Related Experiment Video
Updated: Aug 19, 2026

Primary Culture of Adult Rat Heart Myocytes
Published on: June 16, 2009
Essential role of the beta subunit in modulation of C-class L-type Ca2+ channels by intracellular pH
K Schuhmann1, C Voelker, G F Höfer
1Institut für Pharmakologie und Toxikologie, Karl-Franzens-UniversitätGraz, Austria.
Abstract:
Elevation of intracellular pH (pHi) enhances the activity of native L-type Ca2+ channels in cardiac and smooth muscle. We studied the modulation by pHi of expressed L-type Ca2+ channels comprised of either the alpha1c subunits alone or of alpha1c plus beta2a subunits. Ca2+ channels were expressed in human embryonic kidney cells (HEK 293) and pHi was increased from a basal level of 7.3 to 8.3 by exposure of cells to NH4Cl (20 mM) or by elevation of extracellular pH to 8.5. Elevation of pHi enhanced the activity of Ca2+ channels derived by coexpression of alpah1c and beta2a subunits. This alkalosis-induced stimulation of channel activity was mainly due to an increase in channel availability. Channels derived by expression of alpha1c alone were not affected by intracellular alkalosis. Our results demonstrate that the pHi sensitivity of L-type Ca2+ channels is conferred by the beta subunit of the channel complex.
More Related Videos
13:40Live Cell Calcium Imaging Combined with siRNA Mediated Gene Silencing Identifies Ca2+ Leak Channels in the ER Membrane and their Regulatory Mechanisms
Published on: July 7, 2011
11:33Dissection of Local Ca2+ Signals in Cultured Cells by Membrane-targeted Ca2+ Indicators
Published on: March 22, 2019
Related Concept Videos
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Activation and Inactivation of G Proteins
G-Protein Gated Ion Channels
Sensory organs,...
IP3/DAG Signaling Pathway
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...