A new photocaged puromycin for an efficient labelling of newly translated proteins in living neurons.

Monitoring of newly synthesized proteins is becoming increasingly important to characterize proteome composition in regulatory networks. Puromycin is a peptidyl transfer inhibitor, widely used in cell biology for tagging newly synthesized proteins. Here, we report synthesis and application of an optimized puromycin carrying a photolabile protecting group as a powerful tool for tagging nascent proteins with high spatiotemporal resolution. The photocaged 7-N,N-Diethylamino-cumarin-4-yl]-methoxycarbonyl-puromycin (DEACM-puromycin) was synthesized and compared with the previously developed 6-Nitroveratryloxycarbonyl puromycin (NVOC-puromycin). The photo-chemical behaviour as well as the effectiveness in controlling the puromycylation in living hippocampal neurons using two-photon excitation is superior to the previously used NVOC-puromycin. We further report on the application of light-controlled puromycylation to visualize new translated proteins in neurons.