An E. coli lon mutant conferring partial resistance to colicin may reveal a novel role in regulating proteins involved in the translocation of colicin.
Initially, we found that a lon mutant confers partial resistance against colicin. The results of Western blotting detected a decrease in the protein expression levels of BtuB and OmpF involved in colicin translocation in the lon mutant. Moreover, 2-D gel analysis revealed that the expression level of some scavenger proteins marks the lon mutant as being in a situation similar to oxidative stress. OxyRS and SoxRS are the two major response regulators for oxidative stress. Our RT-PCR analysis revealed an elevation of expression of the oxyS gene in the lon mutant. An immunoblot assay further confirmed that overexpression of oxyS RNA can negatively control on the expression of BtuB protein. Probably the BtuB is negatively regulated by a global regulator, oxyS, induced during oxidative stress.
Lee
Yuan-Yu
YY
Institute of Biochemistry, National Yang Ming University, Shih-Pai, Taipei, Taiwan.
Hu
Hsiao-Tin
HT
Liang
Po-Huang
PH
Chak
Kin-Fu
KF
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D003087:Colicins / Q000378:metabolism / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D004996:Ethidium / Q000031:analogs & derivatives / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D018272:Porins / Q000235:genetics / Q000378:metabolism; D049070:Protease La / Q000235:genetics*; D021381:Protein Transport; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics; D058727:RNA, Small Untranslated
D001425:Bacterial Outer Membrane Proteins; D003087:Colicins; D029968:Escherichia coli Proteins; D004996:Ethidium; D026901:Membrane Transport Proteins; D018272:Porins; D049070:Protease La; D012329:RNA, Bacterial; D012097:Repressor Proteins; D014157:Transcription Factors; C044592:BtuB protein, E coli; C109237:OmpF protein; C499686:oxyS small RNA, E coli; D058727:RNA, Small Untranslated; C067883:dihydroethidium; C483567:Lon protein, E coli