کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1976637 | 1060697 | 2007 | 8 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Tyrosinase localization in mollusc shells Tyrosinase localization in mollusc shells](/preview/png/1976637.png)
In molluscan shellfish, pigmentation is frequently observed in the calcified shell, but the molecular basis of this process is not understood. Here, we report two tyrosinase proteins (Pfty1 and Pfty2) found in the prismatic shell layer of the pearl oyster Pinctada fucata; this layer is recognized as the pigmented region in P. fucata. The protein sequences were deduced from the corresponding cDNAs and confirmed by MALDI-TOF/TOF analysis. The sequences suggest that both tyrosinases have two copper-binding sites in similar N-terminal domains that are homologous to tyrosinases of cephalopods and hemocyanins of gastropods. In turn, this suggests that bivalve tyrosinases are evolved from a common ancestral copper-binding protein in the mollusc. Pfty1 and Pfty2 were specifically expressed in the mantle, and their expression in the mantle is different from each other, suggesting that these tyrosinases have distinctive roles in melanogenesis in shells.
Journal: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology - Volume 146, Issue 2, February 2007, Pages 207–214