EPFL BioE Talks SERIES "Bacterial Proprioception: Precise Adaptation to Mechanical Stimulus in the Chemotaxis Output"
Event details
| Date | 15.05.2023 |
| Hour | 16:00 › 17:00 |
| Speaker | Prof. Pushkar P. Lele, Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX (USA) |
| Location | Online |
| Category | Conferences - Seminars |
| Event Language | English |
WEEKLY EPFL BIOE TALKS SERIES
Abstract:
Bacteria sense and adapt to mechanical cues in their environment, which appears crucial in their quest to colonize surfaces. Cell appendages that can function as tactile sensors are particularly important in mechanosensing and surface adaptation. The bacterial flagellum is a well-known example of such a mechanosensor. The flagellum is rotated by a transmembrane rotary motor that engages one or two force generators (stator units) when it is newly assembled. The stator units utilize the proton-motive force to deliver mechanical forces, turning the flagellum in Escherichia coli. We discovered that when the flagellum adheres to a solid surface, the motor responds to the increased viscous resistance to rotation by recruiting additional stator units. A catch bond within the stator structure likely underpins the mechanosensitive recruitment of the units. The stator has since been implicated in downstream signaling events linked to numerous physiological changes, including biofilm formation. A major question is how stator recruitment in the membrane initiates intracellular signaling. Our recent work demonstrated that stator recruitment modulates the binding of CheY-P, the chemotaxis response regulator, to the cytoplasmic interface of the flagellar motor. Notably, this change in binding affinity is driven purely by mechanical force delivered by the stator units to the membranous motor components. Experiments further revealed significant parallels between the flagellar responses to mechanical and chemical stimuli in the chemotaxis network. The newly discovered link between mechanosensing and chemotaxis function is essential in surface adaptation. It may also provide a handle for understanding epigenetic mechanisms of adaptation to antibiotic stress in bacteria.
Bio:
Zoom link (with one-time registration for the whole series) for attending remotely: https://go.epfl.ch/EPFLBioETalks
Instructions for 1st-year Ph.D. students who are under EDBB’s mandatory seminar attendance rule:
IF you are not attending in-person in the room, please make sure to
Abstract:
Bacteria sense and adapt to mechanical cues in their environment, which appears crucial in their quest to colonize surfaces. Cell appendages that can function as tactile sensors are particularly important in mechanosensing and surface adaptation. The bacterial flagellum is a well-known example of such a mechanosensor. The flagellum is rotated by a transmembrane rotary motor that engages one or two force generators (stator units) when it is newly assembled. The stator units utilize the proton-motive force to deliver mechanical forces, turning the flagellum in Escherichia coli. We discovered that when the flagellum adheres to a solid surface, the motor responds to the increased viscous resistance to rotation by recruiting additional stator units. A catch bond within the stator structure likely underpins the mechanosensitive recruitment of the units. The stator has since been implicated in downstream signaling events linked to numerous physiological changes, including biofilm formation. A major question is how stator recruitment in the membrane initiates intracellular signaling. Our recent work demonstrated that stator recruitment modulates the binding of CheY-P, the chemotaxis response regulator, to the cytoplasmic interface of the flagellar motor. Notably, this change in binding affinity is driven purely by mechanical force delivered by the stator units to the membranous motor components. Experiments further revealed significant parallels between the flagellar responses to mechanical and chemical stimuli in the chemotaxis network. The newly discovered link between mechanosensing and chemotaxis function is essential in surface adaptation. It may also provide a handle for understanding epigenetic mechanisms of adaptation to antibiotic stress in bacteria.
Bio:
- Postdoctoral Fellow, Molecular and Cellular Biology, Harvard University, Cambridge MA, 2015
- Ph.D., Chemical Engineering, University of Delaware, Newark, 2010
- Bachelor, Chemical Engineering, UDCT, Mumbai, 2005
Zoom link (with one-time registration for the whole series) for attending remotely: https://go.epfl.ch/EPFLBioETalks
Instructions for 1st-year Ph.D. students who are under EDBB’s mandatory seminar attendance rule:
IF you are not attending in-person in the room, please make sure to
- send D. Reinhard a note before noon on seminar day, informing that you plan to attend the talk online, and
- be signed in on Zoom with a recognizable user name (not a pseudonym making it difficult or impossible to be identified).
Practical information
- Informed public
- Registration required
Organizer
- Prof. Alexandre Persat, EPFL
Contact
- Institute of Bioengineering (IBI), Dietrich REINHARD