title: Quantification of mRNA and protein and integration with protein turnover in a bacterium.
abstract: Biological function and cellular responses to environmental perturbations are regulated by a complex interplay of DNA, RNA, proteins and metabolites inside cells. To understand these central processes in living systems at the molecular level, we integrated experimentally determined abundance data for mRNA, proteins, as well as individual protein half-lives from the genome-reduced bacterium Mycoplasma pneumoniae. We provide a fine-grained, quantitative analysis of basic intracellular processes under various external conditions. Proteome composition changes in response to cellular perturbations reveal specific stress response strategies. The regulation of gene expression is largely decoupled from protein dynamics and translation efficiency has a higher regulatory impact on protein abundance than protein turnover. Stochastic simulations using in vivo data show how low translation efficiency and long protein half-lives effectively reduce biological noise in gene expression. Protein abundances are regulated in functional units, such as complexes or pathways, and reflect cellular lifestyles. Our study provides a detailed integrative analysis of average cellular protein abundances and the dynamic interplay of mRNA and proteins, the central biomolecules of a cell.
authors.affiliation: EMBL/CRG Systems Biology Research Unit, Centre for Genomic Regulation and UPF, Dr Aiguader 88, Barcelona, Spain. tobias.maier@crg.es
authors.forename: Tobias
authors.initials: T
authors.lastname: Maier
authors.forename: Alexander
authors.initials: A
authors.lastname: Schmidt
authors.forename: Marc
authors.initials: M
authors.lastname: Güell
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kühner
authors.forename: Anne-Claude
authors.initials: AC
authors.lastname: Gavin
authors.forename: Ruedi
authors.initials: R
authors.lastname: Aebersold
authors.forename: Luis
authors.initials: L
authors.lastname: Serrano
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D030541:Databases, Genetic; D004591:Electrophoresis, Polyacrylamide Gel; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial; D013058:Mass Spectrometry; D009177:Mycoplasma pneumoniae / Q000235:genetics* / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D020543:Proteome / Q000235:genetics / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D017423:Sequence Analysis, RNA
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D020543:Proteome; D012333:RNA, Messenger