高等動物アミノ酸膜輸送研究の新展開

概要

論文の詳細を見る
Movement of amino acids into and out of animal cells is mediated by various types of transport system. More than 15 transport systems are well characterized, and they can be classified by two criteria. First, they may accept mainly zwitterionic, cationic or anionic amino acids as substrate and second, they can be either Na+ dependent or independent. Each transport system seems to be composed of system-specific carrier protein (s). Recently, the molecular cloning of two carrier proteins have been reported. One carrier is specific for γ-aminobutyric acid (GABA), a neurotransmitter present in central nervous system. In this case, the carrier protein was first highly purified and the amino acid sequence of N-terminal region was utilized in cloning. The other one is specific for basic amino acid such as L-arginine, L-lysine, and L-ornithine. This carrier protein was first cloned as the receptor for ecotropic murine leukaemia viruses, and later it was identified as the System y+ carrier. In other studies, carrier proteins for Systems XAG- and A are highly purified, and some carriers are expressed in Xenopus oocytes after injection of mRNAs from mammalian cells or tissues. These results can serve as means to obtain cDNA clones corresponding to carrier genes.
日本膜学会の論文