The effect of anions on the human P2X7 receptor

► Extracellular organic/inorganic anions increase/decrease P2X7 receptor activation. ► Extracellular anions modify gating of P2X7 receptors via an allosteric binding site. ► Anions change open probability of P2X7R channels by affecting their shut times. ► Anions do not change P2X7R pore properties. ►The P2X7R is not anion permeable.