A Ratiometric Two‐Photon Fluorescent Probe for Tracking Lysosomal ATP: Direct In Cellulo Observation of Lysosomal Membrane Fusion Processes. Issue 32 (17th July 2018)

• Record Type: Journal Article
• Authors: Jun, Yong Woong; Wang, Taejun; Hwang, Sekyu; Kim, Dokyoung; Ma, Donghee; Kim, Ki Hean; Kim, Sungjee; Jung, Junyang; Ahn, Kyo Han
• Is Part Of: Angewandte Chemie international edition. Volume 57:Issue 32(2018)
• Page Start: 10142
• Page End: 10147
• Publication Date: 2018-07-17
• Subjects: fluorescent probes -- lysosomal ATP -- membrane fusion -- ratiometric imaging -- two-photon microscopy; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201804743
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Vesicles exchange their contents through membrane fusion processes, kiss‐and‐run and full‐collapse fusion. Indirect observation of these fusion processes using artificial vesicles enhanced our understanding on the molecular mechanisms involved. Direct observation of the fusion processes in a real biological system, however, remains a challenge owing to many technical obstacles. We report a ratiometric two‐photon probe offering real‐time tracking of lysosomal ATP with quantitative information for the first time. By applying the probe to two‐photon live‐cell imaging, the lysosomal membrane fusion process in cells has been directly observed and the concentration of its content, lysosomal ATP, has been measured. Results show that the kiss‐and‐run process between lysosomes proceeds through repeated transient interactions with gradual content mixing, whereas the full‐fusion process occurs at once. Furthermore, it is confirmed that both the fusion processes proceed with conservation of the content. Such a small‐molecule probe exerts minimal disturbance and hence has potential for studying various biological processes associated with lysosomal ATP. Abstract : A two‐photon probe for lysosomal ATP was developed, with which real‐time monitoring of lysosomal fusion processes, kiss‐and‐run and full‐collapse fusion, in live cells was realized for the first time by quantitatively tracking content (ATP) mixing between two lysosomes.