TABLE 1

Comparison of uptake rates of TEA and MPP by rOCT1 mutants in which one of the amino acids between positions 212 and 229 was exchanged

rOCT1 wild type and the indicated mutants of rOCT1 were expressed in oocytes. The uptake of 10 μM [14C]TEA or 0.1 μM [3H]MPP over 30 min was corrected for nonspecific uptake by noninjected oocytes and expressed as percentage of the uptake by rOCT1 wild type, which was measured in parallel. Mean ± S.E.M. values from three to six experiments are presented.

Mutants Uptake
TEA MPP
%
M212L 97 ± 10 98 ± 7
V213G 28 ± 9* 51 ± 12
S214G 42 ± 1*** 44 ± 12*
×K215Q 0 ± 0.1*** 0.1 ± 0.1***
×K215R 0.2 ± 0.1*** 1.6 ± 0.5***
G216A 8.7 ± 1.9*** 24 ± 2***
S217G 118 ± 28 128 ± 21
W218F 28 ± 5** 133 ± 43
V219L 69 ± 9 90 ± 20
S220I 26 ± 4** 53 ± 3*
G221A 42 ± 9* 57 ± 9*
Y222F 78 ± 9 122 ± 30
T223I 64 ± 5* 75 ± 24
L224V 17 ± 6** 34 ± 10*
I225G 83 ± 9 92 ± 7
T226A 76 ± 4* 90 ± 3
×E227Q 0.1 ± 0.1*** 0.1 ± 0.2***
×E227D 0 ± 0.1*** 0 ± 0.1***
F228I 89 ± 10 88 ± 12
V229A 32 ± 13* 54 ± 8*
×V229L 0.2 ± 0.1*** 0.1 ± 0.1***
  • ×, inactive mutant.

  • * P < 0.05; ** P < 0.01; *** P < 0.001, statistical significance of differences between wild-type vs. mutants.

  • P < 0.05, statistical significance of difference between TEA vs. MPP in individual mutants.