Mitochondria Recycle Ca 2 1 to the Endoplasmic Reticulum and Prevent the Depletion of Neighboring Endoplasmic Reticulum Regions*
Mitochondria Recycle Ca 2 1 to the Endoplasmic Reticulum and Prevent the Depletion of Neighboring Endoplasmic Reticulum Regions*
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发表时间：
2001
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通讯作者：
S. Arnaudeau;W. Kelley;J. Walsh;N. Demaurex
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作者：
S. Arnaudeau;W. Kelley;J. Walsh;N. Demaurex
为了研究线粒体和内质网（ER）之间的Ca 2 - 1通量，我们使用了“cameleon”指标针对细胞质，ER腔，和线粒体基质。高亲和力的线粒体探针饱和; 20%的线粒体在组胺刺激的HeLa细胞，而低亲和力的探针报告的平均峰值为106 - 6 - 5 M，表明钙2 - 1瞬变达到高水平的线粒体的一部分。在同时ER测量，[Ca 2 1 ] ER平均371 6 21 m M在休息和减少到133 6 14 m M和59 6 5 m M后，组胺和毒胡萝卜素刺激，分别表明，大量的ER再填充发生在激动剂刺激。寡霉素和鱼藤酮阻断线粒体Ca 2 1摄取或CGP 3715 7阻断线粒体Ca 2 1流出时，内质网的耗竭程度更大，表明线粒体摄取的Ca 2 1有一部分被重新用于内质网的再填充。因此，靠近线粒体的内质网区域释放的Ca 2+比缺乏线粒体的内质网区域少.毒胡萝卜素，寡霉素/鱼藤酮，
To study Ca 2 1 fluxes between mitochondria and the endoplasmic reticulum (ER), we used “cameleon” indicators targeted to the cytosol, the ER lumen, and the mitochondrial matrix. High affinity mitochondrial probes saturated in ; 20% of mitochondria during histamine stimulation of HeLa cells, whereas a low affinity probe reported averaged peak values of 106 6 5 m M , indicating that Ca 2 1 transients reach high levels in a fraction of mitochondria. In concurrent ER measurements, [Ca 2 1 ] ER averaged 371 6 21 m M at rest and decreased to 133 6 14 m M and 59 6 5 m M upon stimulation with histamine and thapsigargin, respectively, indicating that substantial ER refilling occur during agonist stimulation. A larger ER depletion was observed when mitochondrial Ca 2 1 uptake was prevented by oligomycin and rotenone or when Ca 2 1 efflux from mitochondria was blocked by CGP 37157, indicating that some of the Ca 2 1 taken up by mitochondria is re-used for ER refilling. Accordingly, ER regions close to mitochondria released less Ca 2 1 than ER regions lacking mitochondria. The ER heterogeneity was abolished by thapsigargin, oligomycin/rotenone,