Identification and characterisation of the BPI/LBP/PLUNC-like gene repertoire in chickens reveals the absence of a LBP gene.
Palate, lung and nasal epithelial clone (PLUNC) proteins are structural homologues to the innate defence molecules LPS-binding protein (LBP) and bactericidal/permeability-increasing protein (BPI). PLUNCs make up the largest portion of the wider BPI/LBP/PLUNC-like protein family and are amongst the most rapidly evolving mammalian genes. In this study we systematically identified and characterised BPI/LBP/PLUNC-like protein-encoding genes in the chicken genome. We identified eleven complete genes (and a pseudogene). Five of them are clustered on a >50 kb locus on chromosome 20, immediately adjacent to BPI. In addition to BPI, we have identified presumptive orthologues LPLUNCs 2, 3, 4 and 6, and BPIL-2. We find no evidence for the existence of single domain containing proteins in birds. Strikingly our analysis also suggests that there is no LBP orthologue in chicken. This observation may in part account for the relative resistance to LPS toxicity observed in birds. Our results indicate significant differences between the avian and mammalian repertoires of BPI/LBP/PLUNC-like genes at the genomic and transcriptional levels and provide a framework for further functional analyses of this gene family in chickens.
Academic Unit of Respiratory Medicine, Department of Infection and Immunity, University of Sheffield, Sheffield S10 2JF, UK.
Shih-Chieh
SC
Chiang
Edwin J A
EJ
Veldhuizen
Frances A
FA
Barnes
C Jeremy
CJ
Craven
Henk P
HP
Haagsman
Colin D
CD
Bingle
D000209:Acute-Phase Proteins / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000235:genetics*; D030161:Avian Proteins / Q000235:genetics*; D001483:Base Sequence; D001798:Blood Proteins / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D002645:Chickens / Q000235:genetics* / Q000276:immunology; D020869:Gene Expression Profiling; D008562:Membrane Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D023181:Antimicrobial Cationic Peptides; D030161:Avian Proteins; D001798:Blood Proteins; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D000099231:Lipopolysaccharide-Binding Protein; C021623:bactericidal permeability increasing protein