Voltage-dependent effects of dihydropyridine Ca agonists on cardiac L-type Ca channels

Adrenergic Signaling Controls RGK-Dependent Trafficking of Cardiac Voltage-Gated L-Type Ca Channels Through PKD1

Ca(2+)-dependent inactivation of cardiac L-type Ca2+ channels does not affect their voltage sensor

Inactivation of currents carried by Ba2+ and Ca2+, as well as intramembrane charge movement from L-type Ca2+ channels were studied in guinea pig ventricular myocytes using the whole-cell patch clamp technique. Prolonged (2 s) conditioning depolarization caused substantial reduction of charge movement between -70 and 10 mV (charge 1, or charge from noninactivated channels). In parallel, the char...

Cav1.4 1 Subunits Can Form Slowly Inactivating Dihydropyridine-Sensitive L-Type Ca Channels Lacking Ca -Dependent Inactivation

The neuronal L-type calcium channels (LTCCs) Cav1.2 1 and Cav1.3 1 are functionally distinct. Cav1.3 1 activates at lower voltages and inactivates more slowly than Cav1.2 1, making it suitable to support sustained L-type Ca 2 inward currents (ICa,L ) and serve in pacemaker functions. We compared the biophysical and pharmacological properties of human retinal Cav1.4 1 using the whole-cell patchc...

Roles of a1 and a1/b Subunits Derived from Cardiac L-Type Ca Channels on Voltage-Dependent Facilitation Mechanisms

diac calcium (Ca) channel plays a crucial role in excitation–contraction coupling in cardiac and other muscles. The cardiac Ca channel comprises four subunits: a1, b, and a2/d. The pore-forming a1 subunit involves the most important functional elements of the L-type Ca channel, including a selectivity filter, a voltage sensor, a motif for Ca-dependent inactivation, and a binding site for dihydr...

Local Ca Entry Through L-Type Ca Channels Activates Ca-Dependent K Channels in Rabbit Coronary Myocytes

Large-conductance Ca-dependent K channels (KCa), which are abundant on the sarcolemma of vascular myocytes, provide negative feedback via membrane hyperpolarization that limits Ca entry through L-type Ca channels (ICaL). We hypothesize that local accumulation of subsarcolemmal Ca 21 during ICaL openings amplifies this feedback. Our goal was to demonstrate that Ca entry through voltage-gated ICa...