Hyper-repression of HUSH target genes by over-expression of the R252W Charcot-Marie-Tooth disease mutant MORC2
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE95453 | GEO | 2017/05/29
SECONDARY ACCESSION(S): PRJNA377250
REPOSITORIES: GEO
Similar Datasets
Project description:HeLa cells lacking MORC2 generated through CRISPR/Cas9-mediated gene disruption were reconstituted with either wild-type or R252W mutant MORC2, and re-repression of HUSH target genes assessed by RNA-seq
2017-05-29 | GSE95455 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below.
2017-05-29 | GSE95480 | GEO
Project description:Dominant mutations in the MORC2 gene have recently been shown to cause axonal Charcot-Marie-Tooth (CMT) disease, but the cellular function of MORC2 is poorly understood. Here, through a genome-wide CRISPR-Cas9-mediated forward genetic screen, we identified MORC2 as an essential gene required for epigenetic silencing by the HUSH complex. HUSH recruits MORC2 to target sites in heterochromatin. We exploited a new method, differential viral accessibility (DIVA), to show that loss of MORC2 results in chromatin decompaction at these target loci, which is concomitant with a loss of H3K9me3 deposition and transcriptional derepression. The ATPase activity of MORC2 is critical for HUSH-mediated silencing, and the most common alteration affecting the ATPase domain in CMT patients (p.Arg252Trp) hyperactivates HUSH-mediated repression in neuronal cells. These data define a critical role for MORC2 in epigenetic silencing by the HUSH complex and provide a mechanistic basis underpinning the role of MORC2 mutations in CMT disease.
| S-EPMC5493197 | biostudies-literature
Project description:Hyper-activation of HUSH complex function by Charcot-Marie-Tooth disease mutation in MORC2
| PRJNA377238 | ENA
Project description:OBJECTIVE:To use linkage analysis and whole exome sequencing to identify the genetic mutation in a multigenerational Australian family with Charcot-Marie-Tooth disease type 2 (CMT2) and pyramidal signs. METHODS:Genome-wide linkage analysis was performed to map the locus. Whole exome sequencing was undertaken on selected individuals (3 affected, 1 normal), and segregation analysis and mutation screening were carried out using high-resolution melt analysis. The GEM.app database was queried to identify additional families with mutations. RESULTS:Significant linkage (2-point LOD score???+3) and haplotype analysis mapped a new locus for CMT2 and pyramidal signs to a 6.6Mb interval on chromosome 22q12.1-q12.3. Whole exome sequencing identified a novel mutation (p.R252W) in the microrchidia CW-type zinc finger 2 (MORC2) gene mapping within the linkage region. The mutation fully segregated with the disease phenotype in the family. Screening additional families and querying unsolved CMT2 exomes, we identified the p.R252W mutation in 2 unrelated early onset CMT2 families and a second mutation p.E236G in 2 unrelated CMT2 families. Both the mutations occurred at highly conserved amino acid residues and were absent in the normal population. INTERPRETATION:We have identified a new locus in which MORC2 mutations are the likely pathogenic cause of CMT2 and pyramidal signs in these families. MORC2 encodes the human CW-type zinc finger 2 protein, which is a chromatin modifier involved in the regulation of DNA repair as well as gene transcription.
| S-EPMC4936275 | biostudies-literature
Project description:Charcot-Marie-Tooth (CMT) disease is a heterogeneous group of genetic disorders presenting with the phenotype of a chronic progressive neuropathy affecting both the motor and sensory nerves. During the last decade over two dozen genes have been identified in which mutations cause CMT. The disease illustrates a multitude of genetic principles, including diverse mutational mechanisms from point mutations to copy number variation (CNV), allelic heterogeneity, age-dependent penetrance and variable expressivity. Population based studies have determined the contributions of the various genes to disease burden enabling evidence-based approaches to genetic testing.
| S-EPMC2947101 | biostudies-literature
Project description:Charcot-Marie-Tooth (CMT) disease is a common neurogenetic disorder and its heterogeneity is a challenge for genetic diagnostics. The genetic diagnostic procedures for a CMT patient can be explored according to the electrophysiological criteria: very slow motor nerve conduction velocity (MNCV) (<15 m/s), slow MNCV (15-25 m/s), intermediate MNCV (25-45 m/s), and normal MNCV (>45 m/s). Based on the inheritance pattern, intermediate CMT can be divided into dominant (DI-CMT) and recessive types (RI-CMT). GJB1 is currently considered to be associated with X-linked DI-CMT, and MPZ, INF2, DNM2, YARS, GNB4, NEFL, and MFN2 are associated with autosomal DI-CMT. Moreover, GDAP1, KARS, and PLEKHG5 are associated with RI-CMT. Identification of these genes is not only important for patients and families but also provides new information about pathogenesis. It is hoped that this review will lead to a better understanding of intermediate CMT and provide a detailed diagnostic procedure for intermediate CMT.
| S-EPMC5562560 | biostudies-other
Project description:MORC2 gene encodes a ubiquitously expressed nuclear protein involved in chromatin remodeling, DNA repair, and transcriptional regulation. Heterozygous mutations in MORC2 gene have been associated with a spectrum of disorders affecting the peripheral nervous system such as Charcot-Marie-Tooth (CMT2Z), spinal muscular atrophy-like with or without cerebellar involvement, and a developmental syndrome associated with impaired growth, craniofacial dysmorphism and axonal neuropathy (DIGFAN syndrome). Such variability in clinical manifestations associated with the increasing number of variants of unknown significance detected by next-generation sequencing constitutes a serious diagnostic challenge. Here we report the characterization of an in vitro model to evaluate the pathogenicity of variants of unknown significance based on MORC2 overexpression in a neuroblastoma cell line SH-EP or cortical neurons. Likewise, we show that MORC2 mutants affect survival and trigger apoptosis over time in SH-EP cell line. Furthermore, overexpression in primary cortical neurons increases apoptotic cell death and decreases neurite outgrowth. Altogether, these approaches establish the pathogenicity of two new variants p.Gly444Arg and p.His446Gln in three patients from two families. These new mutations in MORC2 gene are associated with autosomal dominant CMT and with adult late onset proximal motor neuropathy, further increasing the spectrum of clinical manifestations associated with MORC2 mutations.
| S-EPMC10087860 | biostudies-literature
Project description:BackgroundCharcot-Marie-Tooth (CMT) disease is an exciting field of study, with a growing number of causal genes and an expanding phenotypic spectrum. The microrchidia family CW-type zinc finger 2 gene (MORC2) was newly identified as a causative gene of CMT2Z in 2016. We aimed to describe the phenotypic-genetic spectrum of MORC2-related diseases in the Chinese population.MethodsWith the use of Sanger sequencing and Next Generation Sequencing (NGS) technologies, we screened a cohort of 284 unrelated Chinese CMT2 families. Pathogenicity assessments of MORC2 variants were interpreted according to the ACMG guidelines. Potential pathogenic variants were confirmed by Sanger sequencing.ResultsWe identified 4 different heterozygous MORC2 mutations in four unrelated families, accounting for 1.4% (4/284). A novel mutation c.1397A>G p. D466G was detected in family 1 and all affected patients presented with later onset axonal CMT with hyperCKemia. The patient in family 2 showed a spinal muscular atrophy (SMA)-like disease with cerebellar hypoplasia and mental retardation, with a hot spot de novo mutation c.260C>T p. S87L. The twin sisters in family 3 were identified as having the most common mutation c.754C>T p. R252W and suffered from axonal motor neuropathy with high variability in disease severity and duration. The patient in family 4 developed an early onset axonal motor and sensory neuropathy, with a reported mutation c.1220G>A p.C407Y. All identified mutations associated with MORC2-related neuropathies are localized in the N-terminal ATPase module.ConclusionsOur study confirmed that MORC2-related neuropathies exist in the Chinese population at a relatively high mutation rate. We revealed a complex genotype-phenotype correlation with MORC2 mutations. This report adds a new piece to the puzzle of the genetics of CMT and contributes to a better understanding of the disease mechanisms.
| S-EPMC8166055 | biostudies-literature
Project description:The human silencing hub (HUSH) complex binds to transcripts of LINE-1 retrotransposons (L1s) and other genomic repeats, recruiting MORC2 and other effectors to remodel chromatin. However, how HUSH and MORC2 operate alongside DNA methylation, a central epigenetic regulator of repeat transcription, remains poorly understood. Here we interrogate this relationship in human neural progenitor cells (hNPCs), a somatic model of brain development that tolerates removal of DNA methyltransferase DNMT1. Upon loss of MORC2 or HUSH subunit TASOR in hNPCs, L1s remain silenced by robust promoter methylation. However, genome demethylation and activation of evolutionarily-young L1s attracts MORC2 binding. Simultaneous depletion of DNMT1 and MORC2 causes massive accumulation of L1 transcripts. We identify the same mechanistic hierarchy at pericentromeric α-satellites and clustered protocadherin genes, repetitive elements important for chromosome structure and neurodevelopment respectively. Our data delineate the independent epigenetic control of repeats in somatic cells, with implications for understanding the vital functions of HUSH-MORC2 in hypomethylated contexts throughout human development.
2024-03-26 | GSE242143 | GEO