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Updated: Jun 5, 2026
Spatiotemporal Control of Protein Activity through Optogenetic Allosteric Regulation
Published on: October 4, 2024
Light-induced blockage of cell division with a chromatin-targeted phototoxic fluorescent protein
Ekaterina O Serebrovskaya1, Tatiana V Gorodnicheva, Galina V Ermakova
1Shemiakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, 117997 Moscow, Russia.
Abstract:
Proteins of the GFP (green fluorescent protein) family are widely used as passive reporters for live cell imaging. In the present study we used H2B (histone H2B)-tKR (tandem KillerRed) as an active tool to affect cell division with light. We demonstrated that H2B-tKR-expressing cells behave normally in the dark, but transiently cease proliferation following green-light illumination. Complete light-induced blockage of cell division for approx. 24 h was observed in cultured mammalian cells that were either transiently or stably transfected with H2B-tKR. Illuminated cells then returned to normal division rate. XRCC1 (X-ray cross complementing factor 1) showed immediate redistribution in the illuminated nuclei of H2B-tKR-expressing cells, indicating massive light-induced damage of genomic DNA. Notably, nondisjunction of chromosomes was observed for cells that were illuminated during metaphase. In transgenic Xenopus embryos expressing H2B-tKR under the control of tissue-specific promoters, we observed clear retardation of the development of these tissues in green-light-illuminated tadpoles. We believe that H2B-tKR represents a novel optogenetic tool, which can be used to study mitosis and meiosis progression per se, as well as to investigate the roles of specific cell populations in development, regeneration and carcinogenesis in vivo.
Insights
Histone H2B-tandem KillerRed (H2B-tKR) is a novel optogenetic tool that halts cell division upon light exposure. This method enables precise control over cell proliferation for studying development and disease.
Area of Science:
- Optogenetics
- Cell Biology
- Molecular Biology
Background:
- Green fluorescent protein (GFP) family proteins are common tools for live cell imaging.
- Histone H2B-tandem KillerRed (H2B-tKR) offers a new approach to actively manipulate cellular processes.
Purpose of the Study:
- To investigate the potential of H2B-tKR as an optogenetic tool for controlling cell division.
- To evaluate the impact of light-induced H2B-tKR activation on cell proliferation, DNA integrity, and development.
Main Methods:
- Transfection of mammalian cells and Xenopus embryos with H2B-tKR.
- Illumination of H2B-tKR-expressing cells with green light.
- Analysis of cell proliferation, chromosome segregation, and DNA damage (XRCC1 redistribution).
- Assessment of developmental effects in transgenic Xenopus tadpoles.
Main Results:
- H2B-tKR-expressing cells exhibit normal behavior in darkness but cease proliferation upon green light exposure.
- Complete cell division blockage for approximately 24 hours was observed in illuminated mammalian cells, followed by a return to normal division rates.
- Massive light-induced genomic DNA damage was indicated by XRCC1 redistribution.
- Chromosome nondisjunction occurred in cells illuminated during metaphase.
- Transgenic Xenopus embryos showed retarded tissue development upon illumination.
Conclusions:
- H2B-tKR serves as a novel optogenetic tool for light-induced control of cell division.
- This tool can be used to study mitosis and meiosis.
- H2B-tKR facilitates investigation of specific cell populations in development, regeneration, and carcinogenesis in vivo.
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