AUTHOR=Du Xueqing , Kong Ke , Tang Hong , Tang Haiyan , Jiao Xinan , Huang Jinlin 

TITLE=The Novel Protein Cj0371 Inhibits Chemotaxis of Campylobacter jejuni

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01904

DOI=10.3389/fmicb.2018.01904

ISSN=1664-302X

ABSTRACT=<p><italic>cj0371</italic> is a novel gene that is associated with <italic>Campylobacter jejuni</italic> virulence, and an isogenic mutant of <italic>cj0371</italic> showed hyper chemotaxis and motility. Chemotactic motility is an important virulence factor and is involved in <italic>C. jejuni</italic> pathogenesis. <italic>Campylobacter</italic> sp. has specific variations of the common chemotaxis components, including histidine autokinase CheA, coupling scaffold protein CheV, chemotaxis response regulator protein CheY and several chemoreceptor proteins. In this study, we used immunoprecipitation combined with LC-MS/MS analyses to screen six chemotaxis pathway proteins that potentially interact with the putative protein Cj0371. qRT-PCR was used to quantitatively analyze the expression of these chemotaxis genes and basic flagella genes. The results showed that the expression of <italic>cheV</italic>, <italic>cj1110c</italic>, and <italic>cj0262c</italic> was significantly up-regulated, and four flagella genes also had up-regulated expression in the <italic>cj0371</italic> mutant. GST pull-down analyses found that Cj0371 interacted with the receiver domain of the CheV protein. Enzyme-coupled spectrophotometric assays showed that the ATPase activity of CheA was higher when Cj0371 was not present in the chemotaxis reaction medium. Therefore, we concludes that <italic>cj0371</italic> has a negative influence on <italic>C. jejuni</italic> chemotaxis, which may occur by adjusting the receiver domain of CheV to influence chemotaxis. This paper provides a new component in the chemotaxis pathway of <italic>C. jejuni</italic> for the first time and highlight the complexity of this remarkable pathway.</p>