Translocation of the papillomavirus L2/vDNA complex across the limiting membrane requires the onset of mitosis
AuthorCalton, Christine M.
Bronnimann, Matthew P.
Manson, Ariana R.
Chapman, Janice A.
Williamson, Tatum R.
Molugu, Sudheer K.
Bernal, Ricardo A.
Campos, Samuel K.
AffiliationUniv Arizona, Canc Biol Grad Interdisciplinary Program
Univ Arizona, Inst Bio5
Univ Arizona, Dept Immunobiol
Univ Arizona, Dept Mol & Cellular Biol
Univ Arizona, Dept Cellular & Mol Med
MetadataShow full item record
PublisherPUBLIC LIBRARY SCIENCE
CitationTranslocation of the papillomavirus L2/vDNA complex across the limiting membrane requires the onset of mitosis 2017, 13 (5):e1006200 PLOS Pathogens
Rights© 2017 Calton et al. This is an open access article distributed under the terms of the Creative Commons Attribution License.
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AbstractThe human papillomavirus type 16 (HPV16) L2 protein acts as a chaperone to ensure that the viral genome (vDNA) traffics from endosomes to the trans-Golgi network (TGN) and eventually the nucleus, where HPV replication occurs. En route to the nucleus, the L2/vDNA complex must translocate across limiting intracellular membranes. The details of this critical process remain poorly characterized. We have developed a system based on subcellular compartmentalization of the enzyme BirA and its cognate substrate to detect membrane translocation of L2-BirA from incoming virions. We find that L2 translocation requires transport to the TGN and is strictly dependent on entry into mitosis, coinciding with mitotic entry in synchronized cells. Cell cycle arrest causes retention of L2/vDNA at the TGN; only release and progression past G2/M enables translocation across the limiting membrane and subsequent infection. Microscopy of EdU-labeled vDNA reveals a rapid and dramatic shift in vDNA localization during early mitosis. At late G2/early prophase vDNA egresses from the TGN to a pericentriolar location, accumulating there through prometaphase where it begins to associate with condensed chromosomes. By metaphase and throughout anaphase the vDNA is seen bound to the mitotic chromosomes, ensuring distribution into both daughter nuclei. Mutations in a newly defined chromatin binding region of L2 potently blocked translocation, suggesting that translocation is dependent on chromatin binding during prometaphase. This represents the first time a virus has been shown to functionally couple the penetration of limiting membranes to cellular mitosis, explaining in part the tropism of HPV for mitotic basal keratinocytes.
NoteOpen access journal
VersionFinal published version
SponsorsNational Institute for Allergy and Infectious Diseases [1R01AI108751-01]; HHMI ; National Institute of General Medical Sciences [NIH-NIGMS SC3GM113805]; National Science Foundation [NSF-MRI-0923437]; Welch Foundation [AH-1649]