Fig. 5: Monitoring l-2-HG fluctuations in living bacteria by LHGFR_0N3C.

a Time course of the emission ratio changes of LHGFR_0N3C expressed in E. coli BL21(DE3) in response to exogenous l-2-HG addition. All ratios were normalized to the control (ratio in the absence of l-2-HG at time point zero). b Normalized dose-response curve of LHGFR_0N3C expressed in E. coli BL21(DE3) for increasing concentrations (100 nM to 10 mM) of l-2-HG at time point 60 min. c Time course of the emission ratio changes of LHGFR_0N3C expressed in E. coli BL21(DE3) in response to the addition of 1 mM glutarate, l-2-HG, d-2-HG, or glucose. All data were normalized to the control (ratio in the absence of any tested compounds at time point zero). d Detection of carbon starvation-induced l-2-HG accumulation over time by LHGFR_0N3C expressed in E. coli BL21(DE3). Emission ratio changes of LHGFR_0N3C were measured when cultured in carbon starvation medium (black line) and medium with 20 mM glucose (red line). All data were normalized to samples under carbon starvation conditions at time point zero. e Long-term detection of l-2-HG fluctuations by LHGFR_0N3C expressed in E. coli BL21(DE3). All data were normalized to samples under carbon starvation conditions at time point zero. f Identification of the roles of CsiD and LhgO in endogenous l-2-HG metabolism during carbon starvation by LHGFR_0N3C. Emission ratio changes of LHGFR_0N3C expressed in E. coli MG1655(DE3) wild-type (black line), E. coli MG1655(DE3) (ΔcsiD) (red line), and E. coli MG1655(DE3) (ΔlhgO) (blue line) were measured in carbon starvation medium. All data were normalized to time point zero of the wild-type strain. Inconsistent initial emission ratios were detected in bacterial cells under different conditions. The normalized emission ratios were thus used to monitor the changes of l-2-HG in different bacterial cells. All data shown are means ± s.d. (n = 3 independent experiments).