title: Dynamic localization of the human papillomavirus type 11 origin binding protein E2 through mitosis while in association with the spindle apparatus.
abstract: Papillomaviral DNA replicates as extrachromosomal plasmids in squamous epithelium. Viral DNA must segregate equitably into daughter cells to persist in dividing basal/parabasal cells. We have previously reported that the viral origin binding protein E2 of human papillomavirus types 11 (HPV-11), 16, and 18 colocalized with the mitotic spindles. In this study, we show the localization of the HPV-11 E2 protein to be dynamic. It colocalized with the mitotic spindles during prophase and metaphase. At anaphase, it began to migrate to the central spindle microtubules, where it remained through telophase and cytokinesis. It was additionally observed in the midbody at cytokinesis. A peptide spanning residues 285 to 308 in the carboxyl-terminal domain of HPV-11 E2 (E2C) is necessary and sufficient to confer localization on the mitotic spindles. This region is conserved in HPV-11, -16, and -18 and bovine papillomavirus type 4 (BPV-4) E2 and is also required for the respective E2C to colocalize with the mitotic spindles. The E2 protein of bovine papillomavirus type 1 is tethered to the mitotic chromosomes via the cellular protein Brd4. However, the HPV-11 E2 protein did not associate with Brd4 during mitosis. Lastly, a chimeric BPV-1 E2C containing the spindle localization domain from HPV-11 E2C gained the ability to localize to the mitotic spindles, whereas the reciprocal chimera lost the ability. We conclude that this region of HPV E2C is critical for localization with the mitotic apparatus, enabling the HPV DNA to sustain persistent infections.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL 35294-0005, USA.
authors.forename: Luan D
authors.initials: LD
authors.lastname: Dao
authors.forename: Aaron
authors.initials: A
authors.lastname: Duffy
authors.forename: Brian A
authors.initials: BA
authors.lastname: Van Tine
authors.forename: Shwu-Yuan
authors.initials: SY
authors.lastname: Wu
authors.forename: Cheng-Ming
authors.initials: CM
authors.lastname: Chiang
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Broker
authors.forename: Louise T
authors.initials: LT
authors.lastname: Chow
mesh_terms: D000818:Animals; D019556:COS Cells; D002417:Cattle; D002522:Chlorocebus aethiops; D004252:DNA Mutational Analysis; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D052140:Human papillomavirus 11 / Q000378:metabolism*; D052162:Human papillomavirus 16 / Q000378:metabolism; D006801:Humans; D008938:Mitosis / Q000502:physiology*; D009856:Oncogene Proteins, Viral / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D018741:Replication Origin; D008941:Spindle Apparatus / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; C051550:E2 protein, Bovine papillomavirus; C117355:E2 protein, Human papillomavirus type 11; C054855:E2 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; C069102:oncogene protein E2, Human papillomavirus type 18; C055789:origin-binding proteins, viral