91勛圖

Abstract

The bacterium Helicobacter pylori, is infecting more than 50% of the population worldwide and is considered a factor for gastric cancer. The cytoskeletal protein MreB is a homolog of eukaryotic actin and participates in several functions within the bacterial cells. In H. pylori, unlike in the most of bacillary bacteria, mreB depletion is non-essential and decreases the activity ofurease, an essential enzyme in the colonization of the bacteria in the host. Therefore, this protein could be involved in the pathogenesis of H. pylori. In our study, the proteins associated with MreB complex in H. pylori 26695 were isolated by pulldown assay in vitro. Mass spectrometry was used for identifying the interacting proteins. 86 proteins from H. pylori 26695 were obtained, 82 of which are involved in functions such as proteolysis, carbohydrate metabolism, nitrogen utilization, protein folding, free radical protection, aminoacid synthesis and metabolism, fatty acid synthesis, tRNA synthesis, ATP production, DNA interaction, transport of molecules, protein translation, respiratory chain and other functions. Furthermore, MreB can participate indirectly in the pathogenesis of H. pylori because it interacts with 4 proteins involved in this process. These proteins are the hemolysin HylB, the gastric epithelium vacuolysing toxin VacA, the urease (an enzyme that allows the neutralization of the acid pH surrounding the bacterium) and the arginine decarboxylase SpeA (a protein that confers acid resistance to H. pylori urease negative strains). However, the protein MreC, a common interaction partner of MreB in bacteria was not obtained in the complex. It could be the evidence that MreB showed different functions from most bacillary bacteria not participating in the regulation of cell shape but influencing the pathogenesis of H. pylori.

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