title: Metazoan evolution of the armadillo repeat superfamily.
abstract: The superfamily of armadillo repeat proteins is a fascinating archetype of modular-binding proteins involved in various fundamental cellular processes, including cell-cell adhesion, cytoskeletal organization, nuclear import, and molecular signaling. Despite their diverse functions, they all share tandem armadillo (ARM) repeats, which stack together to form a conserved three-dimensional structure. This superhelical armadillo structure enables them to interact with distinct partners by wrapping around them. Despite the important functional roles of this superfamily, a comprehensive analysis of the composition, classification, and phylogeny of this protein superfamily has not been reported. Furthermore, relatively little is known about a subset of ARM proteins, and some of the current annotations of armadillo repeats are incomplete or incorrect, often due to high similarity with HEAT repeats. We identified the entire armadillo repeat superfamily repertoire in the human genome, annotated each armadillo repeat, and performed an extensive evolutionary analysis of the armadillo repeat proteins in both metazoan and premetazoan species. Phylogenetic analyses of the superfamily classified them into several discrete branches with members showing significant sequence homology, and often also related functions. Interestingly, the phylogenetic structure of the superfamily revealed that about 30 % of the members predate metazoans and represent an ancient subset, which is gradually evolving to acquire complex and highly diverse functions.
authors: Inflammation Research Center (IRC), VIB, Ghent, Belgium.|Department of Biomedical Molecular Biology, Ghent University, FSVM Building, Technologiepark 927, 9052, Ghent, Belgium.
authors: Ismail Sahin
authors: IS
authors: Gul
authors: Inflammation Research Center (IRC), VIB, Ghent, Belgium.|Department of Biomedical Molecular Biology, Ghent University, FSVM Building, Technologiepark 927, 9052, Ghent, Belgium.
authors: Paco
authors: P
authors: Hulpiau
authors: Inflammation Research Center (IRC), VIB, Ghent, Belgium.|Department of Respiratory Medicine, Ghent University, Ghent, Belgium.
authors: Yvan
authors: Y
authors: Saeys
authors: Inflammation Research Center (IRC), VIB, Ghent, Belgium. frans.vanroy@ugent.be.|Department of Biomedical Molecular Biology, Ghent University, FSVM Building, Technologiepark 927, 9052, Ghent, Belgium. frans.vanroy@ugent.be.
authors: Frans
authors: 0000-0003-4358-1039
authors: F
authors: van Roy
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D051186:Armadillo Domain Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D005075:Biological Evolution; D019143:Evolution, Molecular; D006801:Humans; D008958:Models, Molecular; D010802:Phylogeny; D011487:Protein Conformation; D016415:Sequence Alignment
chemical_list: D051186:Armadillo Domain Proteins
keywords: ARM repeat; Catenins; HEAT repeat; Importins; Metazoa; Molecular evolution; Phylogeny; Premetazoan; Protein domains