Identification of Genomewide Alternative Splicing Events in Sequential, Isogenic Clinical Isolates of Candida albicans Reveals a Novel Mechanism of Drug Resistance and Tolerance to Cellular Stresses.
Identification of Genomewide Alternative Splicing Events in Sequential, Isogenic Clinical Isolates of Candida albicans Reveals a Novel Mechanism of Drug Resistance and Tolerance to Cellular Stresses.
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白色念珠菌序列同基因临床分离株中全基因组选择性剪接事件的鉴定揭示了细胞应激耐药性和耐受性的新机制。
DOI：
10.1128/msphere.00608-20
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发表时间：
2020
期刊：
影响因子：
4.8
通讯作者：
Prasad,Rajendra
中科院分区：
文献类型：
--
作者：
Muzafar,Suraya;Sharma,RaviDatta;Shah,AbdulHaseeb;Gaur,NaseemA;Dasgupta,Ujjaini;Chauhan,Neeraj;Prasad,Rajendra
选择性剪接(AS)--单个基因在真核生物中产生不同的蛋白质亚型的过程--参与了许多基本的细胞过程，但对其在耐药和真菌发病中的作用知之甚少。人类最常见的真菌病原体，白色念珠菌，在其4%至6%的基因中含有内含子，其功能在很大程度上仍不清楚。在这里，我们报告了对白色念珠菌耐药性的调控。对两组不同顺序的、同基因的、对唑敏感和耐药的白色念珠菌分离株的比较RNA测序显示，14个基因的剪接异构体存在差异表达。其中之一是超氧化物歧化酶基因SOD3，它只有一个内含子。Δ/Δ突变体对两性霉素B和甲萘二酮敏感。虽然剪接和非剪接SOD3亚型的过度表达可以挽救AMB的敏感性，但只有剪接的SOD3亚型可以克服MND的敏感性，这表明这种剪接在产生耐药性方面具有功能相关性。此外，与AMB不同，MND抑制SOD3的剪接，并起到剪接抑制的作用。与这些观察结果一致，MND暴露导致无法清除活性氧物种(ROS)的未剪接SOD3亚型水平增加，从而增加了对药物的敏感性。总之，这些观察结果表明，AS是白念珠菌适应压力和克服药物敏感性的一种新机制。白念珠菌是一种机会性病原体，对常用抗真菌药物的耐药性正在成为其治疗的主要障碍。确定新的药物靶点的必要性要求对这种有机体用来产生耐药性的机制有基本的了解。白念珠菌在其4%至6%的基因中含有内含子，其功能在很大程度上仍不清楚。使用来自同基因对唑敏感和耐药的白色念珠菌分离株的RNA测序数据，在这里，我们展示了白色念珠菌如何利用mRNA剪接中的调制来克服抗真菌药物压力。
Alternative splicing (AS)—a process by which a single gene gives rise to different protein isoforms in eukaryotes—has been implicated in many basic cellular processes, but little is known about its role in drug resistance and fungal pathogenesis. The most common human fungal pathogen, Candida albicans, has introns in 4 to 6% of its genes, the functions of which remain largely unknown. Here, we report AS regulating drug resistance in C. albicans. Comparative RNA-sequencing of two different sets of sequential, isogenic azole-sensitive and -resistant isolates of C. albicans revealed differential expression of splice isoforms of 14 genes. One of these was the superoxide dismutase geneSOD3, which contains a single intron. Thesod3Δ/Δ mutant was susceptible to the antifungals amphotericin B (AMB) and menadione (MND). While AMB susceptibility was rescued by overexpression of both the spliced and unsplicedSOD3isoforms, only the spliced isoform could overcome MND susceptibility, demonstrating the functional relevance of this splicing in developing drug resistance. Furthermore, unlike AMB, MND inhibitsSOD3splicing and acts as a splicing inhibitor. Consistent with these observations, MND exposure resulted in increased levels of unsplicedSOD3isoform that are unable to scavenge reactive oxygen species (ROS), resulting in increased drug susceptibility. Collectively, these observations suggest that AS is a novel mechanism for stress adaptation and overcoming drug susceptibility in C. albicans.IMPORTANCEThe emergence of resistance in Candida albicans, an opportunistic pathogen, against the commonly used antifungals is becoming a major obstacle in its treatment. The necessity to identify new drug targets demands fundamental insights into the mechanisms used by this organism to develop drug resistance. C. albicans has introns in 4 to 6% of its genes, the functions of which remain largely unknown. Using the RNA-sequencing data from isogenic pairs of azole-sensitive and -resistant isolates of C. albicans, here, we show how C. albicans uses modulations in mRNA splicing to overcome antifungal drug stress.