title: The Cost of Protein Production.
abstract: The economy of protein production is central to cell physiology, being intimately linked with cell division rate and cell size. Attempts to model cellular physiology are limited by the scarcity of experimental data defining the molecular processes limiting protein expression. Here, we distinguish the relative contribution of gene transcription and protein translation to the slower proliferation of budding yeast producing excess levels of unneeded proteins. In contrast to widely held assumptions, rapidly growing cells are not universally limited by ribosome content. Rather, transcription dominates cost under some conditions (e.g., low phosphate), translation in others (e.g., low nitrogen), and both in other conditions (e.g., rich media). Furthermore, cells adapted to enforced protein production by becoming larger and increasing their endogenous protein levels, suggesting limited competition for common resources. We propose that rapidly growing cells do not exhaust their resources to maximize growth but maintain sufficient reserves to accommodate changing requirements.
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 Biological Services, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Ghil
authors.initials: G
authors.lastname: Jona
authors.affiliation: Department of Molecular Genetics, Weizmann Institute of Science, Rehovot 76100, Israel. Electronic address: naama.barkai@weizmann.ac.il.
authors.forename: Naama
authors.initials: N
authors.lastname: Barkai
mesh_terms: D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D014176:Protein Biosynthesis / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D014158:Transcription, Genetic / Q000502:physiology*
chemical_list: D029701:Saccharomyces cerevisiae Proteins
keywords: budding yeast; fitness cost; protein burden; protein synthesis