Tunable and Photoswitchable Chemically Induced Dimerization for Chemo‐optogenetic Control of Protein and Organelle Positioning

Abstract

The spatiotemporal dynamics of proteins and organelles play an important role in controlling diverse cellular processes. Optogenetic tools using photosensitive proteins and chemically induced dimerization (CID), which allow control of protein dimerization, have been used to elucidate the dynamics of biological systems and to dissect the complicated biological regulatory networks. However, the inherent limitations of current optogenetic and CID systems remain a significant challenge for the fine‐tuning of cellular activity at precise times and locations. Herein, we present a novel chemo‐optogenetic approach, photoswitchable chemically induced dimerization (psCID), for controlling cellular function by using blue light in a rapid and reversible manner. Moreover, psCID is tunable; that is, the dimerization and dedimerization degrees can be fine‐tuned by applying different doses of illumination. Using this approach, we control the localization of proteins and positioning of organelles in live cells with high spatial (μm) and temporal (ms) precision.

Quantitative and Repetitive Control of Subcellular Protein–Protein Interaction Using a Photochromic Dimerizer

“…In addition to temporal regulation, quantitative regulation is crucial for cellular responses in intracellular signaling pathways 11 . A few methods have achieved quantitative protein translocation using caged CID systems 30 or optogenetics 11 . In these cases, the illumination dose was adjusted to control protein translocation levels.…”

“…These caged CID systems revealed complex cellular systems, such as the specialized properties of a kinesin motor 27 and the molecular mechanisms of spindle asymmetry 28 . Furthermore, using two different caging groups in a chemical dimerizer, bidirectional photocontrol of protein localization and diffusion has been achieved in a single cycle 29,30 . However, caged CID systems, in principle, cannot be repetitively switched on and off, unlike optogenetic tools.…”

Red light activatable chemo-optogenetic dimerization regulates cell apoptosis

“…Light control of cellular processes is highly advantageous due to its high spatial resolution, precise temporal control, and non-invasive nature [1,2]. Chemical biologists have adopted chemo-optogenetics, known as a 'chemistry' version of optogenetics, to regulate various cellular functions [3][4][5][6][7][8]. Unlike optogenetics, which utilizes genetically encoded photoreceptors [9] or light-sensitive ion channels [10], chemo-optogenetic tools, such as photoactivatable chemical inducers of dimerization (pCIDs), employ genetically engineered protein tags that specifically accept light-sensitive small molecules [2,11].…”