Optogenetic Downregulation of Protein Levels to Control Programmed Cell Death in Mammalian Cells with a Dual
Patrick Fischbach1, Patrick Gonschorek2,3, Julia Baaske2
1Institute of Synthetic Biology, University of Düsseldorf, Düsseldorf, Germany.
Abstract:
Optogenetic approaches facilitate the study of signaling and metabolic pathways in animal cell systems. In the past 10 years, a plethora of light-regulated switches for the targeted control over the induction of gene expression, subcellular localization of proteins, membrane receptor activity, and other cellular processes have been developed and successfully implemented. However, only a few tools have been engineered toward the quantitative and spatiotemporally resolved downregulation of proteins. Here we present a protocol for reversible and rapid blue light-induced reduction of protein levels in mammalian cells. By implementing a dual-regulated optogenetic switch (Blue-OFF), both repression of gene expression and degradation of the target protein are triggered simultaneously. We apply this system for the blue light-mediated control of programmed cell death. HEK293T cells are transfected with the proapoptotic proteins PUMA and BID integrated into the Blue-OFF system. Overexpression of these proteins leads to programmed cell death, which can be prevented by irradiation with blue light. This experimental approach is very straightforward, requires just simple hardware, and therefore can be easily implemented in state-of-the-art equipped mammalian cell culture labs. The system can be used for targeted cell signaling studies and biotechnological applications.
Insights
Researchers developed a new optogenetic tool, Blue-OFF, for rapid, reversible blue light-induced protein reduction in mammalian cells. This system simultaneously represses gene expression and degrades target proteins, enabling precise control over cellular processes like programmed cell death.
Area of Science:
- Cell Biology
- Molecular Biology
- Biotechnology
Background:
- Optogenetics offers powerful tools for studying cellular pathways by controlling gene expression and protein localization with light.
- Existing optogenetic tools primarily focus on activating cellular processes, with limited options for quantitative, spatiotemporal protein downregulation.
- Controlling protein levels is crucial for understanding signaling pathways and for biotechnological applications.
Purpose of the Study:
- To develop a novel optogenetic system for rapid and reversible blue light-induced protein reduction in mammalian cells.
- To engineer a dual-regulated switch (Blue-OFF) that simultaneously represses gene expression and triggers protein degradation.
- To demonstrate the system's utility in controlling programmed cell death.
Main Methods:
- Implementation of the Blue-OFF optogenetic switch, a dual-regulated system for gene expression repression and protein degradation.
- Transfection of HEK293T cells with proapoptotic proteins (PUMA and BID) integrated into the Blue-OFF system.
- Utilizing blue light irradiation to trigger the protein reduction and observe its effects on cell death.
Main Results:
- The Blue-OFF system successfully achieved reversible and rapid reduction of target protein levels in mammalian cells upon blue light exposure.
- Simultaneous repression of gene expression and degradation of proteins were observed, demonstrating the dual-regulation mechanism.
- Blue light-mediated control of programmed cell death was achieved by regulating the expression of proapoptotic proteins PUMA and BID.
Conclusions:
- The Blue-OFF system provides a straightforward and effective method for precise, light-controlled protein downregulation in mammalian cells.
- This technology facilitates targeted cell signaling studies and offers potential for various biotechnological applications.
- The system's ease of implementation and requirement for simple hardware make it accessible for standard cell culture laboratories.
