Phosphoproteomic Analysis Provides Novel Insights into Stress Responses in Phaeodactylum tricornutum, a Model Diatom
Phosphoproteomic Analysis Provides Novel Insights into Stress Responses in Phaeodactylum tricornutum, a Model Diatom
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磷酸蛋白质组学分析为三角褐指藻（硅藻模型）的应激反应提供了新的见解
DOI：
10.1021/pr401290u
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发表时间：
2014-05-01
影响因子：
4.4
通讯作者：
Ge, Feng
中科院分区：
文献类型：
--
作者：
Chen, Zhuo;Yang, Ming-kun;Ge, Feng
丝氨酸、苏氨酸和酪氨酸（Ser/Thr/Tyr）上的蛋白磷酸化被公认为用于信号转导以控制细胞生长、增殖和应激反应的关键调节性翻译后修饰。然而，关于其在硅藻中的程度和功能知之甚少。三角褐指藻（Phaeodactylum tricornutum）是一种单细胞海洋硅藻，是硅藻分子生物学研究的模式生物。尽管在三角褐指藻中已经预测了超过1000种对Ser/Thr/Tyr残基具有特异性的蛋白激酶和磷酸酶，但是迄今为止还没有经典的生物化学方法揭示磷酸化事件。在这里，我们进行了一个全球磷酸化蛋白质组学分析结合蛋白质/肽分馏，二氧化钛富集，和LC-MS/MS分析。我们总共鉴定了264个独特的磷酸肽，包括245个磷蛋白上的434个体内磷酸化位点。磷酸化的蛋白质参与多种生物过程的调节，包括信号传导、代谢途径和应激反应。通过使用磷酸化特异性抗体的Western印迹进一步验证了六种鉴定的磷蛋白。这些蛋白质的功能进行了讨论的背景下，在三角褐指藻的信号转导网络。我们的研究结果推进了目前的理解硅藻生物学，并将有助于阐明该模型硅藻中的磷中继信号网络。
Protein phosphorylation on serine, threonine, and tyrosine (Ser/Thr/Tyr) is well established as a key regulatory posttranslational modification used in signal transduction to control cell growth, proliferation, and stress responses. However, little is known about its extent and function in diatoms. Phaeodactylum tricornutum is a unicellular marine diatom that has been used as a model organism for research on diatom molecular biology. Although more than 1000 protein kinases and phosphatases with specificity for Ser/Thr/Tyr residues have been predicted in P. tricornutum, no phosphorylation event has so far been revealed by classical biochemical approaches. Here, we performed a global phosphoproteomic analysis combining protein/peptide fractionation, TiO2 enrichment, and LC-MS/MS analyses. In total, we identified 264 unique phosphopeptides, including 434 in vivo phosphorylated sites on 245 phosphoproteins. The phosphorylated proteins were implicated in the regulation of diverse biological processes, including signaling, metabolic pathways, and stress responses. Six identified phosphoproteins were further validated by Western blotting using phospho-specific antibodies. The functions of these proteins are discussed in the context of signal transduction networks in P. tricornutum. Our results advance the current understanding of diatom biology and will be useful for elucidating the phosphor-relay signaling networks in this model diatom.