BiP inactivation due to loss of the deAMPylation function of FICD causes a motor neuron disease.
Genet Med
; 24(12): 2487-2500, 2022 12.
Article
em En
| MEDLINE
| ID: mdl-36136088
ABSTRACT
PURPOSE:
The chaperone protein BiP is the master regulator of the unfolded protein response in the endoplasmic reticulum. BiP chaperone activity is regulated by the post-translational modification AMPylation, exclusively provided by FICD. We investigated whether FICD variants identified in patients with motor neuron disease could interfere with BiP activity regulation.METHODS:
Exome sequencing was performed to identify causative pathogenic variants associated with motor neuron diseases. Functional studies were conducted on fibroblasts from patients to explore the molecular mechanism of the disease.RESULTS:
We identified biallelic variants in FICD causing a neurodegenerative disease of upper and lower motor neurons. Affected individuals harbor a specific missense variant, Arg374His, positioned in the catalytic motif of the enzyme and important for adenosine triphosphate binding. The mutated residue abolishes intramolecular interaction with the regulatory residue Glu234, essential to inhibit AMPylation and to promote de-AMPylation by FICD. Consequently, fibroblasts from patients with FICD variants have abnormally increased levels of AMPylated and thus inactivated BiP.CONCLUSION:
Loss of BiP chaperone activity in patients likely results in a chronic impairment of the protein quality control system in the endoplasmic reticulum. These findings will guide the development of therapeutic strategies for motoneuron and related diseases linked to proteotoxic stress.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doença dos Neurônios Motores
/
Doenças Neurodegenerativas
Tipo de estudo:
Etiology_studies
/
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Genet Med
Assunto da revista:
GENETICA MEDICA
Ano de publicação:
2022
Tipo de documento:
Article