Table 1.
Adenosine Transport Characteristics of ENTs and CNTs
Nucleoside Transporter | Solute Carrier Family | Adenosine Affinity [Km (mM)] | Tissue Distribution | Subcellular Localization | Reference |
---|---|---|---|---|---|
CNT1 | SLC28A1 | -- | Small intestine, Kidney, Liver, | Plasma membrane | (Gray, et al., 2004; J. D. Young, et al., 2013) |
CNT2 | SLC28A2 | 0.008 | Small intestine, Testis, skeletal muscle, liver, kidney, intestine, pancreas, placenta, brain | Plasma membrane | (Duflot, et al., 2004; Gray, et al., 2004; Pastor-Anglada & Perez-Torras, 2018a, 2018b; J. D. Young, et al., 2013) |
CNT3 | SLC28A3 | 0.0024–0.015 | Mammary gland, pancreas, bone marrow, trachea, intestine | Plasma membrane, sometimes intracellular | (Pastor-Anglada & Perez-Torras, 2018a, 2018b; J. D. Young, et al., 2013) |
ENT1 | SLC29A1 | 0.04–0.78 | Widely expressed with high levels in skeletal and smooth muscle, lung, thymus | Plasma, nuclear, and mitochondrial membranes | (Parkinson, et al., 2011; Ward, Sherali, Mo, & Tse, 2000) |
ENT2 | SLC29A2 | 0.14–0.78 | Widely expressed, especially skeletal muscle | Plasma and nuclear membranes | (Parkinson, et al., 2011; Ward, et al., 2000) |
ENT3 | SLC29A3 | 0.78–1.86 | Widely expressed in most tissues | Endosomal, lysosomal, and mitochondrial membranes | (Baldwin, et al., 2005; Kang, et al., 2010; Parkinson, et al., 2011; Pastor-Anglada & Perez-Torras, 2018a, 2018b; Rahman, Askwith, & Govindarajan, 2017) |
ENT4 | SLC29A4 | 0.78 | Heart, brain, skeletal muscle | Plasma membrane | (Barnes, et al., 2006; Parkinson, et al., 2011; Pastor-Anglada & Perez-Torras, 2018a) |