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Pellarin I, Dall'Acqua A, Favero A, Segatto I, Rossi V, Crestan N, Karimbayli J, Belletti B, Baldassarre G. Cyclin-dependent protein kinases and cell cycle regulation in biology and disease. Signal Transduct Target Ther 2025; 10:11. [PMID: 39800748 PMCID: PMC11734941 DOI: 10.1038/s41392-024-02080-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2024] [Revised: 10/16/2024] [Accepted: 11/13/2024] [Indexed: 01/18/2025] Open
Abstract
Cyclin Dependent Kinases (CDKs) are closely connected to the regulation of cell cycle progression, having been first identified as the kinases able to drive cell division. In reality, the human genome contains 20 different CDKs, which can be divided in at least three different sub-family with different functions, mechanisms of regulation, expression patterns and subcellular localization. Most of these kinases play fundamental roles the normal physiology of eucaryotic cells; therefore, their deregulation is associated with the onset and/or progression of multiple human disease including but not limited to neoplastic and neurodegenerative conditions. Here, we describe the functions of CDKs, categorized into the three main functional groups in which they are classified, highlighting the most relevant pathways that drive their expression and functions. We then discuss the potential roles and deregulation of CDKs in human pathologies, with a particular focus on cancer, the human disease in which CDKs have been most extensively studied and explored as therapeutic targets. Finally, we discuss how CDKs inhibitors have become standard therapies in selected human cancers and propose novel ways of investigation to export their targeting from cancer to other relevant chronic diseases. We hope that the effort we made in collecting all available information on both the prominent and lesser-known CDK family members will help in identify and develop novel areas of research to improve the lives of patients affected by debilitating chronic diseases.
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Affiliation(s)
- Ilenia Pellarin
- Division of Molecular Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, National Cancer Institute, Aviano, Italy
| | - Alessandra Dall'Acqua
- Division of Molecular Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, National Cancer Institute, Aviano, Italy
| | - Andrea Favero
- Division of Molecular Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, National Cancer Institute, Aviano, Italy
| | - Ilenia Segatto
- Division of Molecular Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, National Cancer Institute, Aviano, Italy
| | - Valentina Rossi
- Division of Molecular Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, National Cancer Institute, Aviano, Italy
| | - Nicole Crestan
- Division of Molecular Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, National Cancer Institute, Aviano, Italy
| | - Javad Karimbayli
- Division of Molecular Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, National Cancer Institute, Aviano, Italy
| | - Barbara Belletti
- Division of Molecular Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, National Cancer Institute, Aviano, Italy
| | - Gustavo Baldassarre
- Division of Molecular Oncology, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, National Cancer Institute, Aviano, Italy.
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2
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Solorza J, Recabarren R, Alzate-Morales J. Molecular Insights into the Trapping Effect of Ca 2+ in Protein Kinase A: A Molecular Dynamics Study. J Chem Inf Model 2020; 60:898-914. [PMID: 31804819 DOI: 10.1021/acs.jcim.9b00857] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Protein kinase A has become a model system for the study of kinases, and therefore, a comprehensive understanding of the underlying molecular mechanisms in its catalytic cycle is of crucial importance. One of the aspects that has received recent attention is the role that metal cofactors play in the catalytic cycle. Although Mg2+ is the well-known physiological ion used by protein kinases, Ca2+ ions can also assist the phosphoryl transfer reaction but with lower catalytic activities. This inhibitory effect has been attributed to the ability of Ca2+ to trap the reaction products at the active site, and it has been proposed as a possible regulatory mechanism of the enzyme. Thus, in order to get a clearer understanding of these molecular events, computational simulations in the product state of PKA, in the presence of Mg2+ and Ca2+ ions, were performed through molecular dynamics (MD). Different protonation states of the active site were considered in order to model the different mechanistic pathways that have been proposed. Our results show that different protonation states of the phosphorylated serine residue at the peptide substrate (pSer21), as well as the protonation state of residue Asp166, can have a marked influence on the flexibility of regions surrounding the active site. This is the case of the glycine-rich loop, a structural motif that is directly involved in the release of the products from the PKA active site. MD simulations were capable to reproduce the crystallographic conformations but also showed other conformations not previously reported in the crystal structures that may be involved in enhancing the affinity of pSP20 to PKA in the presence of Ca2+. Hydrogen bonding interactions at the PKA-pSP20 interface were influenced whether by the protonation state of the active site or by the metal cofactor used by the enzyme. Altogether, our results provide molecular aspects into the inhibitory mechanism of Ca2+ in PKA and suggest which is the most probable protonation state of the phosphorylated product at the active site.
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Affiliation(s)
- Jocelyn Solorza
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería , Universidad de Talca , 1 Poniente 1141 , Talca , Chile
| | - Rodrigo Recabarren
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería , Universidad de Talca , 1 Poniente 1141 , Talca , Chile
| | - Jans Alzate-Morales
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería , Universidad de Talca , 1 Poniente 1141 , Talca , Chile
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3
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Unity and diversity among viral kinases. Gene 2019; 723:144134. [PMID: 31589960 DOI: 10.1016/j.gene.2019.144134] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 09/12/2019] [Accepted: 09/16/2019] [Indexed: 12/27/2022]
Abstract
Viral kinases are known to undergo autophosphorylation and also phosphorylate viral and host substrates. Viral kinases have been implicated in various diseases and are also known to acquire host kinases for mimicking cellular functions and exhibit virulence. Although substantial analyses have been reported in the literature on diversity of viral kinases, there is a gap in the understanding of sequence and structural similarity among kinases from different classes of viruses. In this study, we performed a comprehensive analysis of protein kinases encoded in viral genomes. Homology search methods have been used to identify kinases from 104,282 viral genomic datasets. Serine/threonine and tyrosine kinases are identified only in 390 viral genomes. Out of seven viral classes that are based on nature of genetic material, only viruses having double-stranded DNA and single-stranded RNA retroviruses are found to encode kinases. The 716 identified protein kinases are classified into 63 subfamilies based on their sequence similarity within each cluster, and sequence signatures have been identified for each subfamily. 11 clusters are well represented with at least 10 members in each of these clusters. Kinases from dsDNA viruses, Phycodnaviridae which infect green algae and Herpesvirales that infect vertebrates including human, form a major group. From our analysis, it has been observed that the protein kinases in viruses belonging to same taxonomic lineages form discrete clusters and the kinases encoded in alphaherpesvirus form host-specific clusters. A comprehensive sequence and structure-based analysis enabled us to identify the conserved residues or motifs in kinase catalytic domain regions across all viral kinases. Conserved sequence regions that are specific to a particular viral kinase cluster and the kinases that show close similarity to eukaryotic kinases were identified by using sequence and three-dimensional structural regions of eukaryotic kinases as reference. The regions specific to each viral kinase cluster can be used as signatures in the future in classifying uncharacterized viral kinases. We note that kinases from giant viruses Marseilleviridae have close similarity to viral oncogenes in the functional regions and in putative substrate binding regions indicating their possible role in cancer.
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4
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Gil RS, Vagnarelli P. Protein phosphatases in chromatin structure and function. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:90-101. [PMID: 30036566 PMCID: PMC6227384 DOI: 10.1016/j.bbamcr.2018.07.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/29/2018] [Accepted: 07/18/2018] [Indexed: 12/19/2022]
Abstract
Chromatin structure and dynamics are highly controlled and regulated processes that play an essential role in many aspects of cell biology. The chromatin transition stages and the factors that control this process are regulated by post-translation modifications, including phosphorylation. While the role of protein kinases in chromatin dynamics has been quite well studied, the nature and regulation of the counteracting phosphatases represent an emerging field but are still at their infancy. In this review we summarize the current literature on phosphatases involved in the regulation of chromatin structure and dynamics, with emphases on the major knowledge gaps that should require attention and more investigation.
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Affiliation(s)
- Raquel Sales Gil
- Colleges of Health and Life Science, Research Institute for Environment Health and Society, Brunel University London, London UB8 3PH, UK
| | - Paola Vagnarelli
- Colleges of Health and Life Science, Research Institute for Environment Health and Society, Brunel University London, London UB8 3PH, UK.
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5
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Cheng J, Lu X, Wang J, Zhang H, Duan P, Li C. Interactome analysis of gene expression profiles of cervical cancer reveals dysregulated mitotic gene clusters. Am J Transl Res 2017; 9:3048-3059. [PMID: 28670392 PMCID: PMC5489904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
Cervical cancer is the second most common malignancy in women worldwide. HPV infections are the leading cause of cervical cancer. Although progress has been made in understanding cervical cancer, knowledge of oncogenic gene clusters that participate in squamous-cell mitosis is still lacking. We performed a computational analysis with qRT-PCR validation of gene expression profiles of cervical cancer tissues. Genes involved in muscle contraction and development were downregulated in cervical cancer tissues, suggesting decreased muscle function in cervical cancer. Among the genes that were upregulated in cervical cancer tissues, several groups of genes were found to interact with each other and synergistically participate in multiple stages of mitosis including DNA replication, cell cycle progression, and cell division. An analysis of gene regulatory networks showed that replicative helicase proteins (MCM2, MCM4, MCM5, MCM6, and MCM10) and DNA polymerases (PLOA1/E2/E3/Q) have enhanced DNA replication in cervical cancer. A group of kinases, cyclins, and transcriptional factors were found to promote cell cycle transitions from G1 phase to S phase and from G2 phase to M phase. Those proteins included CDK1, CCNA2, CCNB2, and TFDP2. Moreover, a set of motor proteins (KIF11, KIF14 and KIF4A) and their partner PRC1 were found to mediate cytokinesis during cervical cancer progression. Those findings present a better understanding of the mechanism of mitosis in cervical cancer from an interactomic perspective and provide potential targets for anticancer therapies.
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Affiliation(s)
- Jing Cheng
- Reproductive Health Center, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhou 325027, Zhejiang, China
| | - Xiaosheng Lu
- Reproductive Health Center, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhou 325027, Zhejiang, China
| | - Jianguang Wang
- Department of Biochemistry, School of Basic Sciences, Wenzhou Medical UniversityWenzhou 325000, Zhejiang, China
| | - Huina Zhang
- Reproductive Health Center, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhou 325027, Zhejiang, China
| | - Ping Duan
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital and Yuying Children’s Hospital of Wenzhou Medical UniversityWenzhou 325027, Zhejiang, China
| | - Chunyang Li
- Department of Biochemistry, School of Basic Sciences, Wenzhou Medical UniversityWenzhou 325000, Zhejiang, China
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6
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Li CM, Miao Y, Lingeman RG, Hickey RJ, Malkas LH. Partial Purification of a Megadalton DNA Replication Complex by Free Flow Electrophoresis. PLoS One 2016; 11:e0169259. [PMID: 28036377 PMCID: PMC5201288 DOI: 10.1371/journal.pone.0169259] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 12/12/2016] [Indexed: 02/03/2023] Open
Abstract
We describe a gentle and rapid method to purify the intact multiprotein DNA replication complex using free flow electrophoresis (FFE). In particular, we applied FFE to purify the human cell DNA synthesome, which is a multiprotein complex that is fully competent to carry-out all phases of the DNA replication process in vitro using a plasmid containing the simian virus 40 (SV40) origin of DNA replication and the viral large tumor antigen (T-antigen) protein. The isolated native DNA synthesome can be of use in studying the mechanism by which mammalian DNA replication is carried-out and how anti-cancer drugs disrupt the DNA replication or repair process. Partially purified extracts from HeLa cells were fractionated in a native, liquid based separation by FFE. Dot blot analysis showed co-elution of many proteins identified as part of the DNA synthesome, including proliferating cell nuclear antigen (PCNA), DNA topoisomerase I (topo I), DNA polymerase δ (Pol δ), DNA polymerase ɛ (Pol ɛ), replication protein A (RPA) and replication factor C (RFC). Previously identified DNA synthesome proteins co-eluted with T-antigen dependent and SV40 origin-specific DNA polymerase activity at the same FFE fractions. Native gels show a multiprotein PCNA containing complex migrating with an apparent relative mobility in the megadalton range. When PCNA containing bands were excised from the native gel, mass spectrometric sequencing analysis identified 23 known DNA synthesome associated proteins or protein subunits.
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Affiliation(s)
- Caroline M. Li
- Department of Molecular and Cellular Biology, Beckman Research Institute at City of Hope, Duarte, California, United States of America
- * E-mail:
| | - Yunan Miao
- Department of Molecular Medicine, Beckman Research Institute at City of Hope, Duarte, California, United States of America
| | - Robert G. Lingeman
- Department of Molecular and Cellular Biology, Beckman Research Institute at City of Hope, Duarte, California, United States of America
| | - Robert J. Hickey
- Department of Molecular Medicine, Beckman Research Institute at City of Hope, Duarte, California, United States of America
| | - Linda H. Malkas
- Department of Molecular and Cellular Biology, Beckman Research Institute at City of Hope, Duarte, California, United States of America
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7
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Hyun SY, Jang YJ. p53 activates G₁ checkpoint following DNA damage by doxorubicin during transient mitotic arrest. Oncotarget 2016; 6:4804-15. [PMID: 25605022 PMCID: PMC4467116 DOI: 10.18632/oncotarget.3103] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 12/30/2014] [Indexed: 01/05/2023] Open
Abstract
Recovery from DNA damage is critical for cell survival. The serious damage is not able to be repaired during checkpoint and finally induces cell death to prevent abnormal cell growth. In this study, we demonstrated that 8N-DNA contents are accumulated via re-replication during prolonged recovery period containing serious DNA damage in mitotic cells. During the incubation for recovery, a mitotic delay and initiation of an abnormal interphase without cytokinesis were detected. Whereas a failure of cytokinesis occurred in cells with no relation with p53/p21, re-replication is an anomalous phenomenon in the mitotic DNA damage response in p53/p21 negative cells. Cells with wild-type p53 are accumulated just prior to the initiation of DNA replication through a G1 checkpoint after mitotic DNA damage, even though p53 does not interrupt pre-RC assembly. Finally, these cells undergo cell death by apoptosis. These data suggest that p53 activates G1 checkpoint in response to mitotic DNA damage. Without p53, cells with mitotic DNA damage undergo re-replication leading to accumulation of damage
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Affiliation(s)
- Sun-Yi Hyun
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine, Dankook University, Cheonan, Korea
| | - Young-Joo Jang
- Department of Nanobiomedical Science & BK21 PLUS Global Research Center for Regenerative Medicine, Dankook University, Cheonan, Korea
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8
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Chae HD, Mitton B, Lacayo NJ, Sakamoto KM. Replication factor C3 is a CREB target gene that regulates cell cycle progression through the modulation of chromatin loading of PCNA. Leukemia 2015; 29:1379-89. [PMID: 25541153 PMCID: PMC4456282 DOI: 10.1038/leu.2014.350] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 10/04/2014] [Accepted: 11/11/2014] [Indexed: 11/09/2022]
Abstract
CREB (cyclic AMP response element-binding protein) is a transcription factor overexpressed in normal and neoplastic myelopoiesis and regulates cell cycle progression, although its oncogenic mechanism has not been well characterized. Replication factor C3 (RFC3) is required for chromatin loading of proliferating cell nuclear antigen (PCNA) which is a sliding clamp platform for recruiting numerous proteins in the DNA metabolism. CREB1 expression, which was activated by E2F, was coupled with RFC3 expression during the G1/S progression in the KG-1 acute myeloid leukemia (AML) cell line. There was also a direct correlation between the expression of RFC3 and CREB1 in human AML cell lines as well as in the AML cells from the patients. CREB interacted directly with the CRE site in RFC3 promoter region. CREB-knockdown inhibited primarily G1/S cell cycle transition by decreasing the expression of RFC3 as well as PCNA loading onto the chromatin. Exogenous expression of RFC3 was sufficient to rescue the impaired G1/S progression and PCNA chromatin loading caused by CREB knockdown. These studies suggest that RFC3 may have a role in neoplastic myelopoiesis by promoting the G1/S progression and its expression is regulated by CREB.
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MESH Headings
- Blotting, Western
- Cell Cycle/physiology
- Cell Proliferation
- Cell Transformation, Neoplastic/genetics
- Cell Transformation, Neoplastic/metabolism
- Cell Transformation, Neoplastic/pathology
- Chromatin/genetics
- Chromatin Immunoprecipitation
- Cyclic AMP Response Element-Binding Protein/genetics
- Cyclic AMP Response Element-Binding Protein/metabolism
- Flow Cytometry
- Humans
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Proliferating Cell Nuclear Antigen/genetics
- Proliferating Cell Nuclear Antigen/metabolism
- Promoter Regions, Genetic/genetics
- RNA, Messenger/genetics
- Real-Time Polymerase Chain Reaction
- Replication Protein C/genetics
- Replication Protein C/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Tumor Cells, Cultured
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Affiliation(s)
- Hee-Don Chae
- Division of Hematology/Oncology, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305
| | - Bryan Mitton
- Division of Hematology/Oncology, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305
| | - Norman J. Lacayo
- Division of Hematology/Oncology, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305
| | - Kathleen M. Sakamoto
- Division of Hematology/Oncology, Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305
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9
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Zappacosta F, Scott GF, Huddleston MJ, Annan RS. An Optimized Platform for Hydrophilic Interaction Chromatography–Immobilized Metal Affinity Chromatography Enables Deep Coverage of the Rat Liver Phosphoproteome. J Proteome Res 2015; 14:997-1009. [DOI: 10.1021/pr501025e] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Francesca Zappacosta
- Proteomics
and Biological
Mass Spectrometry Laboratory, GlaxoSmithKline, Collegeville, Pennsylvania 19426, United States
| | - Gilbert F. Scott
- Proteomics
and Biological
Mass Spectrometry Laboratory, GlaxoSmithKline, Collegeville, Pennsylvania 19426, United States
| | - Michael J. Huddleston
- Proteomics
and Biological
Mass Spectrometry Laboratory, GlaxoSmithKline, Collegeville, Pennsylvania 19426, United States
| | - Roland S. Annan
- Proteomics
and Biological
Mass Spectrometry Laboratory, GlaxoSmithKline, Collegeville, Pennsylvania 19426, United States
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10
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Ramamoorthi R, Graef KM, Krattiger A, Dent JC. WIPO Re:Search: Catalyzing Collaborations to Accelerate Product Development for Diseases of Poverty. Chem Rev 2014; 114:11272-9. [DOI: 10.1021/cr5000656] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Roopa Ramamoorthi
- BIO Ventures for Global Health, 401 Terry Avenue North, Seattle, Washington 98109, United States
| | - Katy M. Graef
- BIO Ventures for Global Health, 401 Terry Avenue North, Seattle, Washington 98109, United States
| | - Anatole Krattiger
- World Intellectual Property Organization, 34, Chemin des Colombettes, CH-1211 Geneva 20, Switzerland
| | - Jennifer C. Dent
- BIO Ventures for Global Health, 401 Terry Avenue North, Seattle, Washington 98109, United States
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11
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He W, Ma X, Yang X, Zhao Y, Qiu J, Hang H. A role for the arginine methylation of Rad9 in checkpoint control and cellular sensitivity to DNA damage. Nucleic Acids Res 2011; 39:4719-27. [PMID: 21321020 PMCID: PMC3113557 DOI: 10.1093/nar/gkq1264] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The genome stability is maintained by coordinated action of DNA repairs and checkpoints, which delay progression through the cell cycle in response to DNA damage. Rad9 is conserved from yeast to human and functions in cell cycle checkpoint controls. Here, a regulatory mechanism for Rad9 function is reported. In this study Rad9 has been found to interact with and be methylated by protein arginine methyltransferase 5 (PRMT5). Arginine methylation of Rad9 plays a critical role in S/M and G2/M cell cycle checkpoints. The activation of the Rad9 downstream checkpoint effector Chk1 is impaired in cells only expressing a mutant Rad9 that cannot be methylated. Additionally, Rad9 methylation is also required for cellular resistance to DNA damaging stresses. In summary, we uncovered that arginine methylation is important for regulation of Rad9 function, and thus is a major element for maintaining genome integrity.
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Affiliation(s)
- Wei He
- National Laboratory of Biomacromolecules and Center for Computational and Systems Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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12
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The malarial CDK Pfmrk and its effector PfMAT1 phosphorylate DNA replication proteins and co-localize in the nucleus. Mol Biochem Parasitol 2010; 172:9-18. [DOI: 10.1016/j.molbiopara.2010.03.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2009] [Revised: 03/11/2010] [Accepted: 03/12/2010] [Indexed: 11/20/2022]
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13
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Prichard MN. Function of human cytomegalovirus UL97 kinase in viral infection and its inhibition by maribavir. Rev Med Virol 2009; 19:215-29. [PMID: 19434630 DOI: 10.1002/rmv.615] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The serine/threonine kinase expressed by human cytomegalovirus from gene UL97 phosphorylates the antiviral drug ganciclovir, but its biological function is the phosphorylation of its natural viral and cellular protein substrates which affect viral replication at many levels. The UL97 kinase null phenotype is therefore complex, as is the mechanism of action of maribavir, a highly specific inhibitor of its enzymatic activity. Studies that utilise the drug corroborate results from genetic approaches and together have elucidated many functions of the UL97 kinase that are critical for viral replication. The kinase phosphorylates eukaryotic elongation factor 1delta, the carboxyl terminal domain of the large subunit of RNA polymerase II, the retinoblastoma tumour suppressor and lamins A and C. Each of these is also phosphorylated and regulated by cdc2/cyclin-dependent kinase 1, suggesting that the viral kinase may perform a similar function. These and other activities of the UL97 kinase appear to stimulate the cell cycle to support viral DNA synthesis, enhance the expression of viral genes, promote virion morphogenesis and facilitate the egress of mature capsids from the nucleus. In the absence of UL97 kinase activity, viral DNA synthesis is inefficient and structural proteins are sequestered in nuclear aggresomes, reducing the efficiency of virion morphogenesis. Mature capsids that do form fail to egress the nucleus as the nuclear lamina are not dispersed by the kinase. The critical functions performed by the UL97 kinase illustrate its importance in viral replication and confirm that the kinase is a target for the development of antiviral therapies.
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Affiliation(s)
- Mark N Prichard
- Department of Pediatrics, University of Alabama School of Medicine, Birmingham, Alabama 35233, USA.
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14
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Tseng SF, Shen ZJ, Tsai HJ, Lin YH, Teng SC. Rapid Cdc13 turnover and telomere length homeostasis are controlled by Cdk1-mediated phosphorylation of Cdc13. Nucleic Acids Res 2009; 37:3602-11. [PMID: 19359360 PMCID: PMC2699520 DOI: 10.1093/nar/gkp235] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Budding yeast telomerase is mainly activated by Tel1/Mec1 (yeast ATM/ATR) on Cdc13 from late S to G2 phase of the cell cycle. Here, we demonstrated that the telomerase-recruitment domain of Cdc13 is also phosphorylated by Cdk1 at the same cell cycle stage as the Tel1/Mec1-dependent regulation. Phosphor-specific gel analysis demonstrated that Cdk1 phosphorylates residues 308 and 336 of Cdc13. The residue T308 of Cdc13 is critical for efficient Mec1-mediated S306 phosphorylation in vitro. Phenotypic analysis in vivo revealed that the mutations in the Cdc13 S/TP motifs phosphorylated by Cdk1 caused cell cycle delay and telomere shortening and these phenotypes could be partially restored by the replacement with a negative charge residue. In the absence of Ku or Tel1, Cdk1-mediated phosphorylation of Cdc13 showed no effect on telomere length maintenance. Moreover, this Cdk1-mediated phosphorylation was required to promote the regular turnover of Cdc13. Together these results demonstrate that Cdk1 phosphorylates the telomerase recruitment domain of Cdc13, thereby preserves optimal function and expression level of Cdc13 for precise telomere replication and cell cycle progression.
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Affiliation(s)
- Shun-Fu Tseng
- Department of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan
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15
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Gao Y, Zhou Y, Xie B, Zhang S, Rahmeh A, Huang HS, Lee MYWT, Lee EYC. Protein Phosphatase-1 Is Targeted to DNA Polymerase δ via an Interaction with the p68 Subunit. Biochemistry 2008; 47:11367-76. [DOI: 10.1021/bi801122t] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yan Gao
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Yajing Zhou
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Bin Xie
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Sufang Zhang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Amal Rahmeh
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Hua-shan Huang
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Marietta Y. W. T. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
| | - Ernest Y. C. Lee
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595
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16
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Tsuji T, Ficarro SB, Jiang W. Essential role of phosphorylation of MCM2 by Cdc7/Dbf4 in the initiation of DNA replication in mammalian cells. Mol Biol Cell 2006; 17:4459-72. [PMID: 16899510 PMCID: PMC1635350 DOI: 10.1091/mbc.e06-03-0241] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
We report the identification of Cdc7/Dbf4 phosphorylation sites in human MCM2 and the determination of the role of Cdc7/Dbf4 phosphorylation of MCM2 in the initiation of DNA replication. Using immunoblotting, immunofluorescence, and high-speed automated cell-imaging analyses with antibodies specific against MCM2 and Cdc7/Dbf4 phosphorylated MCM2, we show that the chromatin recruitment and phosphorylation of MCM2 are regulated during the cell cycle in HeLa cells. Chromatin-bound MCM2 is phosphorylated by Cdc7/Dbf4 during G1/S, which coincides with the initiation of DNA replication. Moreover, we show that baculovirus-expressed purified MCM2-7 complex and its phosphomimetic MCM2E-7 complex display higher ATPase activity when compared with the nonphosphorylatable MCM2A-7 complex in vitro. Furthermore, suppression of MCM2 expression in HeLa cells by siRNA results in the inhibition of DNA replication. The inhibition can be rescued by the coexpression of wild type MCM2 or MCM2E but not MCM2A. Taken together, these results indicate that Cdc7/Dbf4 phosphorylation of MCM2 is essential for the initiation of DNA replication in mammalian cells.
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Affiliation(s)
- Toshiya Tsuji
- *The Burnham Institute for Medical Research, La Jolla, CA 92037; and
| | - Scott B. Ficarro
- Genomics Institute of the Novartis Research Foundation, San Diego, CA 92121
| | - Wei Jiang
- *The Burnham Institute for Medical Research, La Jolla, CA 92037; and
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17
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Rossi ML, Purohit V, Brandt PD, Bambara RA. Lagging strand replication proteins in genome stability and DNA repair. Chem Rev 2006; 106:453-73. [PMID: 16464014 DOI: 10.1021/cr040497l] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Marie L Rossi
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, New York 14642, USA
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18
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Iizuka M, Matsui T, Takisawa H, Smith MM. Regulation of replication licensing by acetyltransferase Hbo1. Mol Cell Biol 2006; 26:1098-108. [PMID: 16428461 PMCID: PMC1347032 DOI: 10.1128/mcb.26.3.1098-1108.2006] [Citation(s) in RCA: 155] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The initiation of DNA replication is tightly regulated in eukaryotic cells to ensure that the genome is precisely duplicated once and only once per cell cycle. This is accomplished by controlling the assembly of a prereplicative complex (pre-RC) which involves the sequential binding to replication origins of the origin recognition complex (ORC), Cdc6/Cdc18, Cdt1, and the minichromosome maintenance complex (Mcm2-Mcm7, or Mcm2-7). Several mechanisms of pre-RC regulation are known, including ATP utilization, cyclin-dependent kinase levels, protein turnover, and Cdt1 binding by geminin. Histone acetylation may also affect the initiation of DNA replication, but at present neither the enzymes nor the steps involved are known. Here, we show that Hbo1, a member of the MYST histone acetyltransferase family, is a previously unrecognized positive regulatory factor for pre-RC assembly. When Hbo1 expression was inhibited in human cells, Mcm2-7 failed to associate with chromatin even though ORC and Cdc6 loading was normal. When Xenopus egg extracts were immunodepleted of Xenopus Hbo1 (XHbo1), chromatin binding of Mcm2-7 was lost, and DNA replication was abolished. The binding of Mcm2-7 to chromatin in XHbo1-depleted extracts could be restored by the addition of recombinant Cdt1.
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Affiliation(s)
- Masayoshi Iizuka
- Department of Microbiology, University of Virginia Health System, P.O. Box 800734, Charlottesville, VA 22908-0734, USA
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19
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Frouin I, Toueille M, Ferrari E, Shevelev I, Hübscher U. Phosphorylation of human DNA polymerase lambda by the cyclin-dependent kinase Cdk2/cyclin A complex is modulated by its association with proliferating cell nuclear antigen. Nucleic Acids Res 2005; 33:5354-61. [PMID: 16174846 PMCID: PMC1226315 DOI: 10.1093/nar/gki845] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
DNA polymerase (Pol) lambda is a member of the Pol X family and possesses four different enzymatic activities, being DNA polymerase, terminal transferase, deoxyribose phosphate lyase and polynucleotide synthetase, all localized in its C-terminal region. On the basis of its biochemical properties, Pol lambda has been implicated in various DNA repair pathways, such as abasic site translesion DNA synthesis, base excision repair and non-homologous end joining of double strand breaks. However, its role in vivo has not yet been elucidated. In addition, Pol lambda has been shown to interact with the replication clamp proliferating cell nuclear antigen (PCNA) in vitro and in vivo. In this work, we searched by affinity chromatography for novel partners and we identified the cyclin-dependent kinase Cdk2 as novel partner of Pol lambda. Pol lambda is phosphorylated in vitro by several Cdk/cyclin complexes, including Cdk2/cyclin A, in its proline-serine-rich domain. While the polymerase activity of Pol lambda was not affected by Cdk2/cyclin A phosphorylation, phosphorylation of Pol lambda was decreased by its interaction with PCNA. Finally, Pol lambda is also phosphorylated in vivo in human cells and this phosphorylation is modulated during the cell cycle.
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Affiliation(s)
| | | | | | | | - Ulrich Hübscher
- To whom correspondence should be addressed. Tel: + 41 16 35 54 72/71; Fax: +41 16 35 68 40;
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20
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Savas S, Ozcelik H. Phosphorylation states of cell cycle and DNA repair proteins can be altered by the nsSNPs. BMC Cancer 2005; 5:107. [PMID: 16111488 PMCID: PMC1208866 DOI: 10.1186/1471-2407-5-107] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2004] [Accepted: 08/19/2005] [Indexed: 01/20/2023] Open
Abstract
Background Phosphorylation is a reversible post-translational modification that affects the intrinsic properties of proteins, such as structure and function. Non-synonymous single nucleotide polymorphisms (nsSNPs) result in the substitution of the encoded amino acids and thus are likely to alter the phosphorylation motifs in the proteins. Methods In this study, we used the web-based NetPhos tool to predict candidate nsSNPs that either introduce or remove putative phosphorylation sites in proteins that act in DNA repair and cell cycle pathways. Results Our results demonstrated that a total of 15 nsSNPs (16.9%) were likely to alter the putative phosphorylation patterns of 14 proteins. Three of these SNPs (CDKN1A-S31R, OGG1-S326C, and XRCC3-T241M) have already found to be associated with altered cancer risk. We believe that this set of nsSNPs constitutes an excellent resource for further molecular and genetic analyses. Conclusion The novel systematic approach used in this study will accelerate the understanding of how naturally occurring human SNPs may alter protein function through the modification of phosphorylation mechanisms and contribute to disease susceptibility.
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Affiliation(s)
- Sevtap Savas
- Fred A. Litwin Centre for Cancer Genetics, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, M5G 1X5, ON, Canada
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, M5G 1X5, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, M5G 1L5, Toronto, ON, Canada
| | - Hilmi Ozcelik
- Fred A. Litwin Centre for Cancer Genetics, Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, M5G 1X5, ON, Canada
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, M5G 1X5, ON, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, M5G 1L5, Toronto, ON, Canada
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21
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Xie B, Li H, Wang Q, Xie S, Rahmeh A, Dai W, Lee MYWT. Further Characterization of Human DNA Polymerase δ Interacting Protein 38. J Biol Chem 2005; 280:22375-84. [PMID: 15811854 DOI: 10.1074/jbc.m414597200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Polymerase delta interacting protein 38 (PDIP38) was identified as a human DNA polymerase (pol) delta interacting protein through a direct interaction with p50, the small subunit of human pol delta. PDIP38 was also found to interact with proliferating cell nuclear antigen, which suggested that it might play a role in vivo in the processes of DNA replication and DNA repair in the nucleus. In order to characterize further this novel protein, we have examined its subcellular localization by the use of immunochemical and cellular fractionation techniques. These studies show that PDIP38 is a novel mitochondrial protein and is localized mainly to the mitochondria. PDIP38 was shown to possess a functional mitochondrial targeting sequence that is located within the first 35 N-terminal amino acid residues. The mature PDIP38 protein is about 50 amino acid residues smaller than the full-length precursor PDIP38 protein, consistent with it being processed by cleavage of the mitochondrial targeting sequence during entry into the mitochondria. His-tagged mature PDIP38 inhibited pol delta activity in vitro and interacted with human papillomavirus 16 E7 oncoprotein, suggesting that PDIP38 might play a role in the pol delta-mediated viral DNA replication. Although the localization of PDIP38 to the mitochondria suggests that it serves functions within the mitochondria, we cannot eliminate the possibility that it may be involved in pol delta-mediated DNA replication or DNA repair under certain conditions such as viral infection.
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Affiliation(s)
- Bin Xie
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
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22
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Toueille M, Hübscher U. Regulation of the DNA replication fork: a way to fight genomic instability. Chromosoma 2004; 113:113-25. [PMID: 15300444 DOI: 10.1007/s00412-004-0303-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2004] [Revised: 06/15/2004] [Accepted: 06/17/2004] [Indexed: 12/18/2022]
Abstract
DNA replication is a complex mechanism that functions due to the coordinated interplay of many factors. In the last few years, numerous studies have suggested that DNA replication factors are closely implicated in several DNA transaction events that maintain the integrity of the genome. Therefore, DNA replication fork factors have to be considered as part of a general process that aims to protect and replicate the genome in order to allow correct functioning of a cell and its eventual daughter cells. This is illustrated by the numerous factors that have a well-defined function at the DNA replication fork, but also play crucial roles in different DNA repair pathways such as base excision repair, nucleotide excision repair, double-strand break repair, and mismatch repair. Moreover, several of the replisome proteins have also been shown to be essential in sensing and transducing DNA damages through the checkpoint cascade pathways, including the recently characterised alternative clamps and clamp-loaders. In this review we present DNA replication factors that are involved in different DNA transaction and checkpoint regulation pathways, with emphasis on the link between DNA replication and maintenance of genomic stability.
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Affiliation(s)
- Magali Toueille
- Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich-Irchel, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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23
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Granja AG, Nogal ML, Hurtado C, Salas J, Salas ML, Carrascosa AL, Revilla Y. Modulation of p53 cellular function and cell death by African swine fever virus. J Virol 2004; 78:7165-74. [PMID: 15194793 PMCID: PMC421689 DOI: 10.1128/jvi.78.13.7165-7174.2004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Modulation of the activity of tumor suppressor p53 is a key event in the replication of many viruses. We have studied the function of p53 in African swine fever virus (ASFV) infection by determining the expression and activity of this transcription factor in infected cells. p53 levels are increased at early times of infection and are maintained throughout the infectious cycle. The protein is transcriptionally active, stabilized by phosphorylation, and localized in the nucleus. p53 induces the expression of p21 and Mdm2. Strikingly, these two proteins are located at the cytoplasmic virus factories. The retention of Mdm2 at the factory may represent a viral mechanism to prevent p53 inactivation by the protein. The expression of apoptotic proteins, such as Bax or active caspase-3, is also increased following ASFV infection, although the increase in caspase-3 does not appear to be, at least exclusively, p53 dependent. Bax probably plays a role in the induction of apoptosis in the infected cells, as suggested by the release of cytochrome c from the mitochondria. The significance of p21 induction and localization is discussed in relation to the shutoff of cellular DNA synthesis that is observed in ASFV-infected cells.
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Affiliation(s)
- Aitor G Granja
- Centro de Biología Molecular Severo Ochoa, Universidad Autonoma, Cantoblanco, 28049 Madrid, Spain
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24
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Prasanth SG, Méndez J, Prasanth KV, Stillman B. Dynamics of pre-replication complex proteins during the cell division cycle. Philos Trans R Soc Lond B Biol Sci 2004; 359:7-16. [PMID: 15065651 PMCID: PMC1693299 DOI: 10.1098/rstb.2003.1360] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Replication of the human genome every time a cell divides is a highly coordinated process that ensures accurate and efficient inheritance of the genetic information. The molecular mechanism that guarantees that many origins of replication fire only once per cell-cycle has been the area of intense research. The origin recognition complex (ORC) marks the position of replication origins in the genome and serves as the landing pad for the assembly of a multiprotein, pre-replicative complex (pre-RC) at the origins, consisting of ORC, cell division cycle 6 (Cdc6), Cdc10-dependent transcript (Cdt1) and mini-chromosome maintenance (MCM) proteins. The MCM proteins serve as key participants in the mechanism that limits eukaryotic DNA replication to once-per-cell-cycle and its binding to the chromatin marks the final step of pre-RC formation, a process referred to as 'replication licensing'. We present data demonstrating how the MCM proteins associate with the chromatin during the G1 phase, probably defining pre-RCs and then anticipate replication fork movement in a precisely coordinated manner during the S phase of the cell cycle. The process of DNA replication must also be carefully coordinated with other cell-cycle processes including mitosis and cytokinesis. Some of the proteins that control initiation of DNA replication are likely to interact with the pathways that control these important cell-cycle transitions. Herein, we discuss the participation of human ORC proteins in other vital functions, in addition to their bona fide roles in replication.
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Affiliation(s)
- Supriya G Prasanth
- Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
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25
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Kesti T, McDonald WH, Yates JR, Wittenberg C. Cell Cycle-dependent Phosphorylation of the DNA Polymerase Epsilon Subunit, Dpb2, by the Cdc28 Cyclin-dependent Protein Kinase. J Biol Chem 2004; 279:14245-55. [PMID: 14747467 DOI: 10.1074/jbc.m313289200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
DNA polymerase epsilon (Polepsilon), one of the three major eukaryotic replicative polymerases, is comprised of the essential catalytic subunit, called Pol2 in budding yeast, and three accessory subunits, only one of which, Dpb2, is essential. Polepsilon is recruited to replication origins during late G(1) phase prior to activation of replication. In this work we show that the budding yeast Dpb2 is phosphorylated in a cell cycle-dependent manner during late G(1) phase. Phosphorylation results in the appearance of a lower mobility species. The appearance of that species in vivo is dependent upon the Cdc28 cyclin-dependent protein kinase (CDK), which can directly phosphorylate Dpb2 in vitro. Either G(1) cyclin (Cln) or B-type cyclin (Clb)-associated CDK is sufficient for phosphorylation. Mapping of phosphorylation sites by mass spectrometry using a novel gel-based proteolysis protocol shows that, of the three consensus CDK phosphorylation sites, at least two, Ser-144 and Ser-616, are phosphorylated in vivo. The Cdc28 CDK phosphorylates only Ser-144 in vitro. Using site-directed mutagenesis, we show that Ser-144 is sufficient for the formation of the lower mobility form of Dpb2 in vivo. In contrast, Ser-616 appears not to be phosphorylated by Cdc28. Finally, inactivation of all three CDK consensus sites in Dpb2 results in a synthetic phenotype with the pol2-11 mutation, leading to decreased spore viability, slow growth, and increased thermosensitivity. We suggest that phosphorylation of Dpb2 during late G(1) phase at CDK consensus sites facilitates the interaction with Pol2 or the activity of Polepsilon
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Affiliation(s)
- Tapio Kesti
- Departments of Molecular Biology and Cell Biology, The Scripps Research Institute, La Jolla, California 92037, USA
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26
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Abstract
The minichromosome maintenance (or MCM) protein family is composed of six related proteins that are conserved in all eukaryotes. They were first identified by genetic screens in yeast and subsequently analyzed in other experimental systems using molecular and biochemical methods. Early data led to the identification of MCMs as central players in the initiation of DNA replication. More recent studies have shown that MCM proteins also function in replication elongation, probably as a DNA helicase. This is consistent with structural analysis showing that the proteins interact together in a heterohexameric ring. However, MCMs are strikingly abundant and far exceed the stoichiometry of replication origins; they are widely distributed on unreplicated chromatin. Analysis of mcm mutant phenotypes and interactions with other factors have now implicated the MCM proteins in other chromosome transactions including damage response, transcription, and chromatin structure. These experiments indicate that the MCMs are central players in many aspects of genome stability.
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Affiliation(s)
- Susan L Forsburg
- Molecular & Cell Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA.
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27
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Ferrari G, Rossi R, Arosio D, Vindigni A, Biamonti G, Montecucco A. Cell cycle-dependent phosphorylation of human DNA ligase I at the cyclin-dependent kinase sites. J Biol Chem 2003; 278:37761-7. [PMID: 12851383 DOI: 10.1074/jbc.m304462200] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have described previously that, during S-phase, human DNA ligase I is phosphorylated on Ser66, a casein kinase II site. Here we investigate the phosphorylation status of DNA ligase I during the cell cycle by gel shift analysis and electrospray mass spectrometry. We show that three residues (Ser51, Ser76, and Ser91), which are part of cyclin-dependent kinase sites, are phosphorylated in a cell cycle-dependent manner. Phosphorylation of Ser91 occurs at G1/S transition and depends on a cyclin binding site in the C-terminal part of the protein. This modification is required for the ensuing phosphorylation of Ser76 detectable in G2/M extracts. The substitution of serines at positions 51, 66, 76, and 91 with aspartic acid to mimic the phosphorylated enzyme hampers the association of DNA ligase I with the replication foci. We suggest that the phosphorylation of DNA ligase I and possibly other replicative enzymes is part of the mechanism that directs the disassembly of the replication machinery at the completion of S-phase.
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Affiliation(s)
- Giovanni Ferrari
- Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerche, via Abbiategrasso 207, 27100 Pavia, Italy
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28
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Henneke G, Koundrioukoff S, Hübscher U. Phosphorylation of human Fen1 by cyclin-dependent kinase modulates its role in replication fork regulation. Oncogene 2003; 22:4301-13. [PMID: 12853968 DOI: 10.1038/sj.onc.1206606] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cyclin-dependent kinase (Cdk) Cdk1-Cyclin A can phosphorylate Flap endonuclease 1 (Fen1), a key-enzyme of the DNA replication machinery, in late S phase. Cdk1-cyclin A forms a complex in vitro and in vivo with Fen1. Furthermore, Fen1 phosphorylation is detected in vivo and depends upon Cdks activity. As a functional consequence of phosphorylation by Cdk1-Cyclin A in vitro, endo- and exonuclease activities of Fen1 are reduced whereas its DNA binding is not affected. Moreover, phosphorylation of Fen1 by Cdk1-Cyclin A abrogates its proliferating cell nuclear antigen (PCNA) binding thus preventing stimulation of Fen1 by PCNA. Concomitantly, human cells expressing the S187A mutant defective for Cdk1-Cyclin A phosphorylation accumulate in S phase consistent with a failure in cell cycle regulation through DNA replication. Our results suggest a novel regulatory role of Cdks onto the end of S phase by targeting directly a key enzyme involved in DNA replication.
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Affiliation(s)
- Ghislaine Henneke
- Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
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