Abstract
Thiamine (vitamin B1) functions as an essential coenzyme in cells. Humans and other mammals cannot synthesise this vitamin de novo and thus have to take it up from their diet. Eventually, every cell needs to import thiamine across its plasma membrane, which is mainly mediated by the two specific thiamine transporters SLC19A2 and SLC19A3. Loss of function mutations in either of these transporters lead to detrimental, life-threatening metabolic disorders. SLC19A3 is furthermore a major site of drug interactions. Many medications, including antidepressants, antibiotics and chemotherapeutics are known to inhibit this transporter, with potentially fatal consequences for patients. Despite a thorough functional characterisation over the past two decades, the structural basis of its transport mechanism and drug interactions has remained elusive. Here, we report seven cryo-electron microscopy (cryo-EM) structures of the human thiamine transporter SLC19A3 in complex with various ligands. Conformation-specific nanobodies enable us to capture different states of SLC19A3’s transport cycle, revealing the molecular details of thiamine recognition and transport. We identify seven previously unknown drug interactions of SLC19A3 and present structures of the transporter in complex with the inhibitors fedratinib, amprolium and hydroxychloroquine. These data allow us to develop an understanding of the transport mechanism and ligand recognition of SLC19A3.
| Original language | English |
|---|---|
| Article number | 8542 |
| Journal | Nature communications |
| Volume | 15 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Dec 2024 |
Bibliographical note
Funding Information:We thank the Sample Preparation and Characterization facility at EMBL (Hamburg, Germany) and the team of the cryo-EM Facility at CSSB for their support, technical assistance and advice. We want to acknowledge T\u00E2nia Cust\u00F3dio, Grzegorz Chojnowski and all group members for fruitful discussions and continuous support and feedback on the project. Part of this work was performed at the CryoEM Facility at CSSB, supported by the UHH and DFG (grant numbers INST 152/772-1\u2009|\u2009152/774-1\u2009|\u2009152/775-1\u2009|\u2009152/776-1\u2009|\u2009152/777-1 FUGG). We further acknowledge the access and services provided by the Imaging Centre at the European Molecular Biology Laboratory (EMBL IC) in Heidelberg, generously supported by the Boehringer Ingelheim Foundation. In this context, we want to thank Joseph Bartho for his help with the cryo-EM data acquisitions at the Imaging Centre. We want to acknowledge the support of the EMBL Metabolomics Core Facility (MCF), and in particular the help of Bernhard Drotleff, in the acquisition and analysis of liquid chromatography-mass spectrometry data. Nanobody discovery was realised through the Nanobodies4Instruct centre and the support by Instruct-ERIC (PID: 23688), which is part of the European Strategy Forum on Research Infrastructures (ESFRI). We want to thank in particular Alison Pirro Lundqvist and Eva Beke from the Steyaert Lab at VUB for their technical assistance during nanobody discovery. The research-stay of F.G. at VUB was supported by an EMBO Scientific Exchange Grand (Nr. 10251).
Funding Information:
We thank the Sample Preparation and Characterization facility at EMBL (Hamburg, Germany) and the team of the cryo-EM Facility at CSSB for their support, technical assistance and advice. We want to acknowledge T\u00E2nia Cust\u00F3dio, Grzegorz Chojnowski and all group members for fruitful discussions and continuous support and feedback on the project. Part of this work was performed at the CryoEM Facility at CSSB, supported by the UHH and DFG (grant numbers INST 152/772-1 | 152/774-1 | 152/775-1 | 152/776-1 | 152/777-1 FUGG). We further acknowledge the access and services provided by the Imaging Centre at the European Molecular Biology Laboratory (EMBL IC) in Heidelberg, generously supported by the Boehringer Ingelheim Foundation. In this context, we want to thank Joseph Bartho for his help with the cryo-EM data acquisitions at the Imaging Centre. We want to acknowledge the support of the EMBL Metabolomics Core Facility (MCF), and in particular the help of Bernhard Drotleff, in the acquisition and analysis of liquid chromatography-mass spectrometry data. Nanobody discovery was realised through the Nanobodies4Instruct centre and the support by Instruct-ERIC (PID: 23688), which is part of the European Strategy Forum on Research Infrastructures (ESFRI). We want to thank in particular Alison Pirro Lundqvist and Eva Beke from the Steyaert Lab at VUB for their technical assistance during nanobody discovery. The research-stay of F.G. at VUB was supported by an EMBO Scientific Exchange Grand (Nr. 10251).
Publisher Copyright:
© The Author(s) 2024.