Protein interactions within the active zone of the nerve terminal are critical for regulation of transmitter release. The SNARE protein syntaxin 1A, primarily known for important interactions that control vesicle fusion, also interacts with presynaptic voltage-gated calcium channels. Based on recordings of calcium channel function in vitro, it has been hypothesized that syntaxin 1A-calcium chan...

Calcium channel blockers, which alter the intracellular calcium concentration by modifying calcium flux across cell membranes and affect various intracellular signaling processes, have been long and widely used to treat essential hypertension and certain types of cardiac diseases such as angina pectoris. Among five subtypes of calcium channels, only specific agents for L-type calcium channels h...

We have developed a quantitative description for calcium permeability of the N-methyl-D-aspartate receptor channel to permit predictions of the reversal potential and calcium influx at different voltages for different extracellular calcium concentrations. Increasing the external calcium concentration markedly shifted the reversal potential to positive values and simultaneously decreased the sin...

Rad, Gem/Kir, Rem, and Rem2 are members of the Ras-related RGK (Rad, Gem, and Kir) family of small GTP-binding proteins. Heterologous expression of RGK proteins interferes with de novo calcium channel assembly/trafficking and dramatically decreases the amplitude of currents arising from preexisting high-voltage-activated calcium channels. These effects probably result from the direct interactio...

Immobile and mobile calcium buffers shape the calcium signal close to a channel by reducing and localizing the transient calcium increase to physiological compartments. In this paper, we focus on the impact of mobile buffers in shaping steady-state calcium gradients in the vicinity of an open channel, i.e. within its "calcium microdomain." We present a linear approximation of the combined react...

The patch clamp technique was used to make whole-cell recordings of calcium channel currents from single muscle cells freshly isolated from rat mesenteric arteries. The cells were found to contain two types of calcium channels; one type is activated by small depolarizations and inactivates quickly, whereas the other requires stronger depolarizations for activation and inactivates more slowly. N...

Voltage-gated calcium channels represent the sole mechanism converting electrical signals of excitable cells into cellular functions such as contraction, secretion and gene regulation. Specific voltage-sensing domains detect changes in membrane potential and control channel gating. Calcium ions entering through the channel function as second messengers regulating cell functions, with the except...