Unraveling the function of a stress sentinel in the bacterial envelope
Transregio TRR 174 Seminar
- Datum: 05.07.2018
- Uhrzeit: 13:15
- Vortragende(r): Dr. Géraldine Laloux
- de Duve Institute, Brussels
- Ort: MPI for Terrestrial Microbiology
- Raum: Lecture hall
- Gastgeber: TRR 174
- Kontakt: thanbichler@uni-marburg.de
Gram-negative bacteria are
surrounded by a complex multi-layered envelope that is essential for
their viability. Intricate mechanisms called envelope stress response
systems have been selected to detect perturbations that affect envelope
integrity and to respond accordingly in order to contain or repair the
damage. One major stress response system in the model bacterium Escherichia coli is
the Cpx two-component system, in which various types of stress trigger a
phosphotransfer from an inner membrane sensor to a cytoplasmic response
regulator. Cpx is mostly known to monitor defects associated with
misfolded protein accumulation and inner membrane stress. We have also
shown that the Cpx sytem can also sense cell wall defects and regulate
cell wall biogenesis. Interestingly, overproduction of NlpE, an outer
membrane lipoprotein of unclear function, is known to activate the Cpx
system. However, NlpE is not directly involved in sensing the known
Cpx-inducing cues. We set out to elucidate the role of NlpE in the Cpx
system and the molecular nature of the signal that is transmitted by
NlpE to trigger the Cpx system. Our results led us to propose that NlpE
serves as a specific Cpx sentinel that reports on key envelope
biogenesis processes.