Heat shock protein 90 localizes to the surface and augments virulence factors of Cryptococcus neoformans.
Heat shock protein 90 localizes to the surface and augments virulence factors of Cryptococcus neoformans.
复制标题
DOI：
10.1371/journal.pntd.0005836
复制
发表时间：
2017-08
影响因子：
3.8
通讯作者：
Tatu U
中科院分区：
文献类型：
--
作者：
Chatterjee S;Tatu U
耐热性是隐球菌致病的一个基本属性，例如该属中只有两种可以在37°C下生长的物种是人类病原体。具有其他毒力因子（包括荚膜形成和黑化）但缺乏在37°C下繁殖能力的物种不是致病性的。在另一种相关的真菌病原体白色念珠菌中，热休克蛋白90被认为是通过控制酵母到菌丝的转变和耐药性来控制致病性的核心参与者。探索热休克蛋白90的生物学在隐球菌的耐热性的背景下，从而突出了重要的监管原则的毒力和开辟新的治疗途径。Hsp 90参与调节隐球菌的耐热性，如在相对于25°C的Hsp 90功能轻度受损后在37°C下的生长超敏性所示。生物化学研究表明，与25°C相比，37°C下药理学抑制剂17-AAG对ATP酶活性的抑制作用更强。在37°C下，蛋白质的催化效率为6.39×10−5μM-1。此外，使用特异性抗体的间接免疫荧光分析揭示了Hsp 90通过内质网高尔基体经典分泌途径的细胞表面定位。发现Hsp 90在囊诱导条件下被诱导，并且Hsp 90抑制导致囊体积减少。最后，破坏Hsp 90功能提高隐球菌对阿尼芬净的耐受性。我们的研究结果表明，热休克蛋白90调节真菌的致病性，通过无数的方式。首先，它参与介导热耐受性，这意味着靶向Hsp 90可以消除热耐受性，从而消除真菌的生长。其次，本研究首次报道了一种致病真菌Hsp 90的生化特性。最后，由于Hsp 90定位于细胞壁，靶向细胞表面Hsp 90可以代表对抗这种致命感染的新策略。耐热性是微生物作为人类病原体成功繁殖的先决条件。本研究探讨了热休克蛋白90在嗜热链球菌致病和耐热中的作用。neoformans，一种引起人类脑膜脑炎的环境真菌。我们发现隐球菌的耐热性关键取决于Hsp 90功能，因为Hsp 90功能的适度抑制，在37°C下强烈损害真菌的生长，在25°C下几乎没有影响。这一观察结果与以下事实相关：药理学抑制剂17-AAG也显示出在37°C下对蛋白质的ATP酶活性的更有效抑制，如与25°C相比较低的IC 50所示。使用CnHsp 90特异性抗体的间接免疫荧光分析揭示了Hsp 90的细胞表面定位。这种表面定位的BFA敏感性表明参与ER-高尔基体经典分泌途径的这种定位。此外，抑制Hsp 90功能不仅可以消除C.此外，新形线虫对细胞壁靶向抑制剂棘白菌素的耐受性降低，但也导致作为病原体的经典毒力决定因素之一的荚膜组装减少。总之，这项研究提供了第一个详细的生化以及功能的见解，热休克蛋白90在管理耐热性和增强毒力因子在C。新人类
Thermotolerance is an essential attribute for pathogenesis of Cryptococcus as exemplified by the fact that only two species in the genus, which can grow at 37°C, are human pathogens. Species which have other virulence factors including capsule formation and melanisation, but lack the ability to propagate at 37°C are not pathogenic. In another related fungal pathogen, Candida albicans, heat shock protein 90 has been implicated to be a central player in commanding pathogenicity by governing yeast to hyphal transition and drug resistance. Exploring Hsp90 biology in Cryptococcus in context of thermotolerance may thus highlight important regulatory principles of virulence and open new therapeutic avenues. Hsp90 is involved in regulating thermotolerance in Cryptococcus as indicated by growth hypersensitivity at 37°C upon mild compromise of Hsp90 function relative to 25°C. Biochemical studies revealed a more potent inhibition of ATPase activity by pharmacological inhibitor 17-AAG at 37°C as compared to 25°C. Catalytic efficiency of the protein at 37°C was found to be 6.39×10−5μM-1. Furthermore, indirect immunofluorescence analysis using a specific antibody revealed cell surface localization of Hsp90 via ER Golgi classical secretory pathway. Hsp90 was found to be induced under capsule inducing conditions and Hsp90 inhibition led to decrease in capsular volume. Finally compromising Hsp90 function improved anidulafungin tolerance in Cryptococcus. Our findings highlight that Hsp90 regulates pathogenicity of the fungus by myriad ways. Firstly, it is involved in mediating thermotolerance which implies targeting Hsp90 can abrogate thermotolerance and hence growth of the fungus. Secondly, this study provides the first report of biochemical properties of Hsp90 of a pathogenic fungus. Finally, since Hsp90 is localised at the cell wall, targeting cell surface Hsp90 can represent a novel strategy to combat this lethal infection. Thermotolerance is a pre-requisite for microbes to propagate successfully as human pathogens. In this study, we have investigated the role of Heat shock protein 90 in the pathogenesis and thermotolerance of C. neoformans, an environmental fungus that causes meningoencephalitis in humans. We show that thermotolerance of Cryptococcus critically depends on Hsp90 function as modest inhibition of Hsp90 function, robustly compromised growth of the fungus at 37°C with little effect at 25°C. This observation correlated with the fact that pharmacological inhibitor, 17-AAG also showed a more potent inhibition of ATPase activity of the protein at 37°C as indicated by a lower IC50 as compared to 25°C. Indirect immunofluorescence analysis using an antibody specific to CnHsp90 revealed cell surface localization of Hsp90. BFA sensitivity of such surface localization indicated involvement of ER-Golgi classical secretory pathway for this localization. Furthermore, inhibition of Hsp90 function not only abrogated the natural resistance of C. neoformans to cell wall targeting inhibitors echinocandins but also led to decrease in capsular assembly which is one of the classical virulence determinants of the pathogen. In all, this study provides the first detailed biochemical as well as functional insights into the role of Hsp90 in governing thermotolerance and augmenting virulence factors in C. neoformans.
登录
查看更多内容
影响因子：
4.5
作者：
Diezmann S;Michaut M;Shapiro RS;Bader GD;Cowen LE
通讯作者：
Cowen LE
影响因子：
5.3
作者：
Forafonov, Fedor;Toogun, Oyetunji A.;Picard, Didier
通讯作者：
Picard, Didier
DOI：
10.1534/g3.112.004242
发表时间：
2013-03
期刊：
G3 (Bethesda, Md.)
影响因子：
--
作者：
Chen YL;Lehman VN;Lewit Y;Averette AF;Heitman J
通讯作者：
Heitman J
影响因子：
4.9
作者：
Maligie, MA;Selitrennikoff, CP
通讯作者：
Selitrennikoff, CP
影响因子：
6.7
作者：
Leach MD;Budge S;Walker L;Munro C;Cowen LE;Brown AJ
通讯作者：
Brown AJ