γ-Secretase Cleaves Bifunctional Fatty Acid-Conjugated Small Molecules with Amide Bonds in Mammalian Cells.

Connecting two small molecules, such as ligands, fluorophores, or lipids, together via a linker with amide bonds is a widely used strategy to generate synthetic bifunctional molecules for various biological and biomedical applications. Such bifunctional molecules have been used in live-cell experiments under the assumption that they should be stable in cells. However, we recently found that a membrane-targeting bifunctional molecule, composed of a lipopeptide and the small-molecule ligand trimethoprim, referred to as mgcTMP, underwent amide-bond cleavage in mammalian cells.

Chemo-optogenetic Protein Translocation System Using a Photoactivatable Self-Localizing Ligand.

Manipulating subcellular protein localization using light is a powerful approach for controlling signaling processes with high spatiotemporal precision. The most widely used strategy for this is based on light-induced protein heterodimerization. The use of small synthetic molecules that can control the localization of target proteins in response to light without the need for a second protein has several advantages.

An Improved Intracellular Synthetic Lipidation-Induced Plasma Membrane Anchoring System for SNAP-Tag Fusion Proteins.

The ability to chemically introduce lipid modifications to specific intracellular protein targets would enable the conditional control of protein localization and activity in living cells. We recently developed a chemical-genetic approach in which an engineered SNAP-tag fusion protein can be rapidly relocated and anchored from the cytoplasm to the plasma membrane (PM) upon post-translational covalent lipopeptide conjugation in cells. However, the first-generation system achieved only low to moderate protein anchoring (recruiting) efficiencies and lacked wide applicability.