Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-0455, USA. amcbride@nih.gov
Papillomavirus infections are long-lived and persistent. The circular DNA of the viral genome is maintained in dividing epithelial cells as an extrachromosomal element. The E2 protein of the virus binds to the viral genome and tethers it to mitotic chromosomes to ensure that the genome is retained and faithfully partitioned in dividing cells. This mechanism has been best studied for bovine papillomavirus type 1. Recent evidence indicates that while this is a common strategy among papillomaviruses, different viruses have selected different chromosomal targets.