Mechanical Genomics Identifies Diverse Modulators of Bacterial Cell Stiffness.
Bacteria must maintain mechanical integrity to withstand the large osmotic pressure differential across the cell membrane and wall. Although maintaining mechanical integrity is critical for proper cellular function, a fact exploited by prominent cell-wall-targeting antibiotics, the proteins that contribute to cellular mechanics remain unidentified. Here, we describe a high-throughput optical method for quantifying cell stiffness and apply this technique to a genome-wide collection of ∼4,000 Escherichia coli mutants. We identify genes with roles in diverse functional processes spanning cell-wall synthesis, energy production, and DNA replication and repair that significantly change cell stiffness when deleted. We observe that proteins with biochemically redundant roles in cell-wall synthesis exhibit different stiffness defects when deleted. Correlating our data with chemical screens reveals that reducing membrane potential generally increases cell stiffness. In total, our work demonstrates that bacterial cell stiffness is a property of both the cell wall and broader cell physiology and lays the groundwork for future systematic studies of mechanoregulation.
Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA.
George K
GK
Auer
Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
Timothy K
TK
Lee
Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
Manohary
M
Rajendram
Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Spencer
S
Cesar
Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.
Amanda
A
Miguel
Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA. Electronic address: kchuang@stanford.edu.
Kerwyn Casey
KC
Huang
Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA. Electronic address: weibel@biochem.wisc.edu.
Douglas B
DB
Weibel
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002462:Cell Membrane; D002473:Cell Wall; D004261:DNA Replication; D004926:Escherichia coli; D023281:Genomics; D055595:Mechanical Phenomena; D013171:Spores, Bacterial; D013314:Stress, Mechanical
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins