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The Pannexin1 membrane channel: distinct conformations and functions
Author(s) -
Dahl Gerhard
Publication year - 2018
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1002/1873-3468.13115
Subject(s) - pannexin , biophysics , purinergic receptor , chemistry , ion channel , membrane potential , microbiology and biotechnology , cleavage (geology) , membrane , chloride channel , biochemistry , biology , extracellular , intracellular , paleontology , receptor , connexin , fracture (geology) , gap junction
The Pannexin1 (Panx1) membrane channel responds to different stimuli with distinct channel conformations. Most stimuli induce a large cation‐ and ATP ‐permeable conformation, hence Panx1 is involved in many physiological processes entailing purinergic signaling. For example, oxygen delivery in the peripheral circulatory system is regulated by ATP released from red blood cells and endothelial cells through Panx1 channels. The same membrane channel, however, when stimulated by positive membrane potential or by cleavage with caspase 3, is highly selective for the passage of chloride ions, excluding cations and ATP . Although biophysical data do not allow a distinction between the chloride‐selective channels induced by voltage or by caspase cleavage, there must be other subtle differences in the structure, because overexpression of wtPanx1 is well tolerated by cells, while expression of the truncation mutant Panx1Δ378 results in slow cell death. Thus, in addition to the well‐characterized two open conformations, there might be a third, more subtle conformational change involved in cell death.