TY - JOUR
T1 - Tyrosine-533 of rat dopamine transporter
T2 - Involvement in interactions with 1-methyl-4-phenylpyridinium and cocaine
AU - Mitsuhata, Chieko
AU - Kitayama, Shigeo
AU - Morita, Katsuya
AU - Vandenbergh, David
AU - Uhl, George R.
AU - Dohi, Toshihiro
N1 - Funding Information:
This work was supported in part by the Grant-in-Aid for Scientific Research on Priority Areas, Ministry of Education, Science and Culture, Japan (#08256229) and the Naito Foundation (SK) and by the NIDA IRP, NIH (GRU).
PY - 1998/5
Y1 - 1998/5
N2 - To improve our understanding of structure-function relationships for neurotransmitter transporters, we performed site-directed mutagenesis of the rat dopamine transporter (DAT) and assessed the functions of the mutants in transiently-expressing COS cells. Tyrosine-533 of rat DAT lies in the 11th transmembrane region, where the corresponding amino acid of human DAT is phenylalanine. Alanine substitution of tyrosine-533 (Y533A) conferred an increased affinity for 1-methyl-4-phenylpyridinium (MPP+). Phenylalanine substitution of tyrosine-533 (Y533F) increased the velocity of MPP+ uptake but decreased DAT's affinity for MPP+. Cocaine's potency in inhibiting dopamine uptake was unchanged with Y533A, but increased with Y533F. Differences in the uptake kinetics and inhibitory potency of cocaine between rat and human DATs were similar to the differences observed between the wild-type and Y533F mutants DATs. Tyrosine-533 may be important for the DAT function and for species differences in transporter functions, including differential sensitivities to cocaine and 1-methyl-1,2,3,6-tetrahydropyridine (MPTP) in humans and rats.
AB - To improve our understanding of structure-function relationships for neurotransmitter transporters, we performed site-directed mutagenesis of the rat dopamine transporter (DAT) and assessed the functions of the mutants in transiently-expressing COS cells. Tyrosine-533 of rat DAT lies in the 11th transmembrane region, where the corresponding amino acid of human DAT is phenylalanine. Alanine substitution of tyrosine-533 (Y533A) conferred an increased affinity for 1-methyl-4-phenylpyridinium (MPP+). Phenylalanine substitution of tyrosine-533 (Y533F) increased the velocity of MPP+ uptake but decreased DAT's affinity for MPP+. Cocaine's potency in inhibiting dopamine uptake was unchanged with Y533A, but increased with Y533F. Differences in the uptake kinetics and inhibitory potency of cocaine between rat and human DATs were similar to the differences observed between the wild-type and Y533F mutants DATs. Tyrosine-533 may be important for the DAT function and for species differences in transporter functions, including differential sensitivities to cocaine and 1-methyl-1,2,3,6-tetrahydropyridine (MPTP) in humans and rats.
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U2 - 10.1016/S0169-328X(98)00032-1
DO - 10.1016/S0169-328X(98)00032-1
M3 - Article
C2 - 9602072
AN - SCOPUS:0032078412
SN - 0169-328X
VL - 56
SP - 84
EP - 88
JO - Molecular Brain Research
JF - Molecular Brain Research
IS - 1-2
ER -