The Cotranslational Function of Ribosome-Associated Hsp70 in Eukaryotic Protein Homeostasis
| Autor: | Véronique Albanèse, Junmin Peng, Judith Frydman, Sebastian Pechmann, Eric B. Dammer, Marta del Alamo, Taotao Chen, Felix Willmund |
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| Rok vydání: | 2013 |
| Předmět: |
Adenosine Triphosphatases
Genetics Protein Folding Saccharomyces cerevisiae Proteins biology Biochemistry Genetics and Molecular Biology(all) Substrate recognition Saccharomyces cerevisiae Protein Homeostasis Ribosome Article General Biochemistry Genetics and Molecular Biology Yeast Hsp70 Cell biology Protein Biosynthesis Chaperone (protein) Proteome biology.protein Substrate specificity HSP70 Heat-Shock Proteins Ribosomes |
| Zdroj: | Cell. 152:196-209 |
| ISSN: | 0092-8674 |
| Popis: | SummaryIn eukaryotic cells a molecular chaperone network associates with translating ribosomes, assisting the maturation of emerging nascent polypeptides. Hsp70 is perhaps the major eukaryotic ribosome-associated chaperone and the first reported to bind cotranslationally to nascent chains. However, little is known about the underlying principles and function of this interaction. Here, we use a sensitive and global approach to define the cotranslational substrate specificity of the yeast Hsp70 SSB. We find that SSB binds to a subset of nascent polypeptides whose intrinsic properties and slow translation rates hinder efficient cotranslational folding. The SSB-ribosome cycle and substrate recognition is modulated by its ribosome-bound cochaperone, RAC. Deletion of SSB leads to widespread aggregation of newly synthesized polypeptides. Thus, cotranslationally acting Hsp70 meets the challenge of folding the eukaryotic proteome by stabilizing its longer, more slowly translated, and aggregation-prone nascent polypeptides. |
| Databáze: | OpenAIRE |
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