Abstract
Molecular chaperones play key roles in maintaining cellular proteostasis. In addition to preventing client aggregation, chaperones often relay substrates within a network while preventing off-pathway chaperones from accessing the substrate. Here we show that a conserved lid motif lining the substrate-binding groove of the Get3 ATPase enables these important functions during the targeted delivery of tail-anchored membrane proteins (TAs) to the endoplasmic reticulum. The lid prevents promiscuous TA handoff to off-pathway chaperones, and more importantly, it cooperates with the Get4/5 scaffolding complex to enable rapid and privileged TA transfer from the upstream co-chaperone Sgt2 to Get3. These findings provide a molecular mechanism by which chaperones maintain the pathway specificity of client proteins in the crowded cytosolic environment.
Original language | English |
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Pages (from-to) | 37-44.e7 |
Journal | Cell Reports |
Volume | 26 |
Issue number | 1 |
DOIs | |
State | Published - 2 Jan 2019 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2018 The Authors
Funding
We thank J. Chartron for advice on generating yeast strains using CRISPR-Cas9; R.S. Hegde for CaM expression vectors; H. Cho, M. Rao, F. Liang, A. Siegel, and S. Wang for reagents; S. Hematian and the Beckman Institute Laser Resource Center for training and use of circular dichroism spectrometer; M. Rao for initial observations; and members of the Shan laboratory for critical discussions and comments on the manuscript. This work was supported by Dean Willard Chair funds to S.W., NIH grant GM107368, Gordon and Betty Moore Foundation grant GBMF2939, and a fellowship from the Weston Havens Foundation to S.S. We thank J. Chartron for advice on generating yeast strains using CRISPR-Cas9; R.S. Hegde for CaM expression vectors; H. Cho, M. Rao, F. Liang, A. Siegel, and S. Wang for reagents; S. Hematian and the Beckman Institute Laser Resource Center for training and use of circular dichroism spectrometer; M. Rao for initial observations; and members of the Shan laboratory for critical discussions and comments on the manuscript. This work was supported by Dean Willard Chair funds to S.W., NIH grant GM107368 , Gordon and Betty Moore Foundation grant GBMF2939 , and a fellowship from the Weston Havens Foundation to S.S.
Funders | Funder number |
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Beckman Institute Laser Resource Center | |
National Institutes of Health | |
National Institute of General Medical Sciences | R01GM107368 |
Gordon and Betty Moore Foundation | GBMF2939 |
Weston Havens Foundation |
Keywords
- ATPase
- chaperone
- membrane protein
- protein targeting
- tail-anchored protein