Table_1_Metabolic Peculiarities of Paracoccidioides brasiliensis Dimorphism as Demonstrated by iTRAQ Labeling Proteomics.XLSX

Paracoccidioidomycosis (PCM), a systemic mycosis with a high incidence in Latin America, is caused by thermodimorphic fungi of the Paracoccidioides genus. The contact with host occurs by the inhalation of conidia or mycelial propagules which once reaching the pulmonary alveoli differentiate into yeast cells. This transition process is vital in the pathogenesis of PCM allowing the fungus survival in the host. Thus, the present work performed a comparative proteome analysis of mycelia, mycelia-to-yeast transition, and yeast cells of Paracoccidioides brasiliensis. For that, tryptic peptides were labeled with iTRAQ and identified by LC–MS/MS and computational data analysis, which allowed the identification of 312 proteins differentially expressed in different morphological stages. Data showed that P. brasiliensis yeast cells preferentially employ aerobic beta-oxidation and the tricarboxylic acid cycle accompanied by oxidative phosphorylation for ATP production, in comparison to mycelia and the transition from mycelia-to-yeast cells. Furthermore, yeast cells show a metabolic reprogramming in amino acid metabolism and in the induction of virulence determinants and heat shock proteins allowing adaptation to environmental conditions during the increase of the temperature. In opposite of that, the alcoholic fermentation found to P. lutzii, at least under laboratory conditions, is strongly favored in mycelium compared to yeast cells. Thereby, the data strongly support substantial metabolic differences among members of the Paracoccidioides complex, when comparing the saprobiotic mycelia and the yeast parasitic phases.

副球孢子菌病（Paracoccidioidomycosis, PCM）是一种在拉丁美洲高发的系统性真菌病，由副球孢子菌属（Paracoccidioides）的温度双态真菌引起。病原菌通过吸入分生孢子或菌丝繁殖体侵染宿主，当其抵达肺泡后会分化为酵母细胞。这一形态转换过程在副球孢子菌病的发病机制中至关重要，可帮助真菌在宿主体内存活。
因此，本研究对巴西副球孢子菌（Paracoccidioides brasiliensis）的菌丝相、菌丝-酵母相转换阶段以及酵母相进行了比较蛋白质组学分析。实验中采用同位素标记相对和绝对定量（iTRAQ）标记胰蛋白酶肽段，并通过液相色谱-串联质谱（LC–MS/MS）及生物信息学数据分析完成鉴定，最终在不同形态阶段中共鉴定出312个差异表达蛋白。
数据分析显示，相较于菌丝相及菌丝-酵母相转换阶段，巴西副球孢子菌的酵母相更倾向于通过有氧β-氧化、三羧酸循环伴随氧化磷酸化途径生成三磷酸腺苷（ATP）。此外，酵母相存在氨基酸代谢重编程，同时诱导毒力决定因子与热休克蛋白的表达，以帮助其在温度升高的过程中适应宿主环境。
与之相反，至少在实验室培养条件下，卢茨副球孢子菌（Paracoccidioides lutzii）的菌丝相较酵母相更偏好酒精发酵途径。综上，本研究数据证实，副球孢子菌复合群内各成员在腐生菌丝相与寄生酵母相的代谢模式上存在显著差异。