Mathelié-Guinlet Marion, Viela Felipe, Dehullu Jérôme, Filimonava Sviatlana, Rauceo Jason M, Lipke Peter N, Dufrêne Yves F
Louvain Institute of Biomolecular Science and Technology, UCLouvain, Croix du Sud, 4-5, bte L7.07.07, 1348, Louvain-la-Neuve, Belgium.
Department of Sciences, John Jay College of the City University of New York, New York, NY, 10019, USA.
Commun Biol. 2021 Jan 4;4(1):33. doi: 10.1038/s42003-020-01498-9.
Sexual agglutinins of the budding yeast Saccharomyces cerevisiae are proteins mediating cell aggregation during mating. Complementary agglutinins expressed by cells of opposite mating types "a" and "α" bind together to promote agglutination and facilitate fusion of haploid cells. By means of an innovative single-cell manipulation assay combining fluidic force microscopy with force spectroscopy, we unravel the strength of single specific bonds between a- and α-agglutinins (~100 pN) which require pheromone induction. Prolonged cell-cell contact strongly increases adhesion between mating cells, likely resulting from an increased expression of agglutinins. In addition, we highlight the critical role of disulfide bonds of the a-agglutinin and of histidine residue H of α-agglutinin. Most interestingly, we find that mechanical tension enhances the interaction strength, pointing to a model where physical stress induces conformational changes in the agglutinins, from a weak-binding folded state, to a strong-binding extended state. Our single-cell technology shows promises for understanding and controlling the complex mechanism of yeast sexuality.
出芽酵母酿酒酵母的性凝集素是在交配过程中介导细胞聚集的蛋白质。由相反交配型“a”和“α”的细胞表达的互补凝集素结合在一起，促进凝集并促进单倍体细胞的融合。通过将流体力学显微镜与力谱相结合的创新单细胞操作分析方法，我们揭示了a凝集素和α凝集素之间单个特异性键的强度（约100皮牛），这需要信息素诱导。长时间的细胞间接触会强烈增加交配细胞之间的粘附力，这可能是由于凝集素表达增加所致。此外，我们强调了a凝集素的二硫键和α凝集素的组氨酸残基H的关键作用。最有趣的是，我们发现机械张力会增强相互作用强度，这指向了一个模型，即物理应力会诱导凝集素发生构象变化，从弱结合折叠状态转变为强结合伸展状态。我们的单细胞技术有望用于理解和控制酵母性行为的复杂机制。
