Characterisation of Dermanyssus gallinae glutathione S-transferases and their potential as acaricide detoxification proteins

Background: glutathione s-transferases (gsts) facilitate detoxification of drugs by catalysing the conjugation of the reduced glutathione (gsh) to electrophilic xenobiotic substrates and therefore have a function in multi-drug resistance. as a result,knowledge of gsts can inform both drug resistance in,and novel interventions for,the control of endo- and ectoparasite species. acaricide resistance and the need for novel control methods are both pressing needs for dermanyssus gallinae,a highly economically important haematophagous ectoparasite of poultry. methods: a transcriptomic database representing d. gallinae was examined and 11 contig sequences were identified with gst blastx identities. the transcripts represented by 3 contigs,designated deg-gst-1,-2 and -3,were fully sequenced and further characterized by phylogenetic analysis. recombinant versions of deg-gst-1,-2 and -3 (rdeg-gst) were enzymically active and acaricide-binding properties of the rdeg-gsts were established by evaluating the ability of selected acaricides to inhibit the enzymatic activity of rdeg-gsts. results: 6 of the identified gsts belonged to the mu class,followed by 3 kappa,1 omega and 1 delta class molecules. deg-gst-1 and -3 clearly partitioned with orthologous mu class gsts and deg-gst-2 partitioned with delta class gsts. phoxim,permethrin and abamectin significantly inhibited rdeg-gst-1 activity by 56,35 and 17 % respectively. phoxim also inhibited rdeg-2-gst (14.8 %) and rdeg-gst-3 (20.6 %) activities. conclusions: deg-gsts may have important roles in the detoxification of pesticides and,with the increased occurrence of acaricide resistance in this species worldwide,deg-gsts are attractive targets for novel interventions. © 2015 bartley et al.