title: Characterization of amino acid transport system L in HTB-41 human salivary gland epidermoid carcinoma cells.
abstract: BACKGROUND
  The amino acid transport system L is a major nutrient transport system that is responsible for transport of neutral amino acids, including several essential amino acids. The current study attempted to investigate the expression and functional characterization of amino acid transport system L in HTB-41 human submaxillary salivary gland epidermoid carcinoma cells.
  
  
  METHODS
  RT-PCR analysis, Western blot analysis and amino acid transport measurements were used.
  
  
  RESULTS
  The HTB-41 cells expressed the L-type amino acid transporter 1 (LAT1) together with its associating protein heavy chain of 4F2 antigen (4F2hc) in the plasma membrane, whereas the HTB-41 cells did not express the L-type amino acid transporter 2 (LAT2). The uptakes of [14C]L-leucine were Na+-independent and completely inhibited by a system L selective inhibitor, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH). The affinity of [14C]L-leucine uptake and the inhibition profile of [14C]L-leucine uptake by various L-amino acids in the HTB-41 cells were comparable with those for the LAT1 expressed in Xenopus oocytes.
  
  
  CONCLUSIONS
  The transport of neutral amino acids including several essential amino acids into the HTB-41 human submaxillary salivary gland epidermoid carcinoma cells are mediated by LAT1.
authors.affiliation: Oral Biology Research Institute and The second stage of BK21, Chosun University College of Dentistry, Gwangju 501-759, Korea.
authors.forename: No-Seung
authors.initials: NS
authors.lastname: Park
authors.forename: Su-Gwan
authors.initials: SG
authors.lastname: Kim
authors.forename: Hak-Kyun
authors.initials: HK
authors.lastname: Kim
authors.forename: Seong-Yong
authors.initials: SY
authors.lastname: Moon
authors.forename: Chun Sung
authors.initials: CS
authors.lastname: Kim
authors.forename: Seon-Ho
authors.initials: SH
authors.lastname: Cho
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Kanai
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Endou
authors.forename: Do Kyung
authors.initials: DK
authors.lastname: Kim
mesh_terms: D027062:Amino Acid Transport System L / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000598:Amino Acids, Cyclic / Q000494:pharmacology; D015153:Blotting, Western; D002250:Carbon Radioisotopes; D002294:Carcinoma, Squamous Cell / Q000378:metabolism*; D045744:Cell Line, Tumor; D006801:Humans; D007930:Leucine / Q000378:metabolism / Q000493:pharmacokinetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012468:Salivary Gland Neoplasms / Q000378:metabolism*; D013363:Submandibular Gland / Q000378:metabolism / Q000473:pathology
chemical_list: D027062:Amino Acid Transport System L; D000598:Amino Acids, Cyclic; D002250:Carbon Radioisotopes; C006504:2-aminobicyclo(2,2,1)heptane-2-carboxylic acid; D007930:Leucine