Singer B, Riezman H
Biocenter, University of Basel, Switzerland.
J Cell Biol. 1990 Jun;110(6):1911-22. doi: 10.1083/jcb.110.6.1911.
alpha-Factor, one of the mating pheromones of Saccharomyces cerevisiae, binds specifically to a receptor on the plasma membrane of a cells, is internalized and delivered to the vacuole, where it is degraded. At 15 degrees C the rate of pheromone uptake is only slightly affected while delivery to the vacuole is markedly slowed down. A transport intermediate carrying alpha-factor to the vacuole can be reversibly trapped by treatment with the metabolic inhibitors, NaN3 and NaF. This intermediate(s) is distinct from the vacuole and the plasma membrane as judged by differential and density gradient centrifugation analysis. We present evidence that the alpha-factor is protected from protease digestion by a detergent-sensitive structure, suggesting that the pheromone resides within a vesicular compartment. We propose that this intermediate(s) represents an endocytic or prevacuolar compartment(s) involved in vesicular traffic from the plasma membrane to the vacuole.
α因子是酿酒酵母的交配信息素之一，它特异性地结合a细胞质膜上的受体，被内化并转运至液泡，在液泡中被降解。在15摄氏度时，信息素的摄取速率仅受到轻微影响，而向液泡的转运则明显减慢。用代谢抑制剂NaN₃和NaF处理可可逆地捕获携带α因子至液泡的运输中间体。通过差速离心和密度梯度离心分析判断，该中间体与液泡和质膜不同。我们提供的证据表明，α因子受到去污剂敏感结构的保护而免受蛋白酶消化，这表明信息素存在于囊泡区室中。我们提出，该中间体代表参与从质膜到液泡的囊泡运输的内吞或液泡前区室。
