Kurokawa Kazuo, Okamoto Michiyo, Nakano Akihiko
Live Cell Molecular Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
1] Live Cell Molecular Imaging Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan [2] Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Nat Commun. 2014 Apr 14;5:3653. doi: 10.1038/ncomms4653.
Protein transport from the endoplasmic reticulum (ER) to the Golgi apparatus is mediated by coat complex II (COPII) vesicles. It has been believed that COPII vesicles containing cargo are released from the ER exit sites (ERES) into the cytosol and then reach and fuse with the first post-ER compartment, cis-Golgi or ER-to-Golgi intermediate compartment (ERGIC). However, it still remains elusive how cargo loading to vesicles, vesicle budding, tethering and fusion are coordinated in vivo. Here we show, using extremely high speed and high resolution confocal microscopy, that the cis-Golgi in the budding yeast Saccharomyces cerevisiae approaches and contacts the ERES. The COPII coat cage then collapses and the cis-Golgi captures cargo. The cis-Golgi, thus loaded with cargo, then leaves the ERES. We propose that this 'hug-and-kiss' behaviour of cis-Golgi ensures efficient and targeted cargo transport from the ERES to cis-Golgi.
蛋白质从内质网(ER)到高尔基体的运输是由II型被膜小泡(COPII)介导的。人们一直认为,含有货物的COPII小泡从内质网出口位点(ERES)释放到细胞质中,然后到达并与内质网后的第一个区室——顺面高尔基体或内质网-高尔基体中间区室(ERGIC)融合。然而,在体内货物如何装载到小泡、小泡出芽、拴系和融合是如何协调的,仍然不清楚。在这里,我们使用极高速度和高分辨率的共聚焦显微镜显示,出芽酵母酿酒酵母中的顺面高尔基体接近并接触ERES。然后COPII被膜笼解体,顺面高尔基体捕获货物。如此装载了货物的顺面高尔基体随后离开ERES。我们提出,顺面高尔基体的这种“拥抱-亲吻”行为确保了从ERES到顺面高尔基体的高效且有针对性的货物运输。