CaV1.2 | voltage-dependent, L type, alpha 1C subunit calcium channel
Family:
Calcium channels
Subgroups:
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)
Topology:
Six transmembrane alpha helices (S1–S6), total of four homologous domains make up the tetrameric alpha subunit structure
Assembling:
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
CaV1.2: Background Information
CaV1.2 is a subunit of L-type voltage-dependent calcium channel. In the heart it forms a complex with the subunits β2 and α2δ1 in a 1:1:1 ratio. The alpha-1 consists of 24 transmembrane segments and is the pore forming element through which ions pass into the cell, whereas the β2 and α2δ1 subunits modulate the channel function. CaV1.2 is widely expressed in the smooth muscle, pancreatic cells, fibroblasts, and neurons. However, it is particularly important and well known for its expression in the heart where it mediates L-type currents, which causes calcium-induced calcium release from the ER Stores via ryanodine receptors. It depolarizes at -30 mV and helps define the shape of the action potential in cardiac and smooth muscle. CaV1.2 is inhibited by the action of STIM1.
Gene:
CACNA1C
Human Protein:
UniProt Q13936
Tissue:
Heart, brain, lymphocytes, prostate, bladder, uterus ,stomach, colon, placenta, adrenal gland
Function/ Application:
Ca2+ entry in excitable cells
Pathology:
Arterial hypertension, Long QT syndrome, schizophrenia, Timothy syndrome, BRGDA3, bipolar disorder, schizophrenia
Interaction:
Kir/Gem, CSN5/Jab1, β1-4 subunits, α2δ subunits, NF-κB, osteoprotegerin
Modulator:
Verapamil, nifedipine, kurtoxin, calcicludine, mibefradil, calciseptine, BAYK-8644, verapamil
Assays:
Patch Clamp: whole cell, room temperature
Particularities:
CaV channels often show a rundown phenomenon. Adequate intra- and extrcellular solutions are essential for a good data quality.
Recommended Reviews:
Catterall WA, Perez-Reyes E, Snutch TP, Striessnig J (2005). "International Union of Pharmacology. XLVIII. Nomenclature and structure-function relationships of voltage-gated calcium channels". Pharmacol Rev. 57 (4): 411–25.
Data and Applications
CaV1.2 - Pharmacology of Nifedipine, using the CiPA protocol
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) data and applications:
Cells were kindly provided by Charles River.
Screenshots of the PatchControl 384 software showing hCaV1.2/β2/α2δ1 current traces in response to the CiPA voltage step protocol and the corresponing current-voltage relationship plot. Measured on the SyncroPatch 384PE using perforated patch methodology (Escin) and multi-hole chips (4 holes per well), the success rate of valuable data for the analysis was 94%. The IC50 value of Nifedipine was determined as 106 nM.
Cardiac Ion Channels - Pharmacology of Sotalol
CardioExcyte 96 and SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) data and applications:
Cells were kindly provided by Charles River and Cellular Dynamics.
The image on the left hand side displays the results of the blocking effect of Sotalol on hERG. The result is in good agreement with manual patch clamp data (Crumb et al., 2016). The compound induced arrhythmia when iPSC-CM were exposed to a minimum concentration of 10 µM. Arrhytmic events were both detected in field potential recordings as well as in the impedance based contractility measurements.
Cardiac Ion Channels - Pharmacology of Vandetanib
CardioExcyte 96 and 
Patchliner data and applications:
Cells were kindly provided by Charles River and Cellular Dynamics.
The image on the left hand side displays the results of the blocking effect of Vandetanib on hERG, NaV1.5, CaV1.2 and KV4.3. The compound induced arrhythmia when iPSC-CM were exposed to a minimum concentration of 1 µM. Arrhytmic events were both detected in field potential recordings as well as in the impedance based contractility.
CaV1.2 - Current Voltage Relationship
SyncroPatch 96 (a predecessor model of SyncroPatch 384PE) data and applications:
Shown are raw current traces (top) and the constructed peak current-voltage relationship (bottom) of CaV1.2 (HEK293) recorded on the SyncroPatch 96.
CaV1.2 - Stable recording from frozen stock cells
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) data and applications:
Cells were kindly provided by Charles River.
Screenshots of the PatchControl 384 software showing hCaV1.2β2/α2δ1 current traces in response to a voltage step protocol and the corresponing current-voltage relationship plot. Measured on the SyncroPatch 384PE using perforated patch methodology (Escin) and multi-hole chips (4 holes per well), the success rate of valuable data for the analysis was 100 %. The cells were used from a frozen cell stock (after induction) and recorded stably for more than 20 minutes. The IC50 value of Nifedipine was determined as 21 nM.
Cardiomyocytes (Ventricular Myocytes) - Recordings
Port-a-Patch data and applicatons:
Thanks to S. Rakovic and D. Terrar from University of Oxford, for preparing the cardiomyocytes used in these experiments.
Ca2+ current recorded from a ventricular myocyte. Raw current voltage relationship and peak current data are plotted (top). From the IV-plot the half-activating voltage was determined as -16 mV. The current was later blocked by the L-type Ca2+ channel blocker, nifedepine (10 µM). Currents were elicited by stepping to +10 mV for 200 ms from a holding potential of -40 mV every 5 seconds.
Application Notes
CaV1.2 - "Stability and Pharmacology of CaV1.2 Channels on Nanion’s SyncroPatch 384PE"
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) application note 
(5.3 MB)
Cells were kidly provided by Charles River.
CaV1.2 - "High Throughput Pharmacology of CaV1.2 Channels on Nanion’s SyncroPatch 384PE"
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) application note: (2.7 MB)
Cells were kindly provided by SB Drug Discovery.
Cardiomyocytes - "Impedance and EFP recordings of Pluricyte Cardiomyocytes on the CardioExcyte 96"
CardioExcyte 96 Application Note (1.3 MB)
Cells were kindly provided by Ncardia.
Cardiomyocytes - "Impedance and EFP recordings of Cor.4U cells using Nanion’s CardioExcyte 96"
CardioExcyte 96 Application Note (1.3 MB)
Cells were kindly provided by Ncardia.
Cardiomyocytes - "Combining automated patch clamp, impedance and EFP of hiPSC-CMs"
CardioExcyte 96 SyncroPatch 3984PE (a predecessor model of SyncroPatch 384i) Patchliner Application Note
Cells kindly provided by Takara-Clonetech.
Cardiac Ion Channels - "Simultaneous Assessment of CiPA Stipulated Ion Channels on the SyncroPatch 384PE"
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) application note (1.3 MB)
Cells were kindly provided by Charles River.
Cardiac Ion Channels - "High Throughput Screening of Cardiac Ion Channels"
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) Patchliner CardioExcyte 96 application note (2.3 MB)
Posters
2018 - High throughput automatic patch clamp: Applications for Safety Pharmacology
SyncroPatch 384PE (a predecessor model of the SyncroPatch 384i) poster, JSPS Meeting 2018 (2.3 MB)
2017 - Cardiomyocytes in Voltage Clamp and Current Clamp by Automated Patch Clamp
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) and Patchliner poster, BPS Meeting 2017 (1.7 MB)
2015 - High Throughput Automated Patch Clamp of Ion Channels Important in Cardiac Safety and Drug Discovery
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) poster, Chantest Meeting 2015 (1.9 MB)
Slide Decks
2017 - HTS in Cardiac Safety
CardioExcyte 96 presentation (slide deck) (4.0 MB)
Publications
2019 - The patient-independent human iPSC model – a new tool for rapid determination of genetic variant pathogenicity in long QT syndrome
CardioExcyte 96 publication in Heart Rhythm (2019)
Authors:
Chavali, N.V., Kryshtal, D.O., Parikh, S.S., Wang, L., Glazer, A.M., Blackwell, D.J., Kroncke, B.M., Shoemaker, M.B., Knollmann, B.C.
2019 - Postpartum hormones oxytocin and prolactin cause pro-arrhythmic prolongation of cardiac repolarization in long QT syndrome type 2
Port-a Patch Publication in EP Europace (2019)
Authors:
Bodi I., Sorge J., Castiglione A., Glatz S.M., Wuelfers E.M., Franke G., Perez-Feliz S., Koren G., Zehender M., Bugger H., Seemann G., Brunner M., Bode C., Odening K.E.
2019 - Electrophysiological evaluation of pentamidine and 17-AAG in human stem cell-derived cardiomyocytes for safety assessment
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) article in European Journal of Pharmacology (2019)
Authors:
Asahi Y., Nomura F., Abe Y., Doi M., Sakakura T., Takasuna K., Yasuda K.
2017 - Structural and electrophysiological dysfunctions due to increased endoplasmic reticulum stress in a long-term pacing model using human induced pluripotent stem cell-derived ventricular cardiomyocytes
CardioExcyte 96 publication in Stem Cell Research and Therapy (2017)
Authors:
Cui C., Geng L., Shi J., Zhu Y., Yang G., Wang Z., Wang J., Chen M.
2017 - L-Type Calcium Channel Inhibition Contributes to the Proarrhythmic Effects of Aconitine in Human Cardiomyocytes
Patchliner publication in PLoS ONE (2017)
Authors:
Wu J., Wang X., Chung Y.Y. Koh C.H. Liu Z., Guo H., Yuan Q., Wang C., Su S., Wei H.
2017 - Correlation between human ether-a-go-go related gene channel inhibition and action potential prolongation
Patchliner publication in British Journal of Pharmacology (2017)
Authors:
Saxena P., Hortigon‐Vinagre M.P., Beyl S.,Baburin I., Andranovits S., Iqbal S.M., Costa A., IJzerman A.P., Kügler P., Timin E., Smith G.L., Hering S.
2016 - Automated Electrophysiological and Pharmacological Evaluation of Human Pluripotent Stem Cell-Derived Cardiomyocytes
Patchliner publication in Stem Cells and Development (2016)
Authors:
Rajamohan D., Kalra S., Hoang M.D., George V., Staniforth A., Russell H., Yang X., Denning C.
2015 - Novel screening techniques for ion channel targeting drugs
Patchliner, SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) and CardioExcyte 96 publication in Channels (2015)
Authors:
Obergrussberger A., Stölzle-Feix S., Becker N., Brüggemann A., Fertig N., Möller C.
2014 - New strategies in ion channel screening for drug discovery: are there ways to improve its productivity?
SyncroPatch 384PE (a predecessor model of SyncroPatch 384i) publication in Journal of Laboratory Automation (2014)
Authors:
Farre C., Fertig N.