Adenosine uptake via a P2-independent adenine-inhibited carrier. Inhibition of 10 μM adenosine uptake in T. equiperdum P (a), T. equiperdum PBR (b), TbAT1 (wild type) (c), and ΔTbAT1 (d). Bars indicate standard deviations (n = 3). Open circles show uptake in the absence of inhibitor, open squares show uptake in the presence of 1 mM inosine (which blocks the P1 transporter), gray diamonds represent uptake in 1 mM inosine and 1 mM hypoxanthine (blocking the P1 adenosine transporter and the H2 hypoxanthine carrier), filled circles show 1 mM inosine and adenine, which inhibits both the P1 and P2 transporters, and open triangles represent uptake with all three of the aforementioned inhibitors.