Amino acid transport across the plasma membrane

Amino acid transport across the plasma membrane Amino acid transport across plasma membranes is critical to the uptake of these molecules from the gut, to their reabsortion in the kidney proximal tubulues, and to their distribution to cells in which they are required for the synthesis of proteins and of amino acid derived small molecules such as neurotransmitters. Physiological studies have defined 18 "systems" that mediate amino acid transport, each characterized by its amino acid substrates, as well as its pH sensitivity and its association (or not) with ion transport. More recently, molecular cloning studies have allowed the identification of the plasma membrane transport proteins that mediate these reactions. Amino acid uptake mediated by 17 of these transporters is annotated here (Broer 2008).