title: Temporal Regulation of theBacillus subtilisAcetylome and Evidence for a Role of MreB Acetylation in Cell Wall Growth.
abstract: Nε-Lysine acetylation has been recognized as a ubiquitous regulatory posttranslational modification that influences a variety of important biological processes in eukaryotic cells. Recently, it has been realized that acetylation is also prevalent in bacteria. Bacteria contain hundreds of acetylated proteins, with functions affecting diverse cellular pathways. Still, little is known about the regulation or biological relevance of nearly all of these modifications. Here we characterize the cellular growth-associated regulation of theBacillus subtilisacetylome. Using acetylation enrichment and quantitative mass spectrometry, we investigate the logarithmic and stationary growth phases, identifying over 2,300 unique acetylation sites on proteins that function in essential cellular pathways. We determine an acetylation motif, EK(ac)(D/Y/E), which resembles the eukaryotic mitochondrial acetylation signature, and a distinct stationary-phase-enriched motif. By comparing the changes in acetylation with protein abundances, we discover a subset of critical acetylation events that are temporally regulated during cell growth. We functionally characterize the stationary-phase-enriched acetylation on the essential shape-determining protein MreB. Using bioinformatics, mutational analysis, and fluorescence microscopy, we define a potential role for the temporal acetylation of MreB in restricting cell wall growth and cell diameter.
  
  
  OBJECTIVE
  The past decade highlightedNε-lysine acetylation as a prevalent posttranslational modification in bacteria. However, knowledge regarding the physiological importance and temporal regulation of acetylation has remained limited. To uncover potential regulatory roles for acetylation, we analyzed how acetylation patterns and abundances change between growth phases inB. subtilis. To demonstrate that the identification of cell growth-dependent modifications can point to critical regulatory acetylation events, we further characterized MreB, the cell shape-determining protein. Our findings led us to propose a role for MreB acetylation in controlling cell width by restricting cell wall growth.
authors.affiliation: Public Health Research Center at New Jersey Medical School, Rutgers University, Newark, New Jersey, USA.
authors.forename: Valerie J
authors.initials: VJ
authors.lastname: Carabetta
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
authors.forename: Todd M
authors.initials: TM
authors.lastname: Greco
authors.affiliation: Public Health Research Center at New Jersey Medical School, Rutgers University, Newark, New Jersey, USA.
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Tanner
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA.
authors.forename: Ileana M
authors.initials: IM
authors.lastname: Cristea
authors.affiliation: Public Health Research Center at New Jersey Medical School, Rutgers University, Newark, New Jersey, USA.
authors.forename: David
authors.initials: D
authors.lastname: Dubnau
keywords: MreB; acetylome; cell wall synthesis; label-free quantification; lysine acetylation; mass spectrometry; peptidoglycan; posttranslational modification; proteomics