Crithidia luciliae: Functional Expression of Nucleoside and Nucleobase Transporters inXenopus laevisOocytes

Autor: Simone T. Hall, Jeffrey Penny, Annette M. Gero, Sanjeev Krishna
Rok vydání: 1998
Předmět:
Zdroj: Experimental Parasitology. 90:181-188
ISSN: 0014-4894
Popis: Hall, S. T., Penny, J. I., Gero, A. M., and Krishna, S. 1998.Crithidia luciliae: Functional expression of nucleoside and nucleobase transporters inXenopus laevisoocytes.Experimental Parasitology90, 181–188. The expression of purine-specific nucleoside and base transporters ofCrithidia luciliaehas been demonstrated inXenopus laevisoocytes. Poly(A)+-mRNA fromC. luciliae, cultured in either purine-replete or purine-starved conditions, was microinjected intoX. laevisoocytes. For “purine-replete” mRNA, expression of adenosine and hypoxanthine uptake in microinjectedX. laevisoocytes was increased on average 9- and 3-fold above water-injected controls, respectively. Expression of adenosine and hypoxanthine uptake in oocytes microinjected with “purine-starved” mRNA was 8 and 3-fold above water-injected controls, respectively. Substrate competition indicated an adenosine/deoxyadenosine transporter and a separate base transporter specific for hypoxanthine. In contrast toC. luciliae in vivo, where the level of activity of adenosine and hypoxanthine transport was regulated by the level of purines in the medium, the heterologous expression of these transporters (from both purine replete and deplete cultures) inX. laevisoocytes was independent of the extracellular purine concentration. These results may suggest that the presence of specific transporter message is independent of the extracellular purine content, indicating that the regulation of activation and expression of these transporters inC. luciliaemay not be under transcriptional control.
Databáze: OpenAIRE