Expression of papillomavirus L1 proteins regulated by authentic gene codon usage is favoured in G2/M-like cells in differentiating keratinocytes.
We investigated whether differentiation-dependent expression of papillomavirus (PV) L1 genes is influenced by the cell cycle state in keratinocytes (KCs) grown in vitro or in vivo. In primary keratinocytes, flow cytometry revealed a clear shift from predominantly G0/G1 to G2/M cells from day 1 to day 7, with a three-fold increase in G2/M-like cells in day 7 keratinocytes that showed approximately 50% of the cells expressed a terminal differentiation marker involucrin. The correlation between the levels of the L1 proteins expressed from authentic (Nat) L1 genes of HPV6b and BPV1 and the frequencies of the G2/M-like KCs was significantly positive, while in contrast, a significantly negative correlation in the levels of L1 proteins expressed from codon-modified (Mod) L1 genes of HPV6b and BPV1 with the frequencies of the G2/M-like KCs was observed. Experiments using cell cycle arrest reagents (all-trans retinoic acid (RA) and colchicine) confirmed that L1 proteins expressed from PV Nat L1 genes were facilitated in G2/M-like KCs upon differentiation. Using immunofluorescence microscopy, it appears that L1 proteins from PV Nat L1 genes were co-expressed with cyclin B1, while the L1 proteins expressed from PV Mod L1 genes were preferentially associated with cyclin D2 in KCs in vitro and in mouse skin. Our results demonstrate that (1) expression of the L1 proteins from Nat L1 genes of HPV6b and BPV1 that have strong codon usage bias with A or T at codon third position dependent on KC differentiation is favoured by the G2/M-like environment and (2) codon modifications can alter the cell differentiation-dependent and cell cycle-associated patterns of expression of the PV L1 proteins in KCs.
Ding
Jianmin
J
Diamantina Institute for Cancer Immunology and Metabolic Medicine, The University of Queensland, Research Extension, Princess Alexandra Hospital, Woolloongabba, Queensland 4102, Australia; Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, St Lucia, Queensland 4072, Australia.
Doorbar
John
J
Division of Virology, The National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK.
Li
Bo
B
Diamantina Institute for Cancer Immunology and Metabolic Medicine, The University of Queensland, Research Extension, Princess Alexandra Hospital, Woolloongabba, Queensland 4102, Australia.
Zhou
Fang
F
Diamantina Institute for Cancer Immunology and Metabolic Medicine, The University of Queensland, Research Extension, Princess Alexandra Hospital, Woolloongabba, Queensland 4102, Australia.
Gu
Wenyi
W
Diamantina Institute for Cancer Immunology and Metabolic Medicine, The University of Queensland, Research Extension, Princess Alexandra Hospital, Woolloongabba, Queensland 4102, Australia.
Zhao
Liang
L
Diamantina Institute for Cancer Immunology and Metabolic Medicine, The University of Queensland, Research Extension, Princess Alexandra Hospital, Woolloongabba, Queensland 4102, Australia.
Saunders
Nicholas A
NA
Diamantina Institute for Cancer Immunology and Metabolic Medicine, The University of Queensland, Research Extension, Princess Alexandra Hospital, Woolloongabba, Queensland 4102, Australia.
Frazer
Ian H
IH
Diamantina Institute for Cancer Immunology and Metabolic Medicine, The University of Queensland, Research Extension, Princess Alexandra Hospital, Woolloongabba, Queensland 4102, Australia.
Zhao
Kong-Nan
KN
Diamantina Institute for Cancer Immunology and Metabolic Medicine, The University of Queensland, Research Extension, Princess Alexandra Hospital, Woolloongabba, Queensland 4102, Australia; University of Queensland Centre for Clinical Research, The University of Queensland, Royal Brisbane & Women's Hospital Campus, Herston, Queensland 4029, Australia; Queensland Institute of Medical Research, Radiation Biology and Oncology, Brisbane, Queensland 4029, Australia. Electronic address: k.zhao@uq.edu.au.
D000818:Animals; D036022:Capsid Proteins / Q000096:biosynthesis / Q000502:physiology*; D002453:Cell Cycle / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D003062:Codon / Q000378:metabolism; D003078:Colchicine / Q000494:pharmacology; D056744:Cyclin B1 / Q000096:biosynthesis / Q000502:physiology; D056742:Cyclin D2 / Q000096:biosynthesis / Q000502:physiology; D016195:G2 Phase / Q000502:physiology*; D015967:Gene Expression Regulation, Viral / Q000187:drug effects / Q000502:physiology*; D005814:Genes, Viral / Q000502:physiology; D015603:Keratinocytes / Q000821:virology*; D051379:Mice; D008938:Mitosis / Q000502:physiology*; D009856:Oncogene Proteins, Viral / Q000096:biosynthesis / Q000502:physiology; D027383:Papillomaviridae / Q000502:physiology*; D030361:Papillomavirus Infections / Q000378:metabolism / Q000821:virology*; D011498:Protein Precursors / Q000096:biosynthesis / Q000502:physiology; D050257:Tubulin Modulators / Q000494:pharmacology
D036022:Capsid Proteins; D003062:Codon; D056744:Cyclin B1; D056742:Cyclin D2; D009856:Oncogene Proteins, Viral; D011498:Protein Precursors; D050257:Tubulin Modulators; C032253:involucrin; D003078:Colchicine