Structure and ion-release mechanism of PIB-4-type ATPases
- University of Copenhagen, Denmark
- Umeå University, Sweden
- Lund University, Sweden
- The University of Texas at Dallas, United States
- University of Cambridge, United Kingdom
Abstract
Transition metals, such as zinc, are essential micronutrients in all organisms, but also highly toxic in excessive amounts. Heavy-metal transporting P-type (PIB) ATPases are crucial for homeostasis, conferring cellular detoxification and redistribution through transport of these ions across cellular membranes. No structural information is available for the PIB-4-ATPases, the subclass with the broadest cargo scope, and hence even their topology remains elusive. Here we present structures and complementary functional analyses of an archetypal PIB‑4‑ATPase, sCoaT from Sulfitobacter sp. NAS14-1. The data disclose the architecture, devoid of classical so-called heavy metal binding domains, and provides fundamentally new insights into the mechanism and diversity of heavy-metal transporters. We reveal several novel P-type ATPase features, including a dual role in heavy-metal release and as an internal counter ion of an invariant histidine. We also establish that the turn-over of PIB‑ATPases is potassium independent, contrasting to many other P-type ATPases. Combined with new inhibitory compounds, our results open up for efforts in e.g. drug discovery, since PIB-4-ATPases function as virulence factors in many pathogens.
Data availability
Atomic coordinates and structure factors for the sCoaT AlF4-- and BeF3--stabilized crystal structures have been deposited at the Protein Data Bank (PDB) under accession codes 7QBZ and 7QC0.
-
Structure and ion-release mechanism of PIB-4-type ATPasesProtein Data Bank, 7QBZ.
-
Structure and ion-release mechanism of PIB-4-type ATPasesProtein Data Bank, 7QC0.
Article and author information
Author details
Funding
Novo Nordisk Fonden (NNF18SA0034956)
- Christina Grønberg
Lundbeckfonden (R313-2019-774,R218-2016-1548,R133-A12689)
- Pontus Gourdon
Knut och Alice Wallenbergs Stiftelse (2020.0194,2015.0131)
- Pontus Gourdon
Carlsbergfondet (CF15-0542,2013_01_0641)
- Pontus Gourdon
Novo Nordisk Fonden (NNF13OC0007471)
- Pontus Gourdon
Brodrene Hartmann (A29519)
- Pontus Gourdon
Agnes og Poul Friis Fond
- Pontus Gourdon
Augustinus Fonden (16-1992)
- Pontus Gourdon
Crafoord (20180652,20170818)
- Pontus Gourdon
Per-Eric and Ulla Schyberg (38267)
- Pontus Gourdon
Swedish Research Council (2016-04474)
- Pontus Gourdon
The memorial foundation of manufacturer Vilhelm Pedersen and wife - and the Aarhus Wilson consortium
- Christina Grønberg
The Independent Research Fund Denmark (9039-00273A)
- Pontus Gourdon
China Scholarship Council
- Qiaoxia Hu
Carl Tryggers Stiftelse för Vetenskaplig Forskning (CTS 17:22)
- Dhani Ram Mahato
Swedish Research Council Starting Grant (2016-03610)
- Magnus Andersson
Robert A. Welke Cancer Research Foundation (AT-1935-20170325 and AT-2073-20210327)
- Gabriele Meloni
National Institute of General Medical Sciences (R35GM128704))
- Gabriele Meloni
National Science Foundation (CHE- 2045984)
- Gabriele Meloni
Swedish Heart-Lung Foundation (20200378)
- Gabriela Godaly
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Reviewing Editor
- Merritt Maduke, Stanford University School of Medicine, United States
Version history
- Received: August 17, 2021
- Preprint posted: September 5, 2021 (view preprint)
- Accepted: December 17, 2021
- Accepted Manuscript published: December 24, 2021 (version 1)
- Version of Record published: February 25, 2022 (version 2)
Copyright
© 2021, Grønberg 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
-
- 1,516
- views
-
- 257
- downloads
-
- 6
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
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)
Structure and ion-release mechanism of PIB-4-type ATPases
eLife 10:e73124.
https://doi.org/10.7554/eLife.73124
Further reading
-
- Biochemistry and Chemical Biology
- Neuroscience
Amyloid β (Aβ) peptides accumulating in the brain are proposed to trigger Alzheimer’s disease (AD). However, molecular cascades underlying their toxicity are poorly defined. Here, we explored a novel hypothesis for Aβ42 toxicity that arises from its proven affinity for γ-secretases. We hypothesized that the reported increases in Aβ42, particularly in the endolysosomal compartment, promote the establishment of a product feedback inhibitory mechanism on γ-secretases, and thereby impair downstream signaling events. We conducted kinetic analyses of γ-secretase activity in cell-free systems in the presence of Aβ, as well as cell-based and ex vivo assays in neuronal cell lines, neurons, and brain synaptosomes to assess the impact of Aβ on γ-secretases. We show that human Aβ42 peptides, but neither murine Aβ42 nor human Aβ17–42 (p3), inhibit γ-secretases and trigger accumulation of unprocessed substrates in neurons, including C-terminal fragments (CTFs) of APP, p75, and pan-cadherin. Moreover, Aβ42 treatment dysregulated cellular homeostasis, as shown by the induction of p75-dependent neuronal death in two distinct cellular systems. Our findings raise the possibility that pathological elevations in Aβ42 contribute to cellular toxicity via the γ-secretase inhibition, and provide a novel conceptual framework to address Aβ toxicity in the context of γ-secretase-dependent homeostatic signaling.
-
- Biochemistry and Chemical Biology
- Cell Biology
Protein homeostasis (proteostasis) deficiency is an important contributing factor to neurological and metabolic diseases. However, how the proteostasis network orchestrates the folding and assembly of multi-subunit membrane proteins is poorly understood. Previous proteomics studies identified Hsp47 (Gene: SERPINH1), a heat shock protein in the endoplasmic reticulum lumen, as the most enriched interacting chaperone for gamma-aminobutyric acid type A (GABAA) receptors. Here, we show that Hsp47 enhances the functional surface expression of GABAA receptors in rat neurons and human HEK293T cells. Furthermore, molecular mechanism study demonstrates that Hsp47 acts after BiP (Gene: HSPA5) and preferentially binds the folded conformation of GABAA receptors without inducing the unfolded protein response in HEK293T cells. Therefore, Hsp47 promotes the subunit-subunit interaction, the receptor assembly process, and the anterograde trafficking of GABAA receptors. Overexpressing Hsp47 is sufficient to correct the surface expression and function of epilepsy-associated GABAA receptor variants in HEK293T cells. Hsp47 also promotes the surface trafficking of other Cys-loop receptors, including nicotinic acetylcholine receptors and serotonin type 3 receptors in HEK293T cells. Therefore, in addition to its known function as a collagen chaperone, this work establishes that Hsp47 plays a critical and general role in the maturation of multi-subunit Cys-loop neuroreceptors.
