Replicon size and the dynamics of DNA replication during staurosporine- and vanadate-stimulated endo-S phases in primary roots of Pisum sativum.
Using immunocytochemistry of BrdUrd-labeled cells and 3H-thymidine DNA fiber autoradiography, the effects of staurosporine (a potent inhibitor of cyclin-dependent kinases, CDKs) and sodium metavanadate (an inhibitor of protein phosphatases) on DNA endoreplication were investigated in primary roots of Pisum sativum. The increased values of labeling indices suggest that CDK inhibitors create favorable conditions to permit a considerably greater number of cell nuclei to assemble pre-replicative complexes and, consequently, to commence DNA endoreplication. However, an opposite effect associated with decreased activity od S phase-specific CDKs seems responsible for rearranged programme of DNA synthesis, including the appearance of extended origin-to-origin distances and the slowed rates of replication fork movement.
D000963:Antimetabolites / Q000378:metabolism; D001973:Bromodeoxyuridine / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology*; D004261:DNA Replication; D004791:Enzyme Inhibitors / Q000378:metabolism; D018532:Pisum sativum / Q000033:anatomy & histology / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000502:physiology*; D012093:Replicon; D019311:Staurosporine / Q000378:metabolism*; D014638:Vanadates / Q000378:metabolism*
D000963:Antimetabolites; D004791:Enzyme Inhibitors; D014638:Vanadates; D001973:Bromodeoxyuridine; D019311:Staurosporine