Table 3.

Gα_q-Dependent Activation of PLCβ3 Variants

variant complex	specific activity [nmol of IP1 min−1 (nmol of complex)−1]a	x-fold maximum activity over basald
Gαq–PLCβ3	0.89 ± 0.15	8
Gαq–PLCβ3 ΔXY1	5.2 ± 1.0b	4
Gαq–PLCβ3 ΔXY2	1.8 ± 0.40b	2
Gαq–PLCβ3-Δ892	0.24 ± 0.06	22
Gαq–PLCβ3-Δ892 ΔXY1	1.1 ± 0.20c	2
Gαq–PLCβ3-Δ892 ΔXY2	2.1 ± 0.40c	3

^aData represent the average of four experiments in duplicate ± SEM.

^bSignificant relative to the Gα_q–PLCβ3 complex (*p ≤ 0.05).

^cSignificant relative to the Gα_q–PLCβ3-Δ892 complex (*p ≤ 0.05).

^dThe x-fold activation was calculated by dividing the basal activity of the Gα_q–PLCβ3 ΔXY complex by the basal activity of the PLCβ3 variant (Table 2).