Inflating bacterial cells by increased protein synthesis

We report that cell size and mass exhibit positive or negative dependences with growth rate depending on the growth limitation applied. In particular, synthesizing large amounts of "useless" proteins led to an inversion of the canonical, positive relation, with slow growing cells enlarged 7- to 8-fold compared to cells growing at similar rates under nutrient limitation. Strikingly, this increase in cell size was accompanied by a 3- to 4-fold increase in cellular DNA content at slow growth, reaching up to an amount equivalent to ~8 chromosomes per cell. Despite drastic changes in cell mass and macromolecular composition, cellular dry mass density remained constant. Our findings reveal an important role of protein synthesis in cell division control.

Source: Molecular Systems Biology - October 30, 2015 Category: Molecular Biology Authors: Basan, M., Zhu, M., Dai, X., Warren, M., Sevin, D., Wang, Y.-P., Hwa, T. Tags: Metabolism, Protein Biosynthesis & Quality Control, Quantitative Biology & Dynamical Systems Reports Source Type: research