Dermatopontin, a shell matrix protein gene from pearl oyster Pinctada martensii, participates in nacre formation

• Published in: Biochemical and biophysical research communications Vol. 425; no. 3; pp. 679 - 683
• Main Authors: Jiao, Yu, Wang, Huan, Du, Xiaodong, Zhao, Xiaoxia, Wang, Qingheng, Huang, Ronglian, Deng, Yuewen
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 31.08.2012
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Chondroitin Sulfate Proteoglycans - genetics; Chondroitin Sulfate Proteoglycans - metabolism; Cloning, Molecular; Dermatopontin; DNA, Complementary - genetics; Extracellular Matrix Proteins - genetics; Extracellular Matrix Proteins - metabolism; Gene Knockdown Techniques; Molecular Sequence Data; Nacre; Nacre - biosynthesis; Pinctada - genetics; Pinctada - metabolism; Pinctada martensii; RNA Interference; RNA, Double-Stranded - genetics; Shell matrix protein; Dermatopontin; Shell matrix protein; RNA interference; Nacre
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2012.07.099

► We obtained the full length of DPT gene in Pinctada martensii. ► DPT mRNA was higher expressed in the mantle and pearl sac. ► RNA interference was used to elucidate the function of DPT gene. ► The obtained DPT was functional for nacre formation in P. martensii. Dermatopontin (DPT) is identified as a major component of the shell matrix protein. However, its exact function in the shell formation remains obscure. In this study, we described the characteristic and function of DPT gene from Pinctada martensii. DPT cDNA was 797bp long, containing an open reading fragment (ORF) of 537bp encoding a polypeptide of 178 amino acids with an estimated molecular mass of 21.4kDa and theoretical isoelectric point of 5.97. The 5′ untranslated region (UTR) was 11bp and the 3′UTR was 249 with 18bp poly (A) tail. In the peptide, there was a signal sequence, six potential phosphorylation sites, one glycosylation site and eight cysteine residues. Moreover, a sequence motif (D-R-X-W/F/Y-X-F/Y/I/L/M-X1–2-C) was contained and repeated itself three times in the entire sequence. DPT mRNA was constitutively expressed in all studied tissues with the most abundant mRNA in the mantle, which was nacre formation-related tissue. After decreasing DPT expression using RNA interference (RNAi) technology in the mantle, the nacreous layer showed a disordered growth; whereas the prismatic layer of the shells has no significant changes. These results suggested that DPT obtained in this study was a constitutive matrix protein and participated in nacre formation in P. martensii.