Ultra-rapid activation and deactivation of store-operated Ca(2+) entry in skeletal muscle.

Edwards JN, Murphy RM, Cully TR, von Wegner F, Friedrich O, Launikonis BS (2010)

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2010

Journal

Cell calcium

Book Volume: 47

Pages Range: 458-67

Journal Issue: 5

URI: http://www.sciencedirect.com/science/article/pii/S0143416010000643

DOI: 10.1016/j.ceca.2010.04.001

Abstract

Skeletal muscle is highly specialized for the rapid delivery of Ca(2+) to the contractile apparatus during excitation-contraction coupling (EC coupling). Previous studies have shown the presence of a relatively fast-activated store-operated Ca(2+) entry (SOCE) mechanism (<1s) to be present in skeletal muscle, unlike the situation occurring in non-excitable cells. We simultaneously imaged [Ca(2+)] in the t-system and cytoplasm in mechanically skinned fibers during SR Ca(2+) release and observed both cell-wide Ca(2+) release and Ca(2+) waves. SOCE activation followed cell-wide Ca(2+) release from high sarcoplasmic reticulum (SR) [Ca(2+)] ([Ca(2+)](SR)) by seconds, consistent with depletion of [Ca(2+)](SR) to an absolute threshold for SOCE and an unformed SOCE complex at high [Ca(2+)](SR). Ca(2+) waves occurred at low [Ca(2+)](SR), close to the threshold for SOCE, minimizing the time between Ca(2+) release and Ca(2+) influx. Local activation of SOCE during Ca(2+) waves occurred in approximately 27ms following local initiation of SR depletion indicating a steep relationship between [Ca(2+)](SR) and SOCE activation. Most of this delay was due to slow release of Ca(2+) from SR, leaving only milliseconds at most for the activation of Ca(2+) entry following store depletion. SOCE was also observed to deactivate effectively instantly during store refilling at low [Ca(2+)](SR). These rapid kinetics of SOCE persisted as subsequent Ca(2+) waves propagated along the fiber. Thus we show for the first time millisecond activation and deactivation of SOCE during low amplitude [Ca(2+)](SR) oscillations at low [Ca(2+)](SR). To account for the observed Ca(2+) movements we propose the SOCE complex forms during the progressive depletion of [Ca(2+)](SR) prior to reaching the activation threshold of SOCE and this complex remains stable at low [Ca(2+)](SR).

Authors with CRIS profile

Oliver Friedrich Lehrstuhl für Medizinische Biotechnologie

Related research project(s)

Membrane Excitability and Cellular Calcium Regulation in the peripheral Nervous System under different (patho)-physiological Conditions and in Inflammatory Disease (ARC International Linkage Fellowship) April 1, 2008 - March 31, 2009

Involved external institutions

La Trobe University AU Australia (AU) University of Queensland AU Australia (AU) Goethe-Universität Frankfurt am Main DE Germany (DE)

How to cite

APA:

Edwards, J.N., Murphy, R.M., Cully, T.R., von Wegner, F., Friedrich, O., & Launikonis, B.S. (2010). Ultra-rapid activation and deactivation of store-operated Ca(2+) entry in skeletal muscle. Cell calcium, 47(5), 458-67. https://doi.org/10.1016/j.ceca.2010.04.001

MLA:

Edwards, Joshua N., et al. "Ultra-rapid activation and deactivation of store-operated Ca(2+) entry in skeletal muscle." Cell calcium 47.5 (2010): 458-67.

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