Channel activity of recombinant pannexin 1

Romanov, Roman A.; Bystrova, M. F.; Rogachevskaya, O. A.; Kolesnikov, Stanislav S.

doi:10.1134/s1990747811050126

Cited by 3 publications

(3 citation statements)

References 10 publications

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“…On the contrary, our preliminary recordings (Romanov et al, 2011) suggested that expression of Panx1 in HEK 293 cells resulted in the appearance of ,60 pS anion channels, the observation being completely consistent with the results of Ma et al (Ma et al, 2012). Here, we confirmed those findings and carried out a more accurate analysis of Panx1 channels.…”

Section: Atp Release In Taste Cells From Panx1-null Micesupporting

confidence: 82%

Dispensable ATP permeability of Pannexin 1 channels in a heterologous system and in mammalian taste cells

Romanov

Bystrova

Rogachevskaya

et al. 2012

Journal of Cell Science

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154

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SummaryAfferent output in type II taste cells is mediated by ATP liberated through ion channels. It is widely accepted that pannexin 1 (Panx1) channels are responsible for ATP release in diverse cell types, including taste cells. While biophysical evidence implicates slow deactivation of ion channels following ATP release in taste cells, recombinant Panx1 activates and deactivates rapidly. This inconsistency could indicate that the cellular context specifies Panx1 functioning. We cloned Panx1 from murine taste tissue, and heterologously expressed it in three different cell lines: HEK-293, CHO and neuroblastoma SK-N-SH cells. In all three cell lines, Panx1 transfection yielded outwardly rectifying anion channels that exhibited fast gating and negligible permeability to anions exceeding 250 Da. Despite expression of Panx1, the host cells did not liberate ATP upon stimulation, making it unclear whether Panx1 is involved in taste-related ATP secretion. This issue was addressed using mice with genetic ablation of the Panx1 gene. The ATP-biosensor assay revealed that, in taste cells devoid of Panx1, ATP secretion was robust and apparently unchanged compared with the control. Our data suggest that Panx1 alone forms a channel that has insufficient permeability to ATP. Perhaps, a distinct subunit and/or a regulatory circuit that is absent in taste cells is required to enable a high ATP-permeability mode of a native Panx1-based channel.

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Section: Atp Release In Taste Cells From Panx1-null Micesupporting

confidence: 82%

Dispensable ATP permeability of Pannexin 1 channels in a heterologous system and in mammalian taste cells

Romanov

Bystrova

Rogachevskaya

et al. 2012

Journal of Cell Science

Self Cite

154

View full text Add to dashboard Cite

show abstract

“…There are also at least five open substates (corresponding to 5, 25, 30, and 90% of the fully open unitary conductance) (Bao et al, 2004) and, following activation, Panx1 channels will often deactivate again over several seconds to a lower subconductance state (Bruzzone et al, 2003; Bao et al, 2004). It is becoming clear, however, that the cellular context in which Panx finds itself has influence over the channel's biophysical properties, as recent unitary recordings of Panx1 channels excised from over-expressing HEK293 cells reveal an upper conductance limit of 60–70 pS (Romanov et al, 2011, 2012; Ma et al, 2012) and size exclusion of molecules as small as 237 Da (Romanov et al, 2012). While studying the zebrafish Panx1b-EGFP channel, over-expressed in HeLa cells, we too have observed a much smaller unitary conductance (123 pS) from excised membrane patches (Bond et al, 2012).…”

Section: Pannexinsmentioning

confidence: 99%

The pannexins: past and present

Bond

Naus

2014

Front. Physiol.

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The pannexins (Panxs) are a family of chordate proteins homologous to the invertebrate gap junction forming proteins named innexins. Three distinct Panx paralogs (Panx1, Panx2, and Panx3) are shared among the major vertebrate phyla, but they appear to have suppressed (or even lost) their ability to directly couple adjacent cells. Connecting the intracellular and extracellular compartments is now widely accepted as Panx's primary function, facilitating the passive movement of ions and small molecules along electrochemical gradients. The tissue distribution of the Panxs ranges from pervasive to very restricted, depending on the paralog, and are often cell type-specific and/or developmentally regulated within any given tissue. In recent years, Panxs have been implicated in an assortment of physiological and pathophysiological processes, particularly with respect to ATP signaling and inflammation, and they are now considered to be a major player in extracellular purinergic communication. The following is a comprehensive review of the Panx literature, exploring the historical events leading up to their discovery, outlining our current understanding of their biochemistry, and describing the importance of these proteins in health and disease.

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“…Px is widely expressed in human tissues and organs, such as osteoblasts, chondroblasts, spleen cells, skin tissues, the kidney, and the central nervous system ( 12 ). Px forms hemichannels in the cell membrane, which can be induced to open by hypoxia, low permeability, mechanical stress, cell depolarization, and Ca 2+ concentration increases to mediate ATP release and intercellular Ca 2+ wave transmission, regulating blood flow or the immune response ( 13 , 14 ). Px1 is a newly discovered mechanical stimuli-sensitive channel protein; however, whether Px1 participates in MSC osteogenic differentiation and signal transduction after mechanical stimulation has been rarely reported.…”

Section: Introductionmentioning

confidence: 99%

Carbenoxolone inhibits mechanical stress-induced osteogenic differentiation of mesenchymal stem cells by regulating p38 MAPK phosphorylation

Wang

Han

et al. 2018

Exp Ther Med

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The aim of the present study was to explore the effects of pannexin1 (Px1) protein channels on osteogenic differentiation of mesenchymal stem cells (MSCs) under mechanical stress stimulation. MSCs were isolated from Sprague Dawley rats (3 weeks old, weighing 100–120 g) and cultured in vitro. A safe concentration of carbenoxolone was determined (CBX, an inhibitor of Px1 channels; 100 µM) on MSCs using the Cell Counting Kit-8 (CCK8) method. MSCs were divided into 6 groups: Control, stress (4,000 µ strain), and stress following 3, 6, 12, and 24 h pretreatment with CBX. Stress groups were stimulated with mechanical stress for 15 min. Alkaline phosphatase (ALP) activity, type I collagen expression, intracellular calcium ion (Ca2+) concentration, Px1 expression, p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated phosphorylation were determined. ALP activity was increased in the stress group, and this was prevented by pretreatment with CBX. Similarly, stress-induced increases in type I collagen expression, Ca2+ concentration, Px1 expression, and p38 MAPK phosphorylation decreased in the presence of CBX. ERK phosphorylation was decreased by stress, however was not affected by CBX treatment. Altogether, the results suggest that mechanical stress promoted the osteogenic differentiation of MSCs, and this promotion was inhibited by pretreatment with CBX, possibly through regulating the phosphorylation of p38 MAPK.

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Channel activity of recombinant pannexin 1

Cited by 3 publications

References 10 publications

Dispensable ATP permeability of Pannexin 1 channels in a heterologous system and in mammalian taste cells

Dispensable ATP permeability of Pannexin 1 channels in a heterologous system and in mammalian taste cells

The pannexins: past and present

Carbenoxolone inhibits mechanical stress-induced osteogenic differentiation of mesenchymal stem cells by regulating p38 MAPK phosphorylation

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