Huntingtin structure is orchestrated by HAP40 and shows a polyglutamine expansion-specific interaction with exon 1.
Commun Biol
; 4(1): 1374, 2021 12 08.
Article
en En
| MEDLINE
| ID: mdl-34880419
ABSTRACT
Huntington's disease results from expansion of a glutamine-coding CAG tract in the huntingtin (HTT) gene, producing an aberrantly functioning form of HTT. Both wildtype and disease-state HTT form a hetero-dimer with HAP40 of unknown functional relevance. We demonstrate in vivo and in cell models that HTT and HAP40 cellular abundance are coupled. Integrating data from a 2.6 Å cryo-electron microscopy structure, cross-linking mass spectrometry, small-angle X-ray scattering, and modeling, we provide a near-atomic-level view of HTT, its molecular interaction surfaces and compacted domain architecture, orchestrated by HAP40. Native mass spectrometry reveals a remarkably stable hetero-dimer, potentially explaining the cellular inter-dependence of HTT and HAP40. The exon 1 region of HTT is dynamic but shows greater conformational variety in the polyglutamine expanded mutant than wildtype exon 1. Our data provide a foundation for future functional and drug discovery studies targeting Huntington's disease and illuminate the structural consequences of HTT polyglutamine expansion.
Texto completo:
1
Base de datos:
MEDLINE
Asunto principal:
Péptidos
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Proteínas Nucleares
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Exones
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Enfermedad de Huntington
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Proteína Huntingtina
Idioma:
En
Revista:
Commun Biol
Año:
2021
Tipo del documento:
Article