A Click Cage: Organelle‐Specific Uncaging of Lipid Messengers

Abstract

Lipid messengers exert their function on short time scales at distinct subcellular locations, yet most experimental approaches for perturbing their levels trigger cell‐wide concentration changes. Herein, we report on a coumarin‐based photocaging group that can be modified with organelle‐targeting moieties by click chemistry and thus enables photorelease of lipid messengers in distinct organelles. We show that caged arachidonic acid and sphingosine derivatives can be selectively delivered to mitochondria, the ER, lysosomes, and the plasma membrane. By comparing the cellular calcium transients induced by localized uncaging of arachidonic acid and sphingosine, we show that the precise intracellular localization of the released second messenger is crucial for the signaling outcome. Ultimately, we anticipate that this new class of caged compounds will greatly facilitate the study of cellular processes on the organelle level.

Live-cell lipid biochemistry reveals a role of diacylglycerol side-chain composition for cellular lipid dynamics and protein affinities

“…Photoactivation Allows Acute DAG Density Increases at the Plasma Membrane. Photoliberation of native lipid species from caged lipids constitutes the most straightforward experimental approach to induce well-defined, temporally controlled density increases of a single lipid species in individual membrane leaflets (23)(24)(25), which is essential for kinetic analysis (Fig. 1A).…”

Tetrazine as a general phototrigger to turn on fluorophores

“…The combination of subcellular targeting and photodecaging has provided a platform for precise control of site-specic molecular release. [58][59][60][61] Accordingly, we explored the possibility of combining a tetrazine phototrigger with subcellular targeting moieties. To stably conjugate organelle-targeting moieties to Tz-BODIPY without affecting the its photochemical properties, we developed a robust synthetic approach for functionalizing the BODIPY molecule (Fig.…”

Design, Synthesis, and Photochemical Properties of Clickable Caged Compounds

“…In addition, we previously developed the (6-bromo-7-hydroxycoumarin-4-yl)methyl (Bhc) group and successfully synthesized various caged compounds of neurotransmitters 28 , second messengers 29,30 , and oligonucleotides 31,32,33 exhibiting large one-and two-photon excitation crosssections. If additional properties can be installed easily into the caging groups without compromising their photosensitivity, then the repertoire of caged compounds can be expanded 34,35,36,37,38,39 . We therefore designed modular caged compounds that comprise three parts, namely the Bhc group as a photo-responsive core, chemical handles for the installation of additional functionalities, and the molecules that are to be masked 40,41 .…”