Table 1.

Substrate transport and electrophysiological properties of WT and mutant EAAT1 transporters

	3H-L-glutamate uptake (fmol/ oocyte/min)	K0.5 (μM)		Erev (mV)				I at +60 mV (nA)
		L-glutamate	L-aspartate	L-glutamate		L-aspartate		L-glutamate	L-aspartate
				Cl−	NO3−	Cl−	NO3−
EAAT1	113 ± 7	31 ± 2	18 ± 3	24 ± 1	−30 ± 4	7 ± 1	−50 ± 1	640 ± 80	1100 ± 100
S366A	112 ± 2	32 ±4	34 ± 5	18 ± 2	−31 ± 1	7 ± 2	−39 ± 1c	1100 ± 80b	1500 ± 10
S366V	77 ± 3	16 ± 2	14 ± 2	14 ± 1	−44 ± 2a	11 ± 1	−49 ± 2	480 ± 50	690 ± 70
L369A	21 ± 1	ND	ND	ND	ND	ND	ND	ND	ND
L369V	84 ± 4	25 ± 2	10 ± 2	50 ± 7c	−18 ± 3a	33 ± 5c	−36 ± 1c	700 ± 100	1000 ± 100
F373V	82 ± 2	15 ± 2	13 ± 2	−1 ± 3c	−35 ± 2	−8 ± 1c	−39 ± 1c	1550 ± 90c	1700 ± 100
R388A	89 ± 1	25 ± 3	8 ± 2	16 ± 2	−51 ± 1c	10 ± 1	−51 ± 1	2400 ± 200c	2700 ± 300c
R388L	82 ± 2	12 ± 1	14 ± 2	22 ± 3	−50 ± 3b	19 ± 3	−50 ± 1	1600 ± 300c	2000 ± 300a
P392A	78 ± 7	8 ± 1	4.7 ± 0.6	59 ± 4c	−46 ± 3c	11 ± 2	−66 ± 2c	600 ± 50	1340 ± 70
P392V	85 ± 3	23 ± 3	20 ± 3	0 ± 3c	−56 ± 3c	−13 ± 2c	−60 ± 2c	4100 ± 300c	6700 ± 500c
T396A	90 ± 2	27 ± 2	9 ± 2	64 ± 2c	−8 ± 2c	58 ± 3c	−14 ± 1c	39 ± 3a	67 ± 11c
T396V	73 ± 4	40 ± 2	14.7 ± 0.4	44 ± 3b	−18 ± 2a	37 ± 4c	−38 ± 1c	190 ± 14a	300 ± 20b

³H-L-glutamate uptake was performed for 10 min with oocytes expressing WT and mutant EAAT1 transporters. Background (uninjected oocytes) ³H-L-glutamate uptake of 0.8 fmol/oocyte/min was subtracted from the data presented. Apparent substrate affinity (K_0.5) values were determined from concentration responses conducted at −60 mV. Reversal potentials (E_rev) were obtained from 30 μM substrate-elicited currents in 96 mM Cl⁻- or NO₃⁻-based buffers. Raw current (I) at +60 mV in NO₃⁻-containing buffer are shown for comparison. ND indicates that no electrophysiological data could be obtained.

^aData shown represents the mean ± SE (n ≥ 3) with p < 0.05 compared to WT EAAT1.

^bData shown represents the mean ± SE (n ≥ 3) with p < 0.01 compared to WT EAAT1.

^cData shown represents the mean ± SE (n ≥ 3) with p < 0.001 compared to WT EAAT1.