Auxiliary subunits of voltage-dependent ion channels can be subdivided into two classes. One class consists of the entirely cytoplasmic intracellular subunits, which have no transmembrane domains such as the b subunit of the voltage-dependent Ca channel and the b subunit of the voltage-dependent K channel. The other class of auxiliary subunits contains at least one transmembrane domain and an e...

The crucial role of L-type Ca2+ channels in the initiation of cardiac and smooth muscle contraction has made them major therapeutic targets for the treatment of cardiovascular disease. L-type channels share a common pharmacological profile, including high-affinity voltage- and frequency-dependent block by the phenylalkylamines, the benz(othi)azepines, and the dihydropyridines. These drugs are t...

When a cell's transmembrane potential is increased from a physiological one to more than 370 mV, the transmembrane current increases more than hundredfold within a millisecond. This is due to the formation of conductive pores in the membrane. We construct a model in which we conceive of pore formation as a voltage sensitive chemical reaction. The model predicts the logarithm of the pore formati...

The transmembrane potential of voltage-clamped squid giant axon is increased to compensate for a reduction in the rate of potassium channel kinetics when artificial seawater with trivalent erbium ion is substituted for artificial seawater. The additional potential required to produce an equivalent rise time is a measure of the potential shift produced by the erbium ions. When the kinetics of K+...

(A) a2d associates with a1 to regulate the properties of voltage-gated calcium channels. a2d consists of two domains, the extracellular a2 domain and the transmembrane domain d, which are linked by disulfide bonds. Various protein interaction motifs are found on a2. (B) a2d regulates synapse formation and shape independently of voltage-gated calcium channels: a possible model. Thrombospondins, ...

We present a palette of brightly fluorescent genetically encoded voltage indicators (GEVIs) with excitation and emission peaks spanning the visible spectrum, sensitivities from 6 – 10% F/F per 100 mV, and half-maximal response times from 1 – 7 ms. A fluorescent protein is fused to an Archaerhodopsin-derived voltage sensor. Voltage-induced shifts in the absorption spectrum of the rhodopsin lead...