TY - JOUR
T1 - Expression regulation of polycistronic lee3 genes of enterohaemorrhagic Escherichia coli
AU - Sun, Wei Sheng W.
AU - Chen, Jenn Wei
AU - Wu, Yi Chih
AU - Tsai, Hsing Yuan
AU - Kuo, Yu Liang
AU - Syu, Wan Jr
N1 - Funding Information:
Support was provided by the Ministry of Science and Technology MOST 103-2320-B-010- 022-MY3 and Ministry of Science and Technology MOST 104-2321-B-010-016 from the Taiwan Ministry of Science Technology (https://www.most.gov.tw/) received by WJS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Publisher Copyright:
© 2016 Sun et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2016/5
Y1 - 2016/5
N2 - Enterohaemorrhagic Escherichia coli O157:H7 (EHEC) carries a pathogenic island LEE that is consisted mainly of five polycistronic operons. In the lee3 operon, mpc is the first gene and has been reported to down regulate the type-3 secretion system of EHEC when its gene product is over-expressed. Furthermore, mpc has been suggested to have a regulationfunction via translation but the mechanism remains unclear. To clarify this hypothesis, we dissected the polycistron and examined the translated products. We conclude that translationof mpc detrimentally governs the translation of the second gene, escV, which in turn affects the translation of the third gene, escN. Then sequentially, escN affects the expressionof the downstream genes. Furthermore, we located a critical cis element within the mpc open-reading frame that plays a negative role in the translation-dependent regulationof lee3. Using qRT-PCR, we found that the amount of mpc RNA transcript present in EHEC was relatively limited when compared to any other genes within lee3. Taken together, when the transcription of LEE is activated, expression of mpc is tightly controlled by a restriction of the RNA transcript of mpc, translation of which is then critical for the efficient production of the operon's downstream gene products.
AB - Enterohaemorrhagic Escherichia coli O157:H7 (EHEC) carries a pathogenic island LEE that is consisted mainly of five polycistronic operons. In the lee3 operon, mpc is the first gene and has been reported to down regulate the type-3 secretion system of EHEC when its gene product is over-expressed. Furthermore, mpc has been suggested to have a regulationfunction via translation but the mechanism remains unclear. To clarify this hypothesis, we dissected the polycistron and examined the translated products. We conclude that translationof mpc detrimentally governs the translation of the second gene, escV, which in turn affects the translation of the third gene, escN. Then sequentially, escN affects the expressionof the downstream genes. Furthermore, we located a critical cis element within the mpc open-reading frame that plays a negative role in the translation-dependent regulationof lee3. Using qRT-PCR, we found that the amount of mpc RNA transcript present in EHEC was relatively limited when compared to any other genes within lee3. Taken together, when the transcription of LEE is activated, expression of mpc is tightly controlled by a restriction of the RNA transcript of mpc, translation of which is then critical for the efficient production of the operon's downstream gene products.
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U2 - 10.1371/journal.pone.0155578
DO - 10.1371/journal.pone.0155578
M3 - Article
C2 - 27182989
AN - SCOPUS:84969651367
SN - 1932-6203
VL - 11
JO - PloS one
JF - PloS one
IS - 5
M1 - e0155578
ER -