Synthesis and application of a photocaged-l-lactate for studying the biological roles of l-lactate
摘要
l-Lactate, once considered a metabolic waste product of glycolysis, is now recognized as a vitally important metabolite and signaling molecule in multiple biological pathways. However, exploring l-lactate’s emerging intra- and extra-cellular roles is hindered by a lack of tools to perturb l-lactate concentration intracellularly and extracellularly. Photocaged compounds are a powerful way to introduce bioactive molecules with spatiotemporal precision using illumination. Here, we report the development of a photocaged derivative of l-lactate, 4-methoxy-7-nitroindolinyl-l-lactate (MNI-l-lac), that releases l-lactate upon illumination. We validated MNI-l-lac in cell culture by demonstrating that the photorelease of l-lactate elicits a response from genetically encoded extra- and intracellular l-lactate biosensors (eLACCO1, eLACCO2.1, R-iLACCO1.2). To demonstrate the utility of MNI-l-lac, we employed the photorelease of l-lactate to activate G protein-coupled receptor 81 (GPR81), as revealed by the inhibition of adenylyl cyclase activity and concomitant decrease of cAMP. These results indicate that MNI-l-lac may be useful for perturbing the concentration of endogenous l-lactate in order to investigate l-lactate’s roles in metabolic and signaling pathways.