Pore dilation of neuronal P2X receptor channels

10.1038/7225 ◽  
1999 ◽  
Vol 2 (4) ◽  
pp. 315-321 ◽  
Author(s):  
C. Virginio ◽  
A. MacKenzie ◽  
F. A. Rassendren ◽  
R. A. North ◽  
A. Surprenant
Keyword(s):  
P2x Receptor ◽  
Pore Dilation

scholarly journals Physical basis of apparent pore dilation of ATP-activated P2X receptor channels

2015 ◽  
Vol 18 (11) ◽  
pp. 1577-1583 ◽  
Author(s):  
Mufeng Li ◽  
Gilman E S Toombes ◽  
Shai D Silberberg ◽  
Kenton J Swartz
Keyword(s):  
Physical Basis ◽  
P2x Receptor ◽  
Pore Dilation

scholarly journals Structural basis for the functional properties of the P2X7 receptor for extracellular ATP

2021 ◽  
Author(s):  
Lin-Hua Jiang ◽  
Emily A. Caseley ◽  
Steve P. Muench ◽  
Sébastien Roger
Keyword(s):  
Functional Properties ◽  
P2x7 Receptor ◽  
Site Directed Mutagenesis ◽  
P2x Receptor ◽  
Structural Basis ◽  
Structure Characteristic ◽  
Purinergic Signalling ◽  
Directed Mutagenesis ◽  
Important Mediator ◽  
Receptor Family

AbstractThe P2X7 receptor, originally known as the P2Z receptor due to its distinctive functional properties, has a structure characteristic of the ATP-gated ion channel P2X receptor family. The P2X7 receptor is an important mediator of ATP-induced purinergic signalling and is involved the pathogenesis of numerous conditions as well as in the regulation of diverse physiological functions. Functional characterisations, in conjunction with site-directed mutagenesis, molecular modelling, and, recently, structural determination, have provided significant insights into the structure–function relationships of the P2X7 receptor. This review discusses the current understanding of the structural basis for the functional properties of the P2X7 receptor.

scholarly journals Synaptotagmin-Ca2+triggers two sequential steps in regulated exocytosis in rat PC12 cells: fusion pore opening and fusion pore dilation

2006 ◽  
Vol 570 (2) ◽  
pp. 295-307 ◽  
Author(s):  
Chih-Tien Wang ◽  
Jihong Bai ◽  
Payne Y. Chang ◽  
Edwin R. Chapman ◽  
Meyer B. Jackson
Keyword(s):  
Pc12 Cells ◽  
Fusion Pore ◽  
Regulated Exocytosis ◽  
Pore Opening ◽  
Pore Dilation

Antagonism of endogenous putative P2Y receptors reduces the growth of MDCK-derived cysts cultured in vitro

2007 ◽  
Vol 292 (1) ◽  
pp. F15-F25 ◽  
Author(s):  
Clare M. Turner ◽  
Brian F. King ◽  
Kaila S. Srai ◽  
Robert J. Unwin
Keyword(s):  
Therapeutic Potential ◽  
Cyst Formation ◽  
P2y Receptors ◽  
P2x Receptor ◽  
P2y Receptor ◽  
Cyst Size ◽  
Reactive Blue 2 ◽  
Cyst Growth

P2Y receptors couple to G proteins and either mobilize intracellular Ca2+ or alter cAMP levels to modulate the activity of Ca2+- and cAMP-sensitive ion channels. We hypothesize that increased ion transport into the lumen of MDCK cysts can osmotically drive fluid movement and increase cyst size. Furthermore, activation of the adenylate cyclase/cAMP pathway may trigger cell proliferation via an extracellular signal-related kinase cascade. To test this hypothesis, several P2Y receptor inhibitors were used on the MDCK in vitro model of renal cyst formation. The nonspecific P2 receptor inhibitors reactive blue 2 and suramin reduced cyst growth significantly, as did PPADS and, to a lesser extent, the P2Y1-specific antagonist MRS2179. Cyst growth was reduced by ∼50% when ATP was removed from the culture medium with apyrase, although stable analogs of ATP failed to increase cyst size. The nonselective P2X receptor inhibitor Coomassie brilliant blue G was ineffective at reducing cyst growth, suggesting no involvement of P2X receptors. Finally, the presence of selective inhibitors of ERK activation (either PD98059 or U0126) greatly reduced cyst growth, whereas in untreated cysts ERK activity was observed to increase with time. We conclude that stimulation of endogenous P2Y receptors by extracellular ATP increases growth of MDCK cysts via cAMP-dependent activation of the ERK pathway. P2Y receptor antagonists may have therapeutic potential in reducing cyst size and slowing disease progression; although further studies in vitro and in vivo are needed to investigate the specificity and role of these P2Y receptors in renal cystic diseases.

scholarly journals Activity-Dependent Fusion Pore Dilation Mediated by a Dynamin I-Syndapin Pathway

2011 ◽  
Vol 100 (3) ◽  
pp. 408a
Author(s):  
Prattana Samasilp ◽  
Bryan Doreian ◽  
Shyue-An Chan ◽  
Corey Smith
Keyword(s):  
Fusion Pore ◽  
Pore Dilation ◽  
Dynamin I ◽  
Activity Dependent

scholarly journals Functional Coupling between the P2X7 Receptor and Pannexin-1 Channel in Rat Trigeminal Ganglion Neurons

2021 ◽  
Vol 22 (11) ◽  
pp. 5978
Author(s):  
Hiroyuki Inoue ◽  
Hidetaka Kuroda ◽  
Wataru Ofusa ◽  
Sadao Oyama ◽  
Maki Kimura ◽  
...  
Keyword(s):  
Trigeminal Ganglion ◽  
P2x7 Receptor ◽  
P2x Receptor ◽  
Functional Coupling ◽  
Dependent Manner ◽  
High Concentration ◽  
Receptor Antagonists ◽  
P2x7 Receptors ◽  
Pannexin 1 ◽  
Ganglion Neurons

The ionotropic P2X receptor, P2X7, is believed to regulate and/or generate nociceptive pain, and pain in several neuropathological diseases. Although there is a known relationship between P2X7 receptor activity and pain sensing, its detailed functional properties in trigeminal ganglion (TG) neurons remains unclear. We examined the electrophysiological and pharmacological characteristics of the P2X7 receptor and its functional coupling with other P2X receptors and pannexin-1 (PANX1) channels in primary cultured rat TG neurons, using whole-cell patch-clamp recordings. Application of ATP and Bz-ATP induced long-lasting biphasic inward currents that were more sensitive to extracellular Bz-ATP than ATP, indicating that the current was carried by P2X7 receptors. While the biphasic current densities of the first and second components were increased by Bz-ATP in a concentration dependent manner; current duration was only affected in the second component. These currents were significantly inhibited by P2X7 receptor antagonists, while only the second component was inhibited by P2X1, 3, and 4 receptor antagonists, PANX1 channel inhibitors, and extracellular ATPase. Taken together, our data suggests that autocrine or paracrine signaling via the P2X7-PANX1-P2X receptor/channel complex may play important roles in several pain sensing pathways via long-lasting neuronal activity driven by extracellular high-concentration ATP following tissue damage in the orofacial area.

scholarly journals Permeation and block of TRPV1 channels by the cationic lidocaine derivative QX-314

2013 ◽  
Vol 109 (7) ◽  
pp. 1704-1712 ◽  
Author(s):  
Michelino Puopolo ◽  
Alexander M. Binshtok ◽  
Gui-Lan Yao ◽  
Seog Bae Oh ◽  
Clifford J. Woolf ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Neuronal Cell ◽  
Reversal Potential ◽  
Dorsal Root Ganglion Neurons ◽  
C6 Glioma Cells ◽  
Transient Receptor Potential Vanilloid ◽  
Trpv1 Channels ◽  
Inward Currents ◽  
Pore Dilation ◽  
Ganglion Neurons

QX-314 ( N-ethyl-lidocaine) is a cationic lidocaine derivative that blocks voltage-dependent sodium channels when applied internally to axons or neuronal cell bodies. Coapplication of external QX-314 with the transient receptor potential vanilloid 1 protein (TRPV1) agonist capsaicin produces long-lasting sodium channel inhibition in TRPV1-expressing neurons, suggestive of QX-314 entry into the neurons. We asked whether QX-314 entry occurs directly through TRPV1 channels or through a different pathway (e.g., pannexin channels) activated downstream of TRPV1 and whether QX-314 entry requires the phenomenon of “pore dilation” previously reported for TRPV1. With external solutions containing 10 or 20 mM QX-314 as the only cation, inward currents were activated by stimulation of both heterologously expressed and native TRPV1 channels in rat dorsal root ganglion neurons. QX-314-mediated inward current did not require pore dilation, as it activated within several seconds and in parallel with Cs-mediated outward current, with a reversal potential consistent with PQX-314/ PCs = 0.12. QX-314-mediated current was no different when TRPV1 channels were expressed in C6 glioma cells, which lack expression of pannexin channels. Rapid addition of QX-314 to physiological external solutions produced instant partial inhibition of inward currents carried by sodium ions, suggesting that QX-314 is a permeant blocker. Maintained coapplication of QX-314 with capsaicin produced slowly developing reduction of outward currents carried by internal Cs, consistent with intracellular accumulation of QX-314 to concentrations of 50–100 μM. We conclude that QX-314 is directly permeant in the “standard” pore formed by TRPV1 channels and does not require either pore dilation or activation of additional downstream channels for entry.

Co-expression of P2X receptor subunits on rat nodose neurons that bind the isolectin GS-I-B4

Neuroreport ◽  
2001 ◽  
Vol 12 (13) ◽  
pp. 2995-2997 ◽  
Author(s):  
Charles H. Hubscher ◽  
Jeffrey C. Petruska ◽  
Kristofer K. Rau ◽  
Richard D. Johnson
Keyword(s):  
P2x Receptor
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