Chromatin structure is required to block transcription of the methylated herpes simplex virus thymidine kinase gene
Inhibition of herpes simplex virus (HSV) thymidine kinase (TK) gene transcription (pHSV-106, pML-BPV-TK4) by DNA methylation is an indirect effect, which occurs with a latency period of approx. 8 hr microinjection of the DNA into TK/sup -/ rat 2 and mouse LTK/sup -/ cells. The authors have strong evidence that chromatin formation is critical for the transition of the injected DNA from methylation insensitivity to methylation sensitivity. Chromatin was reconstituted in vitro by using methylated and mock-methylated HSV TK DNA and purified chicken histone octamers. After microinjection, the methylated chromatin was always biologically inactive, as tested by autoradiography of the cells after incubation with (/sup 3/H)thymidine and by RNA dot blot analysis. However, in transformed cell lines, reactivation of the methylated chromatic occurred after treatment with 5-azacytidine. Furthermore, integration of the TK chromatin into the host genome is not required to block expression of the methylated TK gene. Mouse cells that contained the pML-BPV-TK4 chromatin permanently in an episomal state also did not support TK gene expression as long as the TK DNA remained methylated.
- Research Organization:
- Freie Universitaet Berlin, West Germany
- OSTI ID:
- 6023113
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 84:5
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHROMATIN
MOLECULAR STRUCTURE
DNA
AUTORADIOGRAPHY
METHYLATION
TRANSCRIPTION
INHIBITION
CELL NUCLEI
CHICKENS
GENES
HERPES SIMPLEX
PHOSPHOTRANSFERASES
PLASMIDS
THYMIDINE
TRANSMISSION ELECTRON MICROSCOPY
TRITIUM COMPOUNDS
VIRUSES
ANIMALS
AZINES
BIRDS
CELL CONSTITUENTS
CHEMICAL REACTIONS
DISEASES
ELECTRON MICROSCOPY
ENZYMES
FOWL
HETEROCYCLIC COMPOUNDS
INFECTIOUS DISEASES
LABELLED COMPOUNDS
MICROORGANISMS
MICROSCOPY
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PARASITES
PHOSPHORUS-GROUP TRANSFERASES
PYRIMIDINES
RIBOSIDES
SKIN DISEASES
TRANSFERASES
VERTEBRATES
VIRAL DISEASES
550201* - Biochemistry- Tracer Techniques