Cloning of the sodium-dependent, broad-scope, neutral amino acid transporter Bo from a human placental choriocarcinoma cell line.
We have isolated a cDNA from a human placental choriocarcinoma cell cDNA library which, when expressed in HeLa cells, induces a Na+-dependent amino acid transport system with preference for zwitterionic amino acids. Anionic amino acids, cationic amino acids, imino acids, and N-methylated amino acids are excluded by this system. These characteristics are identical to those described for the amino acid transporter Bo. When expressed in Xenopus laevis oocytes that do not have detectable endogenous activity of the amino acid transporter Bo, the cloned transporter increases alanine transport in the oocytes severalfold and induces alanine-evoked inward currents in the presence of Na+. The cDNA codes for a polypeptide containing 541 amino acids with 10 putative transmembrane domains. Amino acid sequence homology predicts this transporter (hATBo) to be a member of a superfamily consisting of the glutamate transporters, the neutral amino acid transport system ASCT, and the insulin-activable neutral/anionic amino acid transporter. Chromosomal assignment studies with somatic cell hybrid analysis and fluorescent in situ hybridization have located the ATBo gene to human chromosome 19q13.3.
Kekuda
R
R
Department of Biochemistry and Molecular Biology, Medical College of Georgia, Augusta, Georgia 30912, USA.
Prasad
P D
PD
Fei
Y J
YJ
Torres-Zamorano
V
V
Sinha
S
S
Yang-Feng
T L
TL
Leibach
F H
FH
Ganapathy
V
V
D000409:Alanine / Q000378:metabolism; D000595:Amino Acid Sequence; D026962:Amino Acid Transport System ASC; D026905:Amino Acid Transport Systems; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism*; D002822:Choriocarcinoma / Q000235:genetics / Q000378:metabolism; D002874:Chromosome Mapping; D002888:Chromosomes, Human, Pair 19 / Q000235:genetics; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D006801:Humans; D015778:Minor Histocompatibility Antigens; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011991:Receptors, Virus / Q000235:genetics* / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis
D026962:Amino Acid Transport System ASC; D026905:Amino Acid Transport Systems; D002352:Carrier Proteins; D018076:DNA, Complementary; D015778:Minor Histocompatibility Antigens; D012333:RNA, Messenger; D011991:Receptors, Virus; C420506:SLC1A5 protein, human; D012964:Sodium; D000409:Alanine