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:6.3.2.19 (
ubiquitin-protein ligase
)
799
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Caffeine
has been reported to induce premature chromosome condensation (PCC) in S-phase cells in the presence of an inhibitor of DNA synthesis. We found that when S-phase cells are treated with
caffeine
and hydroxyurea after X irradiation, substantially more potentially lethal damage (PLD) is expressed, but the addition of cycloheximide, which inhibits PCC induction in S-phase cells, in the presence of
caffeine
and hydroxyurea reduces the expression of PLD to the same level as seen with
caffeine
alone. This can be interpreted to mean that the expression of PLD seen with
caffeine
in the absence of an inhibitor of DNA synthesis is not associated with chromosome condensation. Evidence that PCC induction in S-phase cells and the influence of
caffeine
on PLD expression were suppressed by incubation at 40 degrees C of tsBN75 cells with a ts defect in
ubiquitin-activating enzyme
indicates the involvement of ubiquitin in these two processes. These observations as well as previous findings on ubiquitin suggest to us that
caffeine
induces changes in DNA-chromatin conformation, which are caused by induction of PCC or ubiquitination of chromosomal protein. Such changes occurring postirradiation would favor expression of PLD.
...
PMID:X-ray-related potentially lethal damage expressed by chromosome condensation and the influence of caffeine. 279 83
