Anatomy

Neuroscience

Triad (sociology)

Organic chemistry

Signal transducing adaptor protein

Voltage-dependent calcium channel

Calcium signaling

Muscle contraction

Biology

Ryanodine receptor

Biophysics

Psychoanalysis

Coupling (piping)

Psychology

Chemistry

Metallurgy

Materials science

RYR1

Skeletal muscle

Calcium

Signal transduction

Cell biology

Calmodulin

T-type calcium channel

Calcium channel

N-type calcium channel

Biochimica et Biophysica Acta (BBA) - Molecular Cell Research

Excitation-contraction coupling is the signaling process by which action potentials control calcium release and consequently the force of muscle contraction. Until recently, three triad proteins were known to be essential for skeletal muscle EC coupling: the voltage-gated calcium channel CaV1.1 acting as voltage sensor, the SR calcium release channel RyR1 representing the only relevant calcium source, and the auxiliary CaV β1a subunit. Whether CaV1.1 and RyR1 are directly coupled or whether their interaction is mediated by another triad protein is still unknown. The recent identification of the adaptor protein STAC3 as fourth essential component of skeletal muscle EC coupling prompted vigorous research to reveal its role in this signaling process. Accumulating evidence supports its possible involvement in linking CaV1.1 and RyR1 in skeletal muscle EC coupling, but also indicates a second, much broader role of STAC proteins in the regulation of calcium/calmodulin-dependent feedback regulation of L-type calcium channels.

STAC proteins: The missing link in skeletal muscle EC coupling and new regulators of calcium channel function