Hosobuchi M, Kreis T, Schekman R
Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Nature. 1992 Dec 10;360(6404):603-5. doi: 10.1038/360603a0.
Non-clathrin coated vesicles have been implicated in early steps of intercompartmental transport. A distinct set of coat proteins are peripherally associated with the exterior of purified mammalian intra-Golgi transport vesicles. The 'coatomer', a cytosolic complex containing a similar subunit composition to and sharing at least one subunit (beta-COP) with the coat found on vesicles, has been postulated to be the precursor of this non-clathrin coat. Here we describe the characterization of SEC21, an essential gene required for protein transport from the endoplasmic reticulum to the Golgi in the yeast Saccharomyces cerevisiae. The 105K product of this gene, Sec21p, participates in a cytosolic complex that we show to be a yeast homologue of the mammalian coatomer. These observations demonstrate that a non-clathrin coat protein plays an essential role in intercompartmental transport.
非网格蛋白包被囊泡参与了细胞内不同区室间运输的早期步骤。一组独特的包被蛋白与纯化的哺乳动物高尔基体内运输囊泡的外部周边相关。“外被体”是一种胞质复合物，其亚基组成与囊泡上发现的包被相似，并且至少共享一个亚基（β-COP），据推测它是这种非网格蛋白包被的前体。在此，我们描述了SEC21的特性，SEC21是酿酒酵母中蛋白质从内质网运输到高尔基体所需的一个必需基因。该基因的105K产物Sec21p参与了一个胞质复合物，我们证明它是哺乳动物外被体的酵母同源物。这些观察结果表明，一种非网格蛋白包被蛋白在细胞内不同区室间运输中起着至关重要的作用。
