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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
2005-6-20
pubmed:abstractText
In all organisms studied, elevated temperatures induce the expression of a variety of stress proteins, among them small Hsps (sHsp). sHsps are chaperones that prevent the unspecific aggregation of proteins by forming stable complexes with unfolded polypeptides. Reactivation of captured proteins requires the assistance of other ATP-dependent chaperones. How sHsps and ATP-dependent chaperones work together is poorly understood. Here, we analyzed the interplay of chaperones present in the cytosol of Saccharomyces cerevisiae. Specifically, we characterized the influence of Hsp104 and Ssa1 on the disassembly of Hsp26 x substrate complexes in vitro and in vivo. We show that recovery of proteins from aggregates in the cell requires the chaperones to work together with defined but overlapping functions. During reactivation, proteins are transferred from a stable complex with Hsp26 to Hsp104 and Hsp70. The need for ATP-dependent chaperones depends on the type of sHsp x substrate complex. Although Ssa1 is able to release substrate proteins from soluble Hsp26 x substrate complexes, Hsp104 is essential to dissociate substrate proteins from aggregates with incorporated sHsps. Our results are consistent with a model of several interrelated defense lines against protein aggregation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
24
pubmed:volume
280
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23861-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Disassembling protein aggregates in the yeast cytosol. The cooperation of Hsp26 with Ssa1 and Hsp104.
pubmed:affiliation
Department Chemie, Technische Universität München, D-85747 Garching, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't