Department of Pathology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel.
Leibniz Institute for Age Research - Fritz Lipmann Institute, Jena, Germany.
Bioessays. 2022 Oct;44(10):e2200064. doi: 10.1002/bies.202200064. Epub 2022 Aug 19.
An entirely different mechanism and localization were recently proposed for the COPII coat complex, challenging its well-accepted function to select and concentrate cargo into small COPII-coated spherical transport vesicles. Instead, the COPII complex is suggested to form a dynamic yet stationary collar that forms a boundary between the ER and the ER export membrane domain. This membrane domain, the ER exit site (ERES), is the site of COPII-mediated sorting and concentration of transport competent proteins. Subsequently, the ERES is implicated to mature and bud to form a sizeable pleiomorphic transport carrier that translocate on microtubules to fuse with the Golgi apparatus. Despite this drastic mechanistic dogma shift, most of the underlying protein-protein and protein-membrane interactions remain unchanged. Here, we attempt to provide a detailed description of the newly proposed model of how ER to Golgi transport works by describing the role of several essential proteins of the transport machinery.
最近提出了一种完全不同的机制和定位，用于 COPII 外套复合物，这对其公认的功能提出了挑战，即选择和浓缩货物到小的 COPII 包裹的球形运输小泡中。相反，COPII 复合物被认为形成一个动态但稳定的套管，形成内质网和内质网出口膜域之间的边界。这个膜域，内质网出口部位（ERES），是 COPII 介导的运输能力蛋白分拣和浓缩的部位。随后，ERES 被认为成熟并出芽形成一个相当大的多形态运输载体，该载体在微管上移位并与高尔基体融合。尽管这种机械教条发生了巨大的转变，但大多数潜在的蛋白质-蛋白质和蛋白质-膜相互作用仍然保持不变。在这里，我们试图通过描述运输机制的几个基本蛋白质的作用，详细描述 ER 到高尔基体运输的新提出的模型。
