title: Molecular characterization of ABC transporters in marine ciliate, Euplotes crassus: Identification and response to cadmium and benzo[a]pyrene.
abstract: ATP-binding cassette (ABC) transporters participate in transporting various substances, including xenobiotics, in or out of cells. However, their genetic information and function in ciliates remain still unclear. In this study, we sequenced and characterized two ABC transporter genes (EcABCB and EcABCC), and investigated the effect of cadmium (Cd) and benzo[a]pyrene (B[a]P) on their function and gene expression, using efflux assay and real-time reverse transcription-polymerase chain reaction (qRT-PCR), respectively, in the marine ciliate, Euplotes crassus. Sequencing analysis and efflux assay showed that EcABCB and EcABCC are typical ABC transporters, possessing conserved function. Exposure to Cd (≥5mg/L) and B[a]P (≥50.5μg/L) enhanced accumulation of a substrate. A significant increase in the expression of EcABCB and EcABC mRNA was observed at lower concentration in response to Cd and B[a]P. Our findings indicate that Cd and B[a]P could inhibit the efflux function of ABC transporters, leading to cellular toxicity in the ciliate.
authors.affiliation: Department of Life Science, College of Natural Sciences, Sangmyung University, Seoul 03016, South Korea.
authors.forename: Hokyun
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Life Science, College of Natural Sciences, Sangmyung University, Seoul 03016, South Korea.
authors.forename: Bora
authors.initials: B
authors.lastname: Yim
authors.affiliation: Department of Life Science, College of Natural Sciences, Sangmyung University, Seoul 03016, South Korea.
authors.forename: Jisoo
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Life Science, College of Natural Sciences, Sangmyung University, Seoul 03016, South Korea.
authors.forename: Haeyeon
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Life Science, College of Natural Sciences, Sangmyung University, Seoul 03016, South Korea. Electronic address: ymlee70@smu.ac.kr.
authors.forename: Young-Mi
authors.initials: YM
authors.lastname: Lee
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism; D001564:Benzo(a)pyrene / Q000633:toxicity*; D015415:Biomarkers / Q000032:analysis; D002104:Cadmium / Q000633:toxicity*; D004781:Environmental Exposure; D016812:Euplotes / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D015800:Protozoan Proteins / Q000235:genetics* / Q000378:metabolism; D018570:Risk Assessment; D017422:Sequence Analysis, DNA; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D018528:ATP-Binding Cassette Transporters; D015415:Biomarkers; D015800:Protozoan Proteins; D014874:Water Pollutants, Chemical; D002104:Cadmium; D001564:Benzo(a)pyrene
keywords: ABC transporter; Benzo[a]pyrene; Cadmium; Ciliate; Efflux test; Euplotes crassus