核融合基因KAR2和新型蛋白质是内质网膜融合所必需的。

The karyogamy gene KAR2 and novel proteins are required for ER-membrane fusion.

作者信息

Latterich M, Schekman R

机构信息

Howard Hughes Medical Institute, University of California, Berkeley 94720.

出版信息

Cell. 1994 Jul 15;78(1):87-98. doi: 10.1016/0092-8674(94)90575-4.

DOI:10.1016/0092-8674(94)90575-4

PMID:8033215

Abstract

We have developed assays using cells and isolated membranes to identify factors mediating fusion of the ER-nuclear membrane network in yeast. When cells containing distinctly tagged ER-nuclear envelope membranes are observed during mating, the markers of both parental membranes become colocalized in a process sharing a genetic requirement with karyogamy. Using isolated membranes, we find that fusion between ER compartments requires ATP, but not cytosol, Sec17p (alpha-SNAP), or Sec18p (NSF), the latter two being required at the fusion step in vesicular transport. Proteins tightly associated with the ER membrane are essential for fusion, as is Kar2p (BiP), an ER lumenal hsp70 homolog. BiP may activate an ER-localized fusogen, allowing nuclear fusion and karyogamy in yeast.

摘要

我们开发了利用细胞和分离的膜来鉴定介导酵母内质网 - 核膜网络融合因子的检测方法。在酵母交配过程中观察含有明显标记的内质网 - 核被膜的细胞时，双亲膜的标记物在一个与核融合有共同遗传需求的过程中会共定位。利用分离的膜，我们发现内质网区室之间的融合需要ATP，但不需要细胞质、Sec17p（α - SNAP）或Sec18p（NSF），后两者是囊泡运输融合步骤所必需的。与内质网膜紧密相关的蛋白质对于融合至关重要，内质网腔hsp70同源物Kar2p（BiP）也是如此。BiP可能激活内质网定位的融合蛋白，从而使酵母中的核融合和核配得以发生。