AID2 technology gives superior degradation control. Homo sapiens

Protein knockdown by the auxin-inducible degron (AID) technology is useful to study protein function in living cells owing to its rapid depletion, that makes possible to observe an immediate phenotype. However, the current AID system has two major drawbacks; leaky degradation and use of a high dose of auxin. These negative features make difficult to precisely control the expression level of a protein of interest in living cells and to apply this method to mice. Here, we overcame these problems by taking an advantage of a bump-and-hole approach and established AID version 2 (AID2) systems. AID2 employing an OsTIR1(F74G) mutant and a new ligand, 5-Ph-IAA, show significantly low leaky degradation, requires a 670-fold less ligand concentration, and achieves even quicker degradation. We demonstrate that successful generation of human cell mutants for genes that were previously difficult to deal with, and that AID2 works not only in yeast and mammalian cells, but even in mice to achieve rapid target depletion.