title: Characterization of the Cadherin-Catenin Complex of the Sea Anemone Nematostella vectensis and Implications for the Evolution of Metazoan Cell-Cell Adhesion.
abstract: The cadherin-catenin complex (CCC) mediates cell-cell adhesion in bilaterian animals by linking extracellular cadherin-based adhesions to the actin cytoskeleton. However, it is unknown whether the basic organization of the complex is conserved across all metazoans. We tested whether protein interactions and actin-binding properties of the CCC are conserved in a nonbilaterian animal, the sea anemone Nematostella vectensis We demonstrated that N. vectensis has a complete repertoire of cadherin-catenin proteins, including two classical cadherins, one α-catenin, and one β-catenin. Using size-exclusion chromatography and multi-angle light scattering, we showed that α-catenin and β-catenin formed a heterodimer that bound N. vectensis Cadherin-1 and -2. Nematostella vectensis α-catenin bound F-actin with equivalent affinity as either a monomer or an α/β-catenin heterodimer, and its affinity for F-actin was, in part, regulated by a novel insert between the N- and C-terminal domains. Nematostella vectensis α-catenin inhibited Arp2/3 complex-mediated nucleation of actin filaments, a regulatory property previously thought to be unique to mammalian αE-catenin. Thus, despite significant differences in sequence, the key interactions of the CCC are conserved between bilaterians and cnidarians, indicating that the core function of the CCC as a link between cell adhesions and the actin cytoskeleton is ancestral in the eumetazoans.
authors.affiliation: Department of Biology, Stanford University.
authors.forename: Donald Nathaniel
authors.initials: DN
authors.lastname: Clarke
authors.affiliation: Department of Molecular and Cellular Physiology, Stanford University School of Medicine.
authors.forename: Phillip W
authors.initials: PW
authors.lastname: Miller
authors.affiliation: Department of Biology, Stanford University.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Lowe
authors.affiliation: Department of Molecular and Cellular Physiology, Stanford University School of Medicine Department of Structural Biology, Stanford University School of Medicine.
authors.forename: William I
authors.initials: WI
authors.lastname: Weis
authors.affiliation: Department of Biology, Stanford University Department of Molecular and Cellular Physiology, Stanford University School of Medicine wjnelson@stanford.edu.
authors.forename: William James
authors.initials: WJ
authors.lastname: Nelson
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D005075:Biological Evolution; D015820:Cadherins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051177:Catenins / Q000235:genetics / Q000378:metabolism; D002448:Cell Adhesion / Q000235:genetics / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism; D011485:Protein Binding; D012615:Sea Anemones / Q000166:cytology / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D051178:alpha Catenin / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
chemical_list: D000199:Actins; D015820:Cadherins; D051177:Catenins; D051178:alpha Catenin; D051176:beta Catenin
keywords: adherens junction; cadherin; catenin; cell adhesion; cnidarians; evolution