An analog-sensitive allele of Aurora kinase B is lethal in mouse

The mammalian genome encodes three Aurora protein kinase homologs (AURKA/B/C) which regulate chromosome segregation in nearly every cell type. AURKC expression is largely limited to meiotic cells. Because of the similarity in sequences between AURKB and AURKC, determining their separate functions during meiosis is challenging. We designed a chemical genetics approach to investigate AURKB function. Using Crispr/Cas9 genome editing in mouse, we replaced an ATP binding pocket amino acid to permit binding of cell-permeable ATP analogs. We also introduced a second site supressor mutation to tolerate the pocket enlargement. Heterozygous mice were fertile, but never produced homozygous analog-sensitive mice. Because Aurkb is an essential gene, we conclude that this analog-sensitive allele is either catalytically inactive or not fully catalytically active in mouse.