Table 1.

Voltage dependence of activity.

VSP	TAPP FV fits			PLC FV fits
	n	V1/2 up	V1/2 down	n	V1/2 down	V1/2 up
WT*	24	9 ± 5	44 ± 3	16	37 ± 4	70 ± 5
Y522A*	8	18 ± 6	51 ± 4	7	47 ± 4	87 ± 6*
Y522F*	8	27 ± 5*	58 ± 4**	6	58 ± 5*	94 ± 6**
CS*	18	60 ± 1	n/a	16	n/a@	n/a
ΔC2*	9	64 ± 5#	n/a	9	n/a@	n/a
QuadK*	6	50 ± 9*	99 ± 5***	7	68 ± 4***	115 ± 5***
K553Q*	6	32 ± 2***	53 ± 2*	6	49 ± 7	79 ± 7
K554Q*	6	14 ± 6	52 ± 8	7	37 ± 4	63 ± 3
K555Q*	6	38 ± 9*	72 ± 8*	6	58 ± 12	89 ± 13
K558Q*	6	15 ± 3	39 ± 3	6	40 ± 6	77 ± 5

Average V_1/2 from double Boltzmann fits to each cell (n) for the TAPP FVs and single Boltzmann fits for the PLC FVs. Student t-tests,

^*p ≤ 0.05;

^**p ≤ 0.01;

^***p ≤ 0.001 (compared to WT^*).

^#Not significant (compared to CS^*); n/a, no data to fit; n/a

^@, amplitude too small to fit.