Store-Operated Ca2+ Entry in Muscle Physiology

Marco      Brotto; Noah      Weisleder; Jianjie      Ma

doi:10.2174/2212796810701010087

Abstract

Store-operated Ca2+ entry (SOCE) represents a unique Ca2+ entry mechanism, where Ca2+ channels located on the plasma membrane sense the Ca2+ filling status of intracellular Ca2+ stores and gate the entry of Ca2+ from the extracellular reservoir to replenish intracellular Ca2+ storage. This pathway has received great interest not only because of its unusual nature as a retrograde signal, but also due to its wide occurrence in both excitable and non-excitable cells and its potential role in various physiological and pathophysiological situations. In skeletal muscle, contractility is contingent upon the maintenance of intracellular Ca2+ homeostasis, which requires the preservation of low levels of resting cytosolic Ca 2+, readily available releasable pool of Ca2+ from the sarcoplasmic reticulum, as well as functional Ca2+ uptake and extrusion mechanisms. Recent studies have demonstrated that SOCE is present in skeletal muscle, and may play a significant role in muscle physiology. While the need for SOCE is increased during strenuous muscle exercise and fatigue, disruption of this process can lead to pathophysiological conditions. Repressed SOCE activity has been linked to aging related dysfunction. Elevated SOCE could lead to elevated intracellular Ca2+ in dystrophic muscle cells and progression of muscular dystrophy. The role of SOCE in the physiology and pathophysiology of skeletal muscle is a subject of increasing interest in the muscle biology field. Manipulation of SOCE by chemical, pharmacological and genetic approaches should have great potential in the treatment of muscle disorders that involve dysfunctional Ca2+ homeostasis.

Keywords: transient receptor potential (TRP) protein, Muscle fatigue, Aging, skeletal muscle fibers death, sarcoplasmic reticulum (SR)

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