Polybromo 1 (PBRM1)

The deduced 1,582-amino acid BAF180 protein, which is 90% identical to the chicken polybromo-1 protein, possesses 5 bromodomains, 2 bromo-adjacent homology (BAH) regions, and 1 high-mobility group (HMG) motif. BAF180 is also highly homologous to yeast Rsc1, Rsc2, and Rsc3, essential proteins that are required for cell cycle progression through mitosis.

Northern blot analysis revealed wide expression of 9.5- and 7.5-kb BAF180 transcripts. Immunofluorescence microscopy demonstrated that BAF180 was expressed in the nucleus during interphase but colocalized with cytoplasmic dynein at some kinetochores during prometaphase. The localization of BAF180 at kinetochores was not observed in metaphase, anaphase, or telophase.