Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-2-5
pubmed:abstractText
Heat shock proteins of the 82-90 kDa class (hsp82 and hsp90) are abundant, conserved, and ubiquitous from prokaryotes to eukaryotes. Although proposed to be chaperones, they had not been reported to possess enzymatic activity until our recent observation that pure trypanosomatid hsp83 had potent ATPase activity (Nadeau, K., Sullivan, M., Engman, D., and Walsh, C. T. (1992) Protein Sci. 1, 970-979). We have now purified the hsp90 homolog from Escherichia coli (HtpG) and from Saccharomyces cerevisiae (hsp82) to homogeneity and observe ATPase activity with kcat values of 3 min-1 and 140 min-1. In addition, examinations of purified rat hsp90 and human hsp90 detect ATPase activity with a kcat of 0.6 min-1 and 10 min-1. Each of these hsp90s undergoes autophosphorylation on serine or threonine residues. In prokaryotes and eukaryotes, the induction of hsps during heat shock is controlled, respectively, by the binding of an alternate sigma 32 or a transcriptional activator (heat shock factor or HSF) at heat shock promoter elements. Here we show that E. coli HtpG immobilized to Affi-Gel beads selectively retains sigma 32 while the yeast hsp90 and rat hsp90 retain HSF. The peptidyl prolyl isomerase hsp59 of the FK506 binding class is known to bind to hsp90. We also detect binding of the other family of PPIases, the cyclophilins, to immobilized hsp90, consistent with a functional convergence of protein foldases.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1479-87
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:8419347-Adenosine Triphosphatases, pubmed-meshheading:8419347-Amino Acid Isomerases, pubmed-meshheading:8419347-Animals, pubmed-meshheading:8419347-Carrier Proteins, pubmed-meshheading:8419347-Crithidia fasciculata, pubmed-meshheading:8419347-Cyclosporins, pubmed-meshheading:8419347-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:8419347-Escherichia coli, pubmed-meshheading:8419347-Heat-Shock Proteins, pubmed-meshheading:8419347-Hot Temperature, pubmed-meshheading:8419347-Humans, pubmed-meshheading:8419347-Kinetics, pubmed-meshheading:8419347-Molecular Weight, pubmed-meshheading:8419347-Peptidylprolyl Isomerase, pubmed-meshheading:8419347-Phosphorylation, pubmed-meshheading:8419347-Promoter Regions, Genetic, pubmed-meshheading:8419347-Protein Binding, pubmed-meshheading:8419347-Rats, pubmed-meshheading:8419347-Saccharomyces cerevisiae, pubmed-meshheading:8419347-Transcription Factors
pubmed:year
1993
pubmed:articleTitle
Hsp90 chaperonins possess ATPase activity and bind heat shock transcription factors and peptidyl prolyl isomerases.
pubmed:affiliation
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't