Targeted Degradation of Mouse Embryo Proteins Using Trim-Away.

Trim-Away is an antibody-based method for the degradation of endogenous cellular proteins without prior genetic manipulation. From the effect that protein degradation has on the phenotype, one can infer the function of the protein-coding gene. Among the strengths of Trim-Away, the authors highlight the possibility to target embryonic proteins that have not yet been produced or are not yet functionally required at the time of antibody delivery. Conversely, a limitation of Trim-Away is the possibility that while the target protein is being degraded, de novo translation may replenish it, whereby the two processes offset each other, and the phenotype is inconspicuous. Appropriate controls, as described, are therefore essential for the correct interpretation of Trim-Away results. With these considerations in mind, the authors provide guidance on how to set up a Trim-Away experiment in fertilized mouse oocytes, using microinjection as the delivery method and the epithelial CADHERIN protein as an example.