By attaching a hydrogen peroxide reporter protein to cellular microtubule structures, researchers have developed the first sensor able to map the location of the key cellular signaling chemical inside living cells with high resolution over time.
Until development of the new sensor, hydrogen peroxide sensors could only tag certain components of cells, or show that the cells were globally oxidized. To understand the role of hydrogen peroxide in signaling, researchers needed time-resolved location information.
This super-resolution fluorescence microscopy image of HyPer-Tau shows the microtubular structure of a human (HeLa) cancer cell. The image was made using the new super-resolution microscope in the Georgia Tech Institute for Bioengineering & Bioscience (IBB).
Photo: Emilie Warren
The HyPer-Tau sensor was developed by researchers who have already demonstrated several applications for its ability to spatially resolve the chemical’s presence inside cancer and immune cells that are actively responding to environmental cues.
“The chemistry of cells, unlike more traditional chemistry in test tubes, is highly dependent on where a chemical reaction is occurring,” said Christine Payne, an associate professor in Georgia Tech’s School of Chemistry and Biochemistry and one of the paper’s senior authors.
“We needed a tool that could discriminate between locations to provide more than a whole readout of oxidation,” said Melissa Kemp, an associate professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “With very specific spatial information, we will be better informed about how cellular processes or antioxidant therapies are going to operate.”
Other researchers had already created variants of the commercially available HyPer reporter protein, which alters its fluorescence properties in the presence of hydrogen peroxide. Here, the researchers added a tubulin-binding protein known as Tau that anchors the protein to microtubule structures that crisscross cells like railroad tracks. Fluorescence microscopy then allows them to observe the real-time change as oxidation occurs.
The work was supported by the National Institutes of Health and reported in the journal Scientific Reports.
— John Toon