Ask about this productRelated genes to: IMPG2 Blocking Peptide
- Gene:
- IMPG2 NIH gene
- Name:
- interphotoreceptor matrix proteoglycan 2
- Previous symbol:
- -
- Synonyms:
- IPM200, RP56
- Chromosome:
- 3q12.3
- Locus Type:
- gene with protein product
- Date approved:
- 2002-03-15
- Date modifiied:
- 2016-10-05
Related products to: IMPG2 Blocking Peptide
Related articles to: IMPG2 Blocking Peptide
- Retinitis pigmentosa (RP) is a genetically heterogeneous group of inherited retinal dystrophies often accompanied by macular involvement. Variants in are known to cause RP type 56 and vitelliform macular dystrophy type 5, but the pathogenic role of deep intronic variants has rarely been characterized. This study aimed to identify and functionally validate a novel deep intronic variant in a patient with RP. - Source: PubMed
Publication date: 2026/01/22
Zheng GuobingXu ChenxiaXie FenghuaLi QiaoliOu ZhanhuiWang DegangLi Haijun - This narrative review outlines the structure and essential functions of ocular proteoglycans (PGs) in visual processing as documented in the extensive literature on this subject matter. The eye, as one of the most complex sensory organs, relies on the coordinated activity of various tissues and cell types, with PGs playing a central role in facilitating communication and maintaining tissue function. These molecules stabilise ocular tissues; for example, SPACRCAN (IMPG2) and hyaluronan aggregates in the interphotoreceptor matrix protect photoreceptors from oxidative stress. Specialised heparan sulfate PGs, such as pikachurin, eyes-shut, and the neurexin family, stabilise synapses and ensure synaptic specificity and plasticity. Pikachurin is particularly important for the rapid transmission of visual signals at the bipolar ribbon synapse. A diverse array of chondroitin sulfate (aggrecan, versican, neurocan, brevican, phosphacan, NG2), keratan sulfate (SV2), and heparan sulfate (perlecan, agrin, collagen XVIII) PGs are differentially expressed in ocular tissues, contributing to tissue stability and homeostasis. In the cornea, sclera, and choroid, small leucine-rich repeat PGs (SLRPs) maintain three-dimensional structure, corneal transparency, and tissue function through interactions with cytokines and growth factors. The vitreous humour contains opticin and nyctalopin, which support the nutrition of avascular regions and facilitate bipolar ribbon synapse signalling. Ultimately, the effectiveness of the eye as a visual organ depends significantly on the functional roles of its constituent PGs. - Source: PubMed
Publication date: 2026/02/18
Melrose James - We describe a novel missense variant in in a patient with early-onset rod-cone dystrophy with central macular atrophy and evaluate the potential of adenine base editing (ABE) as a therapeutic strategy. Ophthalmic evaluation included ultra-widefield fundus photography, fundus autofluorescence, and spectral-domain optical coherence tomography. Genetic testing was performed with a targeted next-generation sequencing panel and Sanger confirmation. Variant pathogenicity was assessed using in silico prediction tools, protein stability algorithms, and structural modeling. ABE feasibility was analyzed through PAM site identification and guide RNA design. Genetic testing revealed compound heterozygosity for a pathogenic nonsense variant (c.411G>A; p.Trp137*) and a novel missense variant (c.871C>A; p.Arg291Ser) within the SEA-1 domain. While in silico prediction tools classified p.Arg291Ser as benign or neutral, structural modeling and stability analyses supported a destabilizing effect. Base editing assessment indicated that c.411G>A is targetable with ABE. This case underscores the clinical relevance of domain-specific variants and the limitations of in silico predictions. ABE offers a promising therapeutic option for -associated retinopathy. - Source: PubMed
Publication date: 2026/01/01
Abdalla Elsayed Maram E ABarone VincenzoKaukonen MariaRaybould Matthew I JMacLaren Robert E - Pathogenic variants in interphotoreceptor matrix proteoglycan 1 () have been associated with autosomal dominant and recessive retinitis pigmentosa (RP) and autosomal dominant adult vitelliform macular dystrophy (AVMD). Monoallelic pathogenic variants in have been linked to maculopathy and biallelic variants to RP with early onset macular atrophy. Herein we characterise the phenotypic and genotypic features of patients with IMPG1/IMPG2 retinopathy and report novel variants. : Patients with and variants and compatible phenotypes were retrospectively identified. Clinical data were obtained from reviewing the medical records. Phenotypic data included visual acuity, imaging included ultra-widefield pseudo-colour, fundus autofluorescence, and optical coherence tomography (OCT). Genetic testing was performed using next generation sequencing (NGS). Variant pathogenicity was investigated using in silico analysis (SIFT, PolyPhen-2, mutation taster, SpliceAI). The evolutionary conservation of novel missense variants was also investigated. : A total of 13 unrelated patients were identified: 2 (1 male; 1 female) with retinopathy and 11 (7 male; 4 female) with retinopathy. Both retinopathy patients were monoallelic: one patient had adult vitelliform macular dystrophy (AVMD) with drusenoid changes while the other had pattern dystrophy (PD), and they presented to clinic at age 81 and 72 years, respectively. There were 5 monoallelic retinopathy patients with a maculopathy phenotype, of whom 1 had PD and 4 had AVMD. The mean age of symptom onset of this group was 54.2 ± 11.8 years, mean age at presentation was 54.8 ± 11.5 years, and mean BCVAs were 0.15 ± 0.12 logMAR OD and -0.01 ± 0.12 logMAR OS. Six biallelic patients had RP with maculopathy, where the mean age of onset symptom onset was 18.4 years, mean age at examination was 68.7 years, and mean BCVAs were 1.90 logMAR OD and 1.82 logMAR OS. Variants in included one missense and one exon deletion. A total of 11 different variants were identified (4 missense, 7 truncating). A splicing defect was predicted for the c.871C>A p.(Arg291Ser) missense variant. One and five variants were novel. : This study describes the phenotypic spectrum of / retinopathy and six novel variants are reported. The phenotypes of PD and AVMD in monoallelic patients may result from haploinsufficiency, supported by the presence of truncating variants in both monoallelic and biallelic cases. The identification of novel variants expands the known genetic landscape of and retinopathies. These findings contribute to diagnostic accuracy, informed patient counselling regarding inheritance pattern, and may help guide recruitment for future therapeutic interventions. - Source: PubMed
Publication date: 2025/12/09
Al-Khuzaei SaoudShalaby Ahmed KYu JingShanks MoragClouston PennyMacLaren Robert EHalford StephanieDe Silva Samantha RDownes Susan M - The BBSome mediates the retrieval of ubiquitinated membrane proteins from cilia, but its physiological cargoes in photoreceptors remain largely unidentified. Here, we find that K63-linked ubiquitin (UbK63) chains accumulate in the outer segment (OS, equivalent of cilia) of photoreceptors from the onset of OS formation. Through quantitative profiling of the UbK63-associated OS proteome, we identify the transmembrane fragment of interphotoreceptor matrix proteoglycan 2 (IMPG2) as a principal cargo of the BBSome. In mice, ubiquitinated IMPG2 aberrantly accumulates in OSs, and disruption of IMPG2 ubiquitination impairs its retrieval and clearance. Because full-length IMPG2 traffics to the OS to deliver its extracellular domain to the matrix, our data support a model in which IMPG2 undergoes constitutive cycling between the inner and outer segments. These findings redefine the BBSome's role in photoreceptors from quality control to constitutive membrane protein turnover. - Source: PubMed
Publication date: 2025/08/01
Das TirthasreeBradshaw Gary AHyer JeanetteMasek MarkusKuo Yien-MingBachmann-Gagescu RuxandraKalocsay MarianNachury Maxence V