Calcium dynamics in the peroxisomal lumen of living cells
Calcium dynamics in the peroxisomal lumen of living cells
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DOI：
10.1074/jbc.m800600200
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发表时间：
2008-05-23
影响因子：
4.8
通讯作者：
Pozzan, Tullio
中科院分区：
文献类型：
--
作者：
Drago, Ilaria;Giacomello, Marta;Pozzan, Tullio
我们在这里描述了产生新的，绿色荧光蛋白为基础的Ca2+指标针对过氧化物酶体管腔。我们发现(i)活细胞中静止状态下过氧化物酶体的Ca2+浓度与胞浆中的Ca2+浓度相似；（ii）细胞质内Ca2+浓度的增加（由Ca2+从储存中动员或Ca2+通过质膜Ca2+通道流入引起）随后是胞内[Ca2+]的缓慢上升；（iii） Ca2+内流进入过氧化物酶体既不是由atp依赖性泵驱动，也不是由膜电位驱动，也不是由H+(Na+)梯度驱动。过氧化物酶体膜似乎起着低通过滤作用，防止细胞器吸收短暂的细胞质Ca2+瞬态，但在长时间的Ca2+增加期间，允许过氧化物酶体腔内[Ca2+]与细胞质的平衡。因此，过氧化物酶体似乎是一种额外的细胞质Ca2+缓冲液，但它们的内流和外排机制不同于任何其他细胞器。
We here describe the generation of novel, green fluorescent protein-based Ca2+ indicators targeted to the peroxisome lumen. We show that (i) the Ca2+ concentration of peroxisomes in living cells at rest is similar to that of the cytosol; ( ii) increases in cytosolic Ca2+ concentration ( elicited by either Ca2+ mobilization from stores or Ca2+ influx through plasma membrane Ca2+ channels) are followed by a slow rise in intraperoxisomal [ Ca2+]; ( iii) Ca2+ influx into peroxisomes is driven neither by an ATP-dependent pump nor by membrane potential nor by a H+(Na+) gradient. The peroxisomal membrane appears to play a low pass filter role, preventing the organelle from taking up shortlasting cytosolic Ca2+ transients but allowing equilibration of the peroxisomal luminal [Ca2+] with that of the cytosol during prolonged Ca2+ increases. Thus, peroxisomes appear to be an additional cytosolic Ca2+ buffer, but their influx and efflux mechanisms are unlike those of any other cellular organelle.