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Updated: Mar 6, 2026
Author Spotlight: Evaluation of Protein-Condensate Dynamics in Live Human Cells
Published on: January 5, 2024
A genetically encoded toolkit for tracking live-cell histidine dynamics in space and time
Hanyang Hu1,2,3, Yanfang Gu1,2,3, Lei Xu1,2
1Synthetic Biology and Biotechnology Laboratory, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.
Researchers developed novel fluorescent sensors to measure histidine levels in living cells. Histidine concentration is higher in the cytosol than mitochondria and is efficiently transported across membranes, independent of cell metabolism.
Area of Science:
- Cellular Biology
- Biochemistry
- Molecular Imaging
Background:
- Accurate measurement of intracellular histidine is crucial for understanding cellular processes.
- Existing imaging techniques face limitations in spatiotemporal resolution and dynamic range for histidine detection.
Purpose of the Study:
- To develop and validate novel fluorescent sensors for high-resolution spatiotemporal imaging of histidine in living mammalian cells.
- To quantify subcellular free-histidine concentrations under varying metabolic conditions.
Main Methods:
- Development of ratiometric, single fluorescent protein-based histidine sensors with wide dynamic range.
- Application of these sensors for quantifying free-histidine concentrations in the cytosol and mitochondria of glucose-deprived and glucose-fed cells.
- Analysis of histidine transport rates across cellular and mitochondrial membranes.
Main Results:
- Cytosolic free-histidine concentration was found to be higher and more environmentally sensitive than in mitochondria.
- Histidine transport across the plasma membrane and mitochondrial inner membrane occurred at similar rates and constants.
- Cellular metabolic state did not influence histidine transport.
Conclusions:
- The developed histidine sensors enable precise tracking of histidine dynamics within subcellular organelles.
- These tools provide new avenues for investigating histidine signaling pathways.
- Histidine transport is a robust process, largely independent of the immediate metabolic environment.
