Real-time quantification of protein expression at the single-cell level via dynamic protein synthesis translocation reporters

• Published in: Nature communications 2016-04, Vol.7 (1), p.11304-11304, Article 11304
• Main Authors: Aymoz, Delphine, Wosika, Victoria, Durandau, Eric, Pelet, Serge
• Format: Article
• Language: English
• Subjects: 14/35; 631/337; 631/61/32; 631/80/389/2023/2022; 96/31; 96/63; Enzymes; Gene expression; Gene Expression Regulation, Fungal; Genes, Reporter; Glycerol; Glycerol - metabolism; Glycerol-3-Phosphate Dehydrogenase (NAD+) - genetics; Glycerol-3-Phosphate Dehydrogenase (NAD+) - metabolism; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Humanities and Social Sciences; Kinases; Localization; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; multidisciplinary; Noise; Protein Biosynthesis; Protein expression; Protein Processing, Post-Translational; Protein synthesis; Protein Transport; Proteins; Red Fluorescent Protein; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Saccharomyces cerevisiae Proteins - genetics; Saccharomyces cerevisiae Proteins - metabolism; Science; Science (multidisciplinary); Single-Cell Analysis - methods; Time Factors
• ISSN: 2041-1723; 2041-1723
• 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 (p STL1 and p GPD1 ). They display distinct expression dynamics giving rise to strikingly different instantaneous expression noise. Single cells can display large heterogeneity in gene induction. Here, Aymoz et al . present an expression reporter based on protein translocation that can accurately measure both the levels and dynamics of protein synthesis in live single cells with a temporal resolution of less than one minute.