Rappaport Noa, Barkai Naama
Departments of Molecular Genetics and Physics of Complex Systems, Weizmann Institute of Science, Rehovot, 76100 Israel.
J Biol Phys. 2012 Mar;38(2):267-78. doi: 10.1007/s10867-011-9240-x. Epub 2011 Sep 14.
Yeast cells approach a mating partner by polarizing along a gradient of mating pheromones that are secreted by cells of the opposite mating type. The Bar1 protease is secreted by a-cells and, paradoxically, degrades the α-factor pheromones which are produced by cells of the opposite mating type and trigger mating in a-cells. This degradation may assist in the recovery from pheromone signaling but has also been shown to play a positive role in mating. Previous studies suggested that widely diffusing protease can bias the pheromone gradient towards the closest secreting cell. Here, we show that restricting the Bar1 protease to the secreting cell itself, preventing its wide diffusion, facilitates discrimination between equivalent mating partners. This may be mostly relevant during spore germination, where most mating events occur in nature.
酵母细胞通过沿由相反交配型细胞分泌的交配信息素梯度极化来接近交配伙伴。Bar1蛋白酶由a细胞分泌，矛盾的是，它会降解由相反交配型细胞产生并触发a细胞交配的α因子信息素。这种降解可能有助于从信息素信号传导中恢复，但也已证明在交配中起积极作用。先前的研究表明，广泛扩散的蛋白酶会使信息素梯度偏向最接近的分泌细胞。在这里，我们表明将Bar1蛋白酶限制在分泌细胞本身，防止其广泛扩散，有助于区分等效的交配伙伴。这在孢子萌发期间可能最为相关，因为自然界中大多数交配事件都发生在孢子萌发期间。
