Role of a dual splicing and amino acid code in myopia, cone dysfunction and cone dystrophy associated with L/M opsin interchange mutations

双剪接和氨基酸密码在与 L/M 视蛋白互换突变相关的近视、视锥细胞功能障碍和视锥细胞营养不良中的作用

• 批准号: 9893919
• 负责人: MAUREEN E NEITZ
• 金额: $ 44.13万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9893919
• 关键词: Adolescent; Alleles; Amino Acids; Area; Benign; Binding; Biochemical; Biological Assay; Blindness; Catalogs; Cell Culture Techniques; Code; Color Visions; Complex; Cone; Cone dystrophy; Data; Defect; Disease; Exclusion; Exhibits; Exons; Eye; Eye diseases; Feedback; Frequencies; Functional disorder; Genes; Genetic Polymorphism; Genetic Recombination; Genetic Variation; Goals; Growth; Haplotypes; Human; Individual; Lead; Length; Light; Link; MW opsin; Measures; Messenger RNA; Modernization; Molecular Biology; Mutation; Myopia; Nucleotides; Opsin; Outcome; Pathology; Patients; Phenotype; Photoreceptors; Plague; Play; Population; Positioning Attribute; Protein Isoforms; Proteins; RNA Splicing; RNA, Messenger, Splicing; Red-Green Color Blindness; Refractive Errors; Research; Retina; Retinal Cone; Retinal Degeneration; Risk; Risk Factors; Rod; Role; Severities; Single Nucleotide Polymorphism; Spliced Genes; Technology; Therapeutic; Time; Transcript; U1 small nuclear RNA; Uncertainty; Variant; Vision; Vision Disorders; Visual impairment; Visual system structure; Work; base; blue cone monochromacy; clinical Diagnosis; clinical phenotype; emmetropization; exon skipping; family genetics; genetic variant; genome editing; insight; protein function; risk variant; visual feedback

The long-term objective of this research is to understand the mechanism by which intermixing of the human long- (L) and middle- (M) wavelength cone photopigment genes give rise to variants that cause aberrant pre- messenger RNA (mRNA) splicing, and lead to vision loss with a diverse set of clinical phenotypes. 95% of our cones are L or M cones, and except at very low light levels when rods are active, all vision is based on cones. The L and M cones play a critical role in the visually guided feedback mechanism responsible for controlling eye growth (emmetropization). Every aspect of seeing, including high acuity and color vision, depends on the L and M cone photopigments and these genes are important risk factors in common eye disorders that plague modern humans. The L and M (LM) cone photopigment genes, designated OPN1LW and OPN1MW, respectively, exhibit high haplotype diversity in exons 2, 3 and 4. The most is known about two variants, designated LIAVA and LVAVA that are associated with photoreceptor dysfunction and severe vision impairment. They are found in patients with a range of clinical diagnoses including high grade myopia, blue cone monochromacy and cone dystrophy. We and others have recently shown that combinations of single nucleotide polymorphisms (SNPs) associated with these variants cause aberrant pre-mRNA splicing. Our preliminary data show that different combinations of the exon 3 polymorphisms shift the ratio of full length to exon 3 skipped mRNA, producing variability in the severity of the splicing defect that will be extremely useful in elucidating the fundamental mechanisms controlling splicing of this exon. Preliminary data obtained using a cell culture-based splicing assay also suggests that haplotypes of exon 3 that yield moderate levels of exon 3 skipping are associated with an average -1.3 diopters of refractive error compared to low/non-skipping variants. The pathophysiology of the different mutations is complex because superimposed on the effects of subnormal amounts of opsin protein produced by the splicing defects, are the effects of some combinations of the amino acids on protein function. To achieve our goal we propose: Aim 1: To investigate the role of combinations of SNPs in exons 2, 3 and 4 of the L and M opsin genes in splicing by 1.1 fully enumerating the transcript isoforms, and measuring their relative abundances. 1.2 investigating and quantitating the effects of exon 3 haplotypes on splicing in cone photoreceptors and particularly those haplotypes that are risk alleles for juvenile onset myopia. Aim 2: To investigate the mechanism of exon 3 skipping using biochemical and molecular biology approaches Aim 3: To evaluate the potential for exon specific U1 snRNAs to rescue the exon 3 skipping phenotype.

这项研究的长期目标是了解人类基因混合的机制