Background: Hepcidins, a kind of cysteine-rich antimicrobial peptides, play important roles in host
immunological processes and iron regulation, which have been identified from several fish species. The rare
minnow (
Gobiocypris rarus
), an endemic cyprinid fish in China, has been used extensively as model animal in
laboratory. However, little is known about its hepcidin. Here, we report the cloning and characterization of a
hepcidin gene from the liver of Chinese rare minnow.
Results: The full-length cDNA of rare minnow hepcidin is 662 bp, which contains an ORF of 273 bp encoding a
prepropeptide of 90 amino acid residues. The predicted prepropeptide contains three domains: a signal
peptide of 24 amino acids, a prodomain of 41 amino acids, and a mature peptide of 25 amino acids. Sequence
alignment showed eight conserved cysteine residues in the mature peptide, which formed four disulfide
bonds in spatial structure. The deduced structure of mature peptide showed a high degree of homology to the
human hepcidin. Phylogenetic analysis showed that it had a close relationship with zebrafish hepcidin, and
clustered in a clade with these from Cyprinidae. Synthetic peptide of rare minnow hepcidin could inhibit the
growth of Gram positive bacterium
Staphylococcus aureus
and Gram negative bacteria
Escherichia coli
and
Aeromonas hydrophila
.
Conclusion: These results suggested that rare minnow hepcidin had typical structure of hepcidins and
antibacterial activity. It could participate in innate immune response as an antibacterial agent and be used as
antibiotic substance.
