One-step generation of auxin-inducible degron cells with high-efficiency homozygous tagging

Auxin-inducible degron (AID) technology is powerful for chemogenetic control of proteolysis. However, generation of human cell lines to deplete endogenous proteins with AID remains challenging. Typically, homozygous degron-tagging efficiency is low and overexpression of an auxin receptor requires additional engineering steps. Here, we establish a one-step genome editing procedure with high-efficiency homozygous tagging and auxin receptor expression. We demonstrate its application in 5 human cell lines, including embryonic stem (ES) cells. The method allowed isolation of AID single-cell clones in 10 days for 11 target proteins with >80% average homozygous degron-tagging efficiency in A431 cells, and >50% efficiency for 5 targets in H9 ES cells. The tagged endogenous proteins were inducibly degraded in all cell lines, including ES cells and ES-cell derived neurons, with robust expected functional readouts. This method facilitates the application of AID for studying endogenous protein functions in human cells, especially in stem cells. A431 wild-type cells were treated with different inducers: Pico_cvxIAA (0.5 μM), cvxIAA (5 μM) and IAA (500 μM); for 24 h compared to control.