title: Diverse subcellular distribution profiles of pannexin 1 and pannexin 3.
abstract: Pannexins have been proposed to play a role in gap junctional intercellular communication and as single-membrane channels, although many of their molecular characteristics differ from connexins. Localization of untagged Panx1 and Panx3 exogenously expressed in five cultured cell lines revealed a cell surface distribution profile with limited evidence of cell surface clustering and variable levels of intracellular pools. However, N-glycosylation-defective mutants of pannexins exhibited a more prominent intracellular distribution with decreased cell surface labeling, suggesting an important role for pannexin glycosylation in trafficking. Similar to wild-type pannexins, the glycosylation-defective mutants failed to noticeably transfer microinjected fluorescent dyes to neighboring cells, suggesting that few, or no functional intercellular channels were formed. Finally, varied distribution patterns of endogenous Panx1 and Panx3 were observed in cells of osteoblast origin and Madin-Darby canine kidney cells. Collectively, diverse expression and distribution profiles of Panx1 and Panx3 suggest that they may have multiple cellular functions.
authors.affiliation: Department of Anatomy and Cell Biology, University of Western Ontario, London, Ontario, Canada.
authors.forename: Silvia
authors.initials: S
authors.lastname: Penuela
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Celetti
authors.forename: Ruchi
authors.initials: R
authors.lastname: Bhalla
authors.forename: Qing
authors.initials: Q
authors.lastname: Shao
authors.forename: Dale W
authors.initials: DW
authors.lastname: Laird
mesh_terms: D016475:3T3 Cells; D019943:Amino Acid Substitution; D000818:Animals; D002450:Cell Communication / Q000502:physiology; D017630:Connexins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D004285:Dogs; D017629:Gap Junctions / Q000378:metabolism; D006031:Glycosylation; D006367:HeLa Cells; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism*; D051379:Mice; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D051381:Rats
chemical_list: D017630:Connexins; D009419:Nerve Tissue Proteins; C503631:Panx1 protein, mouse; C528477:pannexin 3 protein, mouse