细胞-细胞连接组织结构和信号网络.pdfVIP

Cell–Cell Junctions Organize Structural and Signaling Networks Miguel A. Garcia,1 W. James Nelson,1,2 and Natalie Chavez1 1Department of Biology, Stanford University, Stanford, California 94305 2 Departments of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305 Correspondence: wjnelson@ Cell–cell junctions link cells to each other in tissues, and regulate tissue homeostasis in critical cell processes that include tissue barrier function, cell proliferation, and migration. Defects in cell–cell junctions give rise to a wide range of tissue abnormalities that disrupt homeostasis and are common in genetic abnormalities and cancers. Here, we discuss the organization and function of cell–cell junctions primarily involved in adhesion (tight junc- tion, adherens junction, and desmosomes) in two different epithelial tissues: a simple epi- thelium (intestine) and a stratified epithelium (epidermis). Studies in these tissues reveal similarities and differences in the organization and functions of different cell–cell junctions that meet the requirements for the specialized functions of each tissue. We discuss cell–cell junction responses to genetic and environmental perturbations that provide further insights into their roles in maintaining tissue homeostasis. Overview of Epithelial Tissue Organization The intestinal epithelium is lined by a single layer of cells that have a columnar shape that pithelia are evolutionary conserved and maximizes surface area for nutrient absorption ubiquitous in multicellular organisms. They E and maintenance of a barrier to the outside form a continuous sheet of tightly linked cells environment (Helander and Fandriks 2014). that line the external-facing surfaces of organs