engleski

First evidence of the P-glycoprotein gene expression and multixenobiotic resistance modulation in earthworm

Multixenobiotic resistance (MXR) mechanism is present in many organisms as an important cellular detoxification mechanism and is mediated by the activity of ATP binding cassette (ABC) transporters that bind and actively efflux different toxic substrates out of the cell. Here we present data on molecular identification of ABC efflux transporter - P-glycoprotein (P-gp/Abcb1), as a representative of MXR phenotype, in soil organism - earthworm *Eisenia fetida*. Partial cDNA sequence of *Abcb1 * was identified and its overall identity with ABCB1 homologues of other organisms ranged from 58.5 to 72.5 %. Furthermore we looked at the impact of five modulators (verapamil, cyclosporin A, MK571, probenecid, orthovanadate) to the earthworm’s MXR mechanism activity. To confirm MXR reversion by these agents, we measured in *E. fetida* the accumulation of model substrates rhodamine B and rhodamine 123 in whole body tissue of the adult earthworm. The results showed that MK571, OV and VER modulators significantly inhibit MXR transport activity in experiment performed on filter paper contact test. Our data for the first time evidence the presence of P-gp/Abcb1 related gene in earthworm "E. fetida". In addition, we have demonstrated the importance of MXR as the specific detoxification mechanism that helps earthworms to survive in polluted environments.

ABC transporter proteins ; cellular detoxification mechanism ; modulator ; MXR ; phenotype ; soil organism

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