+ Open data
Open data
- Basic information
Basic information
| Entry | Database: PDB / ID: 9gf8 | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Title | Human Monocarboxylate Transporter 8 | ||||||||||||||||||||||||
|  Components | 
 | ||||||||||||||||||||||||
|  Keywords | TRANSPORT PROTEIN / hormone transport / major facilitator superfamily | ||||||||||||||||||||||||
| Function / homology |  Function and homology information thyroid-stimulating hormone secretion / monocarboxylic acid transmembrane transporter activity / monocarboxylic acid transport / Organic anion transport by SLCO transporters / thyroid hormone metabolic process / negative regulation of neural precursor cell proliferation / thyroid hormone transmembrane transporter activity / thyroid hormone transport / amino acid import across plasma membrane / amino acid transmembrane transporter activity ...thyroid-stimulating hormone secretion / monocarboxylic acid transmembrane transporter activity / monocarboxylic acid transport / Organic anion transport by SLCO transporters / thyroid hormone metabolic process / negative regulation of neural precursor cell proliferation / thyroid hormone transmembrane transporter activity / thyroid hormone transport / amino acid import across plasma membrane / amino acid transmembrane transporter activity / thyroid hormone generation / amino acid metabolic process / transport across blood-brain barrier / apical plasma membrane / identical protein binding / plasma membrane Similarity search - Function | ||||||||||||||||||||||||
| Biological species |  Homo sapiens (human)   Vicugna pacos (alpaca) | ||||||||||||||||||||||||
| Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.5 Å | ||||||||||||||||||||||||
|  Authors | Coscia, F. / Tassinari, M. | ||||||||||||||||||||||||
| Funding support | European Union, 1items 
 | ||||||||||||||||||||||||
|  Citation |  Journal: Nat Commun / Year: 2025 Title: Molecular mechanism of thyroxine transport by monocarboxylate transporters. Authors: Matteo Tassinari / Giorgia Tanzi / Francesco Maggiore / Stefan Groeneweg / Ferdy S van Geest / Matthijs E T Freund / Christiaan J Stavast / Irene Boniardi / Sebastiano Pasqualato / W Edward ...Authors: Matteo Tassinari / Giorgia Tanzi / Francesco Maggiore / Stefan Groeneweg / Ferdy S van Geest / Matthijs E T Freund / Christiaan J Stavast / Irene Boniardi / Sebastiano Pasqualato / W Edward Visser / Francesca Coscia /    Abstract: Thyroid hormones (the common name for prohormone thyroxine and the bioactive form triiodothyronine) control major developmental and metabolic processes. Release of thyroid hormones from the thyroid ...Thyroid hormones (the common name for prohormone thyroxine and the bioactive form triiodothyronine) control major developmental and metabolic processes. Release of thyroid hormones from the thyroid gland into the bloodstream and their transport into target cells is facilitated by plasma membrane transporters, including monocarboxylate transporter (MCT)8 and the highly homologous MCT10. However, the molecular mechanism underlying thyroid hormone transport is unknown. The relevance of such transporters is illustrated in patients with MCT8 deficiency, a severe neurodevelopmental and metabolic disorder. Using cryogenic-sample electron microscopy (cryo-EM), we determined the ligand-free and thyroxine-bound human MCT8 structures in the outward-facing state and the thyroxine-bound human MCT10 in the inward-facing state. Our structural analysis revealed a network of conserved gate residues involved in conformational changes upon thyroxine binding, triggering ligand release in the opposite compartment. We then determined the structure of a folded but inactive patient-derived MCT8 mutant, indicating a subtle conformational change which explains its reduced transport activity. Finally, we report a structure of MCT8 bound to its inhibitor silychristin, locked in the outward-facing state, revealing the molecular basis of its action and specificity. Taken together, this study advances mechanistic understanding of normal and disordered thyroid hormone transport. | ||||||||||||||||||||||||
| History | 
 | 
- Structure visualization
Structure visualization
| Structure viewer | Molecule:  Molmil  Jmol/JSmol | 
|---|
- Downloads & links
Downloads & links
- Download
Download
| PDBx/mmCIF format |  9gf8.cif.gz | 176.2 KB | Display |  PDBx/mmCIF format | 
|---|---|---|---|---|
| PDB format |  pdb9gf8.ent.gz | 138.9 KB | Display |  PDB format | 
| PDBx/mmJSON format |  9gf8.json.gz | Tree view |  PDBx/mmJSON format | |
| Others |  Other downloads | 
-Validation report
| Summary document |  9gf8_validation.pdf.gz | 1.1 MB | Display |  wwPDB validaton report | 
|---|---|---|---|---|
| Full document |  9gf8_full_validation.pdf.gz | 1.1 MB | Display | |
| Data in XML |  9gf8_validation.xml.gz | 31.5 KB | Display | |
| Data in CIF |  9gf8_validation.cif.gz | 44.4 KB | Display | |
| Arichive directory |  https://data.pdbj.org/pub/pdb/validation_reports/gf/9gf8  ftp://data.pdbj.org/pub/pdb/validation_reports/gf/9gf8 | HTTPS FTP | 
-Related structure data
| Related structure data |  51311MC  9fknC  9fotC  9gszC  9gv5C C: citing same article ( M: map data used to model this data | 
|---|---|
| Similar structure data | Similarity search - Function & homology  F&H Search | 
- Links
Links
- Assembly
Assembly
| Deposited unit |  
 | 
|---|---|
| 1 | 
 | 
- Components
Components
| #1: Protein | Mass: 57775.887 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.)  Homo sapiens (human) / Gene: SLC16A2, MCT7, MCT8, XPCT / Production host:  Homo sapiens (human) / References: UniProt: P36021 | 
|---|---|
| #2: Antibody | Mass: 13599.183 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.)   Vicugna pacos (alpaca) / Production host:   Escherichia coli BL21(DE3) (bacteria) | 
| Has protein modification | N | 
-Experimental details
-Experiment
| Experiment | Method: ELECTRON MICROSCOPY | 
|---|---|
| EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction | 
- Sample preparation
Sample preparation
| Component | Name: Monocarboxylate transporter 8 bound ALFA-tag binding nanobody Type: COMPLEX / Details: complex reconstituted in amphipols PMAL-C8 / Entity ID: all / Source: RECOMBINANT | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Molecular weight | Value: 0.07 MDa / Experimental value: NO | |||||||||||||||
| Source (natural) | Organism:  Homo sapiens (human) | |||||||||||||||
| Source (recombinant) | Organism:  Homo sapiens (human) | |||||||||||||||
| Buffer solution | pH: 7.5 | |||||||||||||||
| Buffer component | 
 | |||||||||||||||
| Specimen | Conc.: 0.5 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | |||||||||||||||
| Specimen support | Grid material: COPPER / Grid mesh size: 200 divisions/in. / Grid type: Quantifoil R1.2/1.3 | |||||||||||||||
| Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 279.15 K | 
- Electron microscopy imaging
Electron microscopy imaging
| Experimental equipment |  Model: Titan Krios / Image courtesy: FEI Company | 
|---|---|
| Microscopy | Model: FEI TITAN KRIOS | 
| Electron gun | Electron source:  FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM | 
| Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 1800 nm / Nominal defocus min: 800 nm | 
| Image recording | Electron dose: 70 e/Å2 / Film or detector model: TFS FALCON 4i (4k x 4k) / Num. of grids imaged: 1 / Num. of real images: 41224 | 
- Processing
Processing
| EM software | Name: PHENIX / Version: 1.20.1_4487: / Category: model refinement | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CTF correction | Type: NONE | ||||||||||||||||||||||||
| 3D reconstruction | Resolution: 3.5 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 109595 / Algorithm: BACK PROJECTION / Symmetry type: POINT | ||||||||||||||||||||||||
| Refine LS restraints | 
 | 
 Movie
Movie Controller
Controller







 PDBj
PDBj






