title: CMAP27, a novel chicken cathelicidin-like antimicrobial protein.
abstract: Cathelicidins, antimicrobial peptides with broad spectrum activity, have been almost exclusively found in mammals. Here, we report the cloning of a novel avian cathelicidin, chicken myeloid antimicrobial peptide 27 (CMAP27) from chicken bone marrow cells. A combined expressed sequence tag (EST) and genomic based search revealed a cathelicidin-like gene located at the terminus of chromosome 2. Reverse transcriptase-polymerase chain reaction (RT-PCR) and 5'RACE techniques resulted in a 154 amino acid prepropeptide, homologous to chicken cathelicidin 1 (51%) and most similar to alpha-helical myeloid antibacterial peptides (MAPs; 29-33%). A putative elastase cleavage site (LVQRG/RF) suggests the production of a 27 amino acid antimicrobial peptide, predicted to adopt an alpha-helical configuration followed by a hydrophobic tail. Comparative analyses between antimicrobial peptide domains showed marked similarity between CMAP27 and MAP members of the bovidae family, but not with the alpha-helical chicken cathelicidin 1. Strongest expression of CMAP27 mRNA was found in myeloid/lymphoid tissues, testis and uropygial gland. In accordance with the phylogenetic tree analysis, these findings support the theory of a common ancestral cathelicidin gene and suggest an important role for cathelicidins in chicken innate host defense.
authors.affiliation: Department of Public Health and Food Safety, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, 3508 TD Utrecht, The Netherlands.
authors.forename: Albert
authors.initials: A
authors.lastname: van Dijk
authors.forename: Edwin J A
authors.initials: EJ
authors.lastname: Veldhuizen
authors.forename: Alphons J A M
authors.initials: AJ
authors.lastname: van Asten
authors.forename: Henk P
authors.initials: HP
authors.lastname: Haagsman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics* / Q000276:immunology*; D001483:Base Sequence; D002645:Chickens / Q000235:genetics* / Q000276:immunology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D007113:Immunity, Innate; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
chemical_list: D023181:Antimicrobial Cationic Peptides; C504855:CMAP27 protein, chicken; D018076:DNA, Complementary; D012333:RNA, Messenger