Pore positioning

Boyce, Andrew K. J.; Prager, Ross; Wicki-Stordeur, Leigh E.; Swayne, Leigh Anne

doi:10.4161/chan.27287

Cited by 11 publications

(3 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While our study identifies Panx2 as a novel component of the mammalian ER-mitochondria MCSs, other groups have suggested that ectopic Panx2 localizes within endolysosomal compartments [34,37,52]. However, the glycosylation pattern of Panx2 is inconsistent with its trafficking to endosomal compartments.…”

Section: Discussioncontrasting

confidence: 62%

Pannexin 2 Localizes at ER-Mitochondria Contact Sites

Vasseur

Chen

Huang

et al. 2019

Cancers

View full text Add to dashboard Cite

Endomembrane specialization allows functional compartmentalization but imposes physical constraints to information flow within the cell. However, the evolution of an endomembrane system was associated with the emergence of contact sites facilitating communication between membrane-bound organelles. Contact sites between the endoplasmic reticulum (ER) and mitochondria are highly conserved in terms of their morphological features but show surprising molecular diversity within and across eukaryote species. ER-mitochondria contact sites are thought to regulate key processes in oncogenesis but their molecular composition remains poorly characterized in mammalian cells. In this study, we investigate the localization of pannexin 2 (Panx2), a membrane channel protein showing tumor-suppressing properties in cancer cells. Using a combination of subcellular fractionation, particle tracking in live-cell, and immunogold electron microscopy, we show that Panx2 localizes at ER-mitochondria contact sites in mammalian cells and sensitizes cells to apoptotic stimuli.

show abstract

Section: Discussioncontrasting

confidence: 62%

Pannexin 2 Localizes at ER-Mitochondria Contact Sites

Vasseur

Chen

Huang

et al. 2019

Cancers

View full text Add to dashboard Cite

show abstract

“…As reviewed by Boyce et al [ 42 ], pannexins contain putative recognition sequences for endocytic and endo-lysosomal targeting which could account for the control of pannexin trafficking. Interestingly, recently published work by Boassa et al, described the localization of a recombinant Panx2 fused to mini-SOG tag that was transiently expressed in HeLa cells [ 26 ].…”

Section: Discussionmentioning

confidence: 99%

N-Glycosylation Regulates Pannexin 2 Localization but Is Not Required for Interacting with Pannexin 1

Sanchez-Pupo

Johnston

Peñuela

2018

IJMS

View full text Add to dashboard Cite

Pannexins (Panx1, 2, 3) are channel-forming glycoproteins expressed in mammalian tissues. We previously reported that N-glycosylation acts as a regulator of the localization and intermixing of Panx1 and Panx3, but its effects on Panx2 are currently unknown. Panx1 and Panx2 intermixing can regulate channel properties, and both pannexins have been implicated in neuronal cell death after ischemia. Our objectives were to validate the predicted N-glycosylation site of Panx2 and to study the effects of Panx2 glycosylation on localization and its capacity to interact with Panx1. We used site-directed mutagenesis, enzymatic de-glycosylation, cell-surface biotinylation, co-immunoprecipitation, and confocal microscopy. Our results showed that N86 is the only N-glycosylation site of Panx2. Panx2 and the N86Q mutant are predominantly localized to the endoplasmic reticulum (ER) and cis-Golgi matrix with limited cell surface localization was seen only in the presence of Panx1. The Panx2 N86Q mutant is glycosylation-deficient and tends to aggregate in the ER reducing its cell surface trafficking but it can still interact with Panx1. Our study indicates that N-glycosylation may be important for folding and trafficking of Panx2. We found that the un-glycosylated forms of Panx1 and 2 can readily interact, regulating their localization and potentially their channel function in cells where they are co-expressed.

show abstract

“…We found strong staining in vesicle associated compartments, consistent with endolysosome distributions previously identified by Wicki-Stordeur et al ( 2013 ). Sites for both endocytotic recognition and endolysosomal targeting sequences have also been identified in the Panx2 sequence using consensus sequence analysis programs (Boyce et al, 2014 ). Two endolysomal targeting sequences were identified in the intracellular loop (residue 153–158) and a distal part of the C-terminus (amino acids 647–652) while an area of the C-terminus sequence contained an endocytotic recognition sequence at amino acids 376–379.…”

Section: Discussionmentioning

confidence: 99%

Pannexin2 oligomers localize in the membranes of endosomal vesicles in mammalian cells while Pannexin1 channels traffic to the plasma membrane

Boassa

Nguyen

et al. 2015

Front. Cell. Neurosci.

View full text Add to dashboard Cite

Pannexin2 (Panx2) is the largest of three members of the pannexin proteins. Pannexins are topologically related to connexins and innexins, but serve different functional roles than forming gap junctions. We previously showed that pannexins form oligomeric channels but unlike connexins and innexins, they form only single membrane channels. High levels of Panx2 mRNA and protein in the Central Nervous System (CNS) have been documented. Whereas Pannexin1 (Panx1) is fairly ubiquitous and Pannexin3 (Panx3) is found in skin and connective tissue, both are fully glycosylated, traffic to the plasma membrane and have functions correlated with extracellular ATP release. Here, we describe trafficking and subcellular localizations of exogenous Panx2 and Panx1 protein expression in MDCK, HeLa, and HEK 293T cells as well as endogenous Panx1 and Panx2 patterns in the CNS. Panx2 was found in intracellular localizations, was partially N-glycosylated, and localizations were non-overlapping with Panx1. Confocal images of hippocampal sections immunolabeled for the astrocytic protein GFAP, Panx1 and Panx2 demonstrated that the two isoforms, Panx1 and Panx2, localized at different subcellular compartments in both astrocytes and neurons. Using recombinant fusions of Panx2 with appended genetic tags developed for correlated light and electron microscopy and then expressed in different cell lines, we determined that Panx2 is localized in the membrane of intracellular vesicles and not in the endoplasmic reticulum as initially indicated by calnexin colocalization experiments. Dual immunofluorescence imaging with protein markers for specific vesicle compartments showed that Panx2 vesicles are early endosomal in origin. In electron tomographic volumes, cross-sections of these vesicles displayed fine structural details and close proximity to actin filaments. Thus, pannexins expressed at different subcellular compartments likely exert distinct functional roles, particularly in the nervous system.

show abstract

Pore positioning

Cited by 11 publications

References 53 publications

Pannexin 2 Localizes at ER-Mitochondria Contact Sites

Pannexin 2 Localizes at ER-Mitochondria Contact Sites

N-Glycosylation Regulates Pannexin 2 Localization but Is Not Required for Interacting with Pannexin 1

Pannexin2 oligomers localize in the membranes of endosomal vesicles in mammalian cells while Pannexin1 channels traffic to the plasma membrane

Contact Info

Product

Resources

About