Functional characterization of P-glycoprotein in the intertidal copepod Tigriopus japonicus and its potential role in remediating metal pollution

• Published in: Aquatic toxicology Vol. 156; pp. 135 - 147
• Main Authors: Jeong, Chang-Bum, Kim, Bo-Mi, Kim, Rae-Kwon, Park, Heum Gi, Lee, Su-Jae, Shin, Kyung-Hoon, Leung, Kenneth Mei Yee, Rhee, Jae-Sung, Lee, Jae-Seong
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2014; Elsevier
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; ATP-Binding Cassette, Sub-Family B, Member 1 - analysis; ATP-Binding Cassette, Sub-Family B, Member 1 - metabolism; Biological and medical sciences; Copepod; Copepoda; Copepoda - chemistry; Copepoda - genetics; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation; Inactivation, Metabolic - genetics; Metal; Metals - metabolism; P-glycoprotein; Pollution; Promoter Regions, Genetic; Tigriopus japonicus; Up-Regulation; Water Pollutants, Chemical - metabolism; P-glycoprotein; Copepod; Pollution; Metal; Tigriopus japonicus; Toxicity; P Glycoprotein; Crustacea; Marine environment; Copepoda; Copper; Carrier protein; Transmembrane protein; Cadmium; Detoxification; Transition metal; Gene expression; Zinc; Heavy metal; Trace element; Pollutant; Intertidal zone; Arthropoda; Defense mechanism; Invertebrata; Biological accumulation; ABC transporter; Zooplankton
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/j.aquatox.2014.08.005

•Mechanistic analysis of metal-induced toxicity in copepod.•Novel identification and characterization of P-glycoprotein (P-gp) in copepod.•Comparative analysis of P-gp-mediated metal tolerance in copepod.•Understanding of resistance and adaptation of copepod upon metal pollution. The intertidal copepod Tigriopus japonicus has been widely used in aquatic toxicity testing for diverse environmental pollutants including metals. Despite relatively well-characterized in vivo physiological modulations in response to aquatic pollutants, the molecular mechanisms due to toxicity and detoxification are still unclear. To better understand the mechanisms of metal transport and further detoxification, T. japonicus P-glycoprotein (TJ-P-gp) with conserved motifs/domains was cloned and measured for protein activity against the transcript and protein expression profiles in response to metal exposure. Specifically, we characterized the preliminary efflux activity and membrane topology of TJ-P-gp protein that supports a transport function for chemicals. To uncover whether the efflux activity of TJ-P-gp protein would be modulated by metal treatment, copepods were exposed to three metals (Cd, Cu, and Zn), and were observed for both dose- and time-dependency on the efflux activity of TJ-P-gp protein with or without 10μM of P-gp-specific inhibitors verapamil and zosuquidar (LY335979) for 24h over a wide range of metal concentrations. In particular, treatment with zosuquidar induced metal accumulation in the inner body of T. japonicus. In addition, three metals significantly induced the transporting activity of TJ-P-gp in a concentration-dependent manner in both transcript and protein levels within 24h. Together these data indicate that T. japonicus has a conserved P-gp-mediated metal defense system through the induction of transcriptional up-regulation of TJ-P-gp gene and TJ-P-gp protein activity. This finding provides further understanding of the molecular defense mechanisms involved in P-glycoprotein-mediated metal detoxification in copepods.