Department of Biology and 2 Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305.
J Cell Biol. 2014 Jan 20;204(2):265-79. doi: 10.1083/jcb.201306082.
Cadherins and associated catenins provide an important structural interface between neighboring cells, the actin cytoskeleton, and intracellular signaling pathways in a variety of cell types throughout the Metazoa. However, the full inventory of the proteins and pathways required for cadherin-mediated adhesion has not been established. To this end, we completed a genome-wide (~14,000 genes) ribonucleic acid interference (RNAi) screen that targeted Ca(2+)-dependent adhesion in DE-cadherin-expressing Drosophila melanogaster S2 cells in suspension culture. This novel screen eliminated Ca(2+)-independent cell-cell adhesion, integrin-based adhesion, cell spreading, and cell migration. We identified 17 interconnected regulatory hubs, based on protein functions and protein-protein interactions that regulate the levels of the core cadherin-catenin complex and coordinate cadherin-mediated cell-cell adhesion. Representative proteins from these hubs were analyzed further in Drosophila oogenesis, using targeted germline RNAi, and adhesion was analyzed in Madin-Darby canine kidney mammalian epithelial cell-cell adhesion. These experiments reveal roles for a diversity of cellular pathways that are required for cadherin function in Metazoa, including cytoskeleton organization, cell-substrate interactions, and nuclear and cytoplasmic signaling.
钙黏蛋白及其相关联蛋白为各种类型的细胞提供了一个重要的结构界面，连接着相邻细胞、肌动蛋白细胞骨架和细胞内信号通路，在后生动物中无处不在。然而，钙黏蛋白介导的黏附所必需的蛋白质和途径的完整清单尚未确定。为此，我们完成了一个全基因组（约 14000 个基因）的 RNA 干扰（RNAi）筛选，该筛选针对的是悬浮培养的表达 DE-钙黏蛋白的黑腹果蝇 S2 细胞中的 Ca2+依赖性黏附。这个新的筛选排除了 Ca2+非依赖性细胞间黏附、整联蛋白依赖的黏附、细胞铺展和细胞迁移。我们根据蛋白质功能和蛋白质-蛋白质相互作用，确定了 17 个相互关联的调控枢纽，这些枢纽调节核心钙黏蛋白-连环蛋白复合物的水平，并协调钙黏蛋白介导的细胞间黏附。这些枢纽中的代表性蛋白质在果蝇卵子发生中进一步进行了靶向生殖系 RNAi 分析，在犬肾上皮细胞间黏附中分析了细胞黏附。这些实验揭示了钙黏蛋白在后生动物中发挥功能所必需的多种细胞途径的作用，包括细胞骨架组织、细胞-基质相互作用以及核和细胞质信号转导。
