Institute of Veterinary Physiology, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany.
J Membr Biol. 2023 Feb;256(1):51-61. doi: 10.1007/s00232-022-00251-z. Epub 2022 Jun 23.
Epithelial barriers constitute a fundamental requirement in every organism, as they allow the separation of different environments and set boundaries against noxious and other adverse effectors. In many inflammatory and degenerative diseases, epithelial barrier function is impaired because of a disturbance of the paracellular seal. Recently, the Xenopus laevis oocyte has been established as a heterologous expression model for the analysis of transmembrane tight junction protein interactions and is currently considered to be a suitable screening model for barrier effectors. A prerequisite for this application is a physiological anchoring of claudins to the cytoskeleton via the major scaffolding protein tjp1 (tight junction protein 1, ZO-1). We have analyzed the oocyte model with regard to the interaction of heterologously expressed claudins and tjp1. Our experiments have revealed endogenous tjp1 expression in protein and mRNA analyses of unfertilized Xenopus laevis oocytes expressing human claudin 1 (CLDN1) to claudin 5 (CLDN5). The amphibian cell model can therefore be used for the analysis of claudin interactions.
上皮屏障是每个生物体的基本要求，因为它们允许不同环境的分离，并对有害物质和其他不利效应物设置边界。在许多炎症和退行性疾病中，上皮屏障功能受损，因为细胞旁密封被扰乱。最近，非洲爪蟾卵母细胞已被确立为分析跨膜紧密连接蛋白相互作用的异源表达模型，目前被认为是屏障效应物的合适筛选模型。这种应用的一个前提是通过主要支架蛋白 tjp1（紧密连接蛋白 1，ZO-1）将 Claudin 以生理方式锚定到细胞骨架上。我们已经分析了卵母细胞模型，以研究异源表达的 Claudin 与 tjp1 的相互作用。我们的实验在蛋白质和 mRNA 分析中揭示了未受精的非洲爪蟾卵母细胞中内源性 tjp1 的表达，这些卵母细胞表达了人 Claudin 1（CLDN1）到 Claudin 5（CLDN5）。因此，两栖动物细胞模型可用于 Claudin 相互作用的分析。
