Isolation and characterization of dopamine transporter in Clonorchis sinensis

초록

Dopamine is an organic chemical of the catecholamine and phenethylamine families. The role of dopamine transporter is reabsorption the dopamine after it has been released and sent its message. There is a reports on existence of dopamine receptor in C. sinensis. It also suggest dopamine transporter for reabsorption of dopamine. Therefore, we try to isolate and characterize the dopamine transporter gene from adult C. sinensis. From NCBI database, the target dopamine transporter (CsDT) gene was isolated using reverse-transcription polymerase chain reaction. The open reading frame of CsDT cDNA consist of 1962 base pairs that encoded a 653-amino acid residue protein. Hydropathy analysis suggested that CsDT possess 12 putative membrane-spanning domains. When expressed in Xenopus oocytes, CsDT mediated the transport of radiolabeled dopamine in a time- and sodium-dependent manner. There was no efflux of radiolabeled dopamine by high concentration of extracellular unlabeled dopamine. From concentration dependent uptake, the Km value and Vmax value was 521.1 nM/oocyte/hr and 1616 fmol/oocyte/hr by Lineweaver-Burk equation. These results might give a clue on neurotransmitter cycle in Chinese fluke.