title: Identification of the multidrug resistance-associated protein (mrp) related gene in red mullet (Mullus barbatus).
abstract: Multixenobiotic resistance mechanism (MXR) in aquatic organisms is mediated by the activity of the P-glycoprotein (Pgp) transporter that binds and actively effluxes different chemicals out of cell. In addition to the Pgp, several other, non-Pgp transport proteins have been recently identified in different human and animal tissues. Given their characteristics and tissue distribution we hypothesized that members of the so-called multidrug resistance-associated protein (MRP) family may be expressed in aquatic organisms. This study attempted to identify MRP related genes in different tissues of several marine and freshwater bivalves (Mytilus galloprovincialis, Dreissena polymorpha, Anodonta cygnea) and fish species (Mullus barbatus, Cyprinus carpio, Salmo trutta). Following an alignment of known MRP1 and MRP2 human sequences, as well as the GenBank available mrp2 sequences from different animals, we determined highly conserved regions and used them to design three pairs of consensus primers. Total RNA was isolated, reverse transcribed to cDNA and the obtained cDNAs were PCR amplified with the corresponding primers. The amplified PCR products were sequenced and their homology compared with Pgp and MRP protein sequences from different species. The expression of MRP related mRNA was clearly identified only in liver tissue isolated from red mullet, with homologies at the protein level ranging from 75% to 76%. Described results clearly pointed at the possibility that at least in the red mullet MXR as a general defense mechanism may be mediated by the activities of at least two different types of transport proteins.
authors.affiliation: Laboratory for Molecular Ecotoxicology, Department for Marine and Environmental Research, Rudjer Boskovic Institute, Bijenicka 54, 10002 Zagreb, Croatia.
authors.forename: Roberta
authors.initials: R
authors.lastname: Sauerborn
authors.forename: Darija Stupin
authors.initials: DS
authors.lastname: Polancec
authors.forename: Roko
authors.initials: R
authors.lastname: Zaja
authors.forename: Tvrtko
authors.initials: T
authors.lastname: Smital
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D015870:Gene Expression; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D010473:Perciformes / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D027425:ATP-Binding Cassette, Sub-Family C Proteins