Institute of Medical Microbiology, Immunology and Hygiene, Technical University Munich, Munich, Germany.
Mol Syst Biol. 2010 Jun 8;6:371. doi: 10.1038/msb.2010.29.
Recognition of microbial danger signals by toll-like receptors (TLR) causes re-programming of macrophages. To investigate kinase cascades triggered by the TLR4 ligand lipopolysaccharide (LPS) on systems level, we performed a global, quantitative and kinetic analysis of the phosphoproteome of primary macrophages using stable isotope labelling with amino acids in cell culture, phosphopeptide enrichment and high-resolution mass spectrometry. In parallel, nascent RNA was profiled to link transcription factor (TF) phosphorylation to TLR4-induced transcriptional activation. We reproducibly identified 1850 phosphoproteins with 6956 phosphorylation sites, two thirds of which were not reported earlier. LPS caused major dynamic changes in the phosphoproteome (24% up-regulation and 9% down-regulation). Functional bioinformatic analyses confirmed canonical players of the TLR pathway and highlighted other signalling modules (e.g. mTOR, ATM/ATR kinases) and the cytoskeleton as hotspots of LPS-regulated phosphorylation. Finally, weaving together phosphoproteome and nascent transcriptome data by in silico promoter analysis, we implicated several phosphorylated TFs in primary LPS-controlled gene expression.
Toll 样受体 (TLR) 识别微生物危险信号会导致巨噬细胞重新编程。为了在系统水平上研究 TLR4 配体脂多糖 (LPS) 触发的激酶级联反应,我们使用稳定同位素标记细胞培养中的氨基酸、磷酸肽富集和高分辨率质谱法对原代巨噬细胞的磷酸蛋白质组进行了全局、定量和动态分析。同时,我们还对新生 RNA 进行了分析,将转录因子 (TF) 磷酸化与 TLR4 诱导的转录激活联系起来。我们可重复地鉴定出 1850 种磷酸化蛋白和 6956 个磷酸化位点,其中三分之二以前没有报道过。LPS 引起了磷酸蛋白质组的重大动态变化(24%上调和 9%下调)。功能生物信息学分析证实了 TLR 途径的典型参与者,并突出了其他信号模块(例如 mTOR、ATM/ATR 激酶)和细胞骨架作为 LPS 调节磷酸化的热点。最后,通过计算机启动子分析将磷酸蛋白质组和新生转录组数据编织在一起,我们发现在原发性 LPS 控制的基因表达中涉及几个磷酸化的 TF。