Chen Tong, Wu Xiaoqin, Chen Yanmei, Li Xiaojuan, Huang Mei, Zheng Maozhong, Baluska Frantisek, Samaj Jozef, Lin Jinxing
Key Laboratory of Photosynthesis and Molecular Environmental Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
Plant Physiol. 2009 Feb;149(2):1111-26. doi: 10.1104/pp.108.127514. Epub 2008 Nov 14.
Ca2+-calmodulin (Ca2+-CaM) is a critical molecule that mediates cellular functions by interacting with various metabolic and signaling pathways. However, the protein expression patterns and accompanying serial cytological responses in Ca2+-CaM signaling deficiency remain enigmatic. Here, we provide a global analysis of the cytological responses and significant alterations in protein expression profiles after trifluoperazine treatment in Picea meyeri, which abrogates Ca2+-CaM signaling. Ninety-three differentially displayed proteins were identified by comparative proteomics at different development stages and were assigned to different functional categories closely related to tip growth machinery. The inhibition of Ca2+-CaM signaling rapidly induced an increase in extracellular Ca2+ influx, resulting in dramatically increased cytosolic Ca2+ concentrations and ultrastructural abnormalities in organelles as the primary responses. Secondary and tertiary alterations included actin filament depolymerization, disrupted patterns of endocytosis and exocytosis, and cell wall remodeling, ultimately resulting in perturbed pollen tube extension. In parallel with these cytological events, time-course experiments revealed that most differentially expressed proteins showed time-dependent quantitative changes (i.e. some signaling proteins and proteins involved in organelle functions and energy production changed first, followed by alterations in proteins related to cytoskeletal organization, secretory pathways, and polysaccharide synthesis). Taken together, Ca2+-CaM dysfunction induced serial cytological responses and temporal changes in protein expression profiles, indicating the pivotal role of Ca2+-CaM in the regulation of tip growth machinery.
钙离子 - 钙调蛋白（Ca2+-CaM）是一种关键分子，它通过与各种代谢和信号通路相互作用来介导细胞功能。然而，Ca2+-CaM信号缺陷时的蛋白质表达模式及伴随的一系列细胞学反应仍不清楚。在此，我们对白杄经三氟拉嗪处理后（三氟拉嗪可消除Ca2+-CaM信号）的细胞学反应及蛋白质表达谱的显著变化进行了全面分析。通过比较蛋白质组学在不同发育阶段鉴定出93种差异表达蛋白，并将其归为与顶端生长机制密切相关的不同功能类别。Ca2+-CaM信号的抑制迅速诱导细胞外Ca2+内流增加，导致胞质Ca2+浓度显著升高以及细胞器超微结构异常，这是主要反应。二级和三级变化包括肌动蛋白丝解聚、内吞和外排模式紊乱以及细胞壁重塑，最终导致花粉管延伸受到干扰。与这些细胞学事件同时发生的是，时间进程实验表明，大多数差异表达蛋白呈现出时间依赖性的定量变化（即一些信号蛋白以及参与细胞器功能和能量产生的蛋白首先发生变化，随后是与细胞骨架组织、分泌途径和多糖合成相关的蛋白发生改变）。综上所述，Ca2+-CaM功能障碍诱导了一系列细胞学反应和蛋白质表达谱的时间变化，表明Ca2+-CaM在顶端生长机制调控中起关键作用。
