Fiche publication
Date publication
août 2022
Journal
American journal of human genetics
Auteurs
Membres identifiés du Cancéropôle Est :
Pr FAIVRE Laurence
,
Pr PHILIPPE Christophe
,
Pr GIRODON François
,
Mr DUFFOURD Yannis
,
Pr THAUVIN-ROBINET Christel
,
Dr DUPLOMB-JEGO Laurence
Tous les auteurs :
Thomas Q, Motta M, Gautier T, Zaki MS, Ciolfi A, Paccaud J, Girodon F, Boespflug-Tanguy O, Besnard T, Kerkhof J, McConkey H, Masson A, Denommé-Pichon AS, Cogné B, Trochu E, Vignard V, El It F, Rodan LH, Alkhateeb MA, Jamra RA, Duplomb L, Tisserant E, Duffourd Y, Bruel AL, Jackson A, Banka S, McEntagart M, Saggar A, Gleeson JG, Sievert D, Bae H, Lee BH, Kwon K, Seo GH, Lee H, Saeed A, Anjum N, Cheema H, Alawbathani S, Khan I, Pinto-Basto J, Teoh J, Wong J, Sahari UBM, Houlden H, Zhelcheska K, Pannetier M, Awad MA, Lesieur-Sebellin M, Barcia G, Amiel J, Delanne J, Philippe C, Faivre L, Odent S, Bertoli-Avella A, Thauvin C, Sadikovic B, Reversade B, Maroofian R, Govin J, Tartaglia M, Vitobello A
Lien Pubmed
Résumé
The transmembrane protein TMEM147 has a dual function: first at the nuclear envelope, where it anchors lamin B receptor (LBR) to the inner membrane, and second at the endoplasmic reticulum (ER), where it facilitates the translation of nascent polypeptides within the ribosome-bound TMCO1 translocon complex. Through international data sharing, we identified 23 individuals from 15 unrelated families with bi-allelic TMEM147 loss-of-function variants, including splice-site, nonsense, frameshift, and missense variants. These affected children displayed congruent clinical features including coarse facies, developmental delay, intellectual disability, and behavioral problems. In silico structural analyses predicted disruptive consequences of the identified amino acid substitutions on translocon complex assembly and/or function, and in vitro analyses documented accelerated protein degradation via the autophagy-lysosomal-mediated pathway. Furthermore, TMEM147-deficient cells showed CKAP4 (CLIMP-63) and RTN4 (NOGO) upregulation with a concomitant reorientation of the ER, which was also witnessed in primary fibroblast cell culture. LBR mislocalization and nuclear segmentation was observed in primary fibroblast cells. Abnormal nuclear segmentation and chromatin compaction were also observed in approximately 20% of neutrophils, indicating the presence of a pseudo-Pelger-Huët anomaly. Finally, co-expression analysis revealed significant correlation with neurodevelopmental genes in the brain, further supporting a role of TMEM147 in neurodevelopment. Our findings provide clinical, genetic, and functional evidence that bi-allelic loss-of-function variants in TMEM147 cause syndromic intellectual disability due to ER-translocon and nuclear organization dysfunction.
Mots clés
DNA methylation, LBR, Pelger-Huët anomaly, TMEM147, facial dysmorphism, intellectual disability, neurodevelopmental disorder, nuclear envelope instability, transcriptomics, translocon dysfunction
Référence
Am J Hum Genet. 2022 08 23;:
