Interacting proteins of Helicobacter pylori GroEL protein

Abstract:

[Objective] To obtain the composition spectrum of Helicobacter pylori (HP) GroEL binding proteins and provide new insights into the role of GroEL and its interacting proteins in the pathogenesis of H. pylori. [Methods] Based on the construction of H. pylori GroEL prokaryotic expression recombinant bacteria Escherichia coli BL21(DE3)^{pET-28a(+)-groEL}, the His-tagged GroEL protein was purified and incubated with H. pylori whole-cell protein extract. The complex was captured using Protein G magnetic beads and anti-His tag antibody immunoprecipitation, and the GroEL and its possible binding proteins were identified by mass spectrometry. The proteins were classified according to their main functions, and protein interaction network analysis was performed. [Results] A total of 59 proteins were identified as possible binding partners of GroEL, including 19 metabolic enzymes (7 of which are involved in oxidative stress, such as KatA, GltA, and AhpC; 5 peptidases, such as PepA, RocF, and HtrA; 2 enzymes involved in lipid metabolism; 2 enzymes involved in ATP synthesis; HP17_08079 and 2 urease enzymes), 15 outer membrane proteins (including adhesins BabA, SabA, HapA, and other membrane proteins), 8 transcription and translation-related proteins (such as Tuf and RpoBC), 5 molecular chaperones (such as DnaK and GroES), 3 cytotoxin-related proteins (such as CagA), 3 oxidative stress-related proteins (such as TrxA), 2 signal transduction proteins (TlpB and TlpD), and 4 proteins with unknown functions. Protein interaction analysis revealed that the entire network could form multiple clusters, with GroEL as the central node of the network. The extensive association of outer membrane proteins, particularly the important adhesins BabA, SabA, HapA, with GroEL suggests that GroEL may play an important role in the interaction between H. pylori and host gastric mucosal epithelial cells. [Conclusion] The spectrum of H. pylori GroEL binding proteins is extensive, and the related proteins are involved in H. pylori metabolism, transcription and translation, oxidation-reduction, and adhesion, participating in the survival, colonization, and pathogenic processes. GroEL is expected to become a novel important target for studying H. pylori pathogenicity and developing infection intervention strategies.