Prm1p, a pheromone-regulated multispanning membrane protein, facilitates plasma membrane fusion during yeast mating
Prm1p, a pheromone-regulated multispanning membrane protein, facilitates plasma membrane fusion during yeast mating
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DOI：
10.1083/jcb.151.3.719
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发表时间：
2000-10-30
影响因子：
7.8
通讯作者：
Walter, P
中科院分区：
文献类型：
--
作者：
Heiman, MG;Walter, P
细胞融合发生在整个发育过程中，从受精到器官发生。这些过程中驱动质膜融合的分子机制尚不清楚。虽然酵母交配提供了一个研究细胞融合的极好的模型系统，但所有先前被证明调节这一过程的基因都在细胞壁破裂时或之前起作用，即在两个质膜接触之前。使用一种新的策略，即利用基因组数据来预测哪些基因可能具有给定的功能，我们确定了PrM1，这是一个在交配过程中选择性表达的基因，编码一种多跨跨膜蛋白。Prm1p定位于发生融合的细胞-细胞接触部位。在Delta PRM1突变体之间的交配中，很大一部分细胞启动合子形成并降解分隔交配伙伴的细胞壁，但随后无法融合。电子显微镜分析表明，这些交配对中的两个质膜紧密相对，仅有大约8 nm的均匀间隙，因此，Delta PRM1突变体的表型定义了交配反应中的一个新步骤，即膜可能通过一个明确的粘连连接并列在一起，但仍未融合。这种表型提示Prm1p在质膜融合中起作用。
Cell fusion occurs throughout development, from fertilization to organogenesis. The molecular mechanisms driving plasma membrane fusion in these processes remain unknown. While yeast mating offers an excellent model system in which to study cell fusion, all genes previously shown to regulate the process act at or before cell wall breakdown; i,e,, well before the two plasma membranes have come in contact. Using a new strategy in which genomic data is used to predict which genes may possess a given function, we identified PRM1, a gene that is selectively expressed during mating and that encodes a multispanning transmembrane protein. Prm1p localizes to sites of cell-cell contact where fusion occurs. In matings between Delta prm1 mutants, a large fraction of cells initiate zygote formation and degrade the cell wall separating mating partners but then fail to fuse. Electron microscopic analysis reveals that the two plasma membranes in these mating pairs are tightly apposed, remaining separated only by a uniform gap of similar to8 nm, Thus, the phenotype of Delta prm1 mutants defines a new step in the mating reaction in which membranes are juxtaposed, possibly through a defined adherence junction, yet remain unfused. This phenotype suggests a role for Prm1p in plasma membrane fusion.