title: Danio rerio αE-catenin is a monomeric F-actin binding protein with distinct properties from Mus musculus αE-catenin.
abstract: It is unknown whether homologs of the cadherin·catenin complex have conserved structures and functions across the Metazoa. Mammalian αE-catenin is an allosterically regulated actin-binding protein that binds the cadherin·β-catenin complex as a monomer and whose dimerization potentiates F-actin association. We tested whether these functional properties are conserved in another vertebrate, the zebrafish Danio rerio. Here we show, despite 90% sequence identity, that Danio rerio and Mus musculus αE-catenin have striking functional differences. We demonstrate that D. rerio αE-catenin is monomeric by size exclusion chromatography, native PAGE, and small angle x-ray scattering. D. rerio αE-catenin binds F-actin in cosedimentation assays as a monomer and as an α/β-catenin heterodimer complex. D. rerio αE-catenin also bundles F-actin, as shown by negative stained transmission electron microscopy, and does not inhibit Arp2/3 complex-mediated actin nucleation in bulk polymerization assays. Thus, core properties of α-catenin function, F-actin and β-catenin binding, are conserved between mouse and zebrafish. We speculate that unique regulatory properties have evolved to match specific developmental requirements.
authors.affiliation: Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California 94305, USA.
authors.forename: Phillip W
authors.initials: PW
authors.lastname: Miller
authors.forename: Sabine
authors.initials: S
authors.lastname: Pokutta
authors.forename: Agnidipta
authors.initials: A
authors.lastname: Ghosh
authors.forename: Steven C
authors.initials: SC
authors.lastname: Almo
authors.forename: William I
authors.initials: WI
authors.lastname: Weis
authors.forename: W James
authors.initials: WJ
authors.lastname: Nelson
authors.forename: Adam V
authors.initials: AV
authors.lastname: Kwiatkowski
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002850:Chromatography, Gel; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism*; D063347:Native Polyacrylamide Gel Electrophoresis; D011485:Protein Binding; D012542:Scattering, Radiation; D015027:Zebrafish; D051178:alpha Catenin / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; C034037:F-actin-binding proteins; D008840:Microfilament Proteins; D051178:alpha Catenin
keywords: Actin; Adherens Junction; Catenin; Cell Adhesion; Protein Evolution