title: Expansion of the BPI family by duplication on human chromosome 20: characterization of the RY gene cluster in 20q11.21 encoding olfactory transporters/antimicrobial-like peptides.
abstract: Antimicrobial peptides provide a defense system against microorganisms. One class of these molecules binds lipophilic substrates and is therefore directed against gram-negative bacteria. This family includes proteins related to bactericidal/permeability-increasing protein (BPI). We characterized an approximately 100-kb cluster of three human genes named RYSR, RYA3, and RY2G5 that are related to the BPI family. The RY cluster maps to 20q11.21, >5 Mb upstream of the BPI cluster. The RY and BPI genes have similar exon structures, indicating that they were derived by duplication from a common ancestor. We identified mouse BPI-related and RY orthologues in syntenic regions, indicating that the gene family expanded before mouse and human diverged. Expression analyses show that RYs are strongly expressed in the olfactory epithelium, suggesting that they also could act as odorant transporters or detoxification agents in the olfactory system. Together, these data show how mammals diversified their antimicrobial defenses/olfactory pathways through a duplication-driven adaptive selection process.
authors.affiliation: Institut de Génétique Humaine, CNRS UPR 1142, Rue de la Cardonille, 34396 Montpellier, France.
authors.forename: Jean Baptiste
authors.initials: JB
authors.lastname: Andrault
authors.forename: Isabelle
authors.initials: I
authors.lastname: Gaillard
authors.forename: Dominique
authors.initials: D
authors.lastname: Giorgi
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rouquier
mesh_terms: D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins / Q000235:genetics*; D015152:Blotting, Northern; D002874:Chromosome Mapping; D002890:Chromosomes, Human, Pair 20 / Q000235:genetics*; D016000:Cluster Analysis; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D019143:Evolution, Molecular; D040461:Gene Components / Q000235:genetics; D020440:Gene Duplication; D020869:Gene Expression Profiling; D006801:Humans; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
chemical_list: D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; D017931:DNA Primers; D018076:DNA, Complementary; D008565:Membrane Proteins; C021623:bactericidal permeability increasing protein