马尔尼菲篮状菌Septin基因家族鉴定及表达分析

Identification and expression analysis of the Septin gene family in Talaromyces marneffei

摘要:

【背景】马尔尼菲篮状菌(Talaromyces marneffei)是重要的致死性病原真菌。【目的】探究T. marneffei隔膜蛋白Septin基因家族的基本特征和表达模式。【方法】通过生物信息学方法鉴定T. marneffei Septin基因家族成员，并分析基因结构、理化性质、二级结构、三级结构和亚细胞定位，同时通过实时荧光定量PCR技术分析Septin基因家族在T. marneffei菌丝相和酵母相不同时相的表达情况。【结果】共鉴定出5个Septin基因家族成员，氨基酸长度在346−575 aa之间，均具有GTP-CDC结合域，均属于亲水性蛋白。亚细胞定位主要位于细胞核和线粒体基质。二级结构以α螺旋和无规则卷曲为主，三级结构复杂。不同病原真菌核心Septin高度保守。TmSep2和TmSep4 mRNA表达量在酵母相较菌丝相明显升高，TmSep5 mRNA表达量在酵母相较菌丝相明显降低。TmSep1和TmSep3 mRNA表达量在酵母相较菌丝相略有上升，但无显著差异。【结论】Septin基因家族各基因在T. marneffei双相转换不同时相表达情况不同，部分差异显著，暗示其可能在T. marneffei双相形态转换和致病中发挥重要作用。本研究为进一步探究Septin在T. marneffei中发挥的功能及调控机制提供理论依据。

Abstract:

[Background] Talaromyces marneffei is an important lethal pathogenic fungus. [Objective]To investigate the basic characteristics and expression patterns of the Septin gene family in T. marneffei. [Methods] In this study, bioinformatics methods were used to identify the members of the Septin gene family in T. marneffei and analyze gene structure, physicochemical properties, secondary and tertiary structure, and subcellular localization. Additionally, real-time fluorescence quantitative PCR was employed to analyze the expression of the Septin gene family in the mycelial phases and yeast phases, respectively. [Results] This paper identified 5 members of the Septin gene family, with amino acid lengths ranging from 346 to 575 aa. All members possess GTP-CDC binding domains and are hydrophilic proteins. Subcellular localization was mainly located in the cell nucleus and mitochondrial matrix. The secondary structure is mainly composed of α-helices and random coils, with a complex tertiary structure. The core Septin is highly conserved among different pathogenic fungi. The mRNA expression levels of TmSep2 and TmSep4 were significantly higher in the yeast phase compared to the mycelial phase, while the mRNA expression level of TmSep5 was significantly lower. The mRNA expression levels of TmSep1 and TmSep3 showed a slight increase in the yeast phase compared to the mycelial phase but without significant differences. [Conclusion] The expression of Septin genes varies in different phases of T. marneffei during the dimorphic transition, with some significant differences, which implies the potential roles of Septin in the dimorphic transition and pathogenesis of T. marneffei. This study provides a theoretical basis for further exploration of the functions and regulatory mechanisms of Septin in T. marneffei.