EMD-23756
Tomogram of conditioned medium generated from PC12 14A2.6 cells showing mHTT assemblies
EMD-23756
Tomography
Map released: 20/04/2022
Last modified: 09/11/2022
Sample Organism:
Rattus norvegicus
Sample: Mutant huntingtin exon 1 fused with enhanced green fluorescent protein in conditioned medium collected from induced PC12 14A2.6 cells (EV-enclosed)
Deposition Authors: Nunn K
,
Jiang J
,
Dai W
Sample: Mutant huntingtin exon 1 fused with enhanced green fluorescent protein in conditioned medium collected from induced PC12 14A2.6 cells (EV-enclosed)
Deposition Authors: Nunn K
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Structural insight into transmissive mutant huntingtin species by correlative light and electron microscopy and cryo-electron tomography.
Kuang X,
Nunn K
,
Jiang J
,
Castellano P,
Hardikar U,
Horgan A,
Kong J
,
Tan Z
,
Dai W
(2021) Biochem Biophys Res Commun , 560 , 99 - 104
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(2021) Biochem Biophys Res Commun , 560 , 99 - 104
Abstract:
Aggregates of mutant huntingtin (mHTT) containing an expanded polyglutamine (polyQ) tract are hallmarks of Huntington's Disease (HD). Studies have shown that mHTT can spread between cells, leading to the propagation of misfolded protein pathology. However, the structure of transmissive mHTT species, and the molecular mechanisms underlying their transmission remain unknown. Using correlative light and electron microscopy (CLEM) and cryo-electron tomography (cryo-ET), we identified two types of aggregation-prone granules in conditioned medium from PC12 cells expressing a mHTT N-terminal fragment: densities enclosed by extracellular vesicles (EVs), and uncoated, amorphous meshworks of heterogeneous oligomers that co-localize with clusters of EVs. In vitro assays confirmed that liposomes induce condensation of polyQ oligomers into higher-order assemblies, resembling the uncoated meshworks observed in PC12 conditioned medium. Our findings provide novel insights into formation and architecture of transmissive mHTT proteins, and highlight the potential role of EVs as both carriers and modulators of transmissive mHTT proteins.
Aggregates of mutant huntingtin (mHTT) containing an expanded polyglutamine (polyQ) tract are hallmarks of Huntington's Disease (HD). Studies have shown that mHTT can spread between cells, leading to the propagation of misfolded protein pathology. However, the structure of transmissive mHTT species, and the molecular mechanisms underlying their transmission remain unknown. Using correlative light and electron microscopy (CLEM) and cryo-electron tomography (cryo-ET), we identified two types of aggregation-prone granules in conditioned medium from PC12 cells expressing a mHTT N-terminal fragment: densities enclosed by extracellular vesicles (EVs), and uncoated, amorphous meshworks of heterogeneous oligomers that co-localize with clusters of EVs. In vitro assays confirmed that liposomes induce condensation of polyQ oligomers into higher-order assemblies, resembling the uncoated meshworks observed in PC12 conditioned medium. Our findings provide novel insights into formation and architecture of transmissive mHTT proteins, and highlight the potential role of EVs as both carriers and modulators of transmissive mHTT proteins.