紀要論文

大腸菌増殖の誘導期から対数増殖期への変遷における核様体タンパク質Fisの機能解析

THE ROLE OF FIS NUCLEOID-ASSOCIATED PROTEIN ON TRANSITION FROM LAG PHASE TO LOG PHASE OF ESCHERICHIA COLI

jpn

24368083

https://doi.org/10.15002/00026451

法政大学大学院理工学研究科

法政大学大学院紀要. 理工学研究科編

64

1

2

2023-03-24

Version of Record

The growth of E. coli consists of three phases: lag phase, log phase, and stationary phase. When stationary phase cell is transferred to a fresh medium, it is able to start to grow as similar growth process. E. coli has six major nucleoide-associated proteins (NAPs), Dps, Fis, H-NS, HU, IHF, and StpA, and their intracellular level changes with the growth phases. The detailed roles of these NAPs, however, remain unclear in lag phase. In this study, I showed the role of Fis in the restart of E. coli growth. I found that the level of Fis was maximal immediately before first cell division but the level of fis mRNA was constantly high in all phases. In addition, Western Blotting showed the significant detected level of Fis in ΔclpAXP at stationary phase. Fis is known to increase mRNAs of total 53 tRNA genes. Luciferase reporter assay indicated that thrW and pheU promoter were decreased whereas pheV and proK promoter were increased in Δfis. Taken these results together, the intracellular level of Fis is mainly regulated by Clp protease and reach maximum immediately before log phase, which induces tRNA gene promoters to accelerate translation for proliferation.

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