Effects of PMCA and SERCA pump overexpression on the kinetics of cell Ca2+ signalling
Effects of PMCA and SERCA pump overexpression on the kinetics of cell Ca2+ signalling
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DOI：
10.1093/emboj/19.18.4926
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发表时间：
2000-09-15
期刊：
影响因子：
11.4
通讯作者：
Carafoli, E
中科院分区：
文献类型：
--
作者：
Brini, M;Bano, D;Carafoli, E
活性Ca2+运输的主要途径的动态相互作用已经通过改变其组分的表达在活细胞中进行了分析。质膜（PMCA）和内质网（ER） （SERCA） Ca2+泵在CHO细胞中短暂过表达，并使用Ca2+敏感光蛋白aequorin特异性靶向嵌合体研究了亚细胞室中的Ca2+稳态。在静息细胞中，PMCA和SERCA泵的过表达分别导致ER [Ca2+]水平的降低和增加；而细胞质和线粒体[Ca2+]无显著差异。在肌醇1,4,5-三磷酸（IP3）生成激动剂的刺激下，线粒体和细胞质Ca2+的振幅上升相关，ER [Ca2+]仅达到阈值，超过阈值，Ca2+对IP3通道的反馈抑制似乎是有限的。
The dynamic interactions of the main pathways for active Ca2+ transport have been analysed in living cells by altering the expression of their components. The plasma membrane (PMCA) and the endoplasmic reticulum (ER) (SERCA) Ca2+ pumps were transiently overexpressed in CHO cells, and the Ca2+ homeostasis in the subcellular compartments was investigated using specifically targeted chimaeras of the Ca2+-sensitive photoprotein aequorin, In resting cells, overexpression of the PMCA and SERCA pumps caused a reduction and an increase in ER [Ca2+] levels, respectively; while no significant differences were detected in cytosolic and mitochondrial [Ca2+]. Upon stimulation with an inositol 1,4,5-trisphosphate (IP3)-generating agonist, the amplitude of the mitochondrial and cytosolic Ca2+ rises correlated,vith the ER [Ca2+] only up to a threshold value, above which the feedback inhibition of the IP3 channel by Ca2+ appeared to be limiting.