[Life Sciences Seminar]
▶Subject: Detecting envelope stress by monitoring β-barrel assembly
▶Speaker: Seung-Hyun Cho, Ph.D. (Universite catholique de Louvain)
▶Date: 5:00 PM/July 19(Thur.)/2019
▶Place: Room 104, Life Science Bldg.
The cell envelope protects bacteria from their surroundings. Defects in its integrity or assembly are sensed by signal transduction systems, allowing cells to rapidly adjust. The Rcs phosphorelay responds to outer membrane (OM)- and peptidoglycan-related stress in enterobacteria. We elucidated how the OM lipoprotein RcsF, the upstream Rcs component, senses envelope stress and activates the signaling cascade. RcsF interacts with BamA, the major component of the β-barrel assembly machinery and with major β-barrel OM proteins (OmpA, OmpC, and OmpF). While the Bam complex assembles OM β-barrel proteins, RcsF can be co-assembled with the major OM proteins. However, when the envelope stresses are given, RcsF fails to interact with BamA. RcsF senses envelope damage by monitoring the activity of the Bam machinery.
Here, we show that RcsF can form a complex with BamA in vivo and in vitro. BamA consists of five periplasmic polypeptide transport-associated (POTRA) domains and a 16 β-barrel domain in the OM. The latter is essential in the last step of β-barrel assembly into the OM. We found that mutations in the β-barrel domain cause defects in the interaction of RcsF with BamA. We propose that RcsF interacts with the β-barrel of BamA to monitor the activity of the Bam machinery.
▶Inquiry: Prof. Cheol-Sang Hwang (279-2352)
* This seminar will be given in Korean.
Please refrain from taking photos during seminars. *