CNT1 - "Electrophysiological recordings of CNT1 (SLC28A1) activity on Nanion’s SURFE²R N1"
SURFE2R N1 application note (0.4 MB)
The concentrative nucleoside transporter 1 (CNT1) is a sodium-dependent uptake transporter encoded by the SLC28A1 gene. CNT1 functions as a co-transporter, coupling the uphill nucleoside transport into the cells to the electrochemical gradient of sodium. The stoichiometry of transport is proposed to be 1:1, but a stoichiometry of 2 Na+: 1 nucleoside has also been suggested. CNT1 is an electrogenic transporter, generating a net charge flow. It plays a major role in the uptake of pyrimidines, including uridine and cytidine, from the extracellular milieu into the cytoplasm in nucleoside salvage pathways which is the first step of nucleoside biosynthesis. The transporter is expressed in epithelial tissues including liver, kidney and small intestine where it is localized to the apical membrane. CNTs are important targets for many antiviral and anticancer agents, and CNT1 has been proposed to play a role in tumor biology via a mechanism beyond nucleoside transport. In fact, tumors expressing high levels of CNT1 can indicate a higher risk of relapse for breast cancer patients, suggesting that nucleoside salvage may interfere with chemosensitivity. On the other hand, high expression of the CNT1 protein could promote drug- induced cytotoxicity if patients were treated with suitable hCNT substrates. In any case, hCNT1 is an important mediator in the transport of anticancer and antiviral nucleoside drugs by mechanisms that require further study.
Here we present CNT1 activity measurements on the SURFE2R N1 instrument using purified plasma membrane of CHO cells expressing CNT1.