CaV3.2 | voltage-dependent, T type, alpha 1H subunit calcium channel
L-Type (CaV1.1–CaV1.4), P/Q-Type (CaV2.1), N-Type (CaV2.2), R-Type (CaV2.3), T-Type (CaV3.1–CaV3.3)
Six transmembrane alpha helices (S1–S6), total of four homologous domains make up the tetrameric alpha subunit structure
One large alpha subunit forms a functional channel, accessory subunits ( α1, α2δ, β1-4, and γ) are crucial for robust expression, they functionally modulate the alpha subunit
CaV3.2: Background Information
CaV3.2 give rise to the T-type currents: Low-voltage-activated calcium channels are referred to as 'T' type because their currents are both transient, owing to fast inactivation, and tiny, owing to small conductance. T-type channels are thought to be involved in pacemaker activity, low-threshold calcium spikes, neuronal oscillations and resonance, and rebound burst firing. T-type channels serve pacemaking functions in both central neurons and cardiac nodal cells and support calcium signaling in secretory cells and vascular smooth muscle. They may also be involved in the modulation of firing patterns of neurons which is important for information processing as well as in cell growth processes.
In the adrenal zona glomerulosa, CaV3.2 participates in the signaling pathway leading to aldosterone production in response to either AGT/angiotensin II, or hyperkalemia. Furthermore, CaV3.2 has a proexcitatory impact in small-diameter nociceptors expressing mechanoactivated channels. It is expressed in primary sensory neurons of the dorsal root ganglion (DRG) and contributes to nociceptive and neuropathic pain. CaV3.2 participates in the development of inflammatory hyperalgesia and might play an important role in the sub-acute phase of inflammatory pain due to increased co-localization with TRPV1 receptors.
Brain, ovary, placenta, vascular smooth muscle
Pacemaker activity (brain, heart), hormone secretion, fertilization
Angina, epilepsy (CAE6, EIG6), sleep, breast cancer, autism, pain, cardiac hypertrophy, Hyperaldosteronism, Familial, Type Iv
GNG2, KCNMA1, KDM5B, CACNA1s, CACNBs, CACNGs, NCAM
Kurtoxin, mibefradil, flunarizine, zonisamide, bepridil, nifedipine
Patch Clamp: whole cell, room temperature
CaV channels often show a rundown phenomenon. Adequate intra- and extracellular solutions are essential for a good data quality.
Reviews and Links
- Catterall et al. (2005) International Union of Pharmacology. XLVIII. Nomenclature and structure-function relationships of voltage-gated calcium channels. Pharmacol Rev. 57 (4): 411–25.