Cav2.2
Description: calcium channel, voltage-dependent, N type, alpha 1B subunit Gene: Cacna1b Alias: ca2.2, BIII, CACNN, Cav2.2, CACNL1A5, CACNA1B
The N-type calcium channels, also known as a1B or Cav2.2, are high voltage activated (HCA) calcium channels found presynaptically. For a longer introduction, see page 502 in the review [477]. See also the Channelpedia entry for Cav2.1, as this subunit is similar in many respects.
GeneID: 257648 Cacna1b calcium channel, voltage-dependent, N type, alpha 1B subunit [ Rattus norvegicus ]
Transcript
Species | NCBI accession | Length (nt) | |
---|---|---|---|
Human | NM_000718.4 | 9792 | |
Mouse | NM_001042528.2 | 9772 | |
Rat | NM_001195199.1 | 7065 |
Protein Isoforms
Isoforms
Post-Translational Modifications
The Cav2.2 subunit consists of four homologous domains (I–IV), each consisting of six trans- membrane (TM) segments. The domains are linked by intracellular loops and have intracellular N and C termini. (see Fig. 1A) in [88]
See also figure 7 in [90] for a structural connection between Cav2.1 and Cav2.2.
Cav2.2 predicted AlphaFold size
Methodology for AlphaFold size prediction and disclaimer are available here
The most detailed model can be found in [250]. It is from hippocampal mossy fiber boutons.
For a Hodgkin Huxley rate equation for the Ca2.2 (= N-type) current, see [260].
Model CaN (ID=6)
Animal | Cat | |
CellType | RGC | |
Age | 34 Days | |
Temperature | 36.0°C | |
Reversal | 135.0 mV | |
Ion | Ca + | |
Ligand ion | ||
Reference | [259] S J Huang et. al; Neuroscience 1998 Jul | |
mpower | 2.0 | |
m Alpha | (0.1*(v-20)/(1-exp(-(v-20)/10))) If v neq 20 | |
m Beta | 0.4*exp(-(v+25)/18) | |
hpower | 1.0 | |
h Alpha | 0.01*exp(-(v+50)/10) | |
h Beta | 0.1/(1+exp(-(v+17)/17)) |
Cav2.2 can be found in retinal ganglion cells. [259]
Cav2.2 control the excitability in retinal ganglion cells and thus are crucial for the development of the visual system. [250]
G proteins
See figure 10 in [94] for the mechanism of G protein modulation in calcium channels and the effect of palmitoylation on the interaction of Cav-beta subunits with the I–II linker.
Neurokinin 1 Receptor
Unlike R-type channels encoded by CaV2.3, L-type (CaV1.3), N- type (CaV2.2), and P/Q-type (CaV2.1) channels are inhibited, but not stimulated, through Neurokinin 1 receptors. [89]
Beta 3 Subunit
Overexpressed beta 3 subunit (12.5 ng/cell cRNA) significantly suppressed N- and R-type, but not L-type calcium channel currents at holding potentials of 60 and 80 mV.[92]
Roscovitine
Roscovitine, a potent inhibitor of cyclin-dependent kinases 1, 2, and 5, slows the deactivation of P/Q (Cav2.1) and N-type (Cav2.2) calcium channels. [93]
References
Page KM
et al.
N terminus is key to the dominant negative suppression of Ca(V)2 calcium channels: implications for episodic ataxia type 2.
J. Biol. Chem.,
2010
Jan
8
, 285 (835-44).
Meza U
et al.
Neurokinin 1 receptors trigger overlapping stimulation and inhibition of CaV2.3 (R-type) calcium channels.
Mol. Pharmacol.,
2007
Jan
, 71 (284-93).
Vitko I
et al.
Orientation of the calcium channel beta relative to the alpha(1)2.2 subunit is critical for its regulation of channel activity.
PLoS ONE,
2008
, 3 (e3560).
Yasuda T
et al.
Overexpressed Ca(v)beta3 inhibits N-type (Cav2.2) calcium channel currents through a hyperpolarizing shift of ultra-slow and closed-state inactivation.
J. Gen. Physiol.,
2004
Apr
, 123 (401-16).
Buraei Z
et al.
Slowed N-type calcium channel (CaV2.2) deactivation by the cyclin-dependent kinase inhibitor roscovitine.
Biophys. J.,
2005
Sep
, 89 (1681-91).
Leroy J
et al.
Interaction via a key tryptophan in the I-II linker of N-type calcium channels is required for beta1 but not for palmitoylated beta2, implicating an additional binding site in the regulation of channel voltage-dependent properties.
J. Neurosci.,
2005
Jul
27
, 25 (6984-96).
Helton TD
et al.
Neuronal L-type calcium channels open quickly and are inhibited slowly.
J. Neurosci.,
2005
Nov
2
, 25 (10247-51).
Raghib A
et al.
Dominant-negative synthesis suppression of voltage-gated calcium channel Cav2.2 induced by truncated constructs.
J. Neurosci.,
2001
Nov
1
, 21 (8495-504).
Li L
et al.
Differential gating and recruitment of P/Q-, N-, and R-type Ca2+ channels in hippocampal mossy fiber boutons.
J. Neurosci.,
2007
Dec
5
, 27 (13420-9).
Huang SJ
et al.
Activation and inactivation properties of voltage-gated calcium currents in developing cat retinal ganglion cells.
Neuroscience,
1998
Jul
, 85 (239-47).
Benison G
et al.
Modeling temporal behavior of postnatal cat retinal ganglion cells.
J. Theor. Biol.,
2001
May
21
, 210 (187-99).
Catterall WA
Structure and regulation of voltage-gated Ca2+ channels.
Annu. Rev. Cell Dev. Biol.,
2000
, 16 (521-55).
Black JL
The voltage-gated calcium channel gamma subunits: a review of the literature.
J. Bioenerg. Biomembr.,
2003
Dec
, 35 (649-60).
Mintz IM
et al.
Block of calcium channels in rat neurons by synthetic omega-Aga-IVA.
Neuropharmacology,
1993
Nov
, 32 (1161-9).
Contributors: Rajnish Ranjan, Michael Schartner
To cite this page: [Contributors] Channelpedia https://channelpedia.epfl.ch/wikipages/79/ , accessed on 2024 Mar 19