Lon Protease is Needed to Resume Growth of Escherichia coli rpoH Mutant Following Gamma Radiation

다국어 초록 (Multilingual Abstract)

Heat shock proteins (HSPs) such as chaperones and proteases are upregulated toensure correct protein folding and to prevent the formation of toxic protein aggregates inresponse to heat shock or other insults that increase cellular protein misfolding. In Escherichiacoli, which has been used as a model organism in research in microbial genetics and physiology,HSPs are induced by temperature upshift from 30℃ to 42℃, and their induction is regulated bythe alternative sigma factor, σ32, encoded by the rpoH gene. The observation that post-irradiationincubation of E. coli at temperatures higher than 37°C resulted in increased survival rates hasled to the proposal that HSPs are required to survive stress from ionizing radiation. We haveinvestigated this hypothesis by examining the effects of rpoH mutation on cell survival and postirradiationrecovery. The wild-type E. coli strain (WT) exposed to gamma radiation (γ-radiation)exhibited a clear decrease in survival relative to non-irradiated counterparts, but there was nosignificant difference in the survival outcomes between WT and an rpoH mutant strain (ΔrpoH).
When cells irradiated with doses of 1, 2, and 3 kGy were re-inoculated into fresh media, the lagphase of ΔrpoH became longer than that of WT in a dose-dependent manner. Expression of theheat shock protease Lon could partially restore the growth defect observed in irradiated ΔrpoH.
These findings suggest that Lon may play a role in the post-irradiation recovery period bydegrading its primary substrate SulA, which inhibits cell division.

참고문헌 (Reference)

• 1 Alper T, "‘Restoration’ of Escherichia coli strain B after irradiation: its dependence on suboptimal growth conditions" 18 : 461-472, 1958
• 2 Krueger JH, "groEL and dnaK genes of Escherichia coli are induced by UV irradiation and nalidixic acid in an htpR+-dependent fashion" 81 : 1499-1503, 1984
• 3 Yang K, "The molecular chaperone DnaJ is involved in the peroxide- induced oxidative stress response in Escherichia coli" 18 : 41-47, 2014
• 4 Straus DB, "The heat-shock response of E. coli is regulated by changes in the concentration of sigma 32" 329 : 348-351, 1987
• 5 Craig EA, "The heat-shock response" 18 : 239-280, 1985
• 6 Arsène F, "The heat shock response of Escherichia coli" 55 : 3-9, 2000
• 7 Maslowska KH, "The SOS system: A complex and tightly regulated response to DNA damage" 60 : 368-384, 2019
• 8 Butala M, "The SOS response affects thermoregulation of colicin K synthesis" 283 : 104-111, 2008
• 9 Han M-J, "The Escherichia coli proteome:past, present, and future prospects" 70 : 362-439, 2006
• 10 Bhandari V, "Substrate interaction networks of the Escherichia coli chaperones: trigger factor, DnaK and GroEL" 883 : 271-294, 2015
• 11 Alper T, "Sterilization of Medical Products by Ionizing Radiation (Vol 2)" Muitiscience 9-29, 1978
• 12 Diehl JF, "Safety of Irradiated Foods" Marcel Dekker Inc. 89-132, 1995
• 13 Delaney JM, "Requirement of the Escherichia coli dna Kgene for thermotolerance and protection against H2O2" 136 : 2113-2118, 1990
• 14 Burby PE, "Regulation of cell division in bacteria by monitoring genome integrity and DNA replication status" 202 : e00408-e00419, 2020
• 15 Schumann W, "Regulation of bacterial heat shock stimulons" 21 : 959-968, 2016
• 16 Wu W-F, "Redundant in vivo proteolytic activities of Escherichia coli Lon and the ClpYQ (HslUV) protease" 181 : 3681-3687, 1999
• 17 Kim SY, "Purification of Mlc and analysis of its effects on the pts expression in Escherichia coli" 274 : 25398-25402, 1999
• 18 Neher SB, "Proteomic profiling of ClpXP substrates after DNA damage reveals extensive instability within SOS regulon" 22 : 193-204, 2006
• 19 Kerner MJ, "Proteome-wide analysis of chaperonin-dependent protein folding in Escherichia coli" 122 : 209-220, 2005
• 20 임상용, "Proteome Analysis of Escherichia coli after High-dose Radiation" (사)한국방사선산업학회 5 (5): 1-5, 2011
• 21 Meyer AS, "Proteolysis in the Escherichia coli heat shock response: a player at many levels" 14 : 194-199, 2011
• 22 Grover A, "Molecular biology of stress responses" 7 : 1-5, 2002
• 23 Lund PA, "Microbial molecular chaperones" 44 : 93-140, 2001
• 24 임상용, "Induction of SOS Genes by a Low Dose of Gamma Radiation, 10 Gy, in Salmonella enterica Serovar Typhimurium" (사)한국방사선산업학회 7 (7): 109-113, 2013
• 25 Tsuchido T, "Heat shock response in Escherichia coli influences cell division" 83 : 6959-6963, 1986
• 26 Kusukawa N, "Heat shock protein GroE of Escherichia coli: key protective roles against thermal stress" 2 : 874-882, 1988
• 27 Shin D, "Heat shock RNA polymerase (Eσ32) is involved in the transcription of mlc and crucial for induction of the Mlc regulon by glucose in Escherichia coli" 276 : 25871-25875, 2001
• 28 Lim S, "Gene expression profiles following high-dose exposure to gamma radiation in Salmonella enterica serovar Typhimurium" 2 : 111-119, 2008
• 29 Riley PA, "Free radicals in biology: oxidative stress and the effects of ionizing radiation" 65 : 27-33, 1994
• 30 Straus DB, "Escherichia coli heat shock gene mutants are defective in proteolysis" 2 : 1851-1858, 1988
• 31 Reisz JA, "Effects of ionizing radiation on biological molecules-mechanisms of damage and emerging methods of detection" 21 : 260-292, 2014
• 32 Caillet S, "Effect of gamma radiation on heat shock protein expression of four foodborne pathogens" 105 : 1384-1391, 2008
• 33 Symons MCR, "Direct and indirect damage to DNA by ionizing radiation" 43 : 403-405, 1994
• 34 VanBogelen RA, "Differential induction of heat shock, SOS, and oxidation stress regulons and accumulation of nucleotides in Escherichia coli" 169 : 26-32, 1987
• 35 Yura T, "Bacterial stress responses" ASM press 3-18, 2000
• 36 Greenberg JT, "A global response induced in Escherichia coli by redox-cycling agents overlaps with that induced by peroxide stress" 171 : 3933-3939, 1989