Evolution of ASABF (Ascaris suum antibacterial factor)-type antimicrobial peptides in nematodes: putative rearrangement of disulfide bonding patterns.
ASABF (Ascaris suum antibacterial factor)-type antimicrobial peptides are defensin-like cysteine-rich peptides that are widely distributed in the phylum Nematoda. In known members of ASABF-type antimicrobial peptides, an array consisting of eight cysteine residues is completely conserved. In this study, we report a novel member ASABF-6Cys-alpha, which contains only six cysteine residues, in the pig round worm A. suum. The two cysteine residues deleted in ASABF-6Cys-alpha were not identical to a pair of half-cystine forming a disulfide bridge in ASABF-alpha, suggesting a rearrangement of disulfide bonding patterns. Gene organization and phylogenetic analyses suggested that ASABF-6Cys-alpha was generated from an ancestral ASABF gene after the divergence of Ascaridida from Rhabditida. ASABF-6Cys-alpha transcripts dramatically increased after bacterial injection, suggesting that ASABF-6Cys-alpha may contribute to immunity in nematodes.
Minaba
Masaomi
M
Division of Insect Sciences, National Institute of Agrobiological Sciences, 1-2 Owashi, Tsukuba, Ibaraki, Japan.
Ueno
Satoshi
S
Pillai
Ajitha
A
Kato
Yusuke
Y
D000818:Animals; D017165:Ascaris suum / Q000235:genetics*; D001483:Base Sequence; D003545:Cysteine / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D019143:Evolution, Molecular; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D049810:Genetic Speciation; D015801:Helminth Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D017168:Rhabditida / Q000235:genetics; D013552:Swine
C102532:ASABF protein, Ascaris suum; D004220:Disulfides; D015801:Helminth Proteins; D003545:Cysteine