Nek2A ubiquitination reactions performed with either APC/CCdc20 wild type (APC/CWT) or mutants. APC/C2m is the N392A/E395A mutant of Apc2. APC/C2/4m is the N392A/E395A/R48A/H53A/S51A mutant of Apc2 and Apc4. 