Specific role of two NlpC/P60 endopeptidases in cell division and membrane vesicle formation in Deinococcus radiodurans

 Highlights

  • •
    Three NlpC/P60 endopeptidases identified in Deinococcus radiodurans
  • •
    CwlA is essential for cell viability and cell wall integrity
  • •
    CwlB is involved in cell septation whereas CwlC is dispensable
  • •
    Regulatory link between CwlA expression and the genotoxic stress response pathway

ABSTRACT

The bacterial cell wall is composed of peptidogylcane (PG), a sugar polymer cross-linked by short peptide stems. PG determines cell morphology and protects it from environmental stresses. Cell growth and division require a balance between synthesis and hydrolysis of the PG. One class of PG hydrolase is the NlpC/p60 superfamily which is broadly distributed in bacteria, archaea, eukaryotes and viruses. Deinococcus radiodurans, characterized by its extreme radioresistance, is a diderm bacterium with a thick layer of PG located between the inner and outer membrane. D. radiodurans exhibits three NlpC/P60 endopeptidases, their role in morphogenesis and cell cycle remains unexplored. In this work, we investigated the role of each endopeptidase in cell division to assess their specific role. Here, we showed that the CwlB protein is involved in cell division and that cwlA gene is essential for cell viability. The CwlC protein is not required for cell shape maintenance or cell division. We showed that CwlA protein is homogeneously localized around the cell except on septal region. CwlA-depleted cells lost viability, displayed morphological changes, and produced numerous membrane vesicles, similarly to cells exposed to sublethal mitomycin C (a DNA-damaging agent) or to DdrO depletion, the transcriptional repressor of the main genotoxic stress response in Deinococcus. We showed that cwlA expression is higly repressed under DdrO depletion. These data suggested a link between response pathway to genotoxic conditions and cell wall remodeling.

Read full article for free (open access):
https://www.sciencedirect.com/science/article/pii/S2666517426000234?__cf_chl_tk=maWelbe4DxOqMVZZBp8teWTFjSwWeg6N_atkYIJ3J4Q-1770884142-1.0.1.1-svcZEBl2VUMmitq86Lhhvj9OnJU2HOQnTscVhtqjWc4



Popular posts from this blog

Salivary microbiome diversity is associated with oral health and disease

Image
The oral microbiome is a complex community of bacteria, fungi, and viruses that inhabit the oral cavity. Microbes of the oral microbiome are implicated in health and disease. We collected 220 unstimulated saliva samples from patients with periodontal disease and varying degrees of dental caries, as well as from subjects with no signs of oral disease. Metagenomic analysis of saliva revealed significantly higher abundance of periodontal pathogens in people with gum disease, and significantly higher abundance of cariogenic species in people with dental caries. We also found that salivary microbiome diversity was significantly higher in people with periodontal disease, but not in those with only caries. Furthermore, oral microbiome diversity is affected by oral hygiene habits such as flossing frequency, but not brushing frequency. Clustering and differential analysis allowed us to identify specific commensal species, such as  Prevotella pallens and Veillonella atypica , which are signi...
Read more