ACS Chem. Neurosci., published online 7 November 2011, doi:10.1021/cn2000876

Credit: AMERICAN CHEMICAL SOCIETY

Changes in protein expression in the vertebrate nervous system are regulated by chemical stimuli as well as by changes in behavioral states, and this process is important for various neurological processes, including long-term memory. However, newly synthesized proteins, particularly low-abundance ones, have been difficult to identify. Recently, bio-orthogonal metabolic labeling techniques such as BONCAT or FUNCAT have been developed in which tagged proteins are isolated or visualized, respectively. Hinz et al. for the first time use these techniques in an intact organism, the larval zebrafish. The authors showed that the 'clickable' azidohomoalanine tag—compatible with both techniques—was metabolically incorporated with high specificity into a broad range of newly synthesized proteins, including those found in structures deep within the organism, such as those that make up the nervous system. They concluded that BONCAT could be used to detect newly synthesized proteins by MS after affinity enrichment, whereas FUNCAT could be used to identify regions of nascent protein synthesis as well as metabolically active cells and cell groups. The authors then used these methods to show that stimulation with a GABA receptor antagonist causes a general increase in protein synthesis throughout the proteome. These and related techniques paired with chemical stimuli or changes in behavioral state can be used to identify proteome adjustments in distinct regions of the nervous system.