FIGURE 5.

Regions of the intracellular amino and carboxyl termini involved in regulating time-course. a, shown is a schematic representation of chimeras and representative currents (to 100 μm ATP) of P2X1-2N, P2X1-2Nβ, and P2X1-2 mutations. Mutations are based on the non-conserved amino acid residues within the Nβ region between P2X1 and P2X2 (shown in gray in the amino acid lineup, P2X1 receptor numbering). b, a histogram summary shows the time to 50% decay during continued ATP application. c, shown is a schematic representation and representative currents (to 100 μm ATP) of the reciprocal set of chimeras and P2X2-1 mutations. d, a histogram summary shows the percentage of current remaining at the end of a 20-s 100 μm ATP application. e, a schematic representation and representative currents (to 100 μm ATP) of P2X1-2Cα and P2X1-2 mutations of non-conserved amino acids within this region (non-conserved amino acids between P2X1 and P2X2 are shown in gray on the sequence lineup). f, a histogram summary shows the time to 50% decay during continued ATP application. *, p < 0.05; **, p < 0.01; ***, p < 0.001 (n = 5–17).