Transport proteins in plasma or other biological membranes mediate the passage of charged, hydrophilic, or large substrates across these membranes, otherwise impassable for these molecules. They are hence crucial for virtually any cellular process involving such molecules. Transporters are therefore important drug targets. Many human diseases are caused by the absence or dysfunction of transporters. In addition, transporters attract interest due to their involvement in the uptake, metabolism and excretion of many drugs.
Our group is mainly interested in the transport of cationic amino acids mediated by CATs (Cationic Amino acid Transporters) and HATs (Heteromeric Amino acid Transporters), both assigned to the gene family 7 of solute carriers (SLC7) by the Human Genome Organization. Cationic amino acids feed into protein synthesis, and other enzymatic reactions dependent on these amino acids, including the synthesis of nitric oxide (NO), urea, creatine and agmatine from arginine or the synthesis of polyamines, proline and glutamine from ornithine. Increasing evidence exists that CATs and HATs can be important determinants of these processes.