Five vacuolar Ca2+ exchangers play different roles in calcineurin-dependent Ca2+/Mn2+ tolerance, multistress responses and virulence of a filamentous entomopathogen
Five vacuolar Ca2+ exchangers play different roles in calcineurin-dependent Ca2+/Mn2+ tolerance, multistress responses and virulence of a filamentous entomopathogen
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五种液泡 Ca2 交换器在钙调神经磷酸酶依赖性 Ca2/Mn2 耐受性、多重应激反应和丝状昆虫病原体的毒力中发挥不同的作用
DOI：
10.1016/j.fgb.2014.09.005
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发表时间：
2014-12-01
影响因子：
3
通讯作者：
Feng, Ming-Guang
中科院分区：
文献类型：
--
作者：
Hu, Yue;Wang, Jie;Feng, Ming-Guang
在许多丝状真菌中存在多个VCX1（液泡钙交换器）旁系同源物，但在功能上没有探索，与酵母中的单个VCXL直系同源物不同。在这里，我们表明Beauveria bassiana中的五个VCXL副同源物（VCX1A-E）有条件地对细胞内Ca2+稳态有效，并且对丝状昆虫疾病的多际耐受性和毒力有所不同。每个其他四个伴侣和六个P型Ca2+ -ATP酶的每个VCX1删除的转录表达式急剧上调，导致在25和30摄氏度时通过CA2+胁迫处理的某些缺失或未经处理的ca2+胁迫处理的某些缺失突变体的细胞内Ca2+浓度升高。在五个Delta VCX1突变体中，环孢素A，Ca2+公差降低了11-17％，但在Delta VCX1A和Delta VCX1D中，MN2+敏感性仅升高，在最佳25度处，这两个突变体在30摄氏度c上也更敏感。钙调神经素是活性的，当钙调神经酶无活性时，在25和30摄氏度时显示出较小的生长缺陷。此外，所有Delta VCX1突变体对二硫代醇（应力触发对内质网）和刚果红（细胞壁应激源）更敏感；其中三个始终对氧化剂Menadione和H2O2的耐受性较低。在四个Delta VCX1突变体中，梅洛尼亚幼虫Galleria幼虫的真菌毒力降低了15-40％，不包括Delta VCX1E，这在分生孢子耐碳中是独特的缺陷。每个VCX1互补都恢复了所有变化。我们的发现表明，巴西亚纳芽孢杆菌中的五个VCXL副产品对钙调蛋白依赖性的Ca2+/Mn2+耐受性，跨元素响应和毒力有所不同，并回忆起对丝状真菌中多功能VCXL副同源物的关注。 （c）2014 Elsevier Inc.保留所有权利。
Multiple Vcx1 (vacuolar calcium exchanger) paralogues exist in many filamentous fungi but are functionally unexplored unlike a single Vcxl ortholog well characterized in yeasts. Here we show that five Vcxl paralogues (Vcx1A-E) in Beauveria bassiana are conditionally functional for intracellular Ca2+ homeostasis and contribute differentially to multistress tolerance and virulence in the filamentous entomopathogen. Each vcx1 deletion drastically upregulated transcriptional expressions of four other partners and six P-type Ca2+-ATPases, resulting in elevated or lowered intracellular Ca2+ concentration in some deletion mutants treated with Ca2+ stress or untreated at 25 and 30 degrees C. When calcineurin was inactivated by cyclosporine A, Ca2+ tolerance decreased by 11-17% in five Delta vcx1 mutants, but Mn2+ sensitivity increased only in Delta vcx1A and Delta vcx1D, at optimal 25 degrees C. These two mutants were also more sensitive to Ca2+ stress at 30 degrees C when calcineurin was active, and showed minor growth defect at 25 and 30 degrees C when calcineurin was inactive. Moreover, all the Delta vcx1 mutants were more sensitive to dithiothreitol (stress-response trigger to endoplasmic reticulum) and Congo red (cell wall stressor); three of them were consistently less tolerant to the oxidants menadione and H2O2. The fungal virulence to Galleria mellonella larvae decreased by 15-40% in four Delta vcx1 mutants excluding Delta vcx1E, which was uniquely defective in conidial thermotolerance. All the changes were restored by each vcx1 complementation. Our findings indicate that the five Vcxl paralogues in B. bassiana contribute differentially to calcineurin-dependent Ca2+/Mn2+ tolerance, multistress responses and virulence, and recall attention to multifunctional Vcxl paralogues in filamentous fungi. (C) 2014 Elsevier Inc. All rights reserved.