Pannexin 1 forms an anion-selective channel

Pannexin 1 (Panx1) is expressed in various mammalian tissues including the brain and immune cells. Here, we present evidence that Panx1 when expressed in mammalian cells, forms anion-selective channels, with a rank order of permeabilities: NO (3) (-) > I- > Br- > Cl- > F- a parts per thousand << aEuro parts per thousand aspartate(-) a parts per thousand aEuro parts per thousand glutamate(-) a parts per thousand aEuro parts per thousand gluconate(-). Single-channel Panx1-mediated currents have a unitary conductance around 68 pS. Our results show that Panx1 assembles into a membrane anion channel with a relatively low single-channel conductance.