title: Establishment of stable cell lines with high expression of heterodimers of human 4F2hc and human amino acid transporter LAT1 or LAT2 and delineation of their differential interaction with α-alkyl moieties.
abstract: System L is a major transport system for cellular uptake of neutral amino acids. Among system L transporters, L-type amino acid transporter 1 (LAT1) is responsible for the nutrient uptake in cancer cells, whereas L-type amino acid transporter 2 (LAT2) is a transporter for non-cancer cells. In this study, we have established HEK293 cell lines stably expressing high levels of human LAT1 and LAT2 forming heterodimers with native human 4F2hc of the cells. We have found that L-[(14)C]alanine is an appropriate substrate to examine the function of LAT2, whereas L-[(14)C]leucine is used for LAT1. By using L-[(14)C]alanine on LAT2, we have for the first time directly evaluated the function of human LAT2 expressed in mammalian cells and obtained its reliable kinetics. Using α-alkyl amino acids including α-methyl-alanine and α-ethyl-L-alanine, we have demonstrated that α-alkyl groups interfere with the interaction with LAT2. These cell lines with higher practical advantages would be useful for screening and analyzing compounds to develop LAT1-specific drugs that can be used for cancer diagnosis and therapeutics. The strategy that we took to establish the cell lines would also be applicable to the other heterodimeric transporters with important therapeutic implications.
authors: Division of Bio-system Pharmacology, Department of Pharmacology, Graduate School of Medicine, Osaka University, Japan.
authors: Narakorn
authors: N
authors: Khunweeraphong
authors: Shushi
authors: S
authors: Nagamori
authors: Pattama
authors: P
authors: Wiriyasermkul
authors: Yumiko
authors: Y
authors: Nishinaka
authors: Printip
authors: P
authors: Wongthai
authors: Ryuichi
authors: R
authors: Ohgaki
authors: Hidekazu
authors: H
authors: Tanaka
authors: Hideyuki
authors: H
authors: Tominaga
authors: Hiroyuki
authors: H
authors: Sakurai
authors: Yoshikatsu
authors: Y
authors: Kanai
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000596:Amino Acids / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D027282:Fusion Regulatory Protein 1, Heavy Chain / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D057809:HEK293 Cells / Q000378:metabolism*; D006801:Humans; D027283:Large Neutral Amino Acid-Transporter 1 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D055503:Protein Multimerization
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000596:Amino Acids; D027282:Fusion Regulatory Protein 1, Heavy Chain; C419196:LAT2 protein, human; D027283:Large Neutral Amino Acid-Transporter 1; C545989:SLC3A2 protein, human