Characterization of crustin antimicrobial proteins from Japanese spiny lobster Panulirus japonicus

Crustin antimicrobial proteins (PJC1–4) were identified from a phyllosoma library of Japanese spiny lobster, Panulirus japonicus. The deduced amino acid sequences of PJC1–4 contained open reading frames of 130, 139, 124 and 150 amino acid residues, respectively. These proteins contained a glycine-rich region at the N-terminus and 12 conserved cysteine residues containing a single whey acidic protein (WAP) domain at the C-terminus. A phylogenetic tree and sequences alignment analyses revealed that PJC1–4 are more closely related to shrimp crustins than to other lobster crustins. Transcripts of PJC1, 3 and 4 were detected in heart, nerves, intestine, hemocytes, gills and hepatopancreas, while transcripts of PJC2 were detected only in nerves.