title: An ATM-independent S-phase checkpoint response involves CHK1 pathway.
abstract: After exposure to genotoxic stress, proliferating cells actively slow down the DNA replication through a S-phase checkpoint to provide time for repair. We report that in addition to the ataxia-telangiectasia mutated (ATM)-dependent pathway that controls the fast response, there is an ATM-independent pathway that controls the slow response to regulate the S-phase checkpoint after ionizing radiation in mammalian cells. The slow response of S-phase checkpoint, which is resistant to wortmannin, sensitive to caffeine and UCN-01, and related to cyclin-dependent kinase phosphorylation, is much stronger in CHK1 overexpressed cells, and it could be abolished by Chk1 antisense oligonucleotides. These results provide evidence that the ATM-independent slow response of S-phase checkpoint involves CHK1 pathway.
authors.affiliation: Department of Radiation Oncology, Kimmel Cancer Center of Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
authors.forename: Xiang-Yang
authors.initials: XY
authors.lastname: Zhou
authors.forename: Xiang
authors.initials: X
authors.lastname: Wang
authors.forename: Baocheng
authors.initials: B
authors.lastname: Hu
authors.forename: Jun
authors.initials: J
authors.lastname: Guan
authors.forename: George
authors.initials: G
authors.lastname: Iliakis
authors.forename: Ya
authors.initials: Y
authors.lastname: Wang
mesh_terms: D001260:Ataxia Telangiectasia / Q000473:pathology; D064007:Ataxia Telangiectasia Mutated Proteins; D042846:CDC2-CDC28 Kinases; D018797:Cell Cycle Proteins; D000071877:Checkpoint Kinase 1; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D004261:DNA Replication / Q000187:drug effects / Q000528:radiation effects; D004268:DNA-Binding Proteins; D004789:Enzyme Activation; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000528:radiation effects; D006801:Humans; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000494:pharmacology; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016196:S Phase / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D025521:Tumor Suppressor Proteins
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D016376:Oligonucleotides, Antisense; D025521:Tumor Suppressor Proteins; D004247:DNA; D011494:Protein Kinases; C576324:ATM protein, human; D064007:Ataxia Telangiectasia Mutated Proteins; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases