School of Life Sciences, Swami Ramanand Teerth Marathwada University, Nanded 431606, MS, India.
CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, MS, India.
J Proteomics. 2018 Aug 15;185:25-38. doi: 10.1016/j.jprot.2018.06.018. Epub 2018 Jun 26.
To understand the impact of fetal bovine serum (FBS) on metabolism and cellular architecture in addition to morphogenesis, we have identified FBS responsive proteome of Candida albicans. FBS induced 34% hyphae and 60% pseudohyphae in C. albicans at 30 °C while 98% hyphae at 37 °C. LC-MS/MS analysis revealed that 285 proteins modulated significantly in response to FBS at 30 °C and 37 °C. Out of which 152 were upregulated and 62 were downregulated at 30 °C while 18 were up and 53 were downregulated at 37 °C. Functional annotation suggests that FBS may inhibit glycolysis and fermentative pathway and enhance oxidative phosphorylation (OxPhos), TCA cycle, amino acid and fatty acid metabolism indicating a use of alternative energy source by C. albicans. OxPhos inhibition assay using sodium azide corroborated the correlation between inhibition of glycolysis and enhanced OxPhos with pseudohyphae formation. C. albicans induced hyphae in response to FBS irrespective of down regulation of Ras1,Asr1/Asr2, indicates the possible involvement of MAPK and cAMP-PKA independent pathway. The Cell wall of cells grown in presence of FBS at 30 °C was rich in mannan, Beta 1,3-glucan and chitin while membranes were rich in ergosterol compared to those grown at 37 °C.
This is the first study suggesting a correlation between OxPhos and morphogenesis especially pseudohyphae formation in C. albicans. Our data also indicate that fetal bovine serum (FBS) induced morphogenesis is multifactorial and may involve MAPK and cAMP-PKA independent pathway. In addition to morphogenesis, our study provides an insight in to the modulation of metabolism and cellular architecture of C. albicans in response to FBS.
为了了解胎牛血清（FBS）对代谢和细胞结构的影响，除了形态发生，我们已经确定了白色念珠菌的 FBS 反应蛋白质组。在 30°C 时，FBS 诱导白色念珠菌产生 34%的菌丝和 60%的假菌丝，而在 37°C 时产生 98%的菌丝。LC-MS/MS 分析显示，在 30°C 和 37°C 时，有 285 种蛋白质对 FBS 有显著的调节作用。其中 152 种在 30°C 时上调，62 种下调，而 18 种在 37°C 时上调，53 种下调。功能注释表明，FBS 可能抑制糖酵解和发酵途径，增强氧化磷酸化（OxPhos）、三羧酸循环、氨基酸和脂肪酸代谢，表明白色念珠菌正在使用替代能源。使用叠氮化钠进行 OxPhos 抑制测定证实了糖酵解抑制与增强 OxPhos 与假菌丝形成之间的相关性。白色念珠菌在 FBS 的诱导下形成菌丝，无论 Ras1、Asr1/Asr2 的下调如何，这表明可能涉及 MAPK 和 cAMP-PKA 独立途径。与在 37°C 下生长的细胞相比，在 30°C 下用 FBS 培养的细胞的细胞壁富含甘露聚糖、β1,3-葡聚糖和几丁质，而膜富含麦角固醇。
这是第一项表明 OxPhos 与形态发生，特别是白色念珠菌假菌丝形成之间存在相关性的研究。我们的数据还表明，胎牛血清（FBS）诱导的形态发生是多因素的，可能涉及 MAPK 和 cAMP-PKA 独立途径。除了形态发生，我们的研究还提供了一个深入了解白色念珠菌对 FBS 反应时代谢和细胞结构的调节的视角。
