title: The involvement of L-type amino acid transporters in theanine transport.
abstract: L-Theanine has favorable physiological effects in terms of human health, but the mechanisms that transport it to its target organs or cells are not completely defined. To identify the major transport mechanisms of L-theanine, we screened for candidate transporters of L-3H-theanine in several mammal cell lines that intrinsically express multiple transporters with various specificities. All of the cells tested, T24, HepG2, COS1, 293A, Neuro2a, and HuH7, absorbed L-3H-theanine. Uptake was significantly inhibited by the addition of L-leucine and by a specific inhibitor of the system L transport system, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH). L-3H-Theanine uptake occurred mostly independently of Na+. These results indicate that L-theanine was taken up via a system L like transport system in all of the cells tested. Additionally, in experiments using cells stably expressing two system L isoforms, LAT1 and LAT2, we found that the two isoforms mediated L-theanine transport to similar extents. Taken together, our results indicate that L-theanine is transported mostly via the system L transport pathway and its isoforms.
authors.affiliation: Department of Chemistry, Kyorin University School of Medicine, Tokyo, Japan. s_yamamoto@ks.kyorin-u.ac.jp
authors.forename: Sachiko
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Toru
authors.initials: T
authors.lastname: Kimura
authors.forename: Takashi
authors.initials: T
authors.lastname: Tachiki
authors.forename: Naohiko
authors.initials: N
authors.lastname: Anzai
authors.forename: Takuya
authors.initials: T
authors.lastname: Sakurai
authors.forename: Makoto
authors.initials: M
authors.lastname: Ushimaru
mesh_terms: D026923:Amino Acid Transport Systems, Basic / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D002460:Cell Line; D005971:Glutamates / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D027283:Large Neutral Amino Acid-Transporter 1 / Q000378:metabolism*; D051379:Mice; D012964:Sodium / Q000378:metabolism
chemical_list: D026923:Amino Acid Transport Systems, Basic; D002352:Carrier Proteins; D005971:Glutamates; D027283:Large Neutral Amino Acid-Transporter 1; C469951:SLC7A6 protein, human; C037853:glutamine transport proteins; C026166:theanine; D012964:Sodium