Amino Acids Enhance Polyubiquitination of Rheb and Its Binding to mTORC1 by Blocking Lysosomal ATXN3 Deubiquitinase Activity.
Mol Cell
; 80(3): 437-451.e6, 2020 11 05.
Article
em En
| MEDLINE
| ID: mdl-33157014
ABSTRACT
Amino-acid-induced lysosomal mechanistic target of rapamycin complex 1 (mTORC1) localization through the Rag GTPases is a critical step for its activation by Rheb GTPase. However, how the mTORC1 interacts with Rheb on the lysosome remains elusive. We report that amino acids enhance the polyubiquitination of Rheb (Ub-Rheb), which shows a strong binding preference for mTORC1 and supports its activation, while the Ub-Rheb is subjected to subsequent degradation. Mechanistically, we identified ATXN3 as a Ub-Rheb deubiquitinase whose lysosomal localization is blocked by active Rag heterodimer in response to amino acid stimulation. Consistently, cells lacking functional Rag heterodimer on the lysosome accumulate Ub-Rheb, and blockade of its degradation instigates robust lysosomal mTORC1 localization and its activation without the Ragulator-Rag system. Thus, polyubiquitination of Rheb is an important post-translational modification, which facilitates the binding of mTORC1 to Rheb on the lysosome and is another crosstalk between the amino acid and growth factor signaling for mTORC1 activation.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ataxina-3
/
Alvo Mecanístico do Complexo 1 de Rapamicina
/
Proteína Enriquecida em Homólogo de Ras do Encéfalo
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos