The Hcp2b of APEC induces mitochondrial damage in chicken DF-1 cells

The haemolysin co-regulatory protein (Hcp) plays a significant role in the pathogenicity of avian pathogenic <i>Escherichia coli</i> (APEC) as an effector protein of the type VI secretion system (T6SS) to the host. Meanwhile, mitochondria in the host are the target of effector proteins of various secretion systems. Here, we explored the effects of APEC effector Hcp2b on the mitochondria of DF-1 cells and found that Hcp2b results in damage in mitochondria. Next, 68 target proteins in DF-1 cell lysates were identified that interacted with Hcp2b by streptavidin-biotin pull-down assay combined with LC-MS/MS, among which ADP/ATP transporter carrier (SLC25A4) is a mitochondria-associated protein; protein docking analysis showed that Hcp2b binds well to SLC25A4. Therefore, we hypothesize that the Hcp2b contributes to mitochondrial damage in DF-1 cells through interaction with the SLC25A4.