title: Single-molecule imaging reveals modulation of cell wall synthesis dynamics in live bacterial cells.
abstract: The peptidoglycan cell wall is an integral organelle critical for bacterial cell shape and stability. Proper cell wall construction requires the interaction of synthesis enzymes and the cytoskeleton, but it is unclear how the activities of individual proteins are coordinated to preserve the morphology and integrity of the cell wall during growth. To elucidate this coordination, we used single-molecule imaging to follow the behaviours of the two major peptidoglycan synthases in live, elongating Escherichia coli cells and after perturbation. We observed heterogeneous localization dynamics of penicillin-binding protein (PBP) 1A, the synthase predominantly associated with cell wall elongation, with individual PBP1A molecules distributed between mobile and immobile populations. Perturbations to PBP1A activity, either directly through antibiotics or indirectly through PBP1A's interaction with its lipoprotein activator or other synthases, shifted the fraction of mobile molecules. Our results suggest that multiple levels of regulation control the activity of enzymes to coordinate peptidoglycan synthesis.
authors: Department of Bioengineering, Stanford University, Stanford, California 94305, USA.|Program in Biomedical Informatics, Stanford University, Stanford, California 94305, USA.
authors: Timothy K
authors: TK
authors: Lee
authors: Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, USA.
authors: Kevin
authors: K
authors: Meng
authors: Department of Bioengineering, Stanford University, Stanford, California 94305, USA.
authors: Handuo
authors: H
authors: Shi
authors: Department of Bioengineering, Stanford University, Stanford, California 94305, USA.|Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, USA.
authors: Kerwyn Casey
authors: KC
authors: Huang
mesh_terms: D000560:Amdinocillin / Q000494:pharmacology; D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015311:Cefmetazole / Q000494:pharmacology; D002441:Cefsulodin / Q000494:pharmacology; D002473:Cell Wall / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004058:Diffusion; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D046915:Penicillin-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D010457:Peptidoglycan / Q000096:biosynthesis* / Q000235:genetics; D046928:Peptidoglycan Glycosyltransferase / Q000235:genetics / Q000378:metabolism*; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase / Q000235:genetics / Q000378:metabolism*; D000072760:Single Molecule Imaging / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D046915:Penicillin-Binding Proteins; D010457:Peptidoglycan; D015311:Cefmetazole; D000667:Ampicillin; D046928:Peptidoglycan Glycosyltransferase; C575488:penicillin-binding protein 1A, E coli; C478681:penicillin-binding protein 1B, E coli; D046929:Serine-Type D-Ala-D-Ala Carboxypeptidase; D002441:Cefsulodin; D000560:Amdinocillin