Reviews & Perspectives
- In Brief The interior of the cell is molecularly crowded. Its compartmentalization within organelles enables the regulation of biochemical processes and allows multifunctionality of proteins and RNAs. Subcellular information can thus give insights into the function of these biomolecules. Multiple techniques to measure such information have been established, with ever-increasing throughput and sensitivity. These techniques are covered in this review, and demonstrating their application is providing valuable insights into cellular biology, such as aiding our understanding of single-cell heterogeneity and posttranslational modifications.
- Within cells, proteins can co-assemble into functionally integrated and spatially restricted multicomponent complexes. Often, the affinities between individual proteins are relatively weak, and proteins within such clusters may interact only indirectly with many of their other protein neighbors. This makes proteomic characterization difficult using methods such as immunoprecipitation or cross-linking. Recently, several groups have described the use of enzyme-catalyzed proximity labeling reagents that covalently tag the neighbors of a targeted protein with a small molecule such as fluorescein or biotin.