title: Molecular Structures and Coding Genes of the Water-Borne Protein Pheromones of Euplotes petzi, an Early Diverging Polar Species of Euplotes.
abstract: Euplotes is diversified into dozens of widely distributed species that produce structurally homologous families of water-borne protein pheromones governing self-/nonself-recognition phenomena. Structures of pheromones and pheromone coding genes have so far been studied from species lying in different positions of the Euplotes phylogenetic tree. We have now cloned the coding genes and determined the NMR molecular structure of four pheromones isolated from Euplotes petzi, a polar species which is phylogenetically distant from previously studied species and forms the deepest branching clade in the tree. The E. petzi pheromone genes have significantly shorter sequences than in other congeners, lack introns, and encode products of only 32 amino acids. Likewise, the three-dimensional structure of the E. petzi pheromones is markedly simpler than the three-helix up-down-up architecture previously determined in another polar species, Euplotes nobilii, and in a temperate-water species, Euplotes raikovi. Although sharing the same up-down-up architecture, it includes only two short α-helices that find their topological counterparts with the second and third helices of the E. raikovi and E. nobilii pheromones. The overall picture that emerges is that the evolution of Euplotes pheromones involves progressive increases in the gene sequence length and in the complexity of the three-dimensional molecular structure.
authors.affiliation: Paul Scherrer Institute, Villigen 5232, Switzerland.
authors.forename: Bill
authors.initials: B
authors.lastname: Pedrini
authors.affiliation: Institute of Molecular Biology and Biophysics, ETH Zürich, Zürich 8093, Switzerland.
authors.forename: Thea
authors.initials: T
authors.lastname: Suter-Stahel
authors.affiliation: Laboratory of Eukaryotic Microbiology and Animal Biology, School of Biosciences and Veterinary Medicine, University of Camerino, Camerino (MC) 62032, Italy.
authors.forename: Adriana
authors.initials: A
authors.lastname: Vallesi
authors.affiliation: Laboratory of Eukaryotic Microbiology and Animal Biology, School of Biosciences and Veterinary Medicine, University of Camerino, Camerino (MC) 62032, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Alimenti
authors.affiliation: Laboratory of Eukaryotic Microbiology and Animal Biology, School of Biosciences and Veterinary Medicine, University of Camerino, Camerino (MC) 62032, Italy.
authors.forename: Pierangelo
authors.initials: P
authors.lastname: Luporini
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D044822:Biodiversity; D018929:Cell Culture Techniques; D003081:Cold Climate; D003080:Cold Temperature; D016054:DNA, Protozoan; D016812:Euplotes / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D019143:Evolution, Molecular; D017125:Genes, Protozoan; D005822:Genetic Vectors; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D016366:Open Reading Frames / Q000235:genetics*; D010675:Pheromones / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification; D010802:Phylogeny; D011487:Protein Conformation; D015800:Protozoan Proteins / Q000235:genetics; D012623:Seawater / Q000469:parasitology; D016415:Sequence Alignment; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods
chemical_list: D016054:DNA, Protozoan; D010675:Pheromones; D015800:Protozoan Proteins
keywords: Chemical signals; ciliate pheromones; cysteine-rich proteins; macronuclear genes; protein structure