Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, Virginia, United States of America.
PLoS One. 2011;6(10):e26272. doi: 10.1371/journal.pone.0026272. Epub 2011 Oct 26.
Progression through the cell division cycle is orchestrated by a complex network of interacting genes and proteins. Some of these proteins are known to fluctuate periodically during the cell cycle, but a systematic study of the fluctuations of a broad sample of cell-cycle proteins has not been made until now. Using time-lapse fluorescence microscopy, we profiled 16 strains of budding yeast, each containing GFP fused to a single gene involved in cell cycle regulation. The dynamics of protein abundance and localization were characterized by extracting the amplitude, period, and other indicators from a series of images. Oscillations of protein abundance could clearly be identified for Cdc15, Clb2, Cln1, Cln2, Mcm1, Net1, Sic1, and Whi5. The period of oscillation of the fluorescently tagged proteins is generally in good agreement with the inter-bud time. The very strong oscillations of Net1 and Mcm1 expression are remarkable since little is known about the temporal expression of these genes. By collecting data from large samples of single cells, we quantified some aspects of cell-to-cell variability due presumably to intrinsic and extrinsic noise affecting the cell cycle.
细胞分裂周期的进程是由相互作用的基因和蛋白质的复杂网络调控的。其中一些蛋白质在细胞周期中已知会周期性波动，但直到现在才对广泛的细胞周期蛋白质样本进行了系统的波动研究。我们使用延时荧光显微镜对 16 株 budding yeast 进行了分析，每株都包含 GFP 融合到一个参与细胞周期调控的单一基因上。通过从一系列图像中提取振幅、周期和其他指标，我们对蛋白质丰度和定位的动态进行了描述。Cdc15、Clb2、Cln1、Cln2、Mcm1、Net1、Sic1 和 Whi5 的蛋白质丰度波动可以清晰地识别出来。荧光标记蛋白的振荡周期通常与芽间时间一致。Net1 和 Mcm1 表达的强振荡非常显著，因为关于这些基因的时间表达知之甚少。通过从大量单细胞中收集数据，我们量化了由于影响细胞周期的内在和外在噪声而导致的细胞间变异性的某些方面。
