The Biology of Pichia membranifaciens Killer Toxins.
The Biology of Pichia membranifaciens Killer Toxins.
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DOI：
10.3390/toxins9040112
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发表时间：
2017-03-23
期刊：
影响因子：
4.2
通讯作者：
Santos A
中科院分区：
文献类型：
--
作者：
Belda I;Ruiz J;Alonso A;Marquina D;Santos A
杀手现象被定义为一些酵母菌分泌毒素的能力，这些毒素对其他敏感的酵母菌和丝状真菌是致命的。自从发现能够分泌杀伤毒素的酿酒酵母菌菌株以来，已经获得了许多关于杀伤毒素的信息，这一事实大大促进了细胞生物学和酵母遗传学基础方面的知识。人们对膜性毕赤酵母的杀伤现象已经研究了好几年，在此期间描述了两种毒素。PMKT和PMKT2是一种低分子质量的蛋白，它们分别与位于敏感酵母细胞壁结构上的初级受体结合，PMKT和PMKT2分别为线性（1→6）-β-d-葡聚糖和甘露糖蛋白。Cwp2p也作为PMKT的次级受体。PMKT杀死敏感细胞的特点是离子在质膜上的运动和细胞内pH值的酸化，引发高渗透压甘油（HOG）途径的激活。相反，我们的研究显示了一种杀伤机制，即高浓度PMKT2在早期s期阻滞细胞。然而，我们得出结论，低剂量PMKT2和PMKT诱导死亡确实具有凋亡性质。杀手酵母及其毒素在几个领域有潜在的应用：在食品和饮料生产中，作为生物防治剂，在酵母生物分型中，以及作为新型抗真菌剂。因此，人们已经发现了膜芽孢杆菌杀手毒素的几种应用，从收获前和收获后的植物病原体生物防治到葡萄酒发酵和陈酿过程中的应用（抑制灰霉病菌，布鲁塞尔布雷特anomyces等）。
The killer phenomenon is defined as the ability of some yeast to secrete toxins that are lethal to other sensitive yeasts and filamentous fungi. Since the discovery of strains of Saccharomyces cerevisiae capable of secreting killer toxins, much information has been gained regarding killer toxins and this fact has substantially contributed knowledge on fundamental aspects of cell biology and yeast genetics. The killer phenomenon has been studied in Pichia membranifaciens for several years, during which two toxins have been described. PMKT and PMKT2 are proteins of low molecular mass that bind to primary receptors located in the cell wall structure of sensitive yeast cells, linear (1→6)-β-d-glucans and mannoproteins for PMKT and PMKT2, respectively. Cwp2p also acts as a secondary receptor for PMKT. Killing of sensitive cells by PMKT is characterized by ionic movements across plasma membrane and an acidification of the intracellular pH triggering an activation of the High Osmolarity Glycerol (HOG) pathway. On the contrary, our investigations showed a mechanism of killing in which cells are arrested at an early S-phase by high concentrations of PMKT2. However, we concluded that induced mortality at low PMKT2 doses and also PMKT is indeed of an apoptotic nature. Killer yeasts and their toxins have found potential applications in several fields: in food and beverage production, as biocontrol agents, in yeast bio-typing, and as novel antimycotic agents. Accordingly, several applications have been found for P. membranifaciens killer toxins, ranging from pre- and post-harvest biocontrol of plant pathogens to applications during wine fermentation and ageing (inhibition of Botrytis cinerea, Brettanomyces bruxellensis, etc.).