A novel genetically encoded indicator for deciphering cytosolic and mitochondrial nitric oxide in live cells.

Nitric oxide (NO) has been highlighted as a key gaseous signaling molecule in the body, playing a central role in various physiological and pathological processes. However, a comprehensive analysis of NO metabolism dynamics in living cells remains a significant challenge. To address this, we have developed and characterized a novel genetically encoded NO fluorescence sensor, GefiNO, to investigate NO metabolism dynamics in living cells and subcellular organelles. In the study, we described the protein detection capabilities and subcellular spatiotemporal localization of GefiNO sensors. By analyzing NO metabolic responses in macrophages of different subtypes, we provide a comprehensive view of NO dynamics at the cellular level. The GefiNO sensor represents a valuable tool for monitoring extensive NO dynamics in living cells and offers potential for uncovering new insights into cellular metabolic mechanisms.