scholarly journals A permeant regulating its permeation pore: inhibition of pannexin 1 channels by ATP

2009 ◽  
Vol 296 (2) ◽  
pp. C250-C255 ◽  
Author(s):  
Feng Qiu ◽  
Gerhard Dahl
Keyword(s):  
Mutational Analysis ◽  
Rank Order ◽  
Atp Release ◽  
Binding Affinities ◽  
Channel Activity ◽  
Release Channel ◽  
Pannexin 1 ◽  
Atp Inhibition ◽  
Atp Analogues ◽  
Receptor Agonists And Antagonists

Pannexin 1 forms a large membrane channel that, based on its biophysical properties and its expression pattern, is a prime candidate to represent an ATP release channel. Pannexin 1 channel activity is potentially deleterious for cells as indicated by its involvement in the P2X7 death complex. Here we describe a negative feedback loop controlling pannexin 1 channel activity. ATP, permeant to pannexin 1 channels, was found to inhibit its permeation pathway when applied extracellularly to oocytes expressing pannexin 1 exogenously. ATP analogues, including benzoylbenzoyl-ATP, suramin, and brilliant blue G were even more effective inhibitors of pannexin 1 currents than ATP. These compounds also attenuated the uptake of dyes by erythrocytes, which express pannexin 1. The rank order of the compounds in attenuation of pannexin 1 currents was similar to their binding affinities to the P2X7 receptor, except that receptor agonists and antagonists both were inhibitory to the channel. Mutational analysis identified R75 in pannexin 1 to be critical for ATP inhibition of pannexin 1 currents.

scholarly journals Pannexin-1 Deficient Mice Have an Increased Susceptibility for Atrial Fibrillation and Show a QT-Prolongation Phenotype

2016 ◽  
Vol 38 (2) ◽  
pp. 487-501 ◽  
Author(s):  
Stella Petric ◽  
Sofia Klein ◽  
Lisa Dannenberg ◽  
Tillman Lahres ◽  
Lukas Clasen ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cardiac Electrophysiology ◽  
Electrophysiological Study ◽  
Atp Release ◽  
Release Channel ◽  
Knock Out ◽  
Pannexin 1 ◽  
Significant Prolongation ◽  
Knock Out Mice

Background/Aims: Pannexin-1 (Panx1) is an ATP release channel that is ubiquitously expressed and coupled to several ligand-gated receptors. In isolated cardiac myocytes, Panx1 forms large conductance channels that can be activated by Ca2+ release from the sarcoplasmic reticulum. Here we characterized the electrophysiological function of these channels in the heart in vivo, taking recourse to mice with Panx1 ablation. Methods: Cardiac phenotyping of Panx1 knock-out mice (Panx1-/-) was performed by employing a molecular, cellular and functional approach, including echocardiography, surface and telemetric ECG recordings with QT analysis, physical stress testing and quantification of heart rate variability. In addition, an in vivo electrophysiological study entailed programmed electrical stimulation using an intracardiac octapolar catheter. Results: Panx1 deficiency results in a higher incidence of AV-block, delayed ventricular depolarisation, significant prolongation of QT- and rate corrected QT-interval and a higher incidence of atrial fibrillation after intraatrial burst stimulation. Conclusion: Panx1 seems to play an important role in murine cardiac electrophysiology and warrants further consideration in the context of hereditary forms of atrial fibrillation.

scholarly journals ATP triggers macropinocytosis that internalizes and is regulated by PANX1

2020 ◽  
Author(s):  
Andrew K.J. Boyce ◽  
Emma van der Slagt ◽  
Juan C. Sanchez-Arias ◽  
Leigh Anne Swayne
Keyword(s):  
Neuroblastoma Cells ◽  
Atp Release ◽  
Surface Proteins ◽  
Cell Area ◽  
Release Channel ◽  
Cross Sectional ◽  
Pannexin 1 ◽  
Disease States ◽  
Cellular Area ◽  
Area Expansion

ABSTRACTMacropinocytosis is an endocytic process that allows cells to respond to changes in their environment by internalizing nutrients and cell surface proteins, as well as modulating cell size. Here, we identify that adenosine triphosphate (ATP) triggers macropinocytosis in murine neuroblastoma cells, thereby internalizing the ATP release channel pannexin 1 (PANX1) while concurrently increasing cross-sectional cellular area. Amiloride, a potent inhibitor of macropinocytosis-associated GTPases, abolished ATP-induced PANX1 internalization and cell area expansion. Transient expression of the GTP-hydrolysis resistant GTPase ARF6 Q67L led to increased PANX1 internalization and increased cell area equivalent to levels seen with ATP stimulation. Mutation of an extracellular tryptophan (W74) in PANX1 abolished ATP-evoked cell area enlargement suggesting that PANX1 regulates this form of macropinocytosis. This novel role of PANX1 in macropinocytosis could be particularly important for disease states implicating PANX1, such as cancer, where ATP can act as a purinergic regulator of cell growth/metastasis and as a supplementary energy source following internalization.

scholarly journals Role of an Aromatic–Aromatic Interaction in the Assembly and Trafficking of the Zebrafish Panx1a Membrane Channel

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 272 ◽  
Author(s):  
Ksenia Timonina ◽  
Anna Kotova ◽  
Georg Zoidl
Keyword(s):  
Atp Release ◽  
Integral Membrane Protein ◽  
Membrane Channel ◽  
Release Channel ◽  
Post Translational Modifications ◽  
Mutant Proteins ◽  
Pannexin 1 ◽  
Interaction Testing ◽  
Insight Into

Pannexin 1 (Panx1) is a ubiquitously expressed hexameric integral membrane protein known to function as an adenosine triphosphate (ATP) release channel. Panx1 proteins exist in unglycosylated core form (Gly0). They undergo critical post-translational modifications forming the high mannose glycosylation state (Gly1) in the endoplasmic reticulum (ER) and the complex glycosylation state (Gly2) in the Golgi apparatus. The regulation of transition from the ER to the cell membrane is not fully understood. Using site-specific mutagenesis, dye uptake assays, and interaction testing, we identified two conserved aromatic residues, Trp123 and Tyr205, in the transmembrane domains 2 and 3 of the zebrafish panx1a protein. Results suggest that both residues primarily govern the assembly of panx1a subunits into channels, with mutant proteins failing to interact. The results provide insight into a mechanism enabling regulation of Panx1 oligomerization, glycosylation, and trafficking.

A pannexin 1 channelopathy causes human oocyte death

2019 ◽  
Vol 11 (485) ◽  
pp. eaav8731 ◽  
Author(s):  
Qing Sang ◽  
Zhihua Zhang ◽  
Juanzi Shi ◽  
Xiaoxi Sun ◽  
Bin Li ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Critical Role ◽  
Atp Release ◽  
Cellular Communication ◽  
Human Oocyte ◽  
Channel Activity ◽  
Glycosylation Pattern ◽  
Pannexin 1 ◽  
Independent Families

Connexins and pannexins are two protein families that play an important role in cellular communication. Pannexin 1 (PANX1), one of the members of pannexin family, is a channel protein. It is glycosylated and forms three species, GLY0, GLY1, and GLY2. Here, we describe four independent families in which mutations in PANX1 cause familial or sporadic female infertility via a phenotype that we term “oocyte death.” The mutations, which are associated with oocyte death, alter the PANX1 glycosylation pattern, influence the subcellular localization of PANX1 in cultured cells, and result in aberrant PANX1 channel activity, ATP release in oocytes, and mutant PANX1 GLY1. Overexpression of a patient-derived mutation in mice causes infertility, recapitulating the human oocyte death phenotype. Our findings demonstrate the critical role of PANX1 in human oocyte development, provide a genetic explanation for a subtype of infertility, and suggest a potential target for therapeutic intervention for this disease.

scholarly journals Cryo-EM structures of the ATP release channel pannexin 1

2020 ◽  
Vol 27 (4) ◽  
pp. 373-381 ◽  
Author(s):  
Zengqin Deng ◽  
Zhihui He ◽  
Grigory Maksaev ◽  
Ryan M. Bitter ◽  
Michael Rau ◽  
...  
Keyword(s):  
Atp Release ◽  
Release Channel ◽  
Pannexin 1

scholarly journals Pannexin 1, an ATP Release Channel, Is Activated by Caspase Cleavage of Its Pore-associated C-terminal Autoinhibitory Region

2012 ◽  
Vol 287 (14) ◽  
pp. 11303-11311 ◽  
Author(s):  
Joanna K. Sandilos ◽  
Yu-Hsin Chiu ◽  
Faraaz B. Chekeni ◽  
Allison J. Armstrong ◽  
Scott F. Walk ◽  
...  
Keyword(s):  
Atp Release ◽  
Release Channel ◽  
Caspase Cleavage ◽  
Pannexin 1

scholarly journals The weak voltage dependence of pannexin 1 channels can be tuned by N-terminal modifications

2018 ◽  
Vol 150 (12) ◽  
pp. 1758-1768 ◽  
Author(s):  
Kevin Michalski ◽  
Erik Henze ◽  
Phillip Nguyen ◽  
Patrick Lynch ◽  
Toshimitsu Kawate
Keyword(s):  
Voltage Dependence ◽  
Single Channel ◽  
Atp Release ◽  
Channel Activity ◽  
Patch Clamp Recording ◽  
Open Probability ◽  
Pannexin 1 ◽  
Voltage Dependent ◽  
Gated Channel

Pannexins are a family of ATP release channels important for physiological and pathological processes like blood pressure regulation, epilepsy, and neuropathic pain. To study these important channels in vitro, voltage stimulation is the most common and convenient tool, particularly for pannexin 1 (Panx1). However, whether Panx1 is a voltage-gated channel remains controversial. Here, we carefully examine the effect of N-terminal modification on voltage-dependent Panx1 channel activity. Using a whole-cell patch-clamp recording technique, we demonstrate that both human and mouse Panx1, with their nativeN termini, give rise to voltage-dependent currents, but only at membrane potentials larger than +100 mV. This weak voltage-dependent channel activity profoundly increases when a glycine–serine (GS) motif is inserted immediately after the first methionine. Single-channel recordings reveal that the addition of GS increases the channel open probability as well as the number of unitary conductance classes. We also find that insertions of other amino acid(s) at the same position mimics the effect of GS. On the other hand, tagging the N terminus with GFP abolishes voltage-dependent channel activity. Our results suggest that Panx1 is a channel with weak voltage dependence whose activity can be tuned by N-terminal modifications.

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