Trends in Neurosciences
Facilitation of Ca2+ current in excitable cells
Section snippets
Facilitation by depolarizing voltage steps
An important means by which Ca2+ current was found to be reversibly enhanced (leading to the term ‘facilitation’[9]) was manipulation of the membrane potential. Facilitation by depolarizing prepulses was first identified in bovine chromaffin cells by Neher and colleagues[10](Fig. 2A–D), and has more recently been investigated in detail by Artalejo and Fox9, 12who observed large enhancements of Ca2+ current, often a doubling[12], compared with the smaller enhancement observed previously[10].
Voltage-dependence of G-protein-mediated effects
It is a well-known phenomenon in a number of neuronal and neurosecretory systems that activation of a pertussis-toxin-sensitive G protein causes inhibition of Ca2+ currents, which is manifested by a reduction in amplitude and usually a slowed activation of the currents (Fig. 3; for review, see Ref. [2]). In a number of cell types, this G protein has been identified as Go, either by reconstitution experiments[66], or by experiments using G-protein-specific antibodies to inhibit function67, 68or
Concluding remarks
Facilitation of Ca2+ current has been studied extensively in bovine chromaffin cells in an elegant series of papers by Artalejo and colleagues9, 12, 14, 79, 89. It is typified by a voltage- and phosphorylation-dependent enhancement of Ca2+ current that might be mimicked by cAMP-dependent phosphorylation and by DHP agonists. In other cell types, it has been found that subsets of the different forms of facilitation might occur in different permutations. For example, in cerebellar granule
References (134)
- et al.
J. Biol. Chem.
(1994) FEBS Lett.
(1993)Neuropharmacology
(1993)J. Biol. Chem.
(1988)J. Biol. Chem.
(1991)- et al.
Neuron
(1993) J. Biol. Chem.
(1988)FEBS Lett.
(1993)FEBS Lett.
(1992)J. Biol. Chem.
(1993)
J. Biol. Chem.
J. Biol. Chem.
Prog. Biophys. Mol. Biol.
Neuron
Neurosci. Lett.
Neuron
Neurosci. Lett.
Neuron
Neuroscience
Neuropharmacology
Neuron
Neuron
Neurosci. Lett.
Cell Physiol. Biochem.
Exp. Physiol.
Ann. NY Acad. Sci.
Science
Experientia
J. Physiol.
J. Physiol.
J. Physiol.
Nature
J. Membr. Biol.
Nature
J. Physiol.
J. Physiol.
Nature
J. Physiol.
Proc. Natl Acad. Sci. USA
J. Neurosci.
Nature
Proc. Natl Acad. Sci. USA
Proc. Natl Acad. Sci. USA
EMBO J.
EMBO J.
Nature
Nature
Proc. Natl Acad. Sci. USA
J. Physiol.
Circ. Res.
Cited by (177)
Biochemistry and Pharmacology of Calmodulin-Regulated Phosphatase Calcineurin
2012, Calmodulin and Signal TransductionNeuropeptide Y modulates calcium channels in hamster submandibular ganglion neurons
2012, Neuroscience ResearchCitation Excerpt :According to biophysical criteria, the mode of inhibition of ICa can be classified into a voltage-dependent (VD)- and a voltage-independent (VI)-mode. In the VD-mode, inhibition of ICa is relieved at a higher potential or by means of a strong depolarizing voltage prepulse to positive voltages (Bean, 1989; Dolphin, 1996), whereas in the VI-mode, inhibition of ICa is not affected by a strong depolarizing voltage prepulse (Formenti et al., 1993). As mentioned above, G-proteins are heterotrimeric molecules with α, β and γ subunits.
Calcitonin gene-related peptide- and adrenomedullin-induced facilitation of calcium current in submandibular ganglion
2011, Archives of Oral BiologyCitation Excerpt :Similar observation has been demonstrated in smooth muscle cells12 and cardiac cells.13 There are several mechanisms of VDCCs facilitation.28,29 L-type VDCCs can be facilitated by protein kinases.
Constitutively active μ-opioid receptors
2010, Methods in EnzymologyCitation Excerpt :First, many studies have shown that depolarizing steps can facilitate ICa independently of the Gβγ pathway, although the ICa affected is usually L-(CaV1.x) or P/Q-type rather than N-type (Dolphin 1996). The facilitation can be associated with channel phosphorylation (Dolphin 1996) or be mediated by a direct effect of Ca (Chaudhuri et al., 2007). Ca-dependent facilitation can be minimized without interfering with Gβγ-mediated channel inhibition by using Ba as the charge carrying cation (Chaudhuri et al., 2007).