Aymoz Delphine, Wosika Victoria, Durandau Eric, Pelet Serge
Department of Fundamental Microbiology, University of Lausanne, Lausanne CH-1015, Switzerland.
Nat Commun. 2016 Apr 21;7:11304. doi: 10.1038/ncomms11304.
Protein expression is a dynamic process, which can be rapidly induced by extracellular signals. It is widely appreciated that single cells can display large variations in the level of gene induction. However, the variability in the dynamics of this process in individual cells is difficult to quantify using standard fluorescent protein (FP) expression assays, due to the slow maturation of their fluorophore. Here we have developed expression reporters that accurately measure both the levels and dynamics of protein synthesis in live single cells with a temporal resolution under a minute. Our system relies on the quantification of the translocation of a constitutively expressed FP into the nucleus. As a proof of concept, we used these reporters to measure the transient protein synthesis arising from two promoters responding to the yeast hyper osmolarity glycerol mitogen-activated protein kinase pathway (pSTL1 and pGPD1). They display distinct expression dynamics giving rise to strikingly different instantaneous expression noise.
蛋白质表达是一个动态过程，可被细胞外信号快速诱导。人们普遍认识到，单细胞在基因诱导水平上可表现出很大差异。然而，由于标准荧光蛋白（FP）表达检测中荧光团成熟缓慢，单个细胞中这一过程动力学的变异性难以量化。在此，我们开发了表达报告基因，可在一分钟内的时间分辨率下准确测量活单细胞中蛋白质合成的水平和动力学。我们的系统依赖于对组成型表达的FP向细胞核转位的量化。作为概念验证，我们使用这些报告基因来测量由响应酵母高渗甘油丝裂原活化蛋白激酶途径的两个启动子（pSTL1和pGPD1）产生的瞬时蛋白质合成。它们表现出不同的表达动力学，产生了截然不同的瞬时表达噪声。
