Molecular cloning of the mouse IMINO system: an Na+- and Cl--dependent proline transporter.
Neurotransmitter transporters of the SLC6 family play an important role in the removal of neurotransmitters in brain tissue and in amino acid transport in epithelial cells. Here we demonstrate that the mouse homologue of slc6a20 has all properties of the long-sought IMINO system. The mouse has two homologues corresponding to the single human SLC6A20 gene: these have been named XT3 and XT3s1. Expression of mouse XT3s1, but not XT3, in Xenopus laevis oocytes induced an electrogenic Na+-and-Cl--dependent transporter for proline, hydroxyproline, betaine, N-methylaminoisobutyric acid and pipecolic acid. Expression of XT3s1 was found in brain, kidney, small intestine, thymus, spleen and lung, whereas XT3 prevailed in kidney and lung. Accordingly we suggest that the two homologues be termed 'XT3s1 IMINO(B)' and 'XT3 IMINO(K)' to indicate the tissue expression of the two genes.
Kowalczuk
Sonja
S
Division of Biochemistry and Molecular Biology, Faculty of Science, Australian National University, Canberra, ACT 0200, Australia.
Bröer
Angelika
A
Munzinger
Michael
M
Tietze
Nadine
N
Klingel
Karin
K
Bröer
Stefan
S
D026921:Amino Acid Transport Systems, Neutral / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002712:Chlorides / Q000494:pharmacology*; D003001:Cloning, Molecular; D020869:Gene Expression Profiling; D006801:Humans; D051379:Mice; D009865:Oocytes / Q000378:metabolism; D011392:Proline / Q000378:metabolism; D012964:Sodium / Q000494:pharmacology*; D013379:Substrate Specificity; D014982:Xenopus laevis
D026921:Amino Acid Transport Systems, Neutral; D002712:Chlorides; C502967:XT3 protein, mouse; C033082:proline transporter; D011392:Proline; D012964:Sodium