Staphylococcal ClpXP protease targets the cellular antioxidant system to eliminate fitness-compromised cells in stationary phase

Abdulelah A. Alqarzaee, Sujata S. Chaudhari, Mohammad Mazharul Islam, Vikas Kumar, Matthew C. Zimmerman, Rajib Saha, Kenneth W. Bayles, Dorte Frees, Vinai C. Thomas

Research output: Contribution to journalArticlepeer-review

7 Scopus citations


The transition from growth to stationary phase is a natural response of bacteria to starvation and stress. When stress is alleviated and more favorable growth conditions return, bacteria resume proliferation without a significant loss in fitness. Although specific adaptations that enhance the persistence and survival of bacteria in stationary phase have been identified, mechanisms that help maintain the competitive fitness potential of nondividing bacterial populations have remained obscure. Here, we demonstrate that staphylococci that enter stationary phase following growth in media supplemented with excess glucose, undergo regulated cell death to maintain the competitive fitness potential of the population. Upon a decrease in extracellular pH, the acetate generated as a byproduct of glucose metabolism induces cytoplasmic acidification and extensive protein damage in nondividing cells. Although cell death ensues, it does not occur as a passive consequence of protein damage. Instead, we demonstrate that the expression and activity of the ClpXP protease is induced, resulting in the degeneration of cellular antioxidant capacity and, ultimately, cell death. Under these conditions, inactivation of either clpX or clpP resulted in the extended survival of unfit cells in stationary phase, but at the cost of maintaining population fitness. Finally, we show that cell death from antibiotics that interfere with bacterial protein synthesis can also be partly ascribed to the corresponding increase in clpP expression and activity. The functional conservation of ClpP in eukaryotes and bacteria suggests that ClpP-dependent cell death and fitness maintenance may be a widespread phenomenon in these domains of life.

Original languageEnglish (US)
Article numbere2109671118
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number47
StatePublished - Nov 23 2021


  • ClpP
  • ClpX
  • SodA
  • Staphylococcus aureus
  • Stationary phase fitness

ASJC Scopus subject areas

  • General


Dive into the research topics of 'Staphylococcal ClpXP protease targets the cellular antioxidant system to eliminate fitness-compromised cells in stationary phase'. Together they form a unique fingerprint.

Cite this