Allosteric regulation of the lid domain of PCK2 as a novel strategy for modulating mitochondrial dynamics

Abstract

Aberrant PCK2 overexpression has been linked to an unfavorable prognosis and shorter survival, particularly in hepatocellular carcinoma (HCC). Thus, the inactivation of PCK2 provides a promising strategy for HCC treatment. In this study, we used a chemical genetic strategy to identify a natural-derived small-molecule cucurbitacin B (CuB) as a selective PCK2 inhibitor. CuB covalently bound to PCK2 at a unique Cys63 site, blocking the Ω-loop lid domain formation via a previously undisclosed allosteric mechanism. Additionally, targeted lipidomics analysis also revealed that CuB destroyed mitochondrial membrane integrity, leading to the disruption of mitochondrial fusion–fission dynamics. Taken together, this study highlights the discovery of a small-molecule CuB, which reprograms lipid metabolism for controlling mitochondrial dynamics via targeting PCK2 in cancer cells.