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Ca²⁺ Channels As Integrators of G Protein-Mediated Signaling in Neurons

Department of Pharmacology and Biological Chemistry, Mount Sinai School of Medicine, New York, New York

Received May 3, 2004; accepted July 19, 2004

	Abstract

Top Abstract Classification and Structure of... Mechanisms of G Protein-Mediated... Integration in Loop I-II:... Integration between GPCR and... RGS3 and Calcium-Dependence of... Conclusions References

 
The observations from Dunlap and Fischbach that transmitter-mediated shortening of the duration of action potentials could be caused by a decrease in calcium conductance led to numerous studies of the mechanisms of modulation of voltage-dependent calcium channels. Calcium channels are well known targets for inhibition by receptor-G protein pathways, and multiple forms of inhibition have been described. Inhibition of Ca²⁺ channels can be mediated by G protein -subunits or by kinases, such as protein kinase C and tyrosine kinases. In the last few years, it has been shown that integration of G protein signaling can take place at the level of the calcium channel by regulation of the interaction of the channel pore-forming subunit with different cellular proteins.

	Classification and Structure of High-Voltage-Activated Calcium Channels

Top Abstract Classification and Structure of... Mechanisms of G Protein-Mediated... Integration in Loop I-II:... Integration between GPCR and... RGS3 and Calcium-Dependence of... Conclusions References

 
High voltage-activated calcium channels are classified into Ca_v1.1–3 and Ca_v2.1–3 types based on the gene encoding the pore subunit and their electrophysiological and pharmacological properties. Ca_v1-type channels are ubiquitous (Table 1). They play an important role in excitation-contraction in cardiac and skeletal muscle (Catterall, 2000). Ca_v2.1 and Ca_v2.2 channels are involved in neurotransmission and can coexist in the same nerve terminals (Dunlap et al., 1995). Until recently, the Ca_v2.3 channel was less characterized because of its lack of sensitivity to any known pharmacological blocker. The use of SNX482 as a blocker for this type of channel should facilitate the studies of the function and regulation of Ca_v2.3 channels (Bourinet et al., 2001).

Voltage-dependent calcium channels are multimeric proteins composed of ₁-, -, ₂-, and -subunits (Fig. 1). The ₁-subunit is the pore-forming subunit and accounts for the voltage-dependence of the channel. Channel blockers and naturally occurring toxins exert their actions by binding to this subunit. So far, four -subunits, four -subunits (Qin et al., 2002), and eight -subunits (Tomita et al., 2003) have been cloned. Coexpression of -subunits with different -subunits results in differences in rates of inactivation. In the Ca_v2.2 calcium channel, the -subunit plays a role in the properties of voltage-dependence, prepulse facilitation, and modulation by G proteins (Hanlon et al., 1999). Heterologous expression experiments have shown that in the absence of channel -subunit, the ₁-subunit is retained in the endoplasmic reticulum (Bichet et al., 2000). Under basal conditions (in the absence of transmitter), coexpression of the ₁-subunit with a -subunit puts the channel in a "reluctant" state (Herlitze et al., 2001).

View larger version (32K): [in this window] [in a new window]   Fig. 1. Subunit composition of voltage-dependent calcium channels. Schematic representation of the subunits of voltage-dependent calcium channels. Inset within the 1-subunit represents the six-transmembrane domains found in each of the four repeats of this 24 transmembrane pore-forming subunit. The Src homology domain 3 (SH3) and guanylate kinase domain (GK) are shown in the -subunit.

Overlapping phenotypes observed in mouse models for epilepsy and ataxia are directly related to mutations in genes encoding the auxiliary subunits that help to form the calcium channel complex. The "lethargic" mouse has a mutation in the ₄-subunit that might result in lack of functional expression of the protein (Burgess et al., 1997). These mice display a neurobehavioral phenotype that includes hypoactivity, absence epilepsy, and chronic ataxia. Of the -subunits, ₂, ₃, and ₄ are expressed in brain (Sharp et al., 2001). Kang et al. (2001) have shown that coexpression of ₂ with the _1B- and ₃-subunits in Xenopus laevis oocytes slows the kinetics of activation; the inhibitory effects of ₂ were dependent on the coexpression of ₂. The "stargazer" mouse, which exhibits features that are characteristic of absence epilepsy, and the "waggler" mouse, which exhibits severe ataxia and impaired cerebellar synapse maturation, have mutations in the ₂-subunit. Less is known about the ₂-subunits. A truncation of the ₂₂-subunit has been associated with the phenotype of the "Ducky" mouse (named because of its wide gait), a model for absence epilepsy and ataxia (Brodbeck et al., 2002).

	Mechanisms of G Protein-Mediated Modulation of Cav2.2 Channels

Top Abstract Classification and Structure of... Mechanisms of G Protein-Mediated... Integration in Loop I-II:... Integration between GPCR and... RGS3 and Calcium-Dependence of... Conclusions References

 
Transmitters were first found to inhibit the duration of action potentials in embryonic chick dorsal root ganglion (DRG) neurons (Dunlap and Fischbach, 1978). Subsequent experiments using patch-clamp techniques showed that the effect on the action potential was a result of the inhibition of voltage-dependent calcium channels (Dunlap and Fischbach, 1981). A wide range of transmitters is known to inhibit calcium influx though Ca_v2.1 and Ca_v 2.2 channels through the activation of seven-transmembrane, G protein-coupled receptors (GPCRs) (Hille, 1994; Ikeda and Dunlap, 1999). This review focuses on the modulation of Ca_v2.2 channels.

Many of the receptors known to induce modulation of calcium channels are coupled to heterotrimeric G_i/o proteins, as shown by the observation that pretreatment of cells with pertussis toxin abolishes inhibition of calcium channels (Holz et al., 1986). Inhibition of calcium channels can occur through membrane-delimited or second messenger-mediated signals. The membrane-delimited pathway is mediated by the direct binding of G protein -subunits (G) and results in voltage-dependent inhibition of Ca_v2.2 channels (Fig. 2b) (for review, see Ikeda and Dunlap, 1999). The structural basis of this modulation will be discussed in the next section.

View larger version (35K): [in this window] [in a new window]   Fig. 2. Multiple G protein-mediated pathways inhibit Cav2.2 channels. a, calcium influx through voltage-gated calcium channels during an action potential. In the absence of receptor activation, the G protein exists in its GDP-bound, heterotrimeric form. b, upon receptor activation, the G protein dissociates into -GTP and . G-subunits can bind to the calcium channel, resulting in the inhibition of calcium influx. c, calcium channels can be modulated by protein kinase C. GPCRs coupled to Gi or Gq activate phospholipase C (PLC). Activation of PLC results in the production of inositol 1,4,5-triphosphate (IP3), which releases calcium from internal stores, and diacylglycerol (DAG), a lipid activator of PKC. d, activation of GPCRs can activate nonreceptor tyrosine kinases (TyrK), which can phosphorylate calcium channels.

Phosphorylation is a common mechanism for modulation of ion channels. Early work on Ca_v1 channel modulation in non-neuronal system, such as skeletal muscle and heart, has shown that the channels were a substrate for phosphorylation by cAMP-dependent protein kinase (Catterall, 2000). In neurons, receptors such as the -adrenergic receptor and dopamine D1/D5 receptors modulate Ca_v1 channels through cAMP-dependent pathways. Neuronal Ca_v1 channels are located mainly in the cell bodies and have been shown to regulate transcription through a cAMP-dependent pathway (Catterall, 2000). Ca_v2.2 channels, the focus of this review, are not main targets for modulation by cAMP. Activation of protein kinase C (PKC) results in enhancement of Ca_v2.1 and Ca_v2.2 current (Swartz et al., 1993; Zhu and Ikeda, 1994). Activators of PKC inhibit calcium current in chick DRG neurons (Rane and Dunlap, 1986); it is not known whether the difference observed in DRG neurons is a consequence of variability in the channel sequence. Some differences have been observed in the latency and time course of the effects of activation of PKC on Ca_v2.1 and Ca_v2.2 currents. One possibility is that PKC isozymes target different calcium channel subtypes and might exist in complex with the channel. This notion is supported by a recent report that shows that PKC forms a complex with the Ca_v2.2 channel in rat hippocampal and cortical neurons (Maeno-Hikichi et al., 2003).

Modulation of calcium current by protein kinase C can occur through the activation of G_i or G_q. In the case of G_i, the -subunits activate phospholipase C, which leads to the activation of protein kinase C (Fig. 2c). This response is prevented by pertussis toxin. G_q can inhibit Ca_v2.2 channels in a pertussis toxin-insensitive manner through G_q-mediated activation of phospholipase C. This mechanism has also been reported to be involved in the modulation of Ca_v2.3 channels by muscarinic receptors. Experiments in which Ca_v2.3 channels and muscarinic receptors (M1, M3, and M5 receptor subtypes) receptors are expressed in human embryonic kidney 293 cells show that activation of G_q and PKC is required for modulation (Bannister et al., 2004).

In the last few years, it has been reported that voltage-dependent calcium channels can be modulated by tyrosine kinases (Fig. 2d). The modulation of calcium channels by tyrosine kinases can take place in either short or long time scales. Receptor tyrosine kinases can modulate channel activity by increasing the expression levels of calcium channels. This response occurs at the transcription level and is observed several hours to days after receptor activation. Long-term exposure of rat hippocampal neurons to brain-derived neurotrophic factor (BDNF) induces the synthesis of Ca_v2 channels at the soma (Baldelli et al., 2002). BDNF increases the fraction of Ca_v2.1 and Ca_v2.2 channels contributing to evoked miniature inhibitory postsynaptic currents (Baldelli et al., 2002). In a shorter time scale, Src kinase has been shown to regulate synaptic transmission (Yu and Salter, 1999). Calcium channels are potential targets for this regulation, and it could explain the effects on synaptic transmission. Src kinase forms a complex with Ca_v2.2 channels in rat hippocampal and embryonic chick DRG neurons (Richman et al., 2004). Heterologous expression of Ca_v2.2 channels in COS-7 cells has shown that these channels are modulated by inhibitors of Src kinase (Wijetunge et al., 2002).

A third mechanism of modulation of calcium channels may be the binding of PIP₂ to the channel. This lipid has been shown to interact with G protein-regulated inward-rectifier K⁺ channels bringing the N and C termini of the channel near the inner surface of the membrane (Lei et al., 2003). PIP₂ prevents the rundown of Ca_v2.1 and Ca_v2.2 channels expressed in Xenopus laevis oocytes and plays a role in transmitter-mediated modulation of Ca_v2.2 channels in bullfrog sympathetic neurons (Wu et al., 2002). Because the presence of PIP₂ is required for G-mediated modulation of G protein-regulated inward-rectifier K⁺ channels (Lei et al., 2003), it will be important to test whether PIP₂ regulates the effects of G on Ca_v2.2 current.

Molecular Basis for G Protein-Mediated Modulation of Ca_v2.2 Channels
The molecular cloning of the channel has facilitated structure-function studies; the ₁-subunit has been the focus of many of these studies. Figure 3 summarizes the sites of interaction in the ₁-subunit of Ca_v2.2 channel reported thus far. The intracellular loop I–II of the ₁-subunit has been found to interact with the -subunit of the channel (Witcher et al., 1995) in the region of amino acids 387–400. The consensus sequence for this site found in both Ca_v1.x and Ca_v2.x is QQxExxLxGYxxWIxxxE. In addition, in this site, the G protein -subunits bind directly to the channel loop I–II (aa 359–389), inducing voltage-dependent inhibition. G protein modulation is inferred to be a result of the disruption of channel-subunit interaction. Regions of the C terminus (rat aa 2036–2074) may also be involved in this interaction (Qin et al., 1997).

View larger version (21K): [in this window] [in a new window]   Fig. 3. Interaction of the 1-subunit with cellular proteins. Schematic representation of the 24-transmembrane spanning regions of Cav2.2 1-subunit. The calcium channel -subunit (Cav) and G protein -subunit () bind to loop I-II. SNAP-25, syntaxin, synaptotagmin, and cysteine string protein bind to loop II–III aa 726–984; Mint-1 and CASK bind to the C terminus.

The II–III loop region (aa 726–984) of the Ca_v2.2 channel interacts with some synaptic proteins, such as the v-SNARE synaptotagmin and the t-SNAREs SNAP-25 and syntaxin (Mochida et al., 1996) (Fig. 3). The region of the channel at which this interaction takes place (aa 726–984) has been named the synprint region (Catterall, 1999). The synprint-SNARE interaction is disrupted by channel phosphorylation by cAMP- and calmodulin-dependent kinases (Catterall, 1999). Because SNARE proteins are involved in vesicle fusion and calcium sensitivity during exocytosis, these findings are of great interest.

The C terminus of the ₁-subunit of the Ca_v2.2 calcium channel interacts with the first PDZ (Postsynaptic, Disc large, Zona occludens) domain of Munc-18 interacting protein (Mint-1) and the Src homology 3 (SH3) domain of CASK, two presynaptic modular adapter proteins (Spafford and Zamponi, 2003) (Fig. 3). In addition, calmodulin can bind to the C terminus, conferring the molecular basis for the calcium-dependent inactivation of voltage-dependent calcium channels (Spafford and Zamponi, 2003).

Although the Ca_v-subunit has been found to have a SH3-guanylate kinase module that regulates inactivation of the channel (McGee et al., 2004), there are no published reports of regulation of this module in a receptor-dependent fashion.

	Integration in Loop I–II: Cross-Talk between G Protein Subunits and Protein Kinase C

Top Abstract Classification and Structure of... Mechanisms of G Protein-Mediated... Integration in Loop I-II:... Integration between GPCR and... RGS3 and Calcium-Dependence of... Conclusions References

 
Multiple G protein-mediated pathways are known to converge to modulate calcium channels. The complex timing of events is controlled by interactions between components of several signaling pathways and a dynamic network of cytoskeletal and scaffold structures that can serve as the stratum for interaction between these components and the calcium channel. As the signaling pathways involved in calcium channel regulation have been identified and characterized, some of the questions that have arisen are: 1) Do these signaling pathways interact with each other? 2) Do they converge at the level of the channel level or are there upstream coincidence detection points for integration? 3) What are the rate-limiting steps? What molecular complexes are involved in these rate-limiting steps and thus responsible for the time course of transmitter-mediated responses? For the remainder of this review, we will discuss examples that illustrate the integration of signals at the level of the calcium channel.

The loop I–II of the ₁-subunit is phosphorylated by PKC in a region near the G protein binding site. Phosphorylation of threonine 422 can account for both PKC-mediated up-regulation of channel activity and antagonism of G protein-mediated inhibition (Cooper et al., 2000). Phosphorylation of threonine 422 or an amino acid substitution that mimics phosphorylation T422E prevents somatostatin- and opiate-induced modulation of Ca_v2.2 channels (Cooper et al., 2000). The cross-talk between protein kinase C and the G-subunits is dependent on the G-subunit; phosphorylation by PKC prevents channel modulation by G₁ but does not prevent the effects of other G combinations (Feng et al., 2001). Activation of PKC does not prevent calcium channel modulation by GTP or its hydrolysis-resistant analog guanosine 5'-O-(3-thio)triphosphate. Experiments performed in neonatal rat superior cervical ganglion neurons showed that in the absence of G protein activation, activators of PKC were without effect (Barrett and Rittenhouse, 2000). All these results suggest that phosphorylation by PKC prevents the calcium channel from going into a reluctant or inhibited state.

	Integration between GPCR and Tyrosine Kinase Signaling at the Level of the Calcium Channel

Top Abstract Classification and Structure of... Mechanisms of G Protein-Mediated... Integration in Loop I-II:... Integration between GPCR and... RGS3 and Calcium-Dependence of... Conclusions References

 
Src kinase can work both as an "on" and "off" signal in the modulation of Ca_v2.2 channels. This kinase is preassociated with the Ca²⁺ channel such that it is rapidly activated by the receptors and regulates the magnitude of the inhibition of the Ca²⁺ channel. During the onset of channel modulation by GABA_B receptors, Src kinase phosphorylates the ₁-subunit of the calcium channel (Schiff et al., 2000). The sites of tyrosine phosphorylation by Src kinase in the synprint region and the C terminus of the ₁-subunit (Richman et al., 2004) are conserved in Ca_v2.1 and Ca_v2.2 channels in most species. Inhibition of Src kinase results in changes in the magnitude of the modulation of GABA-induced voltage-independent inhibition. A second effect of the activation of Src kinase is the recruitment of members of the Ras pathway (Fig. 4), which determines of the rate of onset of GABA-mediated inhibition of Ca²⁺ current (Richman et al., 2004). PYK-2, a member of the focal adhesion kinase family, is recruited downstream from Src kinase and is also involved in the determination of the rate of onset of transmitter-mediated inhibition of calcium current. The calcium dependence of PYK-2 activity provides a point of integration of calcium signaling. The decrease in calcium influx will result in less activation of PYK-2 and a decrease in channel modulation, creating a feedback mechanism in the regulation of calcium influx. Recruitment of ShcC, the neuronal form of the Shc adaptor protein, takes place, resulting in activation and recruitment to the calcium channel complex of the Ras exchange factor Sos (Richman et al., 2004). Whereas the GABA-induced activation of MAP kinase does not alter channel activity, it provides a potential mechanism for long-term changes in the cellular environment as a result of changes in channel activity.

View larger version (18K): [in this window] [in a new window]   Fig. 4. Schematic representation of the Src- and Ras-mediated pathways activated by GABAB receptors in embryonic chick DRG neurons. GPCR represents the G protein-coupled receptor, which in this case is the GABAB receptor. The lines ending in a dot represent signal molecules that interact with the calcium channel, resulting in inhibition of the current; lines with arrowheads represent the flow of the signal and activation of the signal molecule; dashed lines represent positive feedback from the calcium channel resulting in the activation of PYK2. Abbreviations: Src, p60 Src kinase; PYK2, proline-rich tyrosine kinase, a calcium-dependent member of the focal adhesion kinase family; Shc, adaptor protein; SOS, son of sevenless, a Ras guanine nucleotide exchange factor; Ras, monomeric GTP-binding protein; MEK, mitogen-activated protein kinase kinase; MAP, mitogen-activated protein.

Modulation of calcium channels by G protein-coupled receptors is a transient phenomenon; neurons become unresponsive upon prolonged exposure to neurotransmitters. The inhibition of calcium current by GABA_B receptors becomes desensitized within 100 s (Schiff et al., 2000). Tyrosine phosphorylation of the ₁-subunit of the channel makes the channel a target for the binding of RGS12, a member of the "regulator of G protein signaling" (RGS) proteins (Schiff et al., 2000). Introduction of a recombinant protein containing the sequence of the phosphotyrosine binding domain from RGS12 slows the rate of desensitization of GABA-induced voltage-independent inhibition of Ca_v2.2 calcium channels, whereas the PDZ domain is without effect. RGS12 coprecipitates with the tyrosine-phosphorylated calcium channel, whereas pretreatment with genistein, a tyrosine kinase inhibitor, decreases the degree of association (Schiff et al., 2000).

	RGS3 and Calcium-Dependence of Transmitter-Mediated Inhibition of Cav2.2 Channels

Top Abstract Classification and Structure of... Mechanisms of G Protein-Mediated... Integration in Loop I-II:... Integration between GPCR and... RGS3 and Calcium-Dependence of... Conclusions References

 
A calcium-feedback mechanism that controls the rate of desensitization of transmitter-mediated inhibition of calcium current has recently been described by Tosetti et al. (2003). They reported that two splicing variants of RGS3 alter the rate of desensitization of GABA_B-mediated inhibition of Ca_v2.2 calcium channels in chick DRG neurons. A rapid effect is mediated by the EF-hand of one of the variants, whereas a slower effect on desensitization is mediated by a variant that lacks the EF-hand and calmodulin. This kind of regulation creates a feedback loop in which the time course of transmitter-mediated inhibition of presynaptic calcium channels could be controlled by synaptic activity.

	Conclusions

Top Abstract Classification and Structure of... Mechanisms of G Protein-Mediated... Integration in Loop I-II:... Integration between GPCR and... RGS3 and Calcium-Dependence of... Conclusions References

 
A wide range of transmitters converges in the modulation of neuronal voltage-dependent calcium channels through the activation of G protein-coupled receptors (Fig. 5). A given transmitter can activate several signaling pathways mediated through different receptor subtypes (Fig. 5). Interactions between Ca_v2.2 channels and signaling molecules can determine the time course of Ca²⁺ channel modulation. Over the long term, such interactions could also affect neuronal function by regulating gene expression. Thus, the integration of signals by channel-dependent scaffolding could offer the framework to produce a variety of presynaptic responses that underlie the long and short-term changes in synaptic function in neurons. Identification of the properties of systems that determine the timing and magnitude of Ca ²⁺ influx is critical for understanding synaptic physiology. Characterization of the endogenous molecular components and spatiotemporal distribution of the neuronal calcium channel macromolecular complexes will be of great importance in the understanding of cellular communication in the nervous system.

View larger version (24K): [in this window] [in a new window]   Fig. 5. G protein-coupled receptors involved in the modulation of Cav2.2 channels. Schematic representation of receptor-G protein coupling to different signaling pathways known to inhibit Cav2.2 channels. Abbreviations: PLC, phospholipase C; 2AR, 2-adrenergic receptor; mGluR1,metabotropic glutamate receptor subtype 1; A1, adenosine receptor type 1; M, muscarinic receptor; CB1, cannabinoid receptor type 1.

	Footnotes

 
This work was supported by National Institutes of Health grant NS37443 and a Hirschl Trust Fund Career Development Award (to M.D.P.).

Article, publication date, and citation information can be found at http://molpharm.aspetjournals.org.

doi:10.1124/mol.104.002261.

ABBREVIATIONS: DRG, dorsal root ganglion; PKC, protein kinase C; BDNF, brain-derived neurotrophic factor; aa, amino acid(s); SNARE, soluble N-ethylmaleimide-sensitive factor attachment protein receptor; SNAP, soluble N-ethylmaleimide-sensitive factor attachment protein; SH3, Src homology 3; RGS, regulator of G protein signaling; GPCR, G protein-coupled receptor; CASK, Ca²⁺/calmodulin-dependent kinase-like domain, SH3 domain, and a guanylate kinase-like domain containing protein; PIP2, phosphatidylinositol 4,5-bisphosphate.

Address correspondence to: María A. Diversé-Pierluissi, Department of Pharmacology and Biological Chemistry, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1603, New York, NY 10029. E-mail: maria.diverse{at}mssm.edu

	References

Top Abstract Classification and Structure of... Mechanisms of G Protein-Mediated... Integration in Loop I-II:... Integration between GPCR and... RGS3 and Calcium-Dependence of... Conclusions References

 
Baldelli P, Novara M, Carabelli V, Hernandez-Guijo JM, and Carbone E (2002) BDNF up-regulates evoked GABAergic transmission in developing hippocampus by potentiating presynaptic N- and P/Q-type Ca²⁺ channels signalling. Eur J Neurosci 16: 2297-2310.[CrossRef][Medline]

Bannister RA, Melliti K, and Adams BA (2004) Differential modulation of Ca_v2.3 channels by Gq/11-coupled muscarinic receptors. Mol Pharmacol 65: 381-388.[Abstract/Free Full Text]

Barrett CF and Rittenhouse AR (2000) Modulation of N-type calcium channel activity by G-proteins and protein kinase C. J Gen Physiol 115: 277-286.[Abstract/Free Full Text]

Bichet D, Cornet V, Geib S, Carlier E, Volsen S, Hoshi T, Mori Y, and De Waard M (2000) The I-II loop of the Ca²⁺ channel alpha1 subunit contains an endoplasmic reticulum retention signal antagonized by the beta subunit. Neuron 25: 177-190.[CrossRef][Medline]

Bourinet E, Stotz SC, Spaetgens RL, Dayanithi G, Lemos J, Nargeot J, and Zamponi GW (2001) Interaction of SNX482 with domains III and IV inhibits activation gating of _1E (Ca_V2.3) calcium channels. Biophys J 81: 79-88.[Abstract/Free Full Text]

Brodbeck J, Davies A, Courtney JM, Meir A, Balaguero N, Canti C, Moss FJ, Page KM, Pratt WS, Hunt SP, et al. (2002). The ducky mutation in Cacna2d2 results in altered Purkinje cell morphology and is associated with the expression of a truncated 2 2 protein with abnormal function. J Biol Chem 277: 7684-7693.[Abstract/Free Full Text]

Burgess DL, Jones JM, Meisler MH, and Noebels JL (1997) Mutation of the Ca²⁺ channel beta subunit gene Cchb4 is associated with ataxia and seizures in the lethargic (lh) mouse. Cell 88: 385-392.[CrossRef][Medline]

Catterall WA (1999) Interactions of presynaptic Ca²⁺ channels and snare proteins in neurotransmitter release. Ann NY Acad Sci 868: 144-159.[Abstract/Free Full Text]

Catterall WA (2000) Structure and regulation of voltage-gated Ca²⁺ channels. Annu Rev Cell Dev Biol 16: 521-555.[CrossRef][Medline]

Cooper CB, Arnot MI, Feng ZP, Jarvis SE, Hamid J, and Zamponi GW (2000) Cross-talk between G-protein and protein kinase C modulation of N-type calcium channels is dependent on the G-protein subunit isoform. J Biol Chem 275: 40777-40781.[Abstract/Free Full Text]

Diversé-Pierluissi M, Remmers AE, Neubig RR, and Dunlap K (1997) Novel form of cross-talk between G protein and tyrosine kinase pathways. Proc Natl Acad Sci USA 94: 5417-5421.[Abstract/Free Full Text]

Dunlap K and Fischbach GD (1978) Neurotransmitters decrease the calcium component of sensory neurone action potentials. Nature (Lond) 276: 837-839.[CrossRef][Medline]

Dunlap K and Fischbach GD (1981) Neurotransmitters decrease the calcium conductance activated by depolarization of embryonic sensory neurone action. J Physiol 317: 519-535.[Abstract/Free Full Text]

Dunlap K, Luebke JI, and Turner TJ (1995) Exocytotic Ca²⁺ channels in mammalian central neurons. Trends Neurosci 18: 89-98.[CrossRef][Medline]

Feng ZP, Arnot MI, Doering CJ, and Zamponi GW (2001). Calcium channel subunits differentially regulate the inhibition of N-type channels by individual G isoforms. J Biol Chem 276: 45051-45058.[Abstract/Free Full Text]

Hanlon MR, Berrow NS, Dolphin AC, and Wallace BA (1999) Modelling of a voltage-dependent Ca²⁺ channel beta subunit as a basis for understanding its functional properties. FEBS Lett 445: 366-370.[CrossRef][Medline]

Herlitze S, Zhong H, Scheuer T, and Catterall WA (2001) Allosteric modulation of Ca²⁺ channels by G proteins, voltage-dependent facilitation, protein kinase C and Ca_v subunits. Proc Natl Acad Sci USA 98: 4699-4704.[Abstract/Free Full Text]

Hille B (1994) Modulation of ion-channel function by G-protein-coupled receptors. Trends Neurosci 17: 531-536.[CrossRef][Medline]

Holz GG 4th, Rane SG, Dunlap K (1986) GTP-binding proteins mediate transmitter inhibition of voltage-dependent calcium channels. Nature (Lond) 319: 670-672.[CrossRef][Medline]

Ikeda SR and Dunlap K (1999) Voltage-dependent modulation of N-type calcium channels: role of G protein subunits. Adv Second Messenger Phosphoprotein Res 33: 131-142.[Medline]

Kang MG, Chen CC, Felix R, Letts VA, Frankel WN, Mori Y, and Campbell KP (2001) Biochemical and biophysical evidence for 2 subunit association with neuronal voltage-activated Ca²⁺ channels. J Biol Chem 276: 32917-32924.[Abstract/Free Full Text]

Lei Q, Jones MB, Talley EM, Garrison JC, and Bayliss DA (2003) Molecular mechanisms mediating inhibition of G protein-coupled inwardly-rectifying K⁺ channels. Mol Cells 15: 1-9.[Medline]

Maeno-Hikichi Y, Chang S, Matsumura K, Lai M, Lin H, Nakagawa N, Kuroda S, and Zhang JF (2003) A PKC epsilon-ENH-channel complex specifically modulates N-type Ca²⁺ channels. Nat Neurosci 6: 468-475.[Medline]

McGee AW, Nunziato DA, Maltez JM, Prehoda KE, Pitt GS, and Bredt DS (2004) Calcium channel function regulated by the SH3-GK module in beta subunits. Neuron 42: 89-99.[CrossRef][Medline]

Mochida S, Sheng ZH, Baker C, Kobayashi H, and Catterall WA (1996) Inhibition of neurotransmission by peptides containing the synaptic protein interaction site of N-type Ca²⁺ channels. Neuron 4: 781-788.

Qin N, Platano D, Olcese R, Stefani E, and Birnbaumer L (1997) Direct interaction of G with a C-terminal G-binding domain of the Ca²⁺ channel ₁ subunit is responsible for channel inhibition by G protein-coupled receptors. Proc Natl Acad Sci USA 94: 8866-8871.[Abstract/Free Full Text]

Qin N, Yafel S, Momplaisir ML, Codd EE, and D'Andrea MR (2002) Molecular cloning and characterization of the human voltage-gated calcium channel ₂-₄ subunit. Mol Pharmacol 62: 485-496.[Abstract/Free Full Text]

Rane SG and Dunlap K (1986) Kinase C activator oleoylacetylglycerol attenuates voltage-dependent calcium current in sensory neurons. Proc Natl Acad Sci USA 83: 184-188.[Abstract/Free Full Text]

Richman RW, Tombler E, Lau KK, Anantharam A, Rodriguez J, O'Bryan JP, and Diverse-Pierluissi MA (2004) N type Ca ²⁺ channels as scaffold proteins in the assembly of signaling molecules for GABAB receptor effects. J Biol Chem 279: 24649-24658.[Abstract/Free Full Text]

Schiff ML, Siderovski DP, Jordan JD, et al. (2000) Tyrosine-kinase-dependent recruitment of RGS12 to the N-type calcium channel. Nature (Lond) 408: 723-727.[CrossRef][Medline]

Sharp AH, Black JL, Dubel SJ, Sundarraj S, Shen J, Yunker AM, Copeland TD, and McEnery MW (2001) Biochemical and anatomical evidence for specialized voltage-dependent calcium channel gamma isoform expression in the epileptic and ataxic mouse, stargazer. Neuroscience 105: 599-617.[CrossRef][Medline]

Spafford JD and Zamponi GW (2003) Functional interactions between presynaptic calcium channels and the neurotransmitter release machinery. Curr Opin Neurobiol 13: 308-314.[CrossRef][Medline]

Swartz KJ, Merritt A, Bean BP, and Lovinger DM (1993) Protein kinase C modulates glutamate receptor inhibition of Ca²⁺ channels and synaptic transmission. Nature (Lond) 361: 165-168.[CrossRef][Medline]

Tomita S, Chen L, Kawasaki Y, Petralia RS, Wenthold RJ, Nicoll RA, and Bredt DS (2003) Functional studies and distribution define a family of transmembrane AMPA receptor regulatory proteins. J Cell Biol 161: 805-816.[Abstract/Free Full Text]

Tosetti P, Pathak N, Jacob MH, and Dunlap K (2003) RGS3 mediates a calcium-dependent termination of G protein signaling in sensory neurons. Proc Natl Acad Sci USA 100: 7337-7342.[Abstract/Free Full Text]

Witcher DR, De Waard M, Liu H, Pragnell M, and Campbell KP (1995) Association of native Ca²⁺ channel subunits with the ₁ subunit interaction domain. J Biol Chem 270: 18088-18093.[Abstract/Free Full Text]

Wijetunge S, Dolphin AC, and Hughes AD (2002) Tyrosine kinases act directly on the ₁ subunit to modulate Ca_v2.2 calcium channels. Biochem Biophys Res Commun 290: 1246-1249.[CrossRef][Medline]

Wu L, Bauer CS, Zhen XG, Xie C, and Yang J (2002) Dual regulation of voltage-gated calcium channels by PtdIns(4,5)P2. Nature (Lond) 419: 947-952.[CrossRef][Medline]

Yu XM and Salter MW (1999) Src, a molecular switch governing gain control of synaptic transmission mediated by N-methyl-D-aspartate receptors. Proc Natl Acad Sci USA 96: 7697-7704.[Abstract/Free Full Text]

Zhu Y and Ikeda SR (1994) Modulation of Ca²⁺-channel currents by protein kinase C in adult rat sympathetic neurons. J Neurophysiol 72: 1549-1560.[Abstract/Free Full Text]

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