Ion pathways in the human pannexin 1 channel

Pannexin 1 is a large pore anion channel located on the plasma membrane. It transports not only small halides but also large molecules such as ATP. Pannexin 1 has an important role in apoptosis signaling and several mutations in the gene cause infertility in human females. Pannexin 1 can activate with a variety of stimuli. Activation by membrane depolarization typically evokes very small chloride currents in the absence of any ATP release. ATP can be released when pannexin 1 is activated by caspase cleavage of its C-terminal tail.