scholarly journals Different receptors use inositol trisphosphate to mobilize Ca2+ from different intracellular pools

2000 ◽  
Vol 351 (3) ◽  
pp. 683-686 ◽  
Author(s):  
Alison D. SHORT ◽  
Gavin P. WINSTON ◽  
Colin W. TAYLOR
Keyword(s):  
Spatial Organization ◽  
Inositol Trisphosphate ◽  
Signalling Pathways ◽  
Free Medium ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
Maximal Stimulation ◽  
293 Cells ◽  
Made In ◽  
Stimulation Of

In cells expressing different receptors linked to Ins(1,4,5)P3 formation, maximal stimulation of any one of them often releases all the Ins(1,4,5)P3-sensitive Ca2+ stores, suggesting that Ins(1,4,5)P3 is used similarly by many receptors. In single HEK-293 cells, ATP and carbamylcholine (CCh) stimulated Ca2+ release from intracellular stores via a pathway that was entirely dependent on Ins(1,4,5)P3. After stimulation with maximal concentrations of ATP or CCh in Ca2+-free medium, there was no response to a second stimulation with the same agonist, indicating that each agonist had emptied the Ins(1,4,5)P3-sensitive stores to which it had access. However, the Ca2+ release evoked by the second agonist was unaffected by prior stimulation with the first. We conclude that Ins(1,4,5)P3 mediates the effects of both receptors, but Ins(1,4,5)P3 is more versatile than hitherto supposed, because the spatial organization of the signalling pathways apparently allows Ins(1,4,5)P3 made in response to each agonist to interact with different Ins(1,4,5)P3 receptors.

scholarly journals Adrenergic receptor activation involves ATP release and feedback through purinergic receptors

2010 ◽  
Vol 299 (5) ◽  
pp. C1118-C1126 ◽  
Author(s):  
Yuka Sumi ◽  
Tobias Woehrle ◽  
Yu Chen ◽  
Yongli Yao ◽  
Andrew Li ◽  
...  
Keyword(s):  
Adrenergic Receptors ◽  
Adrenergic Receptor ◽  
Purinergic Receptors ◽  
Atp Release ◽  
Feedback Mechanisms ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells ◽  
Formyl Peptide ◽  
Stimulation Of

Formyl peptide receptor-induced chemotaxis of neutrophils depends on the release of ATP and autocrine feedback through purinergic receptors. Here, we show that adrenergic receptor signaling requires similar purinergic feedback mechanisms. Real-time RT-PCR analysis revealed that human embryonic kidney (HEK)-293 cells express several subtypes of adrenergic (α1-, α2-, and β-receptors), adenosine (P1), and nucleotide receptors (P2). Stimulation of Gq-coupled α1-receptors caused release of cellular ATP and MAPK activation, which was blocked by inhibiting P2 receptors with suramin. Stimulation of Gi-coupled α2-receptors induced weak ATP release, while Gs-coupled β-receptors caused accumulation of extracellular ADP and adenosine. β-Receptors triggered intracellular cAMP signaling, which was blocked by scavenging extracellular adenosine with adenosine deaminase or by inhibiting A2a adenosine receptors with SCH58261. These findings suggest that adrenergic receptors require purinergic receptors to elicit downstream signaling responses in HEK-293 cells. We evaluated the physiological relevance of these findings using mouse aorta tissue rings. Stimulation of α1-receptors induced ATP release and tissue contraction, which was reduced by removing extracellular ATP with apyrase or in the absence of P2Y2 receptors in aorta rings from P2Y2 receptor knockout mice. We conclude that, like formyl peptide receptors, adrenergic receptors require purinergic feedback mechanisms to control complex physiological processes such as smooth muscle contraction and regulation of vascular tone.

Phospholipid metabolism activated by the stimulation of glutamate receptors in HEK 293 cells stably expressing glutamate receptors-31P-NMR study-

1998 ◽  
Vol 31 ◽  
pp. S87
Author(s):  
Hirokazu Hirai ◽  
Takashi Torashima ◽  
Masahiro Ito ◽  
Keitaro Yoshioka ◽  
Kazuhiro Yamada
Keyword(s):  
Glutamate Receptors ◽  
31P Nmr ◽  
Phospholipid Metabolism ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
Nmr Study ◽  
293 Cells ◽  
Stimulation Of

scholarly journals Cellular mechanisms underlying prostaglandin-induced transient cAMP signals near the plasma membrane of HEK-293 cells

2007 ◽  
Vol 292 (1) ◽  
pp. C319-C331 ◽  
Author(s):  
Thomas C. Rich ◽  
Wenkuan Xin ◽  
Celine Mehats ◽  
Kathryn A. Hassell ◽  
Leslie A. Piggott ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Time Course ◽  
Pde4 Inhibitor ◽  
Prostaglandin E ◽  
Cellular Mechanisms ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells ◽  
Camp Levels ◽  
Stimulation Of

We have previously used cyclic nucleotide-gated (CNG) channels as sensors to measure cAMP signals in human embryonic kidney (HEK)-293 cells. We found that prostaglandin E1 (PGE1) triggered transient increases in cAMP concentration near the plasma membrane, whereas total cAMP levels rose to a steady plateau over the same time course. In addition, we presented evidence that the decline in the near-membrane cAMP levels was due primarily to a PGE1-induced stimulation of phosphodiesterase (PDE) activity, and that the differences between near-membrane and total cAMP levels were largely due to diffusional barriers and differential PDE activity. Here, we examine the mechanisms regulating transient, near-membrane cAMP signals. We observed that 5-min stimulation of HEK-293 cells with prostaglandins triggered a two- to threefold increase in PDE4 activity. Extracellular application of H89 (a PKA inhibitor) inhibited stimulation of PDE4 activity. Similarly, when we used CNG channels to monitor cAMP signals we found that both extracellular and intracellular (via the whole-cell patch pipette) application of H89, or the highly selective PKA inhibitor, PKI, prevented the decline in prostaglandin-induced responses. Following pretreatment with rolipram (a PDE4 inhibitor), H89 had little or no effect on near-membrane or total cAMP levels. Furthermore, disrupting the subcellular localization of PKA with the A-kinase anchoring protein (AKAP) disruptor Ht31 prevented the decline in the transient response. Based on these data we developed a plausible kinetic model that describes prostaglandin-induced cAMP signals. This model has allowed us to quantitatively demonstrate the importance of PKA-mediated stimulation of PDE4 activity in shaping near-membrane cAMP signals.

scholarly journals Hormone Stimulation of Type III Adenylyl Cyclase Induces Ca2+Oscillations in HEK-293 Cells

1995 ◽  
Vol 270 (41) ◽  
pp. 24108-24115 ◽  
Author(s):  
Gary A. Wayman ◽  
Thomas R. Hinds ◽  
Daniel R. Storm
Keyword(s):  
Adenylyl Cyclase ◽  
Hek 293 ◽  
Hormone Stimulation ◽  
Hek 293 Cells ◽  
Type Iii ◽  
293 Cells ◽  
Stimulation Of

scholarly journals Characteristics and requirements of basal autophagy in HEK 293 cells

Autophagy ◽  
2013 ◽  
Vol 9 (9) ◽  
pp. 1407-1417 ◽  
Author(s):  
Patience Musiwaro ◽  
Matthew Smith ◽  
Maria Manifava ◽  
Simon A. Walker ◽  
Nicholas T. Ktistakis
Keyword(s):  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells

Halothane Inhibition of Recombinant Cardiac L-type Ca2+ Channels Expressed in HEK-293 Cells

2005 ◽  
Vol 103 (6) ◽  
pp. 1156-1166 ◽  
Author(s):  
Kevin J. Gingrich ◽  
Son Tran ◽  
Igor M. Nikonorov ◽  
Thomas J. Blanck
Keyword(s):  
Charge Transfer ◽  
Calcium Channels ◽  
Dependent Manner ◽  
Current Time ◽  
Hek 293 ◽  
Hek 293 Cells ◽  
293 Cells ◽  
Dependent Inactivation ◽  
Voltage Dependent

Background Volatile anesthetics depress cardiac contractility, which involves inhibition of cardiac L-type calcium channels. To explore the role of voltage-dependent inactivation, the authors analyzed halothane effects on recombinant cardiac L-type calcium channels (alpha1Cbeta2a and alpha1Cbeta2aalpha2/delta1), which differ by the alpha2/delta1 subunit and consequently voltage-dependent inactivation. Methods HEK-293 cells were transiently cotransfected with complementary DNAs encoding alpha1C tagged with green fluorescent protein and beta2a, with and without alpha2/delta1. Halothane effects on macroscopic barium currents were recorded using patch clamp methodology from cells expressing alpha1Cbeta2a and alpha1Cbeta2aalpha2/delta1 as identified by fluorescence microscopy. Results Halothane inhibited peak current (I(peak)) and enhanced apparent inactivation (reported by end pulse current amplitude of 300-ms depolarizations [I300]) in a concentration-dependent manner in both channel types. alpha2/delta1 coexpression shifted relations leftward as reported by the 50% inhibitory concentration of I(peak) and I300/I(peak)for alpha1Cbeta2a (1.8 and 14.5 mm, respectively) and alpha1Cbeta2aalpha2/delta1 (0.74 and 1.36 mm, respectively). Halothane reduced transmembrane charge transfer primarily through I(peak) depression and not by enhancement of macroscopic inactivation for both channels. Conclusions The results indicate that phenotypic features arising from alpha2/delta1 coexpression play a key role in halothane inhibition of cardiac L-type calcium channels. These features included marked effects on I(peak) inhibition, which is the principal determinant of charge transfer reductions. I(peak) depression arises primarily from transitions to nonactivatable states at resting membrane potentials. The findings point to the importance of halothane interactions with states present at resting membrane potential and discount the role of inactivation apparent in current time courses in determining transmembrane charge transfer.

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