Substrate transport and cocaine binding of human dopamine transporter is reduced by substitution of carboxyl tail with that of bovine dopamine transporter.
A chimeric dopamine transporter (DAT) cDNA encoding mutant human DAT (hDAT) protein in which the intracellular carboxyl-terminal tail is replaced by that of the bovine dopamine transporter (bDAT) was constructed. The chimeric hDAT cDNA was expressed in COS-7 cells, and [3H]dopamine and [3H]MPP+ uptake and [3H]CFT binding capacities were assessed. Substrate transport and ligand binding of bDAT were reduced by 32-43% as a result of substitution of the carboxyl tail in hDAT, suggesting that the functional characteristics of bDAT arise from differences in the carboxyl tail between human and bovine DAT. Thus, it appears that the sequences encoded within the carboxyl terminal of DAT would be one of the important determinants for its functions.
Lee
S H
SH
Department of Biochemistry, College of Medicine, Hanyang University, Seoul, Korea.
Cho
H K
HK
Son
H
H
Lee
Y S
YS
D015655:1-Methyl-4-phenylpyridinium / Q000493:pharmacokinetics; D000818:Animals; D001665:Binding Sites; D001692:Biological Transport; D019556:COS Cells; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D003042:Cocaine / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D050483:Dopamine Plasma Membrane Transport Proteins; D006801:Humans; D007700:Kinetics; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D016296:Mutagenesis; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D014162:Transfection
D002352:Carrier Proteins; D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; C493214:SLC6A3 protein, human; D003042:Cocaine; D015655:1-Methyl-4-phenylpyridinium; D004298:Dopamine