Neurodevelopmental disorder mutations in the purine biosynthetic enzyme IMPDH2 disrupt its allosteric regulation.
J Biol Chem
; 299(8): 105012, 2023 08.
Article
em En
| MEDLINE
| ID: mdl-37414152
ABSTRACT
Inosine 5' monophosphate dehydrogenase (IMPDH) is a critical regulatory enzyme in purine nucleotide biosynthesis that is inhibited by the downstream product GTP. Multiple point mutations in the human isoform IMPDH2 have recently been associated with dystonia and other neurodevelopmental disorders, but the effect of the mutations on enzyme function has not been described. Here, we report the identification of two additional missense variants in IMPDH2 from affected individuals and show that all of the disease-associated mutations disrupt GTP regulation. Cryo-EM structures of one IMPDH2 mutant suggest this regulatory defect arises from a shift in the conformational equilibrium toward a more active state. This structural and functional analysis provides insight into IMPDH2-associated disease mechanisms that point to potential therapeutic approaches and raises new questions about fundamental aspects of IMPDH regulation.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Purinas
/
IMP Desidrogenase
Limite:
Humans
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article