QseA and GrlR/GrlA regulation of the locus of enterocyte effacement genes in enterohemorrhagic Escherichia coli.
نویسندگان
چکیده
Transcription of the locus of enterocyte effacement (LEE) genes in enterohemorrhagic Escherichia coli (EHEC) is regulated by the LEE-encoded Ler and GrlR/GrlA proteins as well as the non-LEE-encoded regulator QseA. This work demonstrates that GrlR/GrlA activate LEE2 transcription in a Ler-independent fashion, whereas transcription of grlRA is activated by QseA in both Ler-dependent and -independent manners.
منابع مشابه
Structure of GrlR and the Implication of Its EDED Motif in Mediating the Regulation of Type III Secretion System in EHEC
Enterohemorrhagic Escherichia coli (EHEC) is a common cause of severe hemorrhagic colitis. EHEC's virulence is dependent upon a type III secretion system (TTSS) encoded by 41 genes. These genes are organized in several operons clustered in the locus of enterocyte effacement. Most of the locus of enterocyte effacement genes, including grlA and grlR, are positively regulated by Ler, and Ler expre...
متن کاملThe GrlR-GrlA regulatory system coordinately controls the expression of flagellar and LEE-encoded type III protein secretion systems in enterohemorrhagic Escherichia coli.
The gene function of the locus of enterocyte effacement (LEE) is essential for full virulence of enterohemorrhagic Escherichia coli (EHEC). Strict control of LEE gene expression is mediated by the coordinated activities of several regulatory elements. We previously reported that the ClpX/ClpP protease positively controls LEE expression by down-regulating intracellular levels of GrlR, a negative...
متن کاملGrlA of enterohemorrhagic Escherichia coli O157:H7 activates LEE1 by binding to the promoter region.
BACKGROUND AND PURPOSE The locus of enterocyte effacement (LEE) of enterohemorrhagic Escherichia coli (EHEC) O157:H7 encodes virulence factors that lead cooperatively to an attaching and effacing lesion on host large intestine cells. Global regulator of LEE activator (GrlA), encoded by the open reading frame 3 in the EHEC LEE, is known to serve as a positive regulator of LEE expression. However...
متن کاملQuorum-sensing Escherichia coli regulator A: a regulator of the LysR family involved in the regulation of the locus of enterocyte effacement pathogenicity island in enterohemorrhagic E. coli.
The locus of enterocyte effacement (LEE) is a chromosomal pathogenicity island that encodes the proteins involved in the formation of the attaching and effacing lesions by enterohemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC). The LEE comprises 41 open reading frames organized in five major operons, LEE1, LEE2, LEE3, tir (LEE5), and LEE4, which encode a type III secretio...
متن کاملClpXP protease controls expression of the type III protein secretion system through regulation of RpoS and GrlR levels in enterohemorrhagic Escherichia coli.
Expression of the type III protein secretion system (TTSS), encoded in the locus of enterocyte effacement (LEE) of enterohemorrhagic Escherichia coli (EHEC), has been shown to be controlled by various regulators. In a search for additional regulatory genes, we identified a DNA fragment containing clpX and clpP that has a positive regulatory effect on LEE expression in EHEC O157. The expression ...
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ورودعنوان ژورنال:
- Journal of bacteriology
دوره 189 14 شماره
صفحات -
تاریخ انتشار 2007