open access

https://hdl.handle.net/2115/86123

Characterization of deoxyribonucleoside transport mediated by concentrative nucleoside transporters

英語

Concentrative nucleoside transporter

2021-06-18

Elsevier

Biochemical and biophysical research communications

558

120-125

Human concentrative nucleoside transporters (CNTs) are responsible for cellular uptake of ribonucleosides; however, although it is important to better characterize CNT-subtype specificity to understand the systemic disposition of deoxyribonucleosides (dNs) and their analogs, the involvement of CNTs in transporting dNs is not fully understood. In this study, using COS-7 cells that transiently expressed CNT1, CNT2, or CNT3, we investigated if CNTs could transport not only ribonucleosides but also dNs, i.e., 2'-deoxyadenosine (dAdo), 2'-deoxyguanosine (dGuo), and 2'-deoxycytidine (dCyd). The cellular uptake study demonstrated that dAdo and dGuo were taken up by CNT2 but not by CNT1. Although dCyd was taken up by CNT1, no significant uptake was detected in COS-7 cells expressing CNT2. Similarly, these dNs were transported by CNT3. The apparent K-m values of their uptake were as follows: CNT1, K-m = 141 mu M for dCyd; CNT2, K-m = 62.4 mM and 54.9 mu M for dAdo and dGuo, respectively; CNT3, K-m = 14.7 mM and 34.4 mu M for dGuo and dCyd, respectively. These results demonstrate that CNTs contribute not only to ribonucleoside transport but also to the transport of dNs. Moreover, our data indicated that CNT1 and CNT2 selectively transported pyrimidine and purine dNs, respectively, and CNT3 was shown to transport both pyrimidine and purine dNs.

学術雑誌論文

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