Browse
Submit Data
Databases
API
Help

Dataset Information

22 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Unusual mode of dimerization of retinitis pigmentosa-associated F220C rhodopsin.

ABSTRACT: Mutations in the G protein-coupled receptor (GPCR) rhodopsin are a common cause of autosomal dominant retinitis pigmentosa, a blinding disease. Rhodopsin self-associates in the membrane, and the purified monomeric apo-protein opsin dimerizes in vitro as it transitions from detergent micelles to reconstitute into a lipid bilayer. We previously reported that the retinitis pigmentosa-linked F220C opsin mutant fails to dimerize in vitro, reconstituting as a monomer. Using fluorescence-based assays and molecular dynamics simulations we now report that whereas wild-type and F220C opsin display distinct dimerization propensities in vitro as previously shown, they both dimerize in the plasma membrane of HEK293 cells. Unexpectedly, molecular dynamics simulations show that F220C opsin forms an energetically favored dimer in the membrane when compared with the wild-type protein. The conformation of the F220C dimer is unique, with transmembrane helices 5 and 6 splayed apart, promoting widening of the intracellular vestibule of each protomer and influx of water into the protein interior. FRET experiments with SNAP-tagged wild-type and F220C opsin expressed in HEK293 cells are consistent with this conformational difference. We speculate that the unusual mode of dimerization of F220C opsin in the membrane may have physiological consequences.

SUBMITTER: Khelashvili G

PROVIDER: S-EPMC8131606 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Dimerization deficiency of enigmatic retinitis pigmentosa-linked rhodopsin mutants.

Project description:Retinitis pigmentosa (RP) is a blinding disease often associated with mutations in rhodopsin, a light-sensing G protein-coupled receptor and phospholipid scramblase. Most RP-associated mutations affect rhodopsin's activity or transport to disc membranes. Intriguingly, some mutations produce apparently normal rhodopsins that nevertheless cause disease. Here we show that three such enigmatic mutations-F45L, V209M and F220C-yield fully functional visual pigments that bind the 11-cis retinal chromophore, activate the G protein transducin, traffic to the light-sensitive photoreceptor compartment and scramble phospholipids. However, tests of scramblase activity show that unlike wild-type rhodopsin that functionally reconstitutes into liposomes as dimers or multimers, F45L, V209M and F220C rhodopsins behave as monomers. This result was confirmed in pull-down experiments. Our data suggest that the photoreceptor pathology associated with expression of these enigmatic RP-associated pigments arises from their unexpected inability to dimerize via transmembrane helices 1 and 5.

| S-EPMC5059438 | biostudies-literature

CRISPRi mediated treatment of dominant rhodopsin-associated retinitis pigmentosa.

Project description:Rhodopsin (RHO) mutations such as Pro23His, are the leading cause of dominantly inherited retinitis pigmentosa in North America. As with other dominant retinal dystrophies, these mutations lead to production of a toxic protein product, and treatment will require knockdown of the mutant allele. The purpose of this study was to develop a CRISPR-Cas9-mediated transcriptional repression strategy using catalytically inactive S. aureus Cas9 (dCas9) fused to the Krüppel-associated box (KRAB) transcriptional repressor domain. Using a reporter construct carrying GFP cloned downstream of the RHO promoter fragment (nucleotides -1403 to +73), we demonstrate a ~74%-84% reduction in RHO promoter activity in RHOpCRISPRi treated vs plasmid only controls. Following subretinal transduction of human retinal explants and transgenic Pro23His mutant pigs, significant knockdown of rhodopsin protein was achieved. Suppression of mutant transgene in vivo was associated with a reduction in ER-stress and apoptosis markers and preservation of photoreceptor cell layer thickness.

2024-03-28 | GSE244786 | GEO

Genomic DNA nanoparticles rescue rhodopsin-associated retinitis pigmentosa phenotype.

Project description:Mutations in the rhodopsin gene cause retinal degeneration and clinical phenotypes including retinitis pigmentosa (RP) and congenital stationary night blindness. Effective gene therapies have been difficult to develop, however, because generating precise levels of rhodopsin expression is critical; overexpression causes toxicity, and underexpression would result in incomplete rescue. Current gene delivery strategies routinely use cDNA-based vectors for gene targeting; however, inclusion of noncoding components of genomic DNA (gDNA) such as introns may help promote more endogenous regulation of gene expression. Here we test the hypothesis that inclusion of genomic sequences from the rhodopsin gene can improve the efficacy of rhodopsin gene therapy in the rhodopsin knockout (RKO) mouse model of RP. We utilize our compacted DNA nanoparticles (NPs), which have the ability to transfer larger and more complex genetic constructs, to deliver murine rhodopsin cDNA or gDNA. We show functional and structural improvements in RKO eyes for up to 8 months after NP-mediated gDNA but not cDNA delivery. Importantly, in addition to improvements in rod function, we observe significant preservation of cone function at time points when cones in the RKO model are degenerated. These results suggest that inclusion of native expression elements, such as introns, can significantly enhance gene expression and therapeutic efficacy and may become an essential option in the array of available gene delivery tools.

| S-EPMC4447225 | biostudies-literature

Gene Therapy for Rhodopsin-associated Autosomal Dominant Retinitis Pigmentosa.

Project description: Not available

| S-EPMC8478325 | biostudies-literature

Flavonoid allosteric modulation of mutated visual rhodopsin associated with retinitis pigmentosa.

Project description:Dietary flavonoids exhibit many biologically-relevant functions and can potentially have beneficial effects in the treatment of pathological conditions. In spite of its well known antioxidant properties, scarce structural information is available on the interaction of flavonoids with membrane receptors. Advances in the structural biology of a specific class of membrane receptors, the G protein-coupled receptors, have significantly increased our understanding of drug action and paved the way for developing improved therapeutic approaches. We have analyzed the effect of the flavonoid quercetin on the conformation, stability and function of the G protein-coupled receptor rhodopsin, and the G90V mutant associated with the retinal degenerative disease retinitis pigmentosa. By using a combination of experimental and computational methods, we suggest that quercetin can act as an allosteric modulator of opsin regenerated with 9-cis-retinal and more importantly, that this binding has a positive effect on the stability and conformational properties of the G90V mutant associated with retinitis pigmentosa. These results open new possibilities to use quercetin and other flavonoids, in combination with specific retinoids like 9-cis-retinal, for the treatment of retinal degeneration associated with retinitis pigmentosa. Moreover, the use of flavonoids as allosteric modulators may also be applicable to other members of the G protein-coupled receptors superfamily.

| S-EPMC5593859 | biostudies-literature

Therapy in Rhodopsin-Mediated Autosomal Dominant Retinitis Pigmentosa.

Project description:Rhodopsin-mediated autosomal dominant retinitis pigmentosa (RHO-adRP) is a hereditary degenerative disorder in which mutations in the gene encoding RHO, the light-sensitive G protein-coupled receptor involved in phototransduction in rods, lead to progressive loss of rods and subsequently cones in the retina. Clinical phenotypes are diverse, ranging from mild night blindness to severe visual impairments. There is currently no cure for RHO-adRP. Although there have been significant advances in gene therapy for inherited retinal diseases, treating RHO-adRP presents a unique challenge since it is an autosomal dominant disease caused by more than 150 gain-of-function mutations in the RHO gene, rendering the established gene supplementation strategy inadequate. This review provides an update on RNA therapeutics and therapeutic editing genome surgery strategies and ongoing clinical trials for RHO-adRP, discussing mechanisms of action, preclinical data, current state of development, as well as risk and benefit considerations. Potential outcome measures useful for future clinical trials are also addressed.

| S-EPMC7545001 | biostudies-literature

Pharmacological clearance of misfolded rhodopsin for the treatment of RHO-associated retinitis pigmentosa.

Project description:Rhodopsin mutation and misfolding is a common cause of autosomal dominant retinitis pigmentosa (RP). Using a luciferase reporter assay, we undertook a small-molecule high-throughput screening (HTS) of 68, 979 compounds and identified nine compounds that selectively reduced the misfolded P23H rhodopsin without an effect on the wild type (WT) rhodopsin protein. Further, we found five of these compounds, including methotrexate (MTX), promoted P23H rhodopsin degradation that also cleared out other misfolded rhodopsin mutant proteins. We showed MTX increased P23H rhodopsin degradation via the lysosomal but not the proteasomal pathway. Importantly, one intravitreal injection (IVI) of 25 pmol MTX increased electroretinogram (ERG) response and rhodopsin level in the retinae of RhoP23H/+ knock-in mice at 1 month of age. Additionally, four weekly IVIs increased the photoreceptor cell number in the retinae of RhoP23H/+ mice compared to vehicle control. Our study indicates a therapeutic potential of repurposing MTX for the treatment of rhodopsin-associated RP.

| S-EPMC7688577 | biostudies-literature

Spectrum of rhodopsin mutations in Korean patients with retinitis pigmentosa.

Project description:PURPOSE: To determine the spectrum and frequency of rhodopsin gene (RHO) mutations in Korean patients with retinitis pigmentosa (RP) and to characterize genotype-phenotype correlations in patients with mutations. METHODS: The RHO mutations were screened by direct sequencing, and mutation prevalence was measured in patients and controls. The impact of missense mutations to RP was predicted by segregation analysis, peptide sequence alignment, and in silico analysis. The severity of disease in patients with the missense mutations was compared by visual acuity, electroretinography, optical coherence tomography, and kinetic visual field testing. RESULTS: Five heterozygous mutations were identified in six of 302 probands with RP, including a novel mutation (c.893C>A, p.A298D) and four known mutations (c.50C>T, p.T17M; c.533A>G, p.Y178C; c.888G>T, p.K296N; and c.1040C>T, p.P347L). The allele frequency of missense mutations was measured in 114 ethnically matched controls. p.A298D, newly identified in a sporadic patient, had never been found in controls and was predicted to be pathogenic. Among the patients with the missense mutations, we observed the most severe phenotype in patients with p.P347L, less severe phenotypes in patients with p.Y178C or p.A298D, and a relatively moderate phenotype in a patient with p.T17M. CONCLUSIONS: The results reveal the spectrum of RHO mutations in Korean RP patients and clinical features that vary according to mutations. Our findings will be useful for understanding these genetic spectra and the genotype-phenotype correlations and will therefore help with predicting disease prognosis and facilitating the development of gene therapy.

| S-EPMC3113629 | biostudies-literature

Autosomal dominant retinitis pigmentosa rhodopsin mutation Q344X drives specific alterations in gene transcription

Project description:The goal of the study was to identify transcriptional modifications in retinal tissues from mouse model of rhodopsin mutation-associated retinitis pigmentosa (RP), Q344X compared to wild-type (WT). We implemented RNA-sequencing (RNA-seq) at poly(A) selected RNA for transcriptomic profiling. Differentially expressed genes were determined by DESeq2 using the Benjamini & Hochberg p-value adjustment and an absolute log2 fold change cutoff. The results indicate that there is specificity in transcriptional patterns in the retina from Q344x mice relative to WT, including differential expression in the potassium channel gene, Kcnv2, and differential expression in histone genes including the H1 family histone member, H1foo, the H3 histone family 3B, H3f3b, and the histone deacetylase 9, Hdac9.

2018-02-21 | GSE102247 | GEO

Spectrum of rhodopsin gene mutations in Chinese patients with retinitis pigmentosa.

Project description:PurposeThis study was to analyze the spectrum and frequency of rhodopsin gene (RHO) mutations in Chinese patients with retinitis pigmentosa (RP).MethodsPatients were given physical examinations, and blood samples were collected for DNA extraction. The RHO mutations were screened with direct sequencing.ResultsEight heterozygous nucleotide changes were detected in eight of 300 probands with RP, including six novel mutations and two known mutations. p.R21C, p.C110S, p.G182V, p.C187G, c.409-426delGTGGTGGTGTGTAAGCCC, and p.P347L were found in six autosomal dominant families. p.T92I and p.Y178C were found in two isolated cases.ConclusionsThe results reveal the spectrum and frequency of RHO mutations in Chinese patients with different forms of RP and demonstrate that RHO mutations account for a high proportion of autosomal dominant RP (adRP) cases.

| S-EPMC4119232 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data