Structural Basis of Protein Translocation by the Vps4-Vta1 AAA ATPase
Abstract
Many important cellular membrane fission reactions are driven by ESCRT pathways, which culminate in disassembly of ESCRT-III polymers by the AAA ATPase Vps4. We report a 4.3 Å resolution cryo-EM structure of the active Vps4 hexamer with its cofactor Vta1, ADP•BeFx, and an ESCRT-III substrate peptide. Four Vps4 subunits form a helix whose interfaces are consistent with ATP-binding, is stabilized by Vta1, and binds the substrate peptide. The fifth subunit approximately continues this helix but appears to be dissociating. The final Vps4 subunit completes a notched-washer configuration as if transitioning between the ends of the helix. We propose that ATP binding propagates growth at one end of the helix while hydrolysis promotes disassembly at the other end, so that Vps4 'walks' along ESCRT-III until it encounters the ordered N-terminal domain to destabilize the ESCRT-III lattice. This model may be generally applicable to other protein-translocating AAA ATPases.
Data availability
-
Vps4-Vta1 complexPublicly available at the RCSB Protein Data Bank (accession no: 5UIE).
-
Vps4-Vta1 complexPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8549).
-
Vps4-Vta1 complex_sharpened mapPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8550).
-
Vps4-HCP hexamerPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8551).
-
Vps4-Vta1 complex_VSL_APublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8552).
-
Vps4-Vta1 complex_VSL_BPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8553).
-
Vps4-Vta1 complex_VSL_CPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8554).
-
Vps4-Vta1 complex_VSL_DPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8555).
-
Vps4-Vta1 complex_VSL_EPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8556).
-
Vps4-Vta1 complex_VSL_FPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8557).
-
Vps4-Vta1 complex, State 3 of subunitFPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8570).
-
Vps4-Vta1 complex, State 2 of subunitFPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8571).
-
Vps4-Vta1 complex, State 1 of subunitFPublicly available at the EMBL-EBI Protein Data Bank (accession no: EMD-8572).
Article and author information
Author details
Funding
National Institutes of Health (P50 GM082545)
- Nicole Monroe
- Han Han
- Peter S Shen
- Wesley I Sundquist
- Christopher P Hill
National Institutes of Health (Microbial Pathogenesis Training Grant T32 AI055434)
- Nicole Monroe
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Sriram Subramaniam, National Cancer Institute, United States
Version history
- Received: December 21, 2016
- Accepted: April 4, 2017
- Accepted Manuscript published: April 5, 2017 (version 1)
- Version of Record published: May 2, 2017 (version 2)
Copyright
© 2017, Monroe et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 6,116
- views
-
- 1,208
- downloads
-
- 120
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Further reading
-
- Biochemistry and Chemical Biology
- Microbiology and Infectious Disease
To date, all major modes of monoclonal antibody therapy targeting SARS-CoV-2 have lost significant efficacy against the latest circulating variants. As SARS-CoV-2 omicron sublineages account for over 90% of COVID-19 infections, evasion of immune responses generated by vaccination or exposure to previous variants poses a significant challenge. A compelling new therapeutic strategy against SARS-CoV-2 is that of single-domain antibodies, termed nanobodies, which address certain limitations of monoclonal antibodies. Here, we demonstrate that our high-affinity nanobody repertoire, generated against wild-type SARS-CoV-2 spike protein (Mast et al., 2021), remains effective against variants of concern, including omicron BA.4/BA.5; a subset is predicted to counter resistance in emerging XBB and BQ.1.1 sublineages. Furthermore, we reveal the synergistic potential of nanobody cocktails in neutralizing emerging variants. Our study highlights the power of nanobody technology as a versatile therapeutic and diagnostic tool to combat rapidly evolving infectious diseases such as SARS-CoV-2.
-
- Biochemistry and Chemical Biology
Phosphoinositide 3-kinase (PI3K) beta (PI3Kβ) is functionally unique in the ability to integrate signals derived from receptor tyrosine kinases (RTKs), G-protein coupled receptors, and Rho-family GTPases. The mechanism by which PI3Kβ prioritizes interactions with various membrane-tethered signaling inputs, however, remains unclear. Previous experiments did not determine whether interactions with membrane-tethered proteins primarily control PI3Kβ localization versus directly modulate lipid kinase activity. To address this gap in our knowledge, we established an assay to directly visualize how three distinct protein interactions regulate PI3Kβ when presented to the kinase in a biologically relevant configuration on supported lipid bilayers. Using single molecule Total Internal Reflection Fluorescence (TIRF) Microscopy, we determined the mechanism controlling PI3Kβ membrane localization, prioritization of signaling inputs, and lipid kinase activation. We find that auto-inhibited PI3Kβ prioritizes interactions with RTK-derived tyrosine phosphorylated (pY) peptides before engaging either GβGγ or Rac1(GTP). Although pY peptides strongly localize PI3Kβ to membranes, stimulation of lipid kinase activity is modest. In the presence of either pY/GβGγ or pY/Rac1(GTP), PI3Kβ activity is dramatically enhanced beyond what can be explained by simply increasing membrane localization. Instead, PI3Kβ is synergistically activated by pY/GβGγ and pY/Rac1 (GTP) through a mechanism consistent with allosteric regulation.