Cadherins: A Molecular Family Important in Selective Cell-Cell Adhesion

The animal body is a collective of heterogeneous cell types. The heterotypic cell are arranged in a precise order to form tissue structures in which the cells never intermix randomly. Generally, cells of the same phenotype are connected to each other and form a group. Groups of cells are demarcated from each other with sharp boundaries, especially between the cell groups expressing different phenotypes. Thus, tissues comprise compartments of different groups of cells. This is a general feature of tissue architecture, seen universally in the animal kingdom. An important property that allows cells to form tissues is their own adhesiveness; multicellular organisms cannot exist without the association of cells. Another important property of cells is the ability to sort themselves from different cell types. These two properties of cells are thus believed to be crucial for the construction of tissues. In this article, I present a summary of our recent knowledge on how animal cells recognize each other and adhere selectively to particular cell types, focusing on a group of cell-cell adhesion molecules called the cadherins.