A polarized epithelium organized by beta- and alpha-catenin predates cadherin and metazoan origins.

Publication Type:

Journal Article

Source:

Science (New York, N.Y.), Volume 331, Issue 6022, p.1336-9 (2011)

Keywords:

Actin Cytoskeletondigestive disease, digestive deseases alpha Catenindigestive disease, digestive deseases beta Catenindigestive disease, digestive deseases Cadherinsdigestive disease, digestive deseases Cell Polaritydigestive disease, digestive deseases Cellulosedigestive disease, digestive deseases Dictyosteliumdigestive disease, digestive deseases Epithelial Cellsdigestive disease, digestive deseases Epitheliumdigestive disease, digestive deseases Intercellular Junctionsdigestive disease, digestive deseases Morphogenesisdigestive disease, digestive deseases Protozoan Proteinsdigestive disease, digestive deseases RNA Interference

Abstract:

A fundamental characteristic of metazoans is the formation of a simple, polarized epithelium. In higher animals, the structural integrity and functional polarization of simple epithelia require a cell-cell adhesion complex that contains a classical cadherin, the Wnt-signaling protein β-catenin and the actin-binding protein α-catenin. We show that the non-metazoan Dictyostelium discoideum forms a polarized epithelium that is essential for multicellular development. Although D. discoideum lacks a cadherin homolog, we identify an α-catenin ortholog that binds a β-catenin-related protein. Both proteins are essential for formation of the epithelium, polarized protein secretion, and proper multicellular morphogenesis. Thus, the organizational principles of metazoan multicellularity may be more ancient than previously recognized, and the role of the catenins in cell polarity predates the evolution of Wnt signaling and classical cadherins.