Usherin (USH2A), exon 13 region (USH2A exon 13)

Exon 13 of USH2A refers to a specific coding exon within the human USH2A gene, which encodes the extracellular matrix protein usherin. USH2A produces multiple isoforms, including a long single‑pass transmembrane protein (~5,202 amino acids) with a large ectodomain containing laminin N-terminal, laminin EGF-like, laminin globular, and numerous fibronectin type III domains, a transmembrane region, and a short intracellular C‑terminus with a PDZ-binding motif. Usherin localizes to basement membranes and the periciliary region of photoreceptors and developing inner-ear hair cells, where it forms the USH2 protein complex with other Usher proteins and contributes to photoreceptor organization, hair bundle architecture, and protein trafficking. Pathogenic USH2A variants are a leading cause of autosomal recessive retinitis pigmentosa and Usher syndrome type IIA (hearing loss with retinitis pigmentosa). “Exon 13 of USH2A” is not itself a protein or receptor; it is a gene segment implicated in genetic testing and potential exon-specific therapeutic strategies rather than a classical drug target.[4][2][3][5][7][1] Essential context and support: - Gene/protein identity and function: USH2A encodes usherin, an extracellular matrix protein found in basement membranes of the inner ear and retina, participating in a protein complex important for development and maintenance of these tissues.[4] The long usherin isoform is a single-pass transmembrane protein (~5,202 aa) with a large ectodomain composed of laminin and fibronectin type III domains and a C‑terminal PDZ-binding motif.[2][3] - Biology: Usherin is localized at photoreceptor periciliary regions and developing hair cells; it contributes to cargo transfer/trafficking and cellular architecture within the USH2 complex.[5][1] - Disease roles: USH2A variants are a common cause of autosomal recessive retinitis pigmentosa and account for over half of Usher syndrome type II cases (type IIA), with extensive allelic heterogeneity.[4] Genotype–phenotype studies describe variant classes associated with nonsyndromic retinal disease versus syndromic disease.[7] - Target status clarification: An exon is a genomic segment, not a receptor or enzyme; thus “Exon 13 of USH2A gene” is not a therapeutic target in the drug–receptor sense. It is relevant for molecular diagnosis and may be an exon-specific intervention site (e.g., antisense splicing correction), but not an interacting protein target for drugs.[4][2][3]

Other names

USH2A exon 13Exon 13 of USH2AUSH2A gene exon 13