• Open Access

Subplasma membrane Ca2+ signals

Authors

  • John G. McCarron,

    Corresponding author
    1. Strathclyde Institute of Pharmacy and Biomedical Sciences, 27 Taylor Street, University of Strathclyde, Glasgow, UK
    • Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, John Arbuthnott Building, 161 Cathedral Street, Glasgow G4 0NR, UK
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    • Tel.: 44 141 548 4119. Fax: 44 141 552 2569;

  • Susan Chalmers,

    1. Strathclyde Institute of Pharmacy and Biomedical Sciences, 27 Taylor Street, University of Strathclyde, Glasgow, UK
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  • Marnie L. Olson,

    1. Strathclyde Institute of Pharmacy and Biomedical Sciences, 27 Taylor Street, University of Strathclyde, Glasgow, UK
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  • John M. Girkin

    Corresponding author
    1. Centre for Advanced Instrumentation, Department of Physics, Durham University, South Road, Durham, UK
    • Centre for Advanced Instrumentation, Department of Physics, Durham University, South Road, Durham DH1 3LE, UK
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    • Tel.: 44 191 33 43589. Fax: 44 191 33 45823;


Abstract

Ca2+ may selectively activate various processes in part by the cell's ability to localize changes in the concentration of the ion to specific subcellular sites. Interestingly, these Ca2+ signals begin most often at the plasma membrane space so that understanding subplasma membrane signals is central to an appreciation of local signaling. Several experimental procedures have been developed to study Ca2+ signals near the plasma membrane, but probably the most prevalent involve the use of fluorescent Ca2+ indicators and fall into two general approaches. In the first, the Ca2+ indicators themselves are specifically targeted to the subplasma membrane space to measure Ca2+ only there. Alternatively, the indicators are allowed to be dispersed throughout the cytoplasm, but the fluorescence emanating from the Ca2+ signals at the subplasma membrane space is selectively measured using high resolution imaging procedures. Although the targeted indicators offer an immediate appeal because of selectivity and ease of use, their limited dynamic range and slow response to changes in Ca2+ are a shortcoming. Use of targeted indicators is also largely restricted to cultured cells. High resolution imaging applied with rapidly responding small molecule Ca2+ indicators can be used in all cells and offers significant improvements in dynamic range and speed of response of the indicator. The approach is technically difficult, however, and realistic calibration of signals is not possible. In this review, a brief overview of local subplasma membrane Ca2+ signals and methods for their measurement is provided. © 2012 IUBMB IUBMB Life, 64(7): 573–585, 2012

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