Abstract:
Desmosomes are multiprotein adhesion complexes that link intermediate filaments to the plasma membrane, ensuring the mechanical integrity of cells across tissues, but how they participate in the wider signaling network to exert their full function is unclear. To investigate this, we carried out protein proximity mapping using biotinylation (BioID). The combined interactomes of the essential desmosomal proteins desmocollin 2a, plakoglobin, and plakophilin 2a (Pkp2a) in Madin-Darby canine kidney epithelial cells were mapped and their differences and commonalities characterized as desmosome matured from Ca2+ dependence to the mature, Ca2+-independent, hyper-adhesive state, which predominates in tissues. Results suggest that individual desmosomal proteins have distinct roles in connecting to cellular signaling pathways and that these roles alter substantially when cells change their adhesion state. The data provide further support for a dualistic concept of desmosomes in which the properties of Pkp2a differ from those of the other, more stable proteins. This body of data provides an invaluable resource for the analysis of desmosome function.
摘要:
桥粒是将中间纤丝连接到质膜的多蛋白粘附复合物,确保细胞在组织中的机械完整性,但是他们如何参与更广泛的信令网络以发挥其全部功能尚不清楚。为了研究这一点,我们使用生物素化(BioID)进行了蛋白质邻近作图。必需桥粒蛋白desmocollin2a的联合节间,对Madin-Darby犬肾上皮细胞中的血红蛋白和脂蛋白2a(Pkp2a)进行了定位,它们的差异和共性表征为桥粒从Ca2依赖性成熟到成熟,Ca2+-非依赖性,超粘合状态,在组织中占主导地位。结果表明,单个桥粒蛋白在连接细胞信号传导途径方面具有不同的作用,并且当细胞改变其粘附状态时,这些作用会发生实质性变化。这些数据为桥粒的二元概念提供了进一步的支持,其中Pkp2a的属性与其他的属性不同,更稳定的蛋白质这些数据为桥粒功能的分析提供了宝贵的资源。