Figure 1

Ca²⁺ movements and related proteins in skeletal muscle. (a) Proteins that are related to, or involved in, EC coupling, relaxation, ECCE, SOCE, integrin signaling, Tie2 signaling or TRPC-mediated extracellular Ca²⁺ entry in skeletal muscle are presented. Ang, angiopoietin; CSQ, calsequestrin; DHPR, dihydropyridine receptors; EC, excitation–contraction; ECCE, excitation-coupled Ca²⁺ entry; JP, junctophilin; MG, mitsugumin; RyR1, ryanodine receptor 1; SERCA1a, sarcoplasmic/endoplasmic reticulum Ca²⁺-ATPase 1a; SOCE, store-operated Ca²⁺ entry; SR, sarcoplasmic reticulum; STIM1, stromal interaction molecule 1; STIM1L, long form of STIM1; Tie2 R, Tie2 receptor; TRPC, canonical-type transient receptor potential cation channels; t-tubule, transverse-tubule. (b) Directions of the signals are presented. Outside-in means signals from the extracellular space or sarcolemmal (or t-tubule) membrane to the inside of cells such as cytosol, the SR membrane or the SR (arrows colored in red). Inside-out means the direction of outside-in signals in reverse (arrows colored in black). (c) The directions of Ca²⁺ movements during EC coupling, relaxation, ECCE, SOCE, integrin signaling, Tie2 signaling or TRPC-mediated extracellular Ca²⁺ entry in skeletal muscle are presented (dashed arrows).