Intercellular Variability in Protein Levels from Stochastic Expression and Noisy Cell Cycle Processes

Author(s)Soltani,Mohammad
Author(s)Vargas-Garcia,Cesar A.
Author(s)Antunes,Duarte
Author(s)Singh,Abhyudai
Ordered AuthorMohammad Soltani, Cesar A. Vargas-Garcia, Duarte Antunes, Abhyudai Singh
UD AuthorSingh, Abhyudai
Date Accessioned2017-07-19T18:48:37Z
Date Available2017-07-19T18:48:37Z
Copyright Date2016 Soltani et al
Publication Date2016-08-18
DescriptionPublisher's PDF
AbstractInside individual cells, expression of genes is inherently stochastic and manifests as cell-to-cell variability or noise in protein copy numbers. Since proteins half-lives can be comparable to the cell-cycle length, randomness in cell-division times generates additional intercellular variability in protein levels. Moreover, as many mRNA/protein species are expressed at low-copy numbers, errors incurred in partitioning of molecules between two daughter cells are significant. We derive analytical formulas for the total noise in protein levels when the cell-cycle duration follows a general class of probability distributions. Using a novel hybrid approach the total noise is decomposed into components arising from i) stochastic expression; ii) partitioning errors at the time of cell division and iii) random cell-division events. These formulas reveal that random cell-division times not only generate additional extrinsic noise, but also critically affect the mean protein copy numbers and intrinsic noise components. Counter intuitively, in some parameter regimes, noise in protein levels can decrease as cell-division times become more stochastic. Computations are extended to consider genome duplication, where transcription rate is increased at a random point in the cell cycle. We systematically investigate how the timing of genome duplication influences different protein noise components. Intriguingly, results show that noise contribution from stochastic expression is minimized at an optimal genome-duplication time. Our theoretical results motivate new experimental methods for decomposing protein noise levels from synchronized and asynchronized single-cell expression data. Characterizing the contributions of individual noise mechanisms will lead to precise estimates of gene expression parameters and techniques for altering stochasticity to change phenotype of individual cells.
DepartmentUniversity of Delaware, Department of Electrical and Computer Engineering University of Delaware, Department of Biomedical Engineering University of Delaware, Department of Mathematical Sciences University of Delaware, Center for Bioinformatics and Computational Biology
CitationSoltani, M., Vargas-Garcia, C. A., Antunes, D., & Singh, A. (2016). Intercellular variability in protein levels from stochastic expression and noisy cell cycle processes. Plos Computational Biology, 12(8), e1004972. doi:10.1371/journal.pcbi.1004972
DOI10.1371/journal.pcbi.1004972
ISSN1553-734X
URLhttp://udspace.udel.edu/handle/19716/21567
LanguageEnglish
PublisherPublic Library Science
dc.rightsCC BY 4.0
dc.sourcePLoS Computational Biology
dc.source.urihttp://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1004972
TitleIntercellular Variability in Protein Levels from Stochastic Expression and Noisy Cell Cycle Processes
TypeArticle
Files
Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Intercellular Variability in Protein Levels from Stochastic Expression and Noisy Cell Cycle Processes.PDF
Size:
822.75 KB
Format:
Adobe Portable Document Format
Description:
Main article