Zap1 Control of Cell-Cell Signaling in Candida albicans Biofilms
Zap1 Control of Cell-Cell Signaling in Candida albicans Biofilms
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DOI：
10.1128/ec.05196-11
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发表时间：
2011-11-01
期刊：
影响因子：
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通讯作者：
Mitchell, Aaron P.
中科院分区：
文献类型：
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作者：
Ganguly, Shantanu;Bishop, Andrew C.;Mitchell, Aaron P.
白色念珠菌的生物膜包括酵母细胞和菌丝。先前的研究表明，zap 1 Delta/Delta突变体，锌调节剂Zap 1缺陷，增加了酵母细胞在生物膜中的积累。这种改变的酵母-菌丝平衡可能来自内部调节改变或对可扩散群体感应（QS）分子产生的影响。在这里，我们开发了表达酵母特异性YWP 1-RFP或菌丝特异性HWP 1-RFP的生物传感器报告菌株，沿着组成型TDH 3-GFP标准化。将这些生物传感器菌株接种到生物膜中允许周围生物膜环境的生物活性测定。zap 1 Delta/Delta生物膜在野生型生物传感器菌株中诱导酵母特异性YWP 1-RFP报告基因，如通过定量逆转录-PCR（qRT-PCR）基因表达测量和共聚焦显微镜所确定。通过锌转运蛋白基因ZRT 2过表达修复zap 1 Delta/Delta锌摄取缺陷逆转酵母特异性YWP 1-RFP报告基因的诱导。已知有机QS分子的气相色谱-质谱（GC-MS）测量结果表明，zap 1 Delta/Delta突变体积累的法尼醇显著低于野生型或补充菌株，ZRT 2过表达不影响法尼醇积累。法尼醇是一种充分表征的菌丝形成抑制剂;因此，zap 1 Delta/Delta生物膜中法尼醇水平的降低是出乎意料的。我们的研究结果认为，Zap 1和锌依赖的信号影响酵母菌丝平衡，它是在低法尼醇环境中的zap 1三角洲/三角洲生物膜。此外，我们的研究结果表明，Zap 1是法尼醇积累的正调控因子。
Biofilms of Candida albicans include both yeast cells and hyphae. Prior studies indicated that a zap1 Delta/Delta mutant, defective in zinc regulator Zap1, has increased accumulation of yeast cells in biofilms. This altered yeast-hypha balance may arise from internal regulatory alterations or from an effect on the production of diffusible quorum-sensing (QS) molecules. Here, we develop biosensor reporter strains that express yeast-specific YWP1-RFP or hypha-specific HWP1-RFP, along with a constitutive TDH3-GFP normalization standard. Seeding these biosensor strains into biofilms allows a biological activity assay of the surrounding biofilm milieu. A zap1 Delta/Delta biofilm induces the yeast-specific YWP1-RFP reporter in a wild-type biosensor strain, as determined by both quantitative reverse transcription-PCR (qRT-PCR) gene expression measurements and confocal microscopy. Remediation of the zap1 Delta/Delta zinc uptake defect through zinc transporter gene ZRT2 overexpression reverses induction of the yeast-specific YWP1-RFP reporter. Gas chromatography-mass spectrometry (GC-MS) measurements of known organic QS molecules show that the zap1 Delta/Delta mutant accumulates significantly less farnesol than wild-type or complemented strains and that ZRT2 overexpression does not affect farnesol accumulation. Farnesol is a well-characterized inhibitor of hypha formation; hence, a reduction in farnesol levels in zap1 Delta/Delta biofilms is unexpected. Our findings argue that a Zap1- and zinc-dependent signal affects the yeast-hypha balance and that it is operative in the low-farnesol environment of the zap1 Delta/Delta biofilm. In addition, our results indicate that Zap1 is a positive regulator of farnesol accumulation.