title: Host-defense peptides from skin secretions of the octoploid frogs Xenopus vestitus and Xenopus wittei (Pipidae): insights into evolutionary relationships.
abstract: The primary structures of host-defense peptides have proved useful in elucidating the evolution history of frogs. Peptidomic analysis was used to compare the diversity of host-defense peptides in norepinephrine-stimulated skin secretions from the octoploid frogs, Xenopus vestitus (Kivu clawed frog) and Xenopus wittei (De Witte's clawed frog) in the family Pipidae. Structural characterization demonstrated that the X. vestitus peptides belong to the magainin (3 peptides), peptide glycine-leucine-amide (PGLa; 4 peptides), xenopsin-precursor fragment (XPF; 1 peptide), and caerulein-precursor fragment (CPF; 5 peptides) families. The X. wittei peptides comprise magainin (4 peptides), PGLa (1 peptide), XPF (2 peptides), and CPF (7 peptides). In addition, secretions from both species contain caerulein, identical to the peptide from Xenopus laevis, but X. wittei secretions contains the novel peptide [R4K]xenopsin. The variability in the numbers of paralogs in each peptide family indicates a selective silencing of the host-defense peptide genes following the polyploidization events. The primary structures of the peptides provide insight into phylogenetic relationships among the octoploid Xenopus frogs. The data support a sister-group relationship between X. vestitus and Xenopus lenduensis, suggestive of bifurcating speciation after allopolyploidization, whereas X. wittei is more closely related to the Xenopus amieti-Xenopus andrei group suggesting a common tetraploid ancestor. Consistent with previous data, the CPF peptides showed the highest growth inhibitory activity against bacteria with CPF-W6 (GIGSLLAKAAKLAAGLV.NH2) combining high antimicrobial potency against Staphylococcus aureus (MIC=4 μM) with relatively low hemolytic activity (LC50=190 μM).
authors.affiliation: Department of Biochemistry, Faculty of Medicine and Health Sciences, United Arab Emirates University, 17666 Al-Ain, United Arab Emirates.
authors.forename: Milena
authors.initials: M
authors.lastname: Mechkarska
authors.affiliation: PISSARO, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen, 76821 Mont-Saint-Aignan, France; CNRS UMR 6270, University of Rouen, 76821 Mont-Saint-Aignan, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Coquet
authors.affiliation: INSERM U-982, PRIMACEN, CNRS, IRIB, University of Rouen, 76821 Mont-Saint-Aignan, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Leprince
authors.affiliation: PISSARO, Institute for Research and Innovation in Biomedicine (IRIB), University of Rouen, 76821 Mont-Saint-Aignan, France; CNRS UMR 6270, University of Rouen, 76821 Mont-Saint-Aignan, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Jouenne
authors.affiliation: INSERM U-982, PRIMACEN, CNRS, IRIB, University of Rouen, 76821 Mont-Saint-Aignan, France.
authors.forename: Hubert
authors.initials: H
authors.lastname: Vaudry
authors.affiliation: Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Washington Street, MC 0477 Blacksburg, VA 24061-0477, USA; Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0477, USA.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Michalak
authors.affiliation: Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Washington Street, MC 0477 Blacksburg, VA 24061-0477, USA; Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061-0477, USA.
authors.forename: Pawel
authors.initials: P
authors.lastname: Michalak
authors.affiliation: Department of Biochemistry, Faculty of Medicine and Health Sciences, United Arab Emirates University, 17666 Al-Ain, United Arab Emirates. Electronic address: jmconlon@uaeu.ac.ae.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Conlon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D008969:Molecular Sequence Data; D012867:Skin / Q000378:metabolism*; D014981:Xenopus / Q000502:physiology*; D029867:Xenopus Proteins / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D029867:Xenopus Proteins; C045866:peptide-Gly-Leu-amide
keywords: Allopolyploidy; Antimicrobial; Caerulein-precursor fragment; Frog skin; Xenopus