Biology subjects

Vincent, J. B.

Publications and source records attributed to Vincent, J. B..

8 recordsLinked to original sources

bioRxiv2025

MeCP2 NID interaction with RNA: Implications for Rett Syndrome-Relevant Protein Regulation

Mutations in the MECP2 gene cause the progressive neurodevelopmental disorder Rett syndrome. Pathogenic missense mutation hotspots exist in the proteins Methyl DNA binding Domain (MBD), and the NCoR Interaction Domain (NID), indicating these regions as critical for MeCP2 function. The NID binds to a co-repressor complex allowing transcriptional repression at target genes. A putative RNA Binding Domain (RBD) was identified that overlaps with the NID, yet the role that RNA interaction plays in MeCP2 function remains underexplored. Using cell-based and in vitro molecular assays, we validated RNA interaction at the NID/RBD of MeCP2 both to a dsRNA probe in vitro and to the lncRNA NEAT1_2 in cells. As expected, this region did not appear to affect MeCP2-chromatin interactions; however, we found that RNA-RBD interaction precludes MeCP2-NCoR binding in cells. Taken together, we find that RNA interaction at this non-canonical RNA binding domain regulates important MeCP2-protein interactions and therefore may be a key part of the pathophysiology of Rett syndrome.

molecular biology↗

bioRxiv2025

Assigning Targetable Molecular Pathways to Transdiagnostic Subgroups Across Autism and Related Neurodevelopmental Disorders

The heterogeneity of autism and related neurodevelopmental conditions has impeded accurate prognoses and treatment discovery. Using translational neuroimaging across 135 mouse models (3,515 mice) and two human MRI datasets (n = 1,234 and n = 1,015), we derived participant subgroups from shared neuroanatomical features. These subgroups did not distinguish autism, ADHD, or OCD diagnoses and only modestly differentiated cognitive and behavioural phenotypes. Instead, they mapped onto four molecular pathways: (1) synaptic function; (2) MAPK and Wnt signalling; (3) chromatin modification and cellular stress responses; and (4) broader chromatin, immune, and second-messenger signalling pathways. This framework bridges preclinical models and idiopathic human neurodevelopmental conditions, linking patients to biologically relevant molecular mechanisms.

neuroscience↗

bioRxiv2024

Identification of Antiviral Drug Candidates Against Monkeypox DNA Polymerase and Profilin-like Protein A42R Utilizing an In-Silico Approach

Monkeypox virus (MPXV) is emerging as a major concern in the field of infectious diseases. Current treatments are limited, highlighting the need for new therapeutic options. The use of computational methods, such as molecular docking and molecular dynamic (MD) simulations, is a valuable approach in identifying potential compounds that can target specific proteins of the virus, like the DNA polymerase and profilin-like protein A42R in this case, with the aim of controlling the disease. Our study focused on screening various libraries of compounds for predicted binding to MPXV DPol and A42R proteins, with the top-performing molecules identified based on their docking scores. Among these, Dorsilurin K and Mangostin in complex with DPol, whereas [2-oxo-2-[3-(3,4,5,6-tetrahydro-2H-azepin-7-ylsulfamoyl)anilino]ethyl] 3,5-dimethylbenzoate and N-[4-[2-[4-(4-methylphenyl)sulfonylpiperazin-1-yl]-2-oxoethoxy]phenyl]furan-2-carboxamide in complex with A42R stand out with notably high docking scores, suggesting they may have a good affinity for binding to the DPol and A42R proteins of MPXV respectively. MD simulations confirmed the stability of these ligand-protein complexes followed by evaluation of the ADMET and oral bioavailability analysis. However, it is important that computational methods can suggest promising candidates, in vitro and eventually in vivo studies are essential to validate these therapeutic candidates. Further studies on these compounds will provide insights into their efficacy, safety, and potential side effects. In conclusion, this study offers promising avenues for developing potential treatments for Monkeypox. If the identified compounds prove effective in further studies, it could be a significant breakthrough in managing this zoonotic disease.

pharmacology and toxicology↗

bioRxiv2024

PTCHD1 interacts with the SNARE-associated protein SNAPIN in vitro via its first exoplasmic loop

BackgroundPatched domain-containing 1 (PTCHD1) is a susceptibility gene for autism spectrum disorder and intellectual disability. Its function in brain development and neurotransmission remains elusive. Studies have sought to characterize PTCHD1 function by elucidating its neural network of interacting proteins. However, given the current paucity of functional information, many PTCHD1 missense variants in clinical databases are classified as variants of uncertain significance (VUSs), severely limiting the healthcare resources available to patients and families. MethodsA yeast two-hybrid assay was used to identify synaptic PTCHD1-interacting proteins. Candidate binding partners were validated by cloning; transient over-expression in HEK293T cells, followed by co-immunoprecipitation and immunoblotting; and immunocytochemistry in differentiated P19 cells. To evaluate the pathogenicity of clinical missense variants, site-directed mutagenesis was employed, followed by transient over-expression and immunocytochemistry in non-neuronal (HEK293T) and neuronal (Neuro-2A cells) systems. ResultsA novel interaction was identified between the first lumenal loop of PTCHD1 and the SNARE-associated protein SNAPIN, which is implicated in synaptic vesicle exocytosis. Clinically associated missense variants within this region did not disrupt SNAPIN binding, indicating that the pathoetiology of these variants is unrelated to this interaction. However, six of the 12 missense variants tested exhibited pronounced retention within the endoplasmic reticulum, and impaired neuronal and non-neuronal trafficking to the plasma membrane. ConclusionsThese data yield insights regarding the role of PTCHD1 in neurodevelopment and neurotransmission, and suggest a neuropathological mechanism for missense variants. These findings provide a platform for diagnostic assay and VUS interpretation, allowing for clinical re-classification of these variants.

molecular biology↗

bioRxiv2022

Nonsynonymous Mutations in Intellectual Disability and Autism Spectrum Disorder Gene PTCHD1 Disrupt N-Glycosylation and Reduce Protein Stability

PTCHD1 has been implicated in Autism Spectrum Disorders (ASD) and/or intellectual disability, where copy number variant losses or loss-of-function coding mutations segregate with disease in an X-linked recessive fashion. Missense variants of PTCHD1 have also been reported in patients. However, the significance of these mutations remains undetermined since the activities, subcellular localization and regulation of the PTCHD1 protein are currently unknown. This paucity of data concerning PTCHD1 prevents the effective evaluation of sequence variants identified during diagnostic screening. Here, we characterize PTCHD1 protein binding partners, extending previously reported interactions with postsynaptic scaffolding protein, SAP102. Six rare missense variants of PTCHD1 were also identified from patients with neurodevelopmental disorders. After modelling these variants on a hypothetical three-dimensional structure of PTCHD1, based on the solved structure of NPC1, PTCHD1 variants harboring these mutations were assessed for protein stability, post-translational processing and protein trafficking. We show here that wild-type PTCHD1 post-translational modification includes complex N-glycosylation and that specific mutant proteins disrupt normal N-link glycosylation processing. However, regardless of their processing, these mutants still localized to PSD95-containing dendritic processes and remained competent for complexing SAP102.

molecular biology↗

bioRxiv2018

Enrichment of gene variants associated with treatable genetic disorders in psychiatric populations

PurposeMany genetic conditions can mimic mental health disorders, with psychiatric symptoms that are difficult to treat with standard psychotropic medications. This study tests the hypothesis that psychiatric populations are enriched for pathogenic variants associated with selected treatable genetic disorders.\n\nMethodsUsing next-generation sequencing, 2046 psychiatric patients were screened for variants in genes associated with four inborn errors of metabolism (IEMs), Niemann-Pick disease type C (NPC), Wilson disease (WD), homocystinuria (HOM), and acute intermittent porphyria (AIP).\n\nResultsAmong the 2046 cases, carrier rates of 0{middle dot}83%, 0{middle dot}98%, 0{middle dot}20%, and 0{middle dot}24% for NPC, WD, HOM, and AIP were seen respectively. An enrichment of known and likely pathogenic variants in the genes associated with NPC and AIP was found in the psychiatric cohort, and especially in schizophrenia patients.\n\nConclusionThe results of this study support that rare genetic disease variants, such as those associated with IEMs, may contribute to the pathogenesis of psychiatric disorders. IEMs should be considered as possible causative factors for psychiatric presentations, especially in psychotic disorders, such as schizophrenia, and in the context of poor treatment response.

genetics↗

bioRxiv2017

The role of N-terminal modification of MeCP2 in the pathophysiology of Rett syndrome

Methyl CpG-binding protein 2 (MeCP2), the mutated protein in Rett syndrome (RTT), is a crucial chromatin-modifying and gene-regulatory protein that has two main isoforms (MeCP2_E1 and MeCP2_ E2) due to the alternative splicing and switching between translation start codons in exons one and two. Functionally, these two isoforms appear to be virtually identical; however, evidence suggests that only MeCP2_E1 is relevant to RTT, including a single RTT missense mutation in exon 1, p.Ala2Val. Here, we show that N-terminal co- and post- translational modifications differ for MeCP2_E1, MeCP2_E1-p.Ala2Val and MeCP2_E2, which result in different protein degradation rates in vitro. We report partial N-methionine excision (NME) for MeCP2_E2, whereas NME for MeCP2_E1 is complete. Surprisingly, we also observed evidence of excision of multiple alanine residues from the N-terminal polyalanine stretch. Regarding MeCP2_E1-Ala2Val, we also observed only partial NME and N-acetylation (NA) of either methionine or valine. The localization of MeCP2_E1 and co-localization with chromatin appear to be unaffected by the p.Ala2Val mutation. However, a higher proteasomal degradation rate was observed for MeCP2_E1-Ala2Val compared with that for wild type (WT) MeCP2_E1. Thus, the etiopathology of p.Ala2Val is likely due to a reduced bio-availability of MeCP2 because of the faster degradation rate of the unmodified defective protein. MeCP2_E1 is thought to have a much higher translational efficiency than MeCP2_E2. Our data suggest that this increased efficiency may be balanced by a higher degradation rate. The higher turnover rate of the MeCP2_E1 protein suggests that it may play a more dynamic role in cells than MeCP2_E2.\n\nSignificance statementThe Rett syndrome protein, MeCP2, undergoes a number of modifications before becoming functionally active in the bodys cells. Here, we report the presence of N-terminal modifications in both MeCP2 isoforms, MeCP2_E1 and MeCP2_E2, and that the only reported Rett missense mutation in exon 1, p.Ala2Val, disrupts these modifications, decreasing the longevity of the protein. Interestingly, p.Ala2Val mutations have been reported in many other disease genes, such as DKCX, ECHS1, IRF6, SMN1, and TNNI3, and the etiopathological mechanism(s) have never been explained. Thus, this work is important not only for the understanding of the pathophysiology of Rett syndrome but also for a deeper understanding of the effects of genetic mutations at the N-terminal end of genes in general.

genetics↗

bioRxiv2016

Mapping Autosomal Recessive Intellectual Disability: Combined Microarray and Exome Sequencing Identifies 26 Novel Candidate Genes in 192 Consanguineous Families

Approximately 1% of the global population is affected by intellectual disability (ID), and the majority receive no molecular diagnosis. Previous studies have indicated high levels of genetic heterogeneity, with estimates of more than 2500 autosomal ID genes, the majority of which are autosomal recessive (AR). Here, we combined microarray genotyping, homozygosity-by-descent (HBD) mapping, copy number variation (CNV) analysis, and whole exome sequencing (WES) to identify disease genes/mutations in 192 multiplex Pakistani and Iranian consanguineous families with non-syndromic ID. We identified definite or candidate mutations (or CNVs) in 51% of families in 72 different genes, including 26 not previously reported for ARID. The new ARID genes include nine with loss-of-function mutations (ABI2, MAPK8, MPDZ, PIDD1, SLAIN1, TBC1D23, TRAPPC6B, UBA7, and USP44), and missense mutations include the first reports of variants in BDNF or TET1 associated with ID. The genes identified also showed overlap with de novo gene sets for other neuropsychiatric disorders. Transcriptional studies showed prominent expression in the prenatal brain. The high yield of AR mutations for ID indicated that this approach has excellent clinical potential and should inform clinical diagnostics, including clinical whole exome and genome sequencing, for populations in which consanguinity is common. As with other AR disorders, the relevance will also apply to outbred populations.

genetics↗