity of the complex- Instead, rebinding of ATP to the Hsp70 prompts the dissociation of the complex- Our data demonstrate that in contrast to previously characterized NEFs for Hsp70 chaperones, the NEF activity of Sse1 requires nucleotide binding, and let us propose a new model for Hsp110 function-
[PUBMED: 18218635]