Differential response of the human cyclin B1 promoter to inhibitors of the cell cycle in NIH3T3 cells.
In this study, NIH3T3 cells stably transfected with a cyclin B1-luciferase reporter vector were utilized to investigate if cyclin B1 promoter activity is linked to either DNA replication or the activities of various cyclin-cyclin dependent kinases (cdks). Synchronized cells treated at the time of serum re-stimulation with 2 micrograms/ml of the DNA synthesis inhibitor, aphidicolin, did not display an increase in luciferase activity in comparison to control cells. When treated with aphidicolin during S phase, luciferase activity decreased. In contrast, luciferase activity increased in cells treated at the time of serum re-stimulation with 200 microM olomoucine, a cyclin-cdk inhibitor. These results indicate that (1) cyclin B1 promoter activity in NIH3T3 cells is linked to a DNA replication checkpoint control mechanism; (2) the cyclin B1 gene can be activated in the absence of functional cyclin E-cdk2, cyclin A-cdk2, or cyclin B-cdk2; and (3) cyclin B1 gene activation can occur in G1 arrested cells under conditions in which the arrest is not directly linked to inhibition of DNA synthesis.
Nuckolls
F J
FJ
Department of Biology, University of North Carolina at Greensboro 27402, USA.
Khan
A S
AS
Butler
R
R
Katula
K S
KS
D016475:3T3 Cells; D000818:Animals; D016590:Aphidicolin / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects* / Q000235:genetics; D019926:Cyclin B / Q000235:genetics*; D056744:Cyclin B1; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors; D004261:DNA Replication / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007701:Kinetin; D008156:Luciferases / Q000378:metabolism; D051379:Mice; D011401:Promoter Regions, Genetic / Q000187:drug effects*; D011687:Purines / Q000494:pharmacology; D015533:Transcriptional Activation
C534699:CCNB1 protein, human; C534700:Ccnb1 protein, mouse; D019926:Cyclin B; D056744:Cyclin B1; D004791:Enzyme Inhibitors; D011687:Purines; D016590:Aphidicolin; C090046:olomoucine; D008156:Luciferases; D018844:Cyclin-Dependent Kinases; D007701:Kinetin