Environment-induced same-sex mating in the yeast Candida albicans through the Hsf1-Hsp90 pathway
Environment-induced same-sex mating in the yeast Candida albicans through the Hsf1-Hsp90 pathway
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环境诱导的白色念珠菌通过 Hsf1-Hsp90 途径进行同性交配
DOI：
10.1371/journal.pbio.2006966
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发表时间：
2019-03-01
期刊：
影响因子：
9.8
通讯作者：
Huang, Guanghua
中科院分区：
文献类型：
--
作者：
Guan, Guobo;Tao, Li;Huang, Guanghua
虽然有性繁殖在真核细胞中普遍存在，但真菌物种实现和完成有性周期的策略是高度多样化和复杂的。许多真菌，包括酿酒酵母和庞氏裂殖酵母，都是同源的(能够与它们自己的有丝分裂后代交配)，这是因为同源转换(HO)内切酶介导的交配型转换。在实验室条件下，人类真菌病原体白色念珠菌可以进行异性恋和同性恋(异性和同性)交配。然而，这两种交配模式都需要两种相反交配类型(MTLa/a和/)的细胞非常接近地存在。鉴于这种酵母在人类宿主中的主要克隆特征，异性和同性交配在自然界中都是罕见的。在这项研究中，我们报道了葡萄糖饥饿和氧化应激，病原体遇到的常见环境应激，诱导交配突起的发展，并有效地允许a交配型(MTLa/a)白色念珠菌进行同性交配。这种诱导绕过了对交配类型相反的细胞的存在的要求，并允许来自单一祖细胞的细胞之间有效的有性交配。葡萄糖饥饿导致细胞内氧化物种的增加，压倒了热休克转录因子1(HSF1)和热休克蛋白(HSP)90介导的应激反应途径。我们进一步证明，HSF1-Hsp90途径的下游效应因子念珠菌反式激活蛋白4(Cta4)和细胞壁转录因子1(Cwt1)通过a型交配的主调节因子MTLa2和信息素前体编码的基因交配因子前体(MF)的转录控制来调节白色念珠菌的同性交配。我们的结果表明，在自然界中，交配可能比最初意识到的更频繁，同性交配可能是白色念珠菌有性繁殖的一种重要模式。作者摘要白色念珠菌是一种臭名昭著的人类真菌病原体，每年导致数百万起鹅口疮和全身感染事件。有性生殖在致病真菌病原体的生物学和生存中起着关键作用。然而，白色念珠菌主要是克隆的，这表明在自然界中，菌株之间的交配和重组将是罕见的。在这里，我们报告了环境压力诱导白念珠菌交配突起和有效的同性交配的发展。这种诱导代表了一种新的同源同源作用模式，它独立于在酿酒酵母和裂殖酵母中观察到的HO内切酶介导的交配型转换。这代表了一个开创性的例子，说明了与环境相关的压力如何诱导真菌的同源交配。
While sexual reproduction is pervasive in eukaryotic cells, the strategies employed by fungal species to achieve and complete sexual cycles is highly diverse and complex. Many fungi, including Saccharomyces cerevisiae and Schizosaccharomyces pombe, are homothallic (able to mate with their own mitotic descendants) because of homothallic switching (HO) endonuclease-mediated mating-type switching. Under laboratory conditions, the human fungal pathogen Candida albicans can undergo both heterothallic and homothallic (opposite- and same-sex) mating. However, both mating modes require the presence of cells with two opposite mating types (MTLa/a and /) in close proximity. Given the predominant clonal feature of this yeast in the human host, both opposite- and same-sex mating would be rare in nature. In this study, we report that glucose starvation and oxidative stress, common environmental stresses encountered by the pathogen, induce the development of mating projections and efficiently permit same-sex mating in C. albicans with an a mating type (MTLa/a). This induction bypasses the requirement for the presence of cells with an opposite mating type and allows efficient sexual mating between cells derived from a single progenitor. Glucose starvation causes an increase in intracellular oxidative species, overwhelming the Heat Shock transcription Factor 1 (Hsf1)- and Heat shock protein (Hsp)90-mediated stress-response pathway. We further demonstrate that Candida TransActivating protein 4 (Cta4) and Cell Wall Transcription factor 1 (Cwt1), downstream effectors of the Hsf1-Hsp90 pathway, regulate same-sex mating in C. albicans through the transcriptional control of the master regulator of a-type mating, MTLa2, and the pheromone precursor-encoding gene Mating factor precursor (MF). Our results suggest that mating could occur much more frequently in nature than was originally appreciated and that same-sex mating could be an important mode of sexual reproduction in C. albicans.Author summary Candida albicans is notorious as a human fungal pathogen that causes millions of incidents of thrush and systemic infection every year. Sexual reproduction plays a pivotal role in the biology and survival of pathogenic fungal pathogens. However, C. albicans is predominantly clonal, suggesting that mating and recombination between isolates would be rare in nature. Here, we report that environmental stresses induce the development of mating projections and efficient same-sex mating in C. albicans. This induction represents a novel mode of homothallism that is independent of the HO endonuclease-mediated mating-type switching observed in Saccharomyces cerevisiae and Schizosaccharomyces pombe. This represents a seminal example of how an environmentally relevant stress induces homothallic mating in fungi.