Genetic interaction mapping reveals functional relationships between peptidoglycan endopeptidases and carboxypeptidases

Obando, Manuela AlvaradoDepartment of Microbiology, Cornell University, NY, Ithaca, United States; Weill Institute for Cell and Molecular Biology, Cornell University, NY, Ithaca, United States (author)

Peptidoglycan (PG) is the main component of the bacterial cell wall; it maintains cell shape while protecting the cell from internal osmotic pressure and external environmental challenges. PG synthesis is essential for bacterial growth and survival, and a series of PG modifications are required to allow expansion of the sacculus. Endopeptidases (EPs), for example, cleave the crosslinks between adjacent PG strands to allow the incorporation of newly synthesized PG. EPs are collectively essential for bacterial growth and must likely be carefully regulated to prevent sacculus degradation and cell death. However, EP regulation mechanisms are poorly understood. Here, we used TnSeq to uncover novel EP regulators in Vibrio cholerae. This screen revealed that the carboxypeptidase DacA1 (PBP5) alleviates EP toxicity. dacA1 is essential for viability on LB medium, and this essentiality was suppressed by EP overexpression, revealing that EP toxicity both mitigates, and is mitigated by, a defect in dacA1. A subsequent suppressor screen to restore viability of ΔdacA1 in LB medium identified hypomorphic mutants in the PG synthesis pathway, as well as mutations that promote EP activation. Our data thus reveal a more complex role of DacA1 in maintaining PG homeostasis than previously assumed.

Rey-Varela, DiegoUmeå universitet,Molekylär Infektionsmedicin, Sverige (MIMS),Umeå Centre for Microbial Research (UCMR),Institutionen för molekylärbiologi (Medicinska fakulteten)(Swepub:umu)diva0017 (author)
Cava, FelipeUmeå universitet,Molekylär Infektionsmedicin, Sverige (MIMS),Umeå Centre for Microbial Research (UCMR),Institutionen för molekylärbiologi (Medicinska fakulteten)(Swepub:umu)feca0003 (author)
Dörr, TobiasDepartment of Microbiology, Cornell University, NY, Ithaca, United States; Weill Institute for Cell and Molecular Biology, Cornell University, NY, Ithaca, United States; Cornell Institute for Host-Microbe Interactions and Disease (CIHMID), NY, Ithaca, United States (author)
Department of Microbiology, Cornell University, NY, Ithaca, United States; Weill Institute for Cell and Molecular Biology, Cornell University, NY, Ithaca, United StatesMolekylär Infektionsmedicin, Sverige (MIMS) (creator_code:org_t)

By the author/editor: Obando, Manuela ...; Rey-Varela, Dieg ...; Cava, Felipe; Dörr, Tobias

About the subject

MEDICAL AND HEALTH SCIENCES: MEDICAL AND HEAL ...; and Basic Medicine; and Microbiology in ...

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.