title: Cyclin-dependent kinases and S phase control in mammalian cells.
abstract: Mammalian DNA replication is an elegantly choreographed process in which multiple components are assembled at the origins to form the prereplication complex. Formation and activation of the prereplication complex requires coordinate actions of G1and S phase cyclin-dependent kinases. Cyclin E-CDK2 and cyclin A-CDK2, together with DBF4-CDC7, phosphorylate several components of the prereplication complex and replication machinery. In this review, we summarize the current understanding of the mechanism of initiation of DNA replication in mammalian cells. The roles of cyclin A/E-CDK2 complexes in driving replication, their relationship with other regulators of S phase, and their role in keeping replication to only once per cell cycle will be discussed. In addition, an important issue is the checks and balances that prevent inappropriate DNA replication, and how a breakdown in these checkpoints can lead to genomic instability and cancer. A critical mediator of these checkpoints, ATM, signals through a comprehensive network of proteins leading to CDK2 inhibition thus preventing DNA synthesis. This will be reviewed in addition to other mechanisms involved in the intra-S phase DNA damage checkpoint.
authors.affiliation: Department of Biochemistry, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong. rwoo@ust.hk
authors.forename: Richard A
authors.initials: RA
authors.lastname: Woo
authors.forename: Randy Y C
authors.initials: RY
authors.lastname: Poon
mesh_terms: D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D042846:CDC2-CDC28 Kinases / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002843:Chromatin / Q000235:genetics / Q000502:physiology*; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage / Q000235:genetics / Q000502:physiology; D004261:DNA Replication / Q000235:genetics / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004706:Endodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D005090:Exodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D016193:G1 Phase / Q000235:genetics / Q000502:physiology; D016195:G2 Phase / Q000235:genetics / Q000502:physiology; D051738:Origin Recognition Complex; D010766:Phosphorylation; D025941:Protein Interaction Mapping; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D018741:Replication Origin / Q000235:genetics / Q000502:physiology; D016160:Retinoblastoma Protein / Q000235:genetics / Q000378:metabolism; D016196:S Phase / Q000235:genetics / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins; D014981:Xenopus / Q000235:genetics / Q000378:metabolism; D029867:Xenopus Proteins
chemical_list: C066503:CDC6 protein, S cerevisiae; D018797:Cell Cycle Proteins; D002843:Chromatin; D004268:DNA-Binding Proteins; C088096:Dbf4 protein, S cerevisiae; D051738:Origin Recognition Complex; D016160:Retinoblastoma Protein; D029701:Saccharomyces cerevisiae Proteins; D025521:Tumor Suppressor Proteins; D029867:Xenopus Proteins; D064007:Ataxia Telangiectasia Mutated Proteins; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495891:Cdk2 protein, Xenopus; D051357:Cyclin-Dependent Kinase 2; D018844:Cyclin-Dependent Kinases; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; C094191:MRE11 protein, S cerevisiae