Mitotic Arrest-Deficient 2 Like 2 (MAD2L2) Interacts with Escherichia coli Effector Protein EspF

Tahoun, Amin; El-Sharkawy, Hanem; Moustafa, Samar M.; Abdel-Hafez, Lina Jamil M; Albrakati, Ashraf; Koegl, Manfred; Haas, Juergen; Mahajan, Aditya; Gally, David L.; Elmahallawy, Ehab Kotb

doi:10.3390/life11090971

Cited by 1 publication

(3 citation statements)

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“…Considering that EspF may activate checkpoint and mitotic control through different mechanisms ( 7 ), we attempted to evaluate the cell cycle status through PI staining and flow cytometry. The proportion of cells in the G0/G1 phase showed a significant decrease in the EHEC group (59.22% ± 0.70%) and the Δ espF / pespF group (56.80% ± 1.19%), compared with the Δ espF group ( 64.81% ± 1.19%) and the control group (70.66% ± 1.84%).…”

Section: Resultsmentioning

confidence: 99%

“…8-Oxoguanine (8-oxoG) and phosphorylated histone H2A variant H2AX are commonly used as biomarkers for oxidative DNA damage and double-strand breaks (DSBs) in colorectal cancer (CRC) ( 4 ). Although the tumorigenic potential of EHEC has been previously discussed ( 5 – 7 ), there is limited evidence of the mechanisms underlying the formation of oxidative DNA lesions.…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, the ATM downstream protein SMC1 was phosphorylated and shifted from the nucleus to the cytoplasm, inhibiting the activation of DDR ( 5 ). Interactions between EspF and mitotic arrest-deficient 2 like 2 (MAD2L2), the latter of which inhibits the Cdc20-related protein (Cdh1) and the anaphase-promoting complex, have been demonstrated, suggesting that EspF plays an essential role in cell cycle and mitotic control ( 7 , 42 – 45 ). The characteristics and mechanisms of DNA lesions and the subsequent DDR during EHEC infection are not fully described, and the genotoxicity of EspF remains to be further demonstrated.…”

Section: Introductionmentioning

confidence: 99%

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Enterohemorrhagic Escherichia coli effector EspF triggers oxidative DNA lesions in intestinal epithelial cells

Fang,

Fu,

et al. 2024

Infect Immun

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Attaching/effacing (A/E) pathogens induce DNA damage and colorectal cancer by injecting effector proteins into host cells via the type III secretion system (T3SS). EspF is one of the T3SS-dependent effector proteins exclusive to A/E pathogens, which include enterohemorrhagic Escherichia coli . The role of EspF in the induction of double-strand breaks (DSBs) and the phosphorylation of the repair protein SMC1 has been demonstrated previously. However, the process of damage accumulation and DSB formation has remained enigmatic, and the damage response is not well understood. Here, we first showed a compensatory increase in the mismatch repair proteins MutS homolog 2 (MSH2) and MSH6, as well as poly(ADP-ribose) polymerase 1, followed by a dramatic decrease, threatening cell survival in the presence of EspF. Flow cytometry revealed that EspF arrested the cell cycle at the G2/M phase to facilitate DNA repair. Subsequently, 8-oxoguanine (8-oxoG) lesions, a marker of oxidative damage, were assayed by ELISA and immunofluorescence, which revealed the accumulation of 8-oxoG from the cytosol to the nucleus. Furthermore, the status of single-stranded DNA (ssDNA) and DSBs was confirmed. We observed that EspF accelerated the course of DNA lesions, including 8-oxoG and unrepaired ssDNA, which were converted into DSBs; this was accompanied by the phosphorylation of replication protein A 32 in repair-defective cells. Collectively, these findings reveal that EspF triggers various types of oxidative DNA lesions with impairment of the DNA damage response and may result in genomic instability and cell death, offering novel insight into the tumorigenic potential of EspF. IMPORTANCE Oxidative DNA lesions play causative roles in colitis-associated colon cancer. Accumulating evidence shows strong links between attaching/effacing (A/E) pathogens and colorectal cancer (CRC). EspF is one of many effector proteins exclusive to A/E pathogens with defined roles in the induction of oxidative stress, double-strand breaks (DSBs), and repair dysregulation. Here, we found that EspF promotes reactive oxygen species generation and 8-oxoguanine (8-oxoG) lesions when the repair system is activated, contributing to sustained cell survival. However, infected cells exposed to EspF presented 8-oxoG, which results in DSBs and ssDNA accumulation when the cell cycle is arrested at the G2/M phase and the repair system is defective or saturated by DNA lesions. In addition, we found that EspF could intensify the accumulation of nuclear DNA lesions through oxidative and replication stress. Overall, our work highlights the involvement of EspF in DNA lesions and DNA damage response, providing a novel avenue by which A/E pathogens may contribute to CRC.

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Section: Resultsmentioning

confidence: 99%