Analysis of the genomic organization of the human cationic amino acid transporters CAT-1, CAT-2 and CAT-4

By screening nucleotide databases, sequences containing the complete genes of the human cationic amino acid transporters (hCATs) 1, 2 and 4 were ident ified. Analysis of the genomic organization revealed that hCAT-2 consists o f 12 translated exons and most likely of 2 untranslated exons. The splice v ariants hCAT-2A and hCAT-2B use exon 7 and 6, respectively. The hCAT-2 gene structure is closely related to the structure of hCAT-1, suggesting that t hey belong to a common gene family. hCAT-4 consists of only 4 translated ex ons and 3 short introns. Exons of identical size and highly homologous to e xon 3 of hCAT-4 are present in hCAT-1 and hCAT-2.