title: Rethinking cell growth models.
abstract: The minimal description of a growing cell consists of self-replicating ribosomes translating the cellular proteome. While neglecting all other cellular components, this model provides key insights into the control and limitations of growth rate. It shows, for example, that growth rate is maximized when ribosomes work at full capacity, explains the linear relation between growth rate and the ribosome fraction of the proteome and defines the maximal possible growth rate. This ribosome-centered model also highlights the challenge of coordinating cell growth with related processes such as cell division or nutrient production. Coordination is promoted when ribosomes don't translate at maximal capacity, as it allows escaping strict exponential growth. Recent data support the notion that multiple cellular processes limit growth. In particular, increasing transcriptional demand may be as deleterious as increasing translational demand, depending on growth conditions. Consistent with the idea of trade-off, cells may forgo maximal growth to enable more efficient interprocess coordination and faster adaptation to changing conditions.
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Kafri
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Eyal
authors.initials: E
authors.lastname: Metzl-Raz
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Felix
authors.initials: F
authors.lastname: Jonas
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel naama.barkai@weizmann.ac.il.
authors.forename: Naama
authors.initials: N
authors.lastname: Barkai
mesh_terms: D000222:Adaptation, Physiological; D008954:Models, Biological; D014176:Protein Biosynthesis; D012270:Ribosomes / Q000378:metabolism*
keywords: growth rate; microorganisms; protein burden; ribosome; transcription; translation