Mammalian sodium/dicarboxylate cotransporters (transport succinate and other Krebs cycle intermediates) fall into two categories based on their substrate affinity. The human gene SLC13A3 encodes a high-affinity sodium/dicarboxlate co-transporter, NaDC3. NaDC3 is expressed in the basolateral membrane of renal proximal tubular epithelial cells, sinusoidal membrane of hepatocytes, and brain synaptosomes. Kinetic studies in human retinal pigment epithelial (HRPE) cells suggest three sodium ions co-transported with every divalent succinate (Wang H et al, 2000).
high-affinity sodium:dicarboxylate symporter activity of SLC13A3 [plasma membrane]