Abstract
Background: It is known that the enterohemorrhagic Escherichia coli (EHEC) O157: H7 EspF is a multifunctional effector that triggers several damage processes in the host cells. However, in the process of EHEC O157: H7 infection, the interaction between EspF or its N/ C-terminus with host proteins are still unclear. Results: In this study, we used co-immunoprecipitation combined with mass spectrometry to screen EspF-interacting proteins. A total of 311 host proteins are detected. The N-terminus of EspF is found to interact with 192 proteins, whereas 205 proteins interact with the C-terminus of EspF. These proteins are mainly involved in RNA splicing, endoplasmic reticulum stress, and a variety of metabolic signaling pathways. We verify for the first time that SMC1 interacts with EspF and more likeliy by its C-terminus, and provide evidence that EspF increases p-SMC1 levels. p-SMC1, known to reduce the S-phase cell cycle arrest and DNA damage repair. Surprisingly, we screen that EspF can also phosphorylate H2AX, suggesting that EspF may directly mediate DNA damage through SMC1 phosphorylation.Conclusion: Taken together, this is the first study describing the interaction between EspF and SMC1. Our work lays a foundation for further research on directly EspF-mediated host cells’ DNA damage, apoptosis, and even colorectal carcinogenesis.
Mass spectrometry-based protein-protein interaction techniques and their applications in studies of DNA damage repair
