YihE Kinase Is a Central Regulator of Programmed Cell Death in Bacteria

Dorsey-Oresto A, et al., 2013. Cell report. 3(2):528-37.

Speaker: Po-Sheng Tsai (蔡伯昇)                  Time: 15:10~16:00, May. 15, 2013

Commentator: Dr. I- Hsiu Huang (黃一修老師)     Place: Room 601

Abstract

Stress-mediated programmed cell death (PCD) in bacteria is a self-destruction in unicellular bacteria, which may provide a selective advantage to bacterial population. On the other hand, PCD may become a novel approach to control pathogen and restrict new resistance from arising. In this regard, the regulation of PCD has emerged as an important theme. In this study, authors report a central regulator, YihE protein kinase, which protects Escherichia coli from antimicrobial agents and some environmental stresses. The results of survival rate in ΔyihE showed that a deficiency ofYihE increased the lethal activity of harsh stress without affecting bacteriostatic activity. By replacing the essential residues of YihE, authors found that the kinase activities of YihE reduce the effects of lethal stress. The recovery of survival rate in ΔmazEF-ΔyihE double mutant indicated the protecting function from PCD of YihE act through the negative effect on MazEF toxin-antitoxin (TA) module. The survival rate of both WT and mutants rise when hydroxyl radical accumulation is inhibited. This result links YihE with a reactive oxygen species cascades. Furthermore, authors demonstrated the poststress PCD even after removal of the antibiotics and hydroxyl radical as the initial stress stimulus. In conclusion, this study identified the YihE protein kinase of E. coli as a central factor of PCD and providing evidence for poststress PCD which functions through the MazEFTA system and oxidative stress pathways.

References:

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