Qr: host:"HCT116"
Showing 1 - 5 of 5 results
1.
A versatile anti-CRISPR platform for opto- and chemogenetic control of CRISPR-Cas9 and Cas12 across a wide range of orthologs.
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Brenker, L
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Aschenbrenner, S
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Bubeck, F
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Staykov, K
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Gebhardt, C
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Wolf, B
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Jendrusch, M
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Kröll, AS
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Becker, J
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Ambiel, I
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Fackler, OT
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Grimm, D
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Mathony, J
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Niopek, D
Abstract:
CRISPR-Cas technologies have revolutionized life sciences by enabling programmable genome editing across diverse organisms. Achieving dynamic and precise control over CRISPR-Cas activity with exogenous triggers, such as light or chemical ligands, remains an important need. Existing tools for CRISPR-Cas control are often limited to specific Cas orthologs or selected applications, restricting their versatility. Anti-CRISPR (Acr) proteins are natural inhibitors of CRISPR-Cas systems and provide a flexible regulatory layer but are constitutively active in their native forms. In this study, we built on our previously reported concept for optogenetic CRISPR-Cas control with engineered, light-switchable anti-CRISPR proteins and expanded it from ortholog-specific Acrs towards AcrIIA5 and AcrVA1, broad-spectrum inhibitors of CRISPR-Cas9 and CRISPR-Cas12a, respectively. We then conceived and implemented a novel, chemogenetic anti-CRISPR platform based on engineered, circularly permuted ligand receptor domains, that together respond to six clinically relevant drugs. The resulting toolbox achieves both optogenetic and chemogenetic control of genome editing in human cells with a wide range of CRISPR-Cas effectors, including type II-A and II-C CRISPR-Cas9s, and CRISPR-Cas12a. In sum, this work establishes a versatile platform for the multidimensional control of CRISPR-Cas systems, with immediate applications in basic research and biotechnology, and with the potential for therapeutic use in the future.
2.
Opto-p53: A light-controllable activation of p53 signaling pathway.
Abstract:
p53 protein, a crucial transcription factor in cellular responses to a wide variety of stress, regulates multiple target genes involved in tumor suppression, senescence induction, and metabolic functions. To characterize the context-dependent roles of p53, it is still needed to develop an experimental system that enables selective activation of p53 in cells and tissues. In this study, we developed an optogenetic tool, Opto-p53, to control p53 signaling by light. Opto-p53 was designed to trigger p53 signaling by reconstituting p53 N-terminal and C-terminal fragments with a light-inducible dimerization (LID) system. Upon light exposure, cells expressing Opto-p53 demonstrated p53 transcriptional activation, resulting in cell death and cell cycle arrest. We further enhanced the efficacy of light-induced p53 activation by introducing specific mutations into Opto-p53 fragments. Our findings unveil the capability of Opto-p53 to serve as a powerful tool for dissecting the complex roles of p53 in cellular processes, thereby contributing to the field of synthetic biology and providing general design principles for optogenetic tools using endogenous transcription factors.Key words: synthetic biology, transcriptional factor, p53, optogenetics.
3.
Spatiotemporally controlled Pseudomonas exotoxin transgene system combined with multifunctional nanoparticles for breast cancer antimetastatic therapy.
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Cheng, Y
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Zou, J
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He, M
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Hou, X
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Wang, H
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Xu, J
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Yuan, Z
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Lan, M
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Yang, Y
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Chen, X
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Gao, F
Abstract:
The tumor microenvironment is a barrier to breast cancer therapy. Cancer-associated fibroblast cells (CAFs) can support tumor proliferation, metastasis, and drug resistance by secreting various cytokines and growth factors. Abnormal angiogenesis provides sufficient nutrients for tumor proliferation. Considering that CAFs express the sigma receptor (which recognizes anisamide, AA), we developed a CAFs and breast cancer cells dual-targeting nano drug delivery system to transport the LightOn gene express system, a spatiotemporal controlled gene expression consisting of a light-sensitive transcription factor and a specific minimal promoter. We adopted RGD (Arg-Gly-Asp) to selectively bind to the αvβ3 integrin on activated vascular endothelial cells and tumor cells. After the LightOn system has reached the tumor site, LightOn gene express system can spatiotemporal controllably express toxic Pseudomonas exotoxin An under blue light irradiation. The LightOn gene express system, combined with multifunctional nanoparticles, achieved high targeting delivery efficiency both in vitro and in vivo. It also displayed strong tumor and CAFs inhibition, anti-angiogenesis ability and anti-metastasis ability, with good safety. Moreover, it improved survival rate, survival time, and lung metastasis rate in a mouse breast cancer model. This study proves the efficacy of combining the LightOn system with targeted multifunctional nanoparticles in tumor and anti-metastatic therapy and provides new insights into tumor microenvironment regulation.
4.
Using Optogenetics to Spatially Control Cortical Dynein Activity in Mitotic Human Cells.
Abstract:
Several light-inducible hetero-dimerization tools have been developed to spatiotemporally control subcellular localization and activity of target proteins or their downstream signaling. In contrast to other genetic technologies, such as CRISPR-mediated genome editing, these optogenetic tools can locally control protein localization on the second timescale. In addition, these tools can be used to understand the sufficiency of target proteins' function and manipulate downstream events. In this chapter, I will present methods for locally activating cytoplasmic dynein at the mitotic cell cortex in human cells, with a focus on how to generate knock-in cell lines and set up a microscope system.
5.
Dynein-Dynactin-NuMA clusters generate cortical spindle-pulling forces as a multi-arm ensemble.
Abstract:
To position the mitotic spindle within the cell, dynamic plus ends of astral microtubules are pulled by membrane-associated cortical force-generating machinery. However, in contrast to the chromosome-bound kinetochore structure, how the diffusion-prone cortical machinery is organized to generate large spindle-pulling forces remains poorly understood. Here, we develop a light-induced reconstitution system in human cells. We find that induced cortical targeting of NuMA, but not dynein, is sufficient for spindle pulling. This spindle-pulling activity requires dynein-dynactin recruitment by NuMA's N-terminal long arm, dynein-based astral microtubule gliding, and NuMA's direct microtubule-binding activities. Importantly, we demonstrate that cortical NuMA assembles specialized focal structures that cluster multiple force-generating modules to generate cooperative spindle-pulling forces. This clustering activity of NuMA is required for spindle positioning, but not for spindle-pole focusing. We propose that cortical Dynein-Dynactin-NuMA (DDN) clusters act as the core force-generating machinery that organizes a multi-arm ensemble reminiscent of the kinetochore.