Showing 1 - 6 of 6 results
1.
Optogenetic Protein Cleavage in Zebrafish Embryos.
Abstract:
A wide array of optogenetic tools is available that allow for precise spatiotemporal control over many cellular processes. These tools have been especially popular among zebrafish researchers who take advantage of the embryo's transparency. However, photocleavable optogenetic proteins have not been utilized in zebrafish. We demonstrate successful optical control of protein cleavage in embryos using PhoCl, a photocleavable fluorescent protein. This optogenetic tool offers temporal and spatial control over protein cleavage events, which we demonstrate in light-triggered protein translocation and apoptosis.
2.
Designer membraneless organelles sequester native factors for control of cell behavior.
Abstract:
Subcellular compartmentalization of macromolecules increases flux and prevents inhibitory interactions to control biochemical reactions. Inspired by this functionality, we sought to build designer compartments that function as hubs to regulate the flow of information through cellular control systems. We report a synthetic membraneless organelle platform to control endogenous cellular activities through sequestration and insulation of native proteins. We engineer and express a disordered protein scaffold to assemble micron-size condensates and recruit endogenous clients via genomic tagging with high-affinity dimerization motifs. By relocalizing up to 90% of targeted enzymes to synthetic condensates, we efficiently control cellular behaviors, including proliferation, division and cytoskeletal organization. Further, we demonstrate multiple strategies for controlled cargo release from condensates to switch cells between functional states. These synthetic organelles offer a powerful and generalizable approach to modularly control cell decision-making in a variety of model systems with broad applications for cellular engineering.
3.
Optical control of protein function through unnatural amino acid mutagenesis and other optogenetic approaches.
Abstract:
Biological processes are naturally regulated with high spatial and temporal resolution at the molecular, cellular, and systems level. To control and study processes with the same resolution, light-sensitive groups and domains have been employed to optically activate and deactivate protein function. Optical control is a noninvasive technique in which the amplitude, wavelength, spatial location, and timing of the light illumination can be easily controlled. This review focuses on applications of genetically encoded unnatural amino acids containing light-removable protecting groups to optically trigger protein function, while also discussing select optogenetic approaches using natural light-sensitive domains to engineer optical control of biological processes.
4.
Light-controlled synthetic gene circuits.
Abstract:
Highly complex synthetic gene circuits have been engineered in living organisms to develop systems with new biological properties. A precise trigger to activate or deactivate these complex systems is desired in order to tightly control different parts of a synthetic or natural network. Light represents an excellent tool to achieve this goal as it can be regulated in timing, location, intensity, and wavelength, which allows for precise spatiotemporal control over genetic circuits. Recently, light has been used as a trigger to control the biological function of small molecules, oligonucleotides, and proteins involved as parts in gene circuits. Light activation has enabled the construction of unique systems in living organisms such as band-pass filters and edge-detectors in bacterial cells. Additionally, light also allows for the regulation of intermediate steps of complex dynamic pathways in mammalian cells such as those involved in kinase networks. Herein we describe recent advancements in the area of light-controlled synthetic networks.
5.
Recent advances in the photochemical control of protein function.
Abstract:
Biological processes are regulated with a high level of spatial and temporal resolution. To understand and manipulate these processes, scientists need to be able to regulate them with Nature's level of precision. In this context, light is a unique regulatory element because it can be precisely controlled in terms of location, timing and amplitude. Moreover, most biological laboratories have a wide range of light sources as standard equipment. This review article summarizes the most recent advances in light-mediated regulation of protein function and its application in a cellular context. Specifically, the photocaging of small-molecule modulators of protein function and of specific amino acid residues in proteins is discussed. In addition, examples of the photochemical control of protein function through the application of genetically engineered natural-light receptors are presented.
6.
Light activation as a method of regulating and studying gene expression.
Abstract:
Recently, several advances have been made in the activation and deactivation of gene expression using light. These developments are based on the application of small molecule inducers of gene expression, antisense- or RNA interference-mediated gene silencing, and the photochemical control of proteins regulating gene function. The majority of the examples employ a classical 'caging technology', through the chemical installation of a light-removable protecting group on the biological molecule (small molecule, oligonucleotide, or protein) of interest and rendering it inactive. UV light irradiation then removes the caging group and activates the molecule, enabling control over gene activity with high spatial and temporal resolution.