Illuminating cell signalling with optogenetic tools

Abstract

The light-based control of ion channels has been transformative for the neurosciences, but the optogenetic toolkit does not stop there. An expanding number of proteins and cellular functions have been shown to be controlled by light, and the practical considerations in deciding between reversible optogenetic systems (such as systems that use light-oxygen-voltage domains, phytochrome proteins, cryptochrome proteins and the fluorescent protein Dronpa) are well defined. The field is moving beyond proof of concept to answering real biological questions, such as how cell signalling is regulated in space and time, that were difficult or impossible to address with previous tools.

Cytoskeletal control of B cell responses to antigens

“…Advances in optical microscopy have been making long strides towards three-dimensional high-resolution imaging and it will be exciting to see this new technology employed for studies of immune cells 76, [163][164][165] . Genetic manipulation is more accessible and precise than ever before, and new optogenetic and nanomechanical methods offer unprecedented temporal and spatial control of manipulation of live cells 166,167 . Mathematical modelling of the cytoskeleton, for example using an active gel theory [G] 168 , has also been informative and may allow to understand counterintuitive mechanisms by which actin regulates cellular functions 169 .…”

Biophysical Tools for Cellular and Subcellular Mechanical Actuation of Cell Signaling

“…Because the use of dimerization domains requires using genetically encoded fusion proteins, the organellar membrane targets are predetermined. Optogenetic systems use proteins that change conformation in response to light for controlling spatiotemporal dynamics of signaling proteins, and it has inherently better spatial control than chemically inducible dimerization (62). Optogenetics is an alternative strategy to manipulating localization of signaling proteins with magnetic tweezers, but it also requires introduction of genetically encoded fusion proteins.…”

Light‐Patterned RNA Interference of 3D‐Cultured Human Embryonic Stem Cells

“…[2,[12][13][14] Light is an ideal stimulus for perturbing the spatiotemporal dynamics of signals in living cells and organisms with high resolution. [15][16][17] The light-based optogenetic field has answered real biological questions [16] and developed tools for light-controlled genome editing and gene transfection. [18][19][20][21][22] However, these approaches rely largely on the visible light excitation sources and the construction of complex protein fusions via viral transfection.…”

“…Other alternatives use photocaged small molecules and biopolymers for light-dependent gene regulation, [4,15,[23][24][25][26] which are limited by cellular delivery hurdles and the use of low tissue-penetrating UV-vis light. [15][16][17] We have developed a novel pulsed near-infrared (NIR) light based technique for the spatiotemporal control of gene silencing in 3D-cultured human embryonic stem cells (hESCs) by RNA interference. NIR light can be tightly focused threedimensionally (down to ≈1 fL) [27] and reach deep through tissues (up to 10 cm).…”