4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl (bromoethyl)carbamate

This benzyl boronate tag is a synthetic means for the subcellular targeting of cargo to the nucleus. Intracellular targeting can be important for understanding the localization of metabolites, proteins, or chemical probes or to increase therapeutic efficacy by concentrating a drug at its site of action and reducing off-target effects. Localization specifically to the nucleus is typically achieved using peptide localization signals and/or relies on passive diffusion. It was recently demonstrated, however, that nuclear targeting could be accomplished instead with a small-molecule motif benzyl boronic acid via synergistic active and passive transport processes. Tang, et al, presented examples using this tag to deliver proteins to the nucleus by the importin α/β pathway, including fluorescent proteins, ribonuclease A (RNase A), and chymotrypsin. The conjugation of this nucleus-targeting building block to other proteins or small molecules will facilitate nuclear localization in varied chemical biology experiments.