PUBLICATION
Pathogenic TRIO variants associated with neurodevelopmental disorders perturb the molecular regulation of TRIO and axon pathfinding in vivo
- Authors
- Bonnet, M., Roche, F., Fagotto-Kaufmann, C., Gazdagh, G., Truong, I., Comunale, F., Barbosa, S., Bonhomme, M., Nafati, N., Hunt, D., Rodriguez, M.P., Chaudhry, A., Shears, D., Madruga, M., Vansenne, F., Curie, A., Kajava, A.V., Baralle, D., Fassier, C., Debant, A., Schmidt, S.
- ID
- ZDB-PUB-230131-33
- Date
- 2023
- Source
- Molecular psychiatry 28(4): 1527-1544 (Journal)
- Registered Authors
- Keywords
- none
- MeSH Terms
-
- Animals
- Axon Guidance*
- Humans
- Neurodevelopmental Disorders*/genetics
- Neurons
- Rho Guanine Nucleotide Exchange Factors
- Zebrafish
- PubMed
- 36717740 Full text @ Mol. Psychiatry
Citation
Bonnet, M., Roche, F., Fagotto-Kaufmann, C., Gazdagh, G., Truong, I., Comunale, F., Barbosa, S., Bonhomme, M., Nafati, N., Hunt, D., Rodriguez, M.P., Chaudhry, A., Shears, D., Madruga, M., Vansenne, F., Curie, A., Kajava, A.V., Baralle, D., Fassier, C., Debant, A., Schmidt, S. (2023) Pathogenic TRIO variants associated with neurodevelopmental disorders perturb the molecular regulation of TRIO and axon pathfinding in vivo. Molecular psychiatry. 28(4):1527-1544.
Abstract
The RhoGEF TRIO is known to play a major role in neuronal development by controlling actin cytoskeleton remodeling, primarily through the activation of the RAC1 GTPase. Numerous de novo mutations in the TRIO gene have been identified in individuals with neurodevelopmental disorders (NDDs). We have previously established the first phenotype/genotype correlation in TRIO-associated diseases, with striking correlation between the clinical features of the individuals and the opposite modulation of RAC1 activity by TRIO variants targeting different domains. The mutations hyperactivating RAC1 are of particular interest, as they are recurrently found in patients and are associated with a severe form of NDD and macrocephaly, indicating their importance in the etiology of the disease. Yet, it remains unknown how these pathogenic TRIO variants disrupt TRIO activity at a molecular level and how they affect neurodevelopmental processes such as axon outgrowth or guidance. Here we report an additional cohort of individuals carrying a pathogenic TRIO variant that reinforces our initial phenotype/genotype correlation. More importantly, by performing conformation predictions coupled to biochemical validation, we propose a model whereby TRIO is inhibited by an intramolecular fold and NDD-associated variants relieve this inhibition, leading to RAC1 hyperactivation. Moreover, we show that in cultured primary neurons and in the zebrafish developmental model, these gain-of-function variants differentially affect axon outgrowth and branching in vitro and in vivo, as compared to loss-of-function TRIO variants. In summary, by combining clinical, molecular, cellular and in vivo data, we provide compelling new evidence for the pathogenicity of novel genetic variants targeting the TRIO gene in NDDs. We report a novel mechanism whereby the fine-tuned regulation of TRIO activity is critical for proper neuronal development and is disrupted by pathogenic mutations.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping