Contribution of RNA polymerase concentration variation to protein expression noise

• Published in: Nature communications 2014-09, Vol.5 (1), p.4761-4761, Article 4761
• Main Authors: Yang, Sora, Kim, Seunghyeon, Rim Lim, Yu, Kim, Cheolhee, An, Hyeong Jeon, Kim, Ji-Hyun, Sung, Jaeyoung, Lee, Nam Ki
• Format: Article
• Language: English
• Subjects: 14/35; 631/337/572; 631/553/2707; Cell cycle; Cell growth; DNA-Directed RNA Polymerases - genetics; DNA-Directed RNA Polymerases - metabolism; E coli; Escherichia coli - genetics; Escherichia coli - metabolism; Gene expression; Genes, Reporter; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Humanities and Social Sciences; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; multidisciplinary; Promoter Regions, Genetic; Protein Binding; Protein expression; Proteins; Red Fluorescent Protein; Ribonucleic acid; RNA; RNA polymerase; Science; Science (multidisciplinary); Transcription, Genetic; Viral Proteins - genetics; Viral Proteins - metabolism
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms5761

Cell-to-cell variation in gene expression, or noise, is a general phenomenon observed within cell populations. Transcription is known to be the key stage of gene expression where noise is generated, however, how variation in RNA polymerase (RNAP) concentration contributes to gene expression noise is unclear. Here, we quantitatively investigate how variations in absolute amounts of RNAP molecules affect noise in the expression of two fluorescent protein reporters driven by identical promoters. We find that intrinsic noise is independent of variation in RNAP concentrations, whereas extrinsic noise, which is variation in gene expression due to varying cellular environments, scales linearly with variation in RNAP abundance. Specifically, the propagation of RNAP abundance variation to expressed protein noise is inversely proportional to the concentration of RNAP, which suggests that the change in noise that results from RNAP fluctuations is determined by the fraction of promoters that is not occupied by RNAP. The quantitative relationship between the fluctuation of specific extrinsic and intrinsic factors, and stochastic fluctuations in gene expression - or noise - has not been clearly established. Here, Yang et al. demonstrate that intrinsic noise is independent of - while extrinsic noise scales linearly with - variation in RNA polymerase abundance.