As a consequence of hypoosmotic shock, yeast cells swell rapidly and increase the surface area by ∼20% in 20 s. Approximately, 35% of this surface increase is mediated by the ER-plasma membrane contact sites, specifically the tricalbins, which are required for the delivery of both lipids and the GPI-anchored protein Crh2 from the cortical ER to the plasma membrane. Therefore, we propose a new function for the tricalbins: mediating the fusion of the ER to the plasma membrane at contact sites. This proposed fusion is triggered by calcium influx via the stretch-gated channel Cch1 and is supported by the anoctamin Ist2.

中文翻译：

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内质网-质膜接触位点输送内质网脂质和蛋白质，以实现细胞表面的快速扩张。


由于低渗休克，酵母细胞迅速膨胀，表面积在 20 秒内增加约 20%。大约 35% 的表面增加是由 ER 质膜接触位点介导的，特别是三卡宾，它是将脂质和 GPI 锚定蛋白 Crh2 从皮质 ER 递送到质膜所必需的。因此，我们提出了三卡宾的新功能：介导内质网与质膜在接触位点的融合。这种融合是由钙通过拉伸门控通道 Cch1 流入触发的，并得到 anoctamin Ist2 的支持。