Aberrant homeodomain-DNA cooperative dimerization underlies distinct developmental defects in two dominant CRX retinopathy models
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ABSTRACT:
ORGANISM(S): synthetic construct Mus musculus
PROVIDER: GSE256215 | GEO | 2024/11/22
REPOSITORIES: GEO
Similar Datasets
Project description:Paired-class homeodomain transcription factors (HD TFs) play essential roles in vertebrate development, and their mutations are linked to human diseases. One unique feature of paired-class HD is cooperative dimerization on specific palindrome DNA sequences. Yet, the functional significance of HD cooperative dimerization in animal development and its dysregulation in diseases remain elusive. Using the retinal TF Cone-rod Homeobox (CRX) as a model, we have studied how blindness-causing mutations in the paired HD, p.E80A and p.K88N, alter CRX's cooperative dimerization, lead to gene misexpression and photoreceptor developmental deficits in dominant manners. CRXE80A maintains binding at monomeric WT CRX motifs but is deficient in cooperative binding at dimeric motifs. CRXE80A's cooperativity defect impacts the exponential increase of photoreceptor gene expression in terminal differentiation and produces immature, non-functional photoreceptors in the CrxE80A retinas. CRXK88N is highly cooperative and localizes to ectopic genomic sites with strong enrichment of dimeric HD motifs. CRXK88N's altered biochemical properties disrupt CRX's ability to direct dynamic chromatin remodeling during development to activate photoreceptor differentiation programs and silence progenitor programs. Our study here provides in vitro and in vivo molecular evidence that paired-class HD cooperative dimerization regulates neuronal development and dysregulation of cooperative binding contributes to severe dominant blinding retinopathies.
| S-EPMC10979960 | biostudies-literature
Project description:Paired-class homeodomain transcription factors (HD TFs) play essential roles in vertebrate development, and their mutations are linked to human diseases. One unique feature of paired-class HD is cooperative dimerization on specific palindrome DNA sequences. Yet, the functional significance of HD cooperative dimerization in animal development and its dysregulation in diseases remain elusive. Using the retinal TF Cone-rod Homeobox (CRX) as a model, we have studied how blindness-causing mutations in the paired HD, p.E80A and p.K88N, alter CRX’s cooperative dimerization, lead to gene misexpression and photoreceptor developmental deficits in dominant manners. CRXE80A maintains binding at monomeric WT CRX motifs but is deficient in cooperative binding at dimeric motifs. CRXE80A’s dimerization defect impacts the exponential increase of photoreceptor gene expression in terminal differentiation and produces immature, non-functional photoreceptors in the CrxE80A retinas. CRXK88N is highly cooperative and localizes to ectopic genomic sites with strong enrichment of dimeric HD motifs. CRXK88N’s altered biochemical properties disrupt CRX’s ability to direct dynamic chromatin remodeling during development to activate photoreceptor differentiation programs and silence progenitor programs. Our study here provides in vitro and in vivo molecular evidence that paired-class HD cooperative dimerization regulates neuronal development and dysregulation of cooperative binding contributes to severe dominant blinding retinopathies.
2024-11-22 | GSE256214 | GEO
Project description:Paired-class homeodomain transcription factors (HD TFs) play essential roles in vertebrate development, and their mutations are linked to human diseases. One unique feature of paired-class HD is cooperative dimerization on specific palindrome DNA sequences. Yet, the functional significance of HD cooperative dimerization in animal development and its dysregulation in diseases remain elusive. Using the retinal TF Cone-rod Homeobox (CRX) as a model, we have studied how blindness-causing mutations in the paired HD, p.E80A and p.K88N, alter CRX’s cooperative dimerization, lead to gene misexpression and photoreceptor developmental deficits in dominant manners. CRXE80A maintains binding at monomeric WT CRX motifs but is deficient in cooperative binding at dimeric motifs. CRXE80A’s dimerization defect impacts the exponential increase of photoreceptor gene expression in terminal differentiation and produces immature, non-functional photoreceptors in the CrxE80A retinas. CRXK88N is highly cooperative and localizes to ectopic genomic sites with strong enrichment of dimeric HD motifs. CRXK88N’s altered biochemical properties disrupt CRX’s ability to direct dynamic chromatin remodeling during development to activate photoreceptor differentiation programs and silence progenitor programs. Our study here provides in vitro and in vivo molecular evidence that paired-class HD cooperative dimerization regulates neuronal development and dysregulation of cooperative binding contributes to severe dominant blinding retinopathies.
2024-11-22 | GSE256213 | GEO
Project description:Paired-class homeodomain transcription factors (HD TFs) play essential roles in vertebrate development, and their mutations are linked to human diseases. One unique feature of paired-class HD is cooperative dimerization on specific palindrome DNA sequences. Yet, the functional significance of HD cooperative dimerization in animal development and its dysregulation in diseases remain elusive. Using the retinal TF Cone-rod Homeobox (CRX) as a model, we have studied how blindness-causing mutations in the paired HD, p.E80A and p.K88N, alter CRX’s cooperative dimerization, lead to gene misexpression and photoreceptor developmental deficits in dominant manners. CRXE80A maintains binding at monomeric WT CRX motifs but is deficient in cooperative binding at dimeric motifs. CRXE80A’s dimerization defect impacts the exponential increase of photoreceptor gene expression in terminal differentiation and produces immature, non-functional photoreceptors in the CrxE80A retinas. CRXK88N is highly cooperative and localizes to ectopic genomic sites with strong enrichment of dimeric HD motifs. CRXK88N’s altered biochemical properties disrupt CRX’s ability to direct dynamic chromatin remodeling during development to activate photoreceptor differentiation programs and silence progenitor programs. Our study here provides in vitro and in vivo molecular evidence that paired-class HD cooperative dimerization regulates neuronal development and dysregulation of cooperative binding contributes to severe dominant blinding retinopathies.
2024-11-22 | GSE256212 | GEO
Project description:Aberrant homeodomain-DNA cooperative dimerization underlies distinct developmental defects in two dominant CRX retinopathy models
| PRJNA1078421 | ENA
Project description:Aberrant homeodomain-DNA cooperative dimerization underlies distinct developmental defects in two dominant CRX retinopathy models [MPRA]
| PRJNA1078424 | ENA
Project description:Aberrant homeodomain-DNA cooperative dimerization underlies distinct developmental defects in two dominant CRX retinopathy models [Coop-seq]
| PRJNA1078425 | ENA
Project description:Aberrant homeodomain-DNA cooperative dimerization underlies distinct developmental defects in two dominant CRX retinopathy models [ATAC-seq]
| PRJNA1078426 | ENA
Project description:Cone-rod homeobox (CRX) protein is a "paired-like" homeodomain transcription factor that is essential for regulating rod and cone photoreceptor transcription. Mutations in human CRX are associated with the dominant retinopathies Retinitis Pigmentosa (RP), Cone-Rod Dystrophy (CoRD) and Leber Congenital Amaurosis (LCA), with variable severity. Heterozygous Crx Knock-Out (KO) mice ("+/-") have normal vision as adults and fail to model the dominant human disease. To investigate how different mutant CRX proteins produce distinct disease pathologies, we generated two Crx Knock-IN (K-IN) mouse models: Crx(E168d2) ("E168d2") and Crx(R90W) ("R90W"). E168d2 mice carry a frameshift mutation in the CRX activation domain, Glu168del2, which is associated with severe dominant CoRD or LCA in humans. R90W mice carry a substitution mutation in the CRX homeodomain, Arg90Trp, which is associated with dominant mild late-onset CoRD and recessive LCA. As seen in human patients, heterozygous E168d2 ("E168d2/+") but not R90W ("R90W/+") mice show severely impaired retinal function, while mice homozygous for either mutation are blind and undergo rapid photoreceptor degeneration. E168d2/+ mice also display abnormal rod/cone morphology, greater impairment of CRX target gene expression than R90W/+ or +/- mice, and undergo progressive photoreceptor degeneration. Surprisingly, E168d2/+ mice express more mutant CRX protein than wild-type CRX. E168d2neo/+, a subline of E168d2 with reduced mutant allele expression, displays a much milder retinal phenotype, demonstrating the impact of Crx expression level on disease severity. Both CRX([E168d2]) and CRX([R90W]) proteins fail to activate transcription in vitro, but CRX([E168d2]) interferes more strongly with the function of wild type (WT) CRX, supporting an antimorphic mechanism. E168d2 and R90W are mechanistically distinct mouse models for CRX-associated disease that will allow the elucidation of molecular mechanisms and testing of novel therapeutic approaches for different forms of CRX-associated disease.
| S-EPMC3916252 | biostudies-literature
Project description:PurposeThe cone-rod homeobox (CRX) transcription factor is essential for photoreceptor gene expression, differentiation, and survival. Human CRX mutations can cause dominant retinopathies of varying onset and phenotype severity. In animal models, dominant frameshift Crx mutations introduce a premature termination codon (PTC), producing inactive truncated proteins that interfere with normal CRX function. Previously, a mutant mouse, TVRM65, was reported to carry a recessive late PTC mutation, Crx-L253X. More detailed phenotype analysis of the pathogenicity of Crx-L253X sheds new light on the variability of CRX-linked diseases.MethodsHomozygous (L253X/X); heterozygous (L253X/+); Crx-/- and control C57BL/6J (WT) mice were analyzed at various ages for changes in retinal function (ERG), morphology (histology) and photoreceptor gene expression (qRT-PCR).ResultsAt 1 month, L253X/X mice lack visual function, show greater reductions in retinal thickness, and distinct gene expression changes relative to Crx-/-, suggesting that the phenotype of L253X/X is more severe than Crx-/-. L253X/+ mice have reduced rod/cone function, but normal retinal morphology at all ages tested. qRT-PCR assays described a complex phenotype in which both developing and mature photoreceptors are unable to maintain proper gene expression. L253X mRNA/protein is overexpressed relative to normal Crx, suggesting a pathogenic mechanism similar to early PTC mutations. However, the overexpression is less pronounced, correlating with a relatively mild dominant phenotype.ConclusionsThe L253X mouse provides a valuable model for CRX-associated retinopathy. The pathogenicity of CRX frameshift mutations depends on the position of the PTC, which in turn determines the degree of mutant mRNA/protein overproduction.
| S-EPMC5597032 | biostudies-literature