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.