Biophysical Methods to Analyze Direct G-Protein Regulation of Neuronal Voltage-Gated Calcium Channels

2021 ◽  
pp. 429-439
Author(s):  
Norbert Weiss ◽  
Michel De Waard
Keyword(s):  
Calcium Channels ◽  
G Protein ◽  
Protein Regulation ◽  
Voltage Gated ◽  
Voltage Gated Calcium Channels

scholarly journals Disabling Gβγ SNARE interaction in transgenic mice disrupts GPCR-mediated presynaptic inhibition leading to physiological and behavioral phenotypes

2018 ◽  
Author(s):  
Zack Zurawski ◽  
Analisa D. Thompson Gray ◽  
Lillian J. Brady ◽  
Brian Page ◽  
Emily Church ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Calcium Channels ◽  
G Protein ◽  
Presynaptic Inhibition ◽  
Receptor Activation ◽  
G Protein Coupled Receptors ◽  
Voltage Gated ◽  
Voltage Gated Calcium Channels ◽  
Crucial Component ◽  
G Protein Coupled

ABSTRACTGi/o-coupled G-protein coupled receptors modulate neurotransmission presynaptically through inhibition of exocytosis. Release of Gβγ subunits decreases the activity of voltage-gated calcium channels (VGCC), decreasing excitability. A less understood Gβγ–mediated mechanism downstream of calcium entry is the binding of Gβγ to SNARE complexes. Here, we create a mouse partially deficient in this interaction. SNAP25Δ3 homozygote animals are developmentally normalbut impaired gait and supraspinal nociception. They also have elevated stress-induced hyperthermia and impaired inhibitory postsynaptic responses to α2A-AR, but normal inhibitory postsynaptic responses to Gi/o-coupled GABAB receptor activation. SNAP25Δ3 homozygotes have deficits in inhibition of hippocampal postsynaptic responses to 5 HT1b agonists that affect hippocampal learning. These data suggest that Gi/o-coupled GPCR inhibition of exocytosis through the Gβγ-SNARE interaction is a crucial component of numerous physiological and behavioral processes.

scholarly journals Inhibitory Effect of Somatostatin-14 on L-Type Voltage-Gated Calcium Channels in Cultured Cone Photoreceptors Requires Intracellular Calcium

2009 ◽  
Vol 102 (3) ◽  
pp. 1801-1810 ◽  
Author(s):  
Kuihuan Jian ◽  
Rola Barhoumi ◽  
Michael L. Ko ◽  
Gladys Y.-P. Ko
Keyword(s):  
Calcium Channels ◽  
Intracellular Calcium ◽  
G Protein ◽  
Inhibitory Effect ◽  
Calcium Stores ◽  
Dependent Effect ◽  
Voltage Gated ◽  
Circadian Phase ◽  
Voltage Gated Calcium Channels ◽  
Somatostatin 14

The inhibitory effects of somatostatin have been well documented for many physiological processes. The action of somatostatin is through G-protein-coupled receptor-mediated second-messenger signaling, which in turn affects other downstream targets including ion channels. In the retina, somatostatin is released from a specific class of amacrine cells. Here we report that there was a circadian phase-dependent effect of somatostatin-14 (SS14) on the L-type voltage-gated calcium channels (L-VGCCs) in cultured chicken cone photoreceptors, and our study reveals that this process is dependent on intracellular calcium stores. Application of 500 nM SS14 for 2 h caused a decrease in L-VGCC currents only during the subjective night but not the subjective day. We then explored the cellular mechanisms underlying the circadian phase-dependent effect of SS14. The inhibitory effect of SS14 on L-VGCCs was mediated through the pertussis-toxin-sensitive G-protein-dependent somatostatin receptor 2 (sst2). Activation of sst2 by SS14 further activated downstream signaling involving phospholipase C and intracellular calcium stores. Mobilization of intracellular Ca2+ was required for somatostatin induced inhibition of photoreceptor L-VGCCs, suggesting that somatostatin plays an important role in the modulation of photoreceptor physiology.

Inhibition of Dendritic Calcium Influx by Activation of G-Protein–Coupled Receptors in the Hippocampus

1997 ◽  
Vol 78 (6) ◽  
pp. 3484-3488 ◽  
Author(s):  
Huanmian Chen ◽  
Nevin A. Lambert
Keyword(s):  
Calcium Channels ◽  
Action Potential ◽  
G Protein ◽  
Pyramidal Neuron ◽  
Action Potentials ◽  
Calcium Influx ◽  
G Protein Coupled Receptors ◽  
Voltage Gated ◽  
Voltage Gated Calcium Channels ◽  
G Protein Coupled

Chen, Huanmian and Nevin A. Lambert. Inhibition of dendritic calcium influx by activation of G-protein–coupled receptors in the hippocampus. J. Neurophysiol. 78: 3484–3488, 1997. Gi proteins inhibit voltage-gated calcium channels and activate inwardly rectifying K+ channels in hippocampal pyramidal neurons. The effect of activation of G-protein–coupled receptors on action potential-evoked calcium influx was examined in pyramidal neuron dendrites with optical and extracellular voltage recording. We tested the hypotheses that 1) activation of these receptors would inhibit calcium channels in dendrites; 2) hyperpolarization resulting from K+ channel activation would deinactivate low-threshold, T-type calcium channels on dendrites, increasing calcium influx mediated by these channels; and 3) activation of these receptors would inhibit propagation of action potentials into dendrites, and thus indirectly decrease calcium influx. Activation of adenosine receptors, which couple to Gi proteins, inhibited calcium influx in cell bodies and proximal dendrites without inhibiting action-potential propagation into the proximal dendrites. Inhibition of dendritic calcium influx was not changed in the presence of 50 μM nickel, which preferentially blocks T-type channels, suggesting influx through these channels is not increased by activation of G-proteins. Adenosine inhibited propagation of action potentials into the distal branches of pyramidal neuron dendrites, leading to a three- to fourfold greater inhibition of calcium influx in the distal dendrites than in the soma or proximal dendrites. These results suggest that voltage-gated calcium channels are inhibited in pyramidal neuron dendrites, as they are in cell bodies and terminals and thatG-protein–mediated inhibition of action-potential propagation can contribute substantially to inhibition of dendritic calcium influx.

scholarly journals G Protein Modulation of Voltage-Gated Calcium Channels

2003 ◽  
Vol 55 (4) ◽  
pp. 607-627 ◽  
Author(s):  
Annette C. Dolphin
Keyword(s):  
Calcium Channels ◽  
G Protein ◽  
Voltage Gated ◽  
Voltage Gated Calcium Channels

scholarly journals Familial hemiplegic migraine type 1 mutations W1684R and V1696I alter G protein-mediated regulation of CaV2.1 voltage-gated calcium channels

2012 ◽  
Vol 1822 (8) ◽  
pp. 1238-1246 ◽  
Author(s):  
Edgar Garza-López ◽  
Alejandro Sandoval ◽  
Ricardo González-Ramírez ◽  
María A. Gandini ◽  
Arn Van den Maagdenberg ◽  
...  
Keyword(s):  
Calcium Channels ◽  
G Protein ◽  
Familial Hemiplegic Migraine ◽  
Hemiplegic Migraine ◽  
Voltage Gated ◽  
Voltage Gated Calcium Channels
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