title: Host-defense peptides from skin secretions of Fraser's clawed frog Xenopus fraseri (Pipidae): Further insight into the evolutionary history of the Xenopodinae.
abstract: Peptidomic analysis of norepinephrine-stimulated skin secretions of the tetraploid frog Xenopus fraseri Boulenger, 1905 (Pipidae) led to identification of 13 host-defense peptides. The primary structures of the peptides demonstrate that they belong to the magainin (3 peptides), peptide glycine-leucine-amide, PGLa (4 peptides), and xenopsin-precursor fragment, XPF (2 peptides) families, first identified in Xenopus laevis, together with caerulein precursor fragment-related peptides, CPF-RP (4 peptides), first identified in Silurana tropicalis. In addition, the secretions contain a molecular variant of xenopsin displaying the substitution Arg(4)→Lys compared with X. laevis xenopsin and peptide glycine-tyrosine-amide (PGYa) (GRIIPIYPEFERVFA KKVYPLY.NH2) whose function is unknown. The most potent antimicrobial peptide identified is CPF-RP-F1 (GFGSVLGKALKFGANLL.NH2) with MIC=12.5μM against Staphylococcus aureus and 50μM against Escherichia coli. On the basis of similarities in morphology and advertisement calls, X. fraseri has been placed in a species group that includes the octoploids Xenopus amieti and Xenopus andrei, and the tetraploid Xenopus pygmaeus. Cladistic analyses based upon the primary structures of magainin, PGLa, and CPF-RP peptides support a close evolutionary relationship between X. fraseri, X. amieti and X. andrei but suggest a more distant relationship with X. pygmaeus.
authors.affiliation: Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, 17666 Al-Ain, United Arab Emirates. Electronic address: m.conlon@ulster.ac.uk.
authors.forename: J Michael
authors.initials: JM
authors.lastname: Conlon
authors.affiliation: Department of Biochemistry, College 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: Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria.
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kolodziejek
authors.affiliation: Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine, Veterinärplatz 1, A-1210 Vienna, Austria; Department of Microbiology and Immunology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman.
authors.forename: Norbert
authors.initials: N
authors.lastname: Nowotny
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
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000032:analysis* / Q000378:metabolism; D054806:Magainins / Q000032:analysis / Q000378:metabolism; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis / Q000378:metabolism; D012867:Skin / Q000737:chemistry*; D014981:Xenopus / Q000382:microbiology* / Q000502:physiology*; D029867:Xenopus Proteins / Q000032:analysis* / Q000378:metabolism
chemical_list: D023181:Antimicrobial Cationic Peptides; D054806:Magainins; D010455:Peptides; D029867:Xenopus Proteins; C016832:xenopsin
keywords: Caerulein-precursor fragment; Frog skin; Host-defense peptide; Magainin; PGLa