Differential introduction of DNA damage and repair in mammalian genes transcribed by RNA polymerase I and II
- University of North Carolina at Chapel Hill (United States)
The authors have developed a general quantitative method for comparing the levels of drug-induced DNA crosslinking in specific mammalian genes. They observed a dramatic difference between the efficiency of the removal of both psoralen monoadducts and interstrand crosslinks from the rRNA genes and the efficiency of their removal from the dihydrofolate reductase (DHFR) gene in cultured human and hamster cells. While 90% of the interstrand crosslinks were removed from the human DHFR gene in 48 h, less than 25% repair occurred in the rRNA genes. Similarly, in Chinese hamster ovary cells, 85% repair of interstrand crosslinks within 8 h in the DHFR gene versus only 20% repair in the rRNA genes. The preferential repair of the DHFR gene relative to that of the rRNA genes was also observed for psoralen monoadducts in cells from both mammalian species. In human-mouse hybrid cells, the active mouse rRNA genes were five times more susceptible to psoralen modification than are the silent rRNA human genes, but adduct removal was similarly inefficient for both classes. They conclude that the repair of chemical damage such as psoralen photadducts in an expressed mammalian gene may depend upon the class of transcription to which it belongs.
- OSTI ID:
- 7176778
- Journal Information:
- Molecular and Cellular Biology; (United States), Vol. 11:4; ISSN 0270-7306
- Country of Publication:
- United States
- Language:
- English
Similar Records
Xeroderma pigmentosum complementation group C cells remove pyrimidine dimers selectively from the transcribed strand of active genes
Nonsense mutations in the dihydrofolate reductase gene affect RNA processing
Related Subjects
CHO CELLS
DNA REPAIR
PSORALEN
BIOLOGICAL EFFECTS
CROSS-LINKING
GENES
OXIDOREDUCTASES
RNA POLYMERASES
TRANSCRIPTION
ANIMAL CELLS
ANTICOAGULANTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CHEMICAL REACTIONS
COUMARINS
DRUGS
ENZYMES
HEMATOLOGIC AGENTS
HETEROCYCLIC COMPOUNDS
NUCLEOTIDYLTRANSFERASES
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
POLYMERASES
POLYMERIZATION
PROTEINS
REPAIR
TRANSFERASES
550200* - Biochemistry