Function
Pannexin (PNX) is a family of single membrane channel-forming glycoprotein. The family is comprised of 3 members. PNX1 is expressed in mammalian tissue and plays a role in releasing signals for apoptotic cell clearance. In addition, PNX1 plays a role in propagation of calcium waves, regulation of vascular tone, mucociliary lung clearance, taste-bud function[1]. PNX1 mediates release of ATP which acts as a signal recruiting macrophages to apoptotic cells. PNX1 activation requires cleavage of its C-terminal tail by caspase[2].
Relevance
PNX1 acts like a tumor suppressor in glioma and is involved in melanoma, epilepsy, glaucoma, hypertension. Alzheimer, diabetes and other diseases[3].
Structural highlights
The 3D structure of human PNX1 shows the pore to constitute 7 subunits. The C-terminal of PNX1 is cleaved by caspase to produce an active PNX1. The pore transmembrane domains are occupied by lipid molecules which interact predominantly with hydrophobic residues[4].
3D structures of pannexin
Updated on 21-August-2023
6ltn, 6lto, 6m02, 6m66, 6v6d, 7dwb, 7f8j, 7f8n, 7f8o – hPNX1 residues 1-426 – human - Cryo EM
6m67, 6m68 – hPNX1 (mutant) residues 1-426 – Cryo EM
7wsv – hPNX1 residues 21-426 – Cryo EM
6wbf, 6wbg, 6wbk – hPNX1 residues 1-373 – Cryo EM
6wbi, 6wbl, 6wbm, 6wbn – hPNX1 (mutant) residues 1-373 – Cryo EM
7xlb, 8f7c – hPNX2 - Cryo EM
7xl6 – hPNX3 - Cryo EM
8a3b – mPNX1 – mouse - Cryo EM
6uzy, 6vd7 – PNX1 – western clawed frog – Cryo EM
- ↑ Penuela S, Gehi R, Laird DW. The biochemistry and function of pannexin channels. Biochim Biophys Acta. 2013 Jan;1828(1):15-22. doi: 10.1016/j.bbamem.2012.01.017. , Epub 2012 Jan 28. PMID:22305965 doi:https://dx.doi.org/10.1016/j.bbamem.2012.01.017
- ↑ Sandilos JK, Chiu YH, Chekeni FB, Armstrong AJ, Walk SF, Ravichandran KS, Bayliss DA. Pannexin 1, an ATP release channel, is activated by caspase cleavage of its pore-associated C-terminal autoinhibitory region. J Biol Chem. 2012 Mar 30;287(14):11303-11. doi: 10.1074/jbc.M111.323378. Epub, 2012 Feb 6. PMID:22311983 doi:https://dx.doi.org/10.1074/jbc.M111.323378
- ↑ Penuela S, Harland L, Simek J, Laird DW. Pannexin channels and their links to human disease. Biochem J. 2014 Aug 1;461(3):371-81. doi: 10.1042/BJ20140447. PMID:25008946 doi:https://dx.doi.org/10.1042/BJ20140447
- ↑ Kuzuya M, Hirano H, Hayashida K, Watanabe M, Kobayashi K, Terada T, Mahmood MI, Tama F, Tani K, Fujiyoshi Y, Oshima A. Structures of human pannexin-1 in nanodiscs reveal gating mediated by dynamic movement of the N terminus and phospholipids. Sci Signal. 2022 Feb 8;15(720):eabg6941. doi: 10.1126/scisignal.abg6941. Epub, 2022 Feb 8. PMID:35133866 doi:https://dx.doi.org/10.1126/scisignal.abg6941