Fig. 6.

The effects of PMA and mGluR1α receptor to R20 substitutions. (a) Example traces of R20C and R20A mutants in response to PMA (100 nM) or mGluR1α receptor stimulation (100 μM glutamate) are shown. Peak amplitudes from control and PMA treated oocytes are shown. In the lower panels ATP evoked currents before and after mGluR1α receptor activation from either R20C (left) or R20A (right) are shown. (b) Summary of effects of amino acid substitution at position R20 at the P2X₁ receptor by cysteine, alanine or isoleucine on potentiation by PMA or glutamate. ***p< 0.001.