Transduction of interphase cells by avian sarcoma virus.
It has been generally believed that oncoretroviruses are dependent on mitosis for efficient nuclear entry of viral DNA. We previously identified a nuclear localization signal in the integrase protein of an oncoretrovirus, avian sarcoma virus (ASV), suggesting an active import mechanism for the integrase-DNA complex (G. Kukolj, R. A. Katz, and A. M. Skalka, Gene 223:157-163, 1998). Here, we have evaluated the requirement for mitosis in nuclear import and integration of ASV DNA. Using a modified ASV encoding a murine leukemia virus amphotropic env gene and a green fluorescent protein (GFP) reporter gene, DNA nuclear import was measured in cell cycle-arrested avian (DF-1) as well as human (HeLa) and mouse cells. The results showed efficient accumulation of nuclear forms of ASV DNA in gamma-irradiation-arrested cells. Efficient transduction of a GFP reporter gene was also observed after infection of cells that were arrested with gamma-irradiation, mitomycin C, nocodazole, or aphidicolin, confirming that nuclear import and integration of ASV DNA can occur in the absence of mitosis. By monitoring GFP expression in individual cells, we also obtained evidence for nuclear import of viral DNA during interphase in cycling cells. Lastly, we observed that ASV can transduce postmitotic mouse neurons. These results support an active nuclear import mechanism for the oncoretrovirus ASV and suggest that this mechanism can operate in both nondividing and dividing cells.
Katz
Richard A
RA
Institute for Cancer Research, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA. R_Katz@fccc.edu
Greger
James G
JG
Darby
Kristen
K
Boimel
Pamela
P
Rall
Glenn F
GF
Skalka
Anna Marie
AM
D021581:Active Transport, Cell Nucleus; D000818:Animals; D016590:Aphidicolin / Q000494:pharmacology; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002642:Chick Embryo; D004279:DNA, Viral / Q000378:metabolism; D016195:G2 Phase; D017930:Genes, Reporter; D005822:Genetic Vectors / Q000235:genetics*; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D006918:Hydroxyurea / Q000494:pharmacology; D007399:Interphase; D008164:Luminescent Proteins / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D016685:Mitomycin / Q000494:pharmacology; D008938:Mitosis; D009474:Neurons; D015739:Nocodazole / Q000494:pharmacology; D012107:Research Design; D014161:Transduction, Genetic
D004279:DNA, Viral; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D016590:Aphidicolin; D016685:Mitomycin; D015739:Nocodazole; D006918:Hydroxyurea