Phenotypic switching in cells transformed with the herpes simplex virus thymidine kinase gene

Journal Article · Tue Jun 01 04:00:00 EDT 1982 · Mol. Cell. Biol.; (United States)

DOI:https://doi.org/10.1128/MCB.2.6.708· OSTI ID:5809822

Ostrander, M; Vogel, S; Silverstein, S

Biochemical transformation of Ltk/sup -/ cells with the herpes simplex virus thymidine kinase (tk) gene resulted in numerous TK/sup +/ colonies that survived selection in hypoxanthine-aminopterin-thymidine medium. Many of these TK/sup +/ cell lines switched phenotypes and reverted to the TK/sup -/ state. In this report, the authors describe the biological and biochemical characteristics of three TK/sup -/ revertant lines. One (K/sub 1/B/sub 5/) transiently expressed TK in the presence of bromodeoxyuridine, which selects for the TK/sup -/ phenotype. Another TK/sup -/ sibling (K/sub 1/B/sub 6//sup n/) expressed TK only after removal from bromodeoxyuridine-containing medium. The last variant (K/sub 1/B/sub 6//sup me/) lost the ability to switch to the TK/sup +/ phenotype, although it maintained the herpes simplex virus sequences coding for TK. Loss of the ability of K/sub 1/B/sub 6//sup me/ cells to express TK was correlated with extensive methylation of the sequence recognized by the restriction endonuclease HpaII (pCpCpGpG). After these cells were treated with 5-azacytidine, they regained the ability to clone in hypoxanthine-aminopterin-thymidine medium and reexpressed virus tk mRNA and enzyme. In addition, the HpaII sites that were previously shown to be refractile to enzyme digestion were converted to a sensitive state, demonstrating that they were no longer methylated.

• Research Organization: Dept. of Microbiology and The Cancer Research Center, College of Physicians and Surgeons, Columbia Univ., New York, NY 10032
• OSTI ID: 5809822
• Journal Information: Mol. Cell. Biol.; (United States), Journal Name: Mol. Cell. Biol.; (United States) Vol. 2:6; ISSN MCEBD
• Country of Publication: United States
• Language: English

Related Subjects

550400* -- Genetics
550700 -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
ANTIMETABOLITES
AROMATICS
AZAARENES
AZINES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL FUNCTIONS
BROMOURACILS
BUDR
CELL CULTURES
CELL TRANSFORMATIONS
CHEMICAL REACTIONS
COLONY FORMATION
CULTURE MEDIA
DISEASES
DNA SEQUENCING
DNA-ASE
DRUGS
ENDONUCLEASES
ENZYME INHIBITORS
ENZYMES
ESTERASES
FUNCTIONS
GENES
HERPES SIMPLEX
HETEROCYCLIC COMPOUNDS
HYDROLASES
HYDROXY COMPOUNDS
HYPOXANTHINE
INFECTIOUS DISEASES
KINETICS
MESSENGER-RNA
METHYLATION
MUTAGENESIS
MUTANTS
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
ORGANIC BROMINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENOTYPE
PHOSPHODIESTERASES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PURINES
PYRIMIDINES
REACTION KINETICS
REVERTANTS
RIBOSIDES
RNA
SKIN DISEASES
STRUCTURAL CHEMICAL ANALYSIS
THYMIDINE
TOXICITY
TRANSFERASES
URACILS
VIRAL DISEASES