Publication Date:
1990-05-18
Description:
The 70-kilodalton family of heat shock proteins (Hsp 70) has been implicated in posttranslational protein assembly and translocation. Binding of cytosolic forms of Hsp 70 (Hsp 72,73) with nascent proteins in the normal cell was investigated and found to be transient and adenosine triphosphate (ATP)-dependent. Interaction of Hsp 72,73 with newly synthesized proteins appeared to occur cotranslationally, because nascent polypeptides released prematurely from polysomes in vivo can be isolated in a complex with Hsp 72,73. Moreover, isolation of polysomes from short-term [35S]Met-labeled cells (pulsed) revealed that Hsp 72,73 associated with nascent polypeptide chains. In cells experiencing stress, newly synthesized proteins coimmunoprecipitated with Hsp 72,73; however, in contrast to normal cells, interaction with Hsp 72,73 was not transient. A model consistent with these data suggests that under normal growth conditions, cytosolic Hsp 72,73 interact transiently with nascent polypeptides to facilitate proper folding, and that metabolic stress interferes with these events.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Beckmann, R P -- Mizzen, L E -- Welch, W J -- GM 33551/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1990 May 18;248(4957):850-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine, University of California, San Francisco 94143.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2188360" target="_blank"〉PubMed〈/a〉
Keywords:
Adenosine Triphosphate/metabolism
;
Azetidinecarboxylic Acid/pharmacology
;
Cycloheximide/pharmacology
;
HeLa Cells/metabolism
;
Heat-Shock Proteins/*metabolism
;
Humans
;
Immunosorbent Techniques
;
Macromolecular Substances
;
Molecular Weight
;
*Protein Biosynthesis
;
Protein Conformation
;
Protein Processing, Post-Translational
;
Proteins/metabolism
;
Puromycin/pharmacology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink
