Related Experiment Video
Updated: Sep 24, 2025
Identification of OTX1 and OTX2 As Two Possible Molecular Markers for Sinonasal Carcinomas and Olfactory Neuroblastomas
Published on: February 28, 2019
Identification and functional assays of single-nucleotide variants of opsins genes in melanocytic tumors
Wei Zhang1, Wen Zeng1, Jianglong Feng2
1Department of Dermatology, Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou, China.
Abstract:
Epidermal melanocytes sense solar light via the opsin-coupled signaling pathway which is involved in a range of biological functions, including regulating pigmentation, proliferation, apoptosis, and tumorigenesis. However, it remains unclear whether there are genetic variants within these opsins that affect opsin protein structure and function, and further melanocyte biological behaviors. Here, we examined single-nucleotide variants (SNVs) of five opsin (RGR, OPN1SW, OPN2, OPN4, and OPN5) genes in MM (malignant melanoma; n = 76) and MN (melanocytic nevi; n = 157), using next-generation sequencing. The effects of these pathogenic single-nucleotide variants (SNVs) on opsin structure and function were further investigated using molecular dynamics (MD) simulations, dynamic cross-correlation (DCC), and site-directed mutagenesis. In total, 107 SNV variants were identified. Of these variants, 14 nonsynonymous SNVs (nsSNVs) of opsin genes were detected, including three mutations in the RGR gene, three mutations in the OPN1SW gene, two mutations in the OPN2 gene, and six mutations in the OPN4 gene. The effect of these missense mutations on opsin function was then assessed using eight prediction tools to estimate the potential impact of an amino acid substitution. The impact of each nsSNV was investigated using MD simulations and DCC analysis. Furthermore, we performed in vitro fluorescence calcium imaging to assess the functional properties of nsSNV proteins using a site-directed mutagenesis method. Taken together, these results revealed that p.A103V (RGR), p.T167I (RGR), p.G141S (OPN1SW), p.R144C (OPN1SW), and p.S231F (OPN4) had more deleterious effects on protein structure and function among the 14 nsSNVs. Opsin gene alterations showed the low frequency of missense mutations in melanocytic tumors, and although rare, some mutations in these opsin genes disrupt the canonical function of opsin. Our findings provide new insight into the role of opsin variants in the loss of function.
Insights
Genetic variants in opsin genes, crucial for melanocyte function, were analyzed in melanoma and nevi. Specific mutations were found to disrupt opsin structure and function, offering insights into melanocytic tumor development.
Area of Science:
- Genetics
- Molecular Biology
- Dermatology
Background:
- Epidermal melanocytes utilize opsin-coupled signaling for light sensing, influencing pigmentation, proliferation, apoptosis, and tumorigenesis.
- The impact of genetic variants within opsin genes on their structure, function, and melanocyte behavior remains largely unexplored.
Purpose of the Study:
- To investigate single-nucleotide variants (SNVs) in five opsin genes (RGR, OPN1SW, OPN2, OPN4, OPN5) within malignant melanoma (MM) and melanocytic nevi (MN) samples.
- To assess the functional and structural consequences of identified pathogenic SNVs on opsin proteins.
Main Methods:
- Next-generation sequencing was employed to identify SNVs in opsin genes from MM (n=76) and MN (n=157) cohorts.
- Molecular dynamics (MD) simulations, dynamic cross-correlation (DCC) analysis, site-directed mutagenesis, and in vitro fluorescence calcium imaging were used to evaluate the impact of nsSNVs.
- Eight prediction tools were utilized to estimate the potential effects of amino acid substitutions.
Main Results:
- A total of 107 SNVs were identified, with 14 nonsynonymous SNVs (nsSNVs) detected across RGR, OPN1SW, OPN2, and OPN4 genes.
- Specific nsSNVs, including p.A103V (RGR), p.T167I (RGR), p.G141S (OPN1SW), p.R144C (OPN1SW), and p.S231F (OPN4), demonstrated significant deleterious effects on protein structure and function.
- Opsin gene alterations were found at low frequencies in melanocytic tumors, but some mutations clearly disrupted canonical opsin function.
Conclusions:
- Rare opsin gene variants can disrupt normal opsin function, potentially contributing to melanocytic tumor development.
- These findings provide novel insights into the role of opsin variants in the loss of function within the context of melanocytic lesions.
