Iwasaki Hirohiko, Yorimitsu Tomohiro, Sato Ken
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan.
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8902, Japan.
FEBS Lett. 2015 May 8;589(11):1234-9. doi: 10.1016/j.febslet.2015.04.006. Epub 2015 Apr 17.
COPII vesicles are formed at specific subdomains of the ER, termed ER exit sites (ERESs). Depending on the cell type, ERESs number from a few to several hundred per cell. However, whether these ERESs are functionally and compositionally identical at the cellular level remains unclear. Our live cell-imaging analysis in Saccharomyces cerevisiae revealed that the isoforms of cargo-adaptor subunits are unequally distributed to each ERES at steady state, whereas this distribution is altered in response to UPR activation. These results suggest that in S. cerevisiae cargo loading to ERES is dynamically controlled in response to environmental changes.
COPII囊泡在被称为内质网出口位点（ERESs）的内质网特定亚结构域形成。根据细胞类型的不同，每个细胞中的内质网出口位点数量从几个到几百个不等。然而，这些内质网出口位点在细胞水平上在功能和组成上是否相同仍不清楚。我们在酿酒酵母中进行的活细胞成像分析表明，货物衔接子亚基的异构体在稳态下不均匀地分布到每个内质网出口位点，而这种分布会随着未折叠蛋白反应（UPR）激活而改变。这些结果表明，在酿酒酵母中，内质网出口位点的货物装载是根据环境变化动态控制的。
