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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #314286

Research Project: Molecular Biology of Human Pathogens Associated with Food

Location: Produce Safety and Microbiology Research

Title: Analysis of the activity and regulon of the two-component regulatory system encoded by Cjj1484 and Cjj1483 of Campylobacter jejuni

Author
item Luethy, Paul - University Of Texas Southwestern Medical Center
item Huynh, Steven
item Parker, Craig
item Hendrixson, David - University Of Texas Southwestern Medical Center

Submitted to: Journal of Bacteriology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2015
Publication Date: 5/15/2015
Citation: Luethy, P.M., Huynh, S., Parker, C., Hendrixson, D.R. 2015. Analysis of the activity and regulon of the two-component regulatory system encoded by Cjj1484 and Cjj1483 of Campylobacter jejuni. Journal of Bacteriology. 197:1592-1605.

Interpretive Summary: Campylobacter jejuni is a leading cause of bacterial diarrheal disease throughout the world and a frequent commensal in the intestinal tract of poultry and many other animals. For maintaining optimal growth and ability to colonize various hosts, C. jejuni depends upon two-component regulatory systems (TCSs) to monitor environmental conditions and promote proper expression of specific genes. In this work, we analyzed the genes, Cjj81176_1484 (Cjj1484) and Cjj81176_1483 (Cjj1483), that encode proteins forming a cognate TCS in C. jejuni. This TCS may influences expression of genes important for C. jejuni growth and colonization. Transcriptome analysis revealed that the Cjj1484 and Cjj1483 appear to form a cognate TCS that generally functions to repress expression of specific genes some of which function in metabolism, iron/heme acquisition, and respiration. Furthermore, this TCS was found to repress expression of Cjj81176_0438 and Cjj81176_0439, which had previously been shown to function as a gluconate dehydrogenase complex required for commensal colonization of the chick intestinal tract. However, the TCS and other specific genes whose expression is repressed by the TCS were not required for commensal colonization of chicks. Additional analysis revealed that the Cjj1483 response regulator appears to bind target promoters both in unphosphorylated and phosphorylated forms and likely is able to influence the expression of some specific genes independently of the Cjj1484 sensor-histidine kinase. This work further expands our knowledge of the signaling mechanisms of C. jejuni and specifically regarding the complex regulation of many genes involved in basic metabolism, respiration, and nutrient acquisition that the bacterium needs for optimal growth in different environments.

Technical Abstract: Campylobacter jejuni is a leading cause of bacterial diarrheal disease throughout the world and a frequent commensal in the intestinal tract of poultry and many other animals. For maintaining optimal growth and ability to colonize various hosts, C. jejuni depends upon two-component regulatory systems (TCSs) to monitor environmental conditions and promote proper expression of specific genes. In this work, we analyzed the potential of Cjj81176_1484 (Cjj1484) and Cjj81176_1483 (Cjj1483) to encode proteins forming a cognate TCS in C. jejuni that influences expression of genes potentially important for C. jejuni growth and colonization. Transcriptome analysis revealed that the Cjj1484 and Cjj1483 appear to form a cognate TCS that generally functions to repress expression of specific genes some of which function in metabolism, iron/heme acquisition, and respiration. Furthermore, this TCS was found to repress expression of Cjj81176_0438 and Cjj81176_0439, which had previously been shown to function as a gluconate dehydrogenase complex required for commensal colonization of the chick intestinal tract. However, the TCS and other specific genes whose expression is repressed by the TCS were not required for commensal colonization of chicks. Additional analysis revealed that the Cjj1483 response regulator appears to bind target promoters both in unphosphorylated and phosphorylated forms and likely is able to influence expression of some specific genes independently of the Cjj1484 histidine kinase. This work further expands the signaling mechanisms of C. jejuni and provides more knowledge regarding the complex regulation of many genes involved in basic metabolism, respiration, and nutrient acquisition that the bacterium needs for optimal growth in different environments.