Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:2.4.2.7 (
adenine phosphoribosyltransferase
)
692
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Irradiation of cells with short wave ultraviolet light (UV-C) induces both cyclobutane pyrimidine dimers (CPD) as well as pyrimidine 6-4 pyrimidone photoproducts (6-4 PP). We have focused on the removal of both types of DNA photolesions from the transcriptionally active
adenine phosphoribosyltransferase
(
APRT
) and hypoxanthine-guanine phosphoribosyltransferase (HPRT) genes and the inactive
c-mos
gene. Induction levels of both CPD and 6-4 PP were similar for all three genes analyzed, with the induction of 6-4 PP being about 3-fold lower than of CPD. Repair of CPD was analyzed using the CPD-specific enzyme T4 endonuclease V; repair of 6-4 PP was examined employing Escherichia coli UvrABC excinuclease. Unlike the HPRT gene, in which CPD were removed selectively from the transcribed strand, both strands of the 16-kilobase fragment encompassing the 2.6-kilobase
APRT
gene were repaired efficiently. This suggests the existence of multiple transcription units in the
APRT
region including transcription units running in the opposite direction of the
APRT
gene. Only a marginal part of the CPD was removed from the inactive
c-mos
gene after 24 h. In all three genes investigated, 6-4 PP were repaired more rapidly than CPD and, as demonstrated for the HPRT and
APRT
genes, without strand specificity. The difference in the repair phenotype of CPD between the HPRT gene and the
APRT
gene coincides with differences between both genes with regard to the DNA strand distribution of previously published UV-induced mutations.
...
PMID:Analysis of repair of cyclobutane pyrimidine dimers and pyrimidine 6-4 pyrimidone photoproducts in transcriptionally active and inactive genes in Chinese hamster cells. 798 59