A fluorescent l -2-hydroxyglutarate biosensor

-2-Hydroxyglutarate (-2-HG) plays important roles in diverse physiological processes, such as carbon starvation response, tumorigenesis, and hypoxic adaptation. Despite its importance and intensively studied metabolism, regulation of -2-HG metabolism remains poorly understood and a regulator specifically responded to -2-HG has never been identified. Based on the genomic neighborhood analysis of the gene encoding -2-HG oxidase (LhgO), LhgR, which represses the transcription of , was identified in W619 in this study. LhgR was demonstrated to recognize -2-HG as its specific effector molecule, and this allosteric transcription factor was then used as a biorecognition element for construction of -2-HG-sensing FRET sensor. The newly developed -2-HG sensor can conveniently monitor the concentrations of -2-HG in various biological samples. In addition to bacterial -2-HG generation during carbon starvation, biological functions of the -2-HG dehydrogenase and hypoxia induced -2-HG accumulation were also revealed by using the -2-HG sensor in human cells.