Rohrer J, Bénédetti H, Zanolari B, Riezman H
Biocenter of the University of Basel, Switzerland.
Mol Biol Cell. 1993 May;4(5):511-21. doi: 10.1091/mbc.4.5.511.
The Saccharomyces cerevisiae alpha-pheromone receptor, a polytopic, G protein-coupled, membrane protein, is internalized after binding of alpha-factor. Mutational analysis suggested that the first 39 residues of the receptor's cytoplasmic tail carries sufficient information for internalization. A point mutation in one of these 39 residues, K337 to R337, renders the receptor nonfunctional for endocytosis. Other residues, D335 and S338, contribute to the efficiency of internalization. When the sequence DAKSS is added onto a severely truncated receptor, endocytosis of the receptor is restored, showing that this sequence functions to mediate or to signal interaction with the endocytic machinery. Analysis of pheromone response and recovery in strains expressing mutant receptors suggests that receptor internalization is not important for response but contributes to recovery from pheromone.
酿酒酵母α-因子受体是一种多次跨膜、G蛋白偶联的膜蛋白，在与α-因子结合后会发生内化。突变分析表明，受体胞质尾的前39个残基携带了足够的内化信息。这39个残基中的一个点突变，即K337突变为R337，会使受体在内吞作用中失去功能。其他残基D335和S338则有助于内化效率。当将序列DAKSS添加到严重截短的受体上时，受体内化得以恢复，表明该序列起到介导或发出与内吞机制相互作用信号的作用。对表达突变受体的菌株中的信息素反应和恢复情况的分析表明，受体内化对反应并不重要，但有助于从信息素作用中恢复。
