Abcb1 gene expression pattern and function of copper detoxification in Fujian oyster, Crassostrea angulata

• Published in: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology Vol. 190; pp. 8 - 15
• Main Authors: Shi, Bo, Xiang, Xu, Ke, Yizhou, Zhou, Long, Ke, Caihuan
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.12.2015
• Subjects: Abcb1; Amino Acid Motifs; Amino Acid Sequence; Animals; ATP Binding Cassette Transporter, Sub-Family B - agonists; ATP Binding Cassette Transporter, Sub-Family B - chemistry; ATP Binding Cassette Transporter, Sub-Family B - genetics; ATP Binding Cassette Transporter, Sub-Family B - metabolism; China; Conserved Sequence; Copper; Copper - toxicity; Crassostrea - cytology; Crassostrea - drug effects; Crassostrea - metabolism; Detoxification; Expression; Gene Expression Regulation - drug effects; Molecular Sequence Data; Osmolar Concentration; Phylogeny; Random Allocation; Recombinant Proteins - chemistry; Recombinant Proteins - metabolism; RNA Interference; RNA, Messenger - metabolism; RNAi; Sequence Alignment; Tissue Distribution; Toxicokinetics; Water Pollutants, Chemical - toxicity; RNAi; Abcb1; Copper; Expression; Detoxification
• ISSN: 1096-4959; 1879-1107
• DOI: 10.1016/j.cbpb.2015.08.007

Oysters are considered hyper-accumulators of Cu, but the molecular mechanism by which they maintain Cu cell homeostasis is still unclear. ATP-binding cassette protein subfamily B member 1 (ABCB1, P-glycoprotein) can transport a variety of substrates across the cell membrane in aquatic animals. In this study, to provide insight into the roles of ABCB1 in resistance against Cu in oysters, complete cDNA of abcb1 gene in Crassostrea angulata was cloned and analyzed. The complete sequence of C. angulata ABCB1 showed high identity to ABCB1 from other bivalves and contained some classical motifs of ABCB transport proteins. Abcb1 was mainly expressed in the apical epithelial cell of gills and epithelia of mantles. Abcb1 expression and Cu accumulation were also studied in control oysters and oysters exposed to Cu (30, 100, 300μg/L Cu, 1–15days). Cu accumulation in the gill and mantle were measured after abcb1 gene interference. The complete sequence of C. angulata ABCB1 showed high identity to ABCB1 from other bivalves and contained some classical motifs of ABCB transport proteins. The mRNA transcript of abcb1 showed hypersensitivity to Cu exposure. A concentration-dependent highest abcb1 mRNA level (up to 5.61-fold to the control) in the gill and mantle existed across all Cu exposure concentrations after 3days of Cu exposure. The gill and mantle Cu concentration were significantly higher after the abcb1 mRNA interference. According to these results, it is here speculated that ABCB1 may underlie cell protection against Cu in C. angulata.