Hsp90 breaks the deadlock of the Hsp70 chaperone system
Summary - Protein folding in the cell requires ATP-driven chaperone machines such as the conserved Hsp70 and Hsp90. It is enigmatic how these machines fold proteins. Here, we show that Hsp90 takes a key role in protein folding by breaking an Hsp70-inflicted folding block, empowering protein clients...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
[3 May 2018]
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| In: |
Molecular cell
Year: 2018, Volume: 70, Issue: 3 |
| ISSN: | 1097-4164 |
| DOI: | 10.1016/j.molcel.2018.03.028 |
| Online Access: | Verlag, Volltext: https://doi.org/10.1016/j.molcel.2018.03.028 Verlag, Volltext: http://www.sciencedirect.com/science/article/pii/S1097276518302314 
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| Author Notes: | Tania Morán Luengo, Roman Kityk, Matthias P. Mayer, Stefan G. D. Rüdiger |
| Summary: | Summary - Protein folding in the cell requires ATP-driven chaperone machines such as the conserved Hsp70 and Hsp90. It is enigmatic how these machines fold proteins. Here, we show that Hsp90 takes a key role in protein folding by breaking an Hsp70-inflicted folding block, empowering protein clients to fold on their own. At physiological concentrations, Hsp70 stalls productive folding by binding hydrophobic, core-forming segments. Hsp90 breaks this deadlock and restarts folding. Remarkably, neither Hsp70 nor Hsp90 alters the folding rate despite ensuring high folding yields. In fact, ATP-dependent chaperoning is restricted to the early folding phase. Thus, the Hsp70-Hsp90 cascade does not fold proteins, but instead prepares them for spontaneous, productive folding. This stop-start mechanism is conserved from bacteria to man, assigning also a general function to bacterial Hsp90, HtpG. We speculate that the decreasing hydrophobicity along the Hsp70-Hsp90 cascade may be crucial for enabling spontaneous folding. |
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| Item Description: | Published: April 26, 2018 Gesehen am 22.07.2019 |
| Physical Description: | Online Resource |
| ISSN: | 1097-4164 |
| DOI: | 10.1016/j.molcel.2018.03.028 |