Bi-allelic variants in DOHH, catalyzing the last step of hypusine biosynthesis, are associated with a neurodevelopmental disorder.
Fiche publication
Date publication
juillet 2022
Journal
American journal of human genetics
Auteurs
Membres identifiés du Cancéropôle Est :
Pr FAIVRE Laurence
Tous les auteurs :
Ziegler A, Steindl K, Hanner AS, Kumar Kar R, Prouteau C, Boland A, Deleuze JF, Coubes C, Bézieau S, Küry S, Maystadt I, Le Mao M, Lenaers G, Navet B, Faivre L, Tran Mau-Them F, Zanoni P, Chung WK, Rauch A, Bonneau D, Park MH
Lien Pubmed
Résumé
Deoxyhypusine hydroxylase (DOHH) is the enzyme catalyzing the second step in the post-translational synthesis of hypusine [N-(4-amino-2-hydroxybutyl)lysine] in the eukaryotic initiation factor 5A (eIF5A). Hypusine is formed exclusively in eIF5A by two sequential enzymatic steps catalyzed by deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase (DOHH). Hypusinated eIF5A is essential for translation and cell proliferation in eukaryotes, and all three genes encoding eIF5A, DHPS, and DOHH are highly conserved throughout eukaryotes. Pathogenic variants affecting either DHPS or EIF5A have been previously associated with neurodevelopmental disorders. Using trio exome sequencing, we identified rare bi-allelic pathogenic missense and truncating DOHH variants segregating with disease in five affected individuals from four unrelated families. The DOHH variants are associated with a neurodevelopmental phenotype that is similar to phenotypes caused by DHPS or EIF5A variants and includes global developmental delay, intellectual disability, facial dysmorphism, and microcephaly. A two-dimensional gel analyses revealed the accumulation of deoxyhypusine-containing eIF5A [eIF5A(Dhp)] and a reduction in the hypusinated eIF5A in fibroblasts derived from affected individuals, providing biochemical evidence for deficiency of DOHH activity in cells carrying the bi-allelic DOHH variants. Our data suggest that rare bi-allelic variants in DOHH result in reduced enzyme activity, limit the hypusination of eIF5A, and thereby lead to a neurodevelopmental disorder.
Mots clés
DHPS, DOHH, EIF5A1, deoxyhypusine hydroxylase, eIF5A, hypusine, microcephaly, neurodevelopmental disorder, post-translational modification, translation
Référence
Am J Hum Genet. 2022 07 14;: