Poly(ADP-ribose) polymerase-1 (PARP-1) is activated by DNA strand breaks during 
cellular genotoxic stress response and catalyzes poly(ADP-ribosyl)ation of 
acceptor proteins. These acceptor proteins include those involved in modulation 
of chromatin structure, DNA synthesis, DNA repair, transcription, and cell cycle 
control. Thus, PARP-1 is believed to play a pivotal role in maintaining genome 
integrity through modulation of protein-protein and protein-DNA interactions. We 
previously described the association of PARP-1 with normal mammalian centromeres 
and human neocentromeres by affinity purification and immunofluorescence. Here 
we investigated the interaction of this protein with, and poly(ADP-ribosyl)ation 
of, three constitutive centromere proteins, Cenpa, Cenpb, and Cenpc, and a 
spindle checkpoint protein, Bub3. Immunoprecipitation and Western blot analyses 
demonstrate that Cenpa, Cenpb, and Bub3, but not Cenpc, interacted with PARP-1, 
and are poly(ADP-ribosyl)ated following induction of DNA damage. The results 
suggest a role of PARP-1 in centromere assembly/disassembly and checkpoint 
control. Demonstration of PARP-1-binding and poly(ADP-ribosyl)ation in three of 
the four proteins tested further suggests that many more centromere proteins may 
behave similarly and implicates PARP-1 as an important regulator of diverse 
centromere function.