Cloning and expression of a cDNA encoding the transporter of taurine and beta-alanine in mouse brain.
A taurine/beta-alanine transporter was cloned from a mouse brain cDNA library by screening with a partial cDNA probe of the glycine transporter at low stringency. The deduced amino acid sequence predicts 590 amino acids with typical characteristics of the sodium-dependent neurotransmitter transporters such as sequence homology and membrane topography. However, the calculated isoelectric point of the taurine/beta-alanine transporter is more acidic (pI = 5.98) than those (pI > 8.0) of other cloned neurotransmitter transporters. Xenopus oocytes injected with cRNA of the cloned transporter expressed uptake activities with Km = 4.5 microM for taurine and Km = 56 microM for beta-alanine. Northern hybridization showed a single transcript of 7.5 kilobases that was highly enriched in kidney and distributed evenly in various parts of the brain. In situ hybridization showed the mRNA of the taurine/beta-alanine transporter to be localized in the corpus callosum, striatum, and anterior commisure. Specific localization of the taurine/beta-alanine transporter in mouse brain suggests a potential function for taurine and beta-alanine as neurotransmitters.
Liu
Q R
QR
Roche Institute of Molecular Biology, Roche Research Center, Nutley, NJ 07110.
López-Corcuera
B
B
Nelson
H
H
Mandiyan
S
S
Nelson
N
N
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001692:Biological Transport; D001921:Brain / Q000378:metabolism; D002352:Carrier Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D015870:Gene Expression; D017403:In Situ Hybridization; D008562:Membrane Glycoproteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D026901:Membrane Transport Proteins; D051379:Mice; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D012964:Sodium / Q000502:physiology; D013654:Taurine / Q000378:metabolism*; D014982:Xenopus laevis; D015091:beta-Alanine / Q000378:metabolism*; D000099247:Taurine Transporters
D002352:Carrier Proteins; D004247:DNA; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D012333:RNA, Messenger; D012964:Sodium; D013654:Taurine; D015091:beta-Alanine; D000099247:Taurine Transporters