Establishment of papillomavirus infection is enhanced by promyelocytic leukemia protein (PML) expression.
Previous studies have suggested that most papillomaviruses enter the host cell via clathrin-dependent receptor-mediated endocytosis but have not addressed later steps in viral entry. To examine these events, we followed the localization of L2 and packaged DNA after entry of infectious virions or L1/L2 pseudovirions. Confocal microscopic analyses of HeLa cells showed a time-dependent uncoating of capsids in cytoplasmic vesicles and the accumulation of both L2 and viral DNA at distinct nuclear domains identified as nuclear domain 10 (ND10). Both L2 and the pseudogenome had a punctate distribution and localized to ND10 in promyelocytic leukemia protein (PML)-expressing cells, whereas L2 had a diffuse nuclear distribution in PML-/- cells. The number of pseudovirus-infected cells was an order of magnitude higher in the PML+ cells compared with the PML-/- cells, and viral genome transcription after infection with authentic bovine papillomavirus virions was similarly elevated in PML+ cells. The results identify a role for PML in the enhancement of viral infectivity in the early part of the life cycle. We propose a model in which L2 chaperones the viral genome to ND10 to efficiently initiate viral transcription.
Day
Patricia M
PM
Laboratory of Cellular Oncology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. pmd@nih.gov
Baker
Carl C
CC
Lowy
Douglas R
DR
Schiller
John T
JT
D000818:Animals; D052688:Bovine papillomavirus 1 / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D002467:Cell Nucleus / Q000378:metabolism / Q000821:virology; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D018613:Microscopy, Confocal; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D030361:Papillomavirus Infections / Q000378:metabolism*; D000071156:Promyelocytic Leukemia Protein; D011544:Pseudogenes / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D014161:Transduction, Genetic; D025521:Tumor Suppressor Proteins; D016335:Zinc Fingers
D036022:Capsid Proteins; D004279:DNA, Viral; C085218:L2 protein, Bovine papillomavirus; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; C513293:Pml protein, mouse; D000071156:Promyelocytic Leukemia Protein; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C070576:PML protein, human