A NEW-AGE FOR MAMMALIAN PLASMA-MEMBRANE AMINO-ACID TRANSPORTERS

A wealth of structural information on amino acid transport-related pro teins has appeared during the last 4 years. Up to date, these proteins are structurally classified into five different families: cationic am ino acid transporters; superfamily of sodium- and chloride-dependent t ransporters; family of glutamate transporters, which includes structur ally related zwitterionic amino acid transporters; family of sodium sy mporters for sugars, amino acids, vitamins and nucleosides; and a fami ly of possible specific activators or subunits of amino acid transport ers. The present review deals with the structural classification of di fferent amino acid transport-related proteins as well as with their fu nctional characterization.