CprV safeguards cellular compartmentalisation in response to early developmental defects during Bacillus subtilis sporulation
Speaker: Chris Rodrigues, University of Warwick, UK
Host: Felipe Cava, MIMS/Institutionen för molekylärbiologi
Venue: Major Groove, Umeå University Hospital
About the lecture:
Bacterial endospores (spores), such as those produced by the soil bacterium Bacillus subtilis and the pathogen Clostridioides difficile, allow bacteria to survive stress, persist in the environment and seed new and recurring infections. Spore formation begins with a polar septum that compartmentalises two transcriptionally distinct cells, the mother cell and forespore (which becomes the spore). At this septum, critical molecular events are coordinated to ensure septal stability, compartmentalisation and efficient spore development. In previous work we showed that coordination between chromosome translocation into the forespore and septal peptidoglycan remodelling is required to maintain transcriptional compartmentalisation at the septal pore through which the chromosome is translocated. This coordination is achieved through a mechanism controlled by the EMP complex (composed of SpoIIIE, SpoIIIM and PbpG) that localises at the septal pore. In this study, we identify CprV as an additional factor that functions with the EMP complex in maintaining septal pore stability and compartmentalisation. Consistent with this idea, sporulating cells lacking CprV exhibit miscompartmentalisation and chromosome translocation defects in a fraction of cells, but removal of CprV in cells lacking SpoIIIM or PbpG, significantly exacerbates these defects. Furthermore, and highlighting CprV’s safeguarding function, CprV localisation at the septal pore depends on SpoIIIE and increases in frequency when chromosome translocation or peptidoglycan remodelling around the septal pore is compromised. Overall, our data support a model whereby CprV safeguards the septal pore, ensuring tight coordination between chromosome translocation and peptidoglycan remodelling during sporulation, in the face of architectural changes to septal pore structure.
