Correlation between protein concentration and bacterial cell size can reveal mechanisms of gene expression.

Published on May 22, 2020in Physical Biology2
· DOI :10.1088/1478-3975/AB891C
Cesar Augusto Nieto-Acuna2
Estimated H-index: 2
(University of Los Andes),
Juan Carlos Arias-Castro4
Estimated H-index: 4
(Harvard University)
+ 2 AuthorsJuan M. Pedraza10
Estimated H-index: 10
(University of Los Andes)
Sources
Abstract
Classical models of gene expression consider this process as a first order chemical reaction with rates dependent of the concentration of the reactants (typically, DNA loci, plasmids, RNA, enzymes, etc). By this, cell size is not usually considered to describe protein synthesis. However, due to the low number of these reactants and not perfectly symmetric cell division and molecule segregation, cell size dynamics may reveal hidden properties of the protein synthesis process. Here, we implement a previously developed model describing cell size dynamics. We added gene expression to that model describing the full process including: Transcription, translation, loci replication, cell division and molecule segregation. As result, we observe that correlation between size and protein concentration can discriminate the transcription strategy. We observe how fluctuations in plasmid segregation can imposes limits in this correlation. Our experiments measuring gene expression of RpOD gene in bacteria growing in a balanced growth in media with either glucose or glycerol as carbon source, seem to agree our predictions.
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