Identification of novel adhesive proteins in pearl oyster by proteomic and bioinformatic analysis

Byssuses, which are proteinaceous fibers secreted by mollusks, are remarkable underwater adhesives. Although mussel adhesives are well known, much less is known about the byssal proteins of pearl oysters especially in the adhesive regions. In this study, adhesive proteins from the pearl oyster Pinctada fucata were studied in depth by transcriptomics and proteomics approaches. In total, 16 novel proteins were identified including a von Willebrand factor type A domain-containing protein, a thrombospondin-1-like protein, tyrosinase, mucin-like proteins, protease inhibitors, and Pinctada unannotated foot protein 3 (PUF3) to PUF6. Interestingly, PUF3-6 are enriched with glycine, serine, and PXG (X = F/Y/W/K/L) motifs and are highly expressed in the foot. The identification of byssal proteins of the pearl oyster is a key step for understanding byssus formation and may inspire the synthesis of novel adhesives for underwater use and the development of anti-biofouling strategies.