POSTERS - BLAST X - University of Utah

BLAST X Poster #56
REACTIVE ALDEHYDES AND MOTILITY IN ESCHERICHIA COLI K12
Changhan Lee, Junghoon Lee, Jongchul Shin, Insook Kim, Kwanghee Baek, and Chankyu
Park
Department of Biological Sciences, KAIST, Daejon, Korea
Graduate School of Biotechnology, Kyung Hee University, Yongin, Korea
The short chain carbohydrates such as glyoxal and methylglyoxal are generated in vivo
from various sugars either by an oxidative stress or by a cellular metabolism, which are believed
to be removed by the glutathione-dependent glyoxalase system. We isolated a number of E. coli
mutants conferring resistance or sensitivity to these aldehydes and found that some of them
affect motility. In the case of glyoxalse I mutant (gloA) that is deficient in the removal of
aldehyde using glutathione, significant reductions in the free-swimming as well as in swarming
behaviors were observed. When we introduced the flhDC-lacZ fusion contained in phage
Lambda into the wild-type and gloA strains, expression of LacZ was considerably reduced in the
gloA mutant compared to that of wild type, suggesting that a decrease in flagellar expression is
responsible for the impaired motility. This is further confirmed by the reduced expression of
flagellin as detected by anti-flagellin antiserum. We observed similar effects of other glyoxalrelated
genes on motility, suggesting a possibility that an intracellular level of aldehyde is
somehow associated with flagellar gene expression. Cellular redox change due to an aldehyde,
affecting motility, will be discussed.
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