1.
Optogenetic activators of apoptosis, necroptosis, and pyroptosis.
Abstract:
Targeted and specific induction of cell death in an individual or groups of cells hold the potential for new insights into the response of tissues or organisms to different forms of death. Here, we report the development of optogenetically controlled cell death effectors (optoCDEs), a novel class of optogenetic tools that enables light-mediated induction of three types of programmed cell death (PCD)—apoptosis, pyroptosis, and necroptosis—using Arabidopsis thaliana photosensitive protein Cryptochrome-2. OptoCDEs enable a rapid and highly specific induction of PCD in human, mouse, and zebrafish cells and are suitable for a wide range of applications, such as sub-lethal cell death induction or precise elimination of single cells or cell populations in vitro and in vivo. As the proof-of-concept, we utilize optoCDEs to assess the differences in neighboring cell responses to apoptotic or necrotic PCD, revealing a new role for shingosine-1-phosphate signaling in regulating the efferocytosis of the apoptotic cell by epithelia.
2.
An optogenetic method for interrogating YAP1 and TAZ nuclear-cytoplasmic shuttling.
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Dowbaj, AM
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Jenkins, RP
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Williamson, D
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Heddleston, JM
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Ciccarelli, A
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Fallesen, T
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Hahn, KM
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O'Dea, RD
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King, JR
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Montagner, M
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Sahai, E
Abstract:
The shuttling of transcription factors and transcriptional regulators into and out of the nucleus is central to the regulation of many biological processes. Here we describe a new method for studying the rates of nuclear entry and exit of transcriptional regulators. A photo-responsive AsLOV (Avena sativa Light Oxygen Voltage) domain is used to sequester fluorescently-labelled transcriptional regulators YAP1 and TAZ/WWTR1 on the surface of mitochondria and reversibly release them upon blue light illumination. After dissociation, fluorescent signals from mitochondria, cytoplasm and nucleus are extracted with a bespoke app and used to generate rates of nuclear entry and exit. Using this method, we demonstrate that phosphorylation of YAP1 on canonical sites enhances its rate of nuclear export. Moreover, we provide evidence that, despite high intercellular variability, YAP1 import and export rates correlated within the same cell. By simultaneously releasing YAP1 and TAZ from sequestration, we show that their rates of entry and exit are correlated. Furthermore, combining the optogenetic release of YAP1 with lattice light-sheet microscopy revealed high heterogeneity of YAP1 dynamics within different cytoplasmic regions, demonstrating the utility and versatility of our tool to study protein dynamics.