Figure. Methods to Identify Substrates of E3 Ligase.
Classes of E3s are indicated in the center, and techniques and approaches for the identification of substrates are categorized as follows (orange boxes): Pull-downs coupled with in vitro ubiquitylation reactions; Cell-based screens; Co-immunoprecipitations (Co-IPs) or affinity purification (AP) of the E3; Substrate traps. Examples of techniques covered under these subcategories are circled.