Reorganization of nuclear domain 10 induced by papillomavirus capsid protein l2.

Nuclear domains (ND) 10 are associated with proteins implicated in transcriptional regulation, growth suppression, and apoptosis. We now show that the minor capsid protein L2 of human papillomavirus (HPV) type 33 induces a reorganization of ND10-associated proteins. Whereas the promyelocytic leukemia protein, the major structural component of ND10, was unaffected by L2, Sp100 was released from ND10 upon L2 expression. The total cellular amount of Sp100, but not of Sp100 mRNA, decreased significantly, suggesting degradation of Sp100. Proteasome inhibitors induced the dispersal of Sp100 and inhibited the nuclear translocation of L2. In contrast to Sp100, Daxx was recruited to ND10 by L2 expression. Coimmunoprecipitation demonstrated interaction of the two proteins. L2-induced reorganization of ND10 was observed both in cell culture and in natural HPV lesions. The differential change in protein composition observed provides further evidence to suggest that the ND10-associated proteins are an important interface of viral life cycle and host cell.