biostudies-literatureHanley MLNIGMS NIH HHS1444-1456https://www.ebi.ac.uk/biostudies/studies/S-EPMC5449145biostudies-literatureUnknown28(11)The chromosomal passenger complex (CPC) is a conserved, essential regulator of cell division. As such, significant anti-cancer drug development efforts have been focused on targeting it, most notably by inhibiting its AURKB kinase subunit. The CPC is activated by AURKB-catalyzed autophosphorylation on multiple subunits, but how this regulates CPC interactions with other mitotic proteins remains unclear. We investigated the hydrodynamic behavior of the CPC in <i>Xenopus laevis</i> egg cytosol using sucrose gradient sedimentation and in HeLa cells using fluorescence correlation spectroscopy. We found that autophosphorylation of the CPC decreases its sedimentation coefficient in egg cytosol and increases its diffusion coefficient in live cells, indicating a decrease in mass. Using immunopreciMolecular biology of the cellChromosomal passenger complex hydrodynamics suggests chaperoning of the inactive state by nucleoplasmin/nucleophosmin.PMC5449145F31 GM116451R01 GM039565R37 GM039565Yoo TYHanley MLNeedleman DJSonnett MMitchison TJfalseChromosomal passenger complex hydrodynamics suggests chaperoning of the inactive state by nucleoplasmin/nucleophosmin.The chromosomal passenger complex (CPC) is a conserved, essential regulator of cell division. As such, significant anti-cancer drug development efforts have been focused on targeting it, most notably by inhibiting its AURKB kinase subunit. The CPC is activated by AURKB-catalyzed autophosphorylation on multiple subunits, but how this regulates CPC interactions with other mitotic proteins remains unclear. We investigated the hydrodynamic behavior of the CPC in <i>Xenopus laevis</i> egg cytosol using sucrose gradient sedimentation and in HeLa cells using fluorescence correlation spectroscopy. We found that autophosphorylation of the CPC decreases its sedimentation coefficient in egg cytosol and increases its diffusion coefficient in live cells, indicating a decrease in mass. Using immunopreci2017-01-01T00:00:00Z2017 Jun2025-04-04T12:36:29.521Z2019-03-27T02:46:20ZS-EPMC54491452840475110.1091/mbc.E16-12-0860