Yoshida Hiderou
Department of Biophysics, Graduate School of Science, Kyoto University, Japan.
IUBMB Life. 2009 Sep;61(9):871-9. doi: 10.1002/iub.229.
The endoplasmic reticulum (ER) response has been thought a cytoprotective mechanism to cope with accumulation of unfolded proteins in the ER. Recent progress has made a quantum leap revealing that ER stress response can be regarded as an autoregulatory system adjusting the ER capacity to cellular demand. This Copernican change raised a novel fundamental question in cell biology: how do cells regulate the capacity of each organelle in accordance with cellular needs? Although this fundamental question has not been fully addressed yet, research about each organelle has been advancing. The proliferation of the peroxisome is regulated by the PPAR alpha pathway, whereas the abundance of mitochondria appears to be regulated by mitochondrial retrograde signaling and the mitochondrial unfolded protein response. The functional capacity of the Golgi apparatus may be regulated by the mechanism of the Golgi stress response. These observations strongly suggest the existence of an elaborate network of organelle autoregulation in eukaryotic cells.
内质网（ER）应激反应一直被认为是一种应对内质网中未折叠蛋白积累的细胞保护机制。最近的进展取得了重大突破，揭示了内质网应激反应可被视为一种根据细胞需求调节内质网容量的自动调节系统。这一哥白尼式的转变在细胞生物学中提出了一个新的基本问题：细胞如何根据细胞需求调节每个细胞器的容量？尽管这个基本问题尚未得到充分解决，但关于每个细胞器的研究一直在推进。过氧化物酶体的增殖受PPARα途径调节，而线粒体的丰度似乎受线粒体逆行信号传导和线粒体未折叠蛋白反应调节。高尔基体的功能能力可能受高尔基体应激反应机制调节。这些观察结果强烈表明真核细胞中存在一个精细的细胞器自动调节网络。
