Measurement of Succinate Levels

The levels of succinate were assessed colorimetrically using the established Succinate Assay Kit (Abcam, Cambridge, UK) according to the manufacturer’s instructions (Karlstaedt et al., 2016). Briefly, cells were washed with cold PBS, resuspended in succinate assay buffer, homogenized, and centrifuged for 12,000 × g for 5 min at 4°C to collect supernatant. The samples were then incubated with the reaction mix for 30 min at 37°C. The standard curve of succinate concentration was prepared. The level of succinate was measured colorimetrically at 450nm (Thermo Scientific).