Cell Biology Caveolae Conducting Calcium

Caveolae are specialized membrane domains that function in endocytosis and contain relatively high concentrations of signaling molecules. Isshiki et al. now present evidence that caveolae serve as preferential sites of Ca²⁺ influx across the plasma membrane when intracellular stores of Ca²⁺ are depleted. The authors fused the calcium sensor yellow chameleon 3.1 to the COOH-terminal end of caveolin-1 to target the sensor to caveolae. Then, they compared Ca²⁺ signals at the caveolae to those from unmodified yellow chameleon in the cytoplasm or from another fusion protein that targeted the sensor to the plasma membrane. When Ca²⁺ was depleted from the endoplasmic reticulum of fetal bovine endothelial cells by exposure of the cells to adenosine triphosphate (ATP) and thapsigargin, Ca²⁺ entry into the cells occurred preferentially at caveolae, apparently through store-operated channels of the TRP (transient receptor potential) family. The authors propose that caveolae may function as preassembled, compartmentalized signaling units that can be recruited when needed by exocytosis and fusion with the plasma membrane

M. Isshiki, Y. Ying, T. Fujita, R. G. W. Anderson, A molecular sensor detects signal transduction from caveolae in living cells. J. Biol. Chem. 277, 43389-43398 (2002). [Abstract] [Full Text]

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A Molecular Sensor Detects Signal Transduction from Caveolae in Living Cells

Masashi Isshiki, Yun-shu Ying, Toshiro Fujita, and Richard G. W. Anderson (1 November 2002)
J. Biol. Chem. 277 (45), 43389. [DOI: 10.1074/jbc.M205411200]
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