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Choi Y, Yu SR, Lee Y, Na AY, Lee S, Heitman J, Seo R, Lee HS, Lee JS, Bahn YS. Casein kinase 2 complex: a central regulator of multiple pathobiological signaling pathways in Cryptococcus neoformans. mBio 2024; 15:e0327523. [PMID: 38193728 PMCID: PMC10865844 DOI: 10.1128/mbio.03275-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 12/11/2023] [Indexed: 01/10/2024] Open
Abstract
The casein kinase 2 (CK2) complex has garnered extensive attention over the past decades as a potential therapeutic target for diverse human diseases, including cancer, diabetes, and obesity, due to its pivotal roles in eukaryotic growth, differentiation, and metabolic homeostasis. While CK2 is also considered a promising antifungal target, its role in fungal pathogens remains unexplored. In this study, we investigated the functions and regulatory mechanisms of the CK2 complex in Cryptococcus neoformans, a major cause of fungal meningitis. The cryptococcal CK2 complex consists of a single catalytic subunit, Cka1, and two regulatory subunits, Ckb1 and Ckb2. Our findings show that Cka1 plays a primary role as a protein kinase, while Ckb1 and Ckb2 have major and minor regulatory functions, respectively, in growth, cell cycle control, morphogenesis, stress response, antifungal drug resistance, and virulence factor production. Interestingly, triple mutants lacking all three subunits (cka1Δ ckb1Δ ckb2Δ) exhibited more severe phenotypic defects than the cka1Δ mutant alone, suggesting that Ckb1/2 may have Cka1-independent functions. In a murine model of systemic cryptococcosis, cka1Δ and cka1Δ ckb1Δ ckb2Δ mutants showed severely reduced virulence. Transcriptomic, proteomic, and phosphoproteomic analyses further revealed that the CK2 complex controls a wide array of effector proteins involved in transcriptional regulation, cell cycle control, nutrient metabolisms, and stress responses. Most notably, CK2 disruption led to dysregulation of key signaling cascades central to C. neoformans pathogenicity, including the Hog1, Mpk1 MAPKs, cAMP/PKA, and calcium/calcineurin signaling pathways. In summary, our study provides novel insights into the multifaceted roles of the fungal CK2 complex and presents a compelling case for targeting it in the development of new antifungal drugs.IMPORTANCEThe casein kinase 2 (CK2) complex, crucial for eukaryotic growth, differentiation, and metabolic regulation, presents a promising therapeutic target for various human diseases, including cancer, diabetes, and obesity. Its potential as an antifungal target is further highlighted in this study, which explores CK2's functions in C. neoformans, a key fungal meningitis pathogen. The CK2 complex in C. neoformans, comprising the Cka1 catalytic subunit and Ckb1/2 regulatory subunits, is integral to processes like growth, cell cycle, morphogenesis, stress response, drug resistance, and virulence. Our findings of CK2's role in regulating critical signaling pathways, including Hog1, Mpk1 MAPKs, cAMP/PKA, and calcium/calcineurin, underscore its importance in C. neoformans pathogenicity. This study provides valuable insights into the fungal CK2 complex, reinforcing its potential as a target for novel antifungal drug development and pointing out a promising direction for creating new antifungal agents.
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Affiliation(s)
- Yeseul Choi
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Seong-Ryong Yu
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Yujin Lee
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - Ann-Yae Na
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Sangkyu Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, South Korea
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, USA
| | - Ran Seo
- AmtixBio Co., Ltd., Hanam-si, Gyeonggi-do, South Korea
| | - Han-Seung Lee
- AmtixBio Co., Ltd., Hanam-si, Gyeonggi-do, South Korea
| | | | - Yong-Sun Bahn
- Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
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2
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Minor Kinases with Major Roles in Cytokinesis Regulation. Cells 2022; 11:cells11223639. [PMID: 36429067 PMCID: PMC9688779 DOI: 10.3390/cells11223639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/07/2022] [Accepted: 11/14/2022] [Indexed: 11/18/2022] Open
Abstract
Cytokinesis, the conclusive act of cell division, allows cytoplasmic organelles and chromosomes to be faithfully partitioned between two daughter cells. In animal organisms, its accurate regulation is a fundamental task for normal development and for preventing aneuploidy. Cytokinesis failures produce genetically unstable tetraploid cells and ultimately result in chromosome instability, a hallmark of cancer cells. In animal cells, the assembly and constriction of an actomyosin ring drive cleavage furrow ingression, resulting in the formation of a cytoplasmic intercellular bridge, which is severed during abscission, the final event of cytokinesis. Kinase-mediated phosphorylation is a crucial process to orchestrate the spatio-temporal regulation of the different stages of cytokinesis. Several kinases have been described in the literature, such as cyclin-dependent kinase, polo-like kinase 1, and Aurora B, regulating both furrow ingression and/or abscission. However, others exist, with well-established roles in cell-cycle progression but whose specific role in cytokinesis has been poorly investigated, leading to considering these kinases as "minor" actors in this process. Yet, they deserve additional attention, as they might disclose unexpected routes of cell division regulation. Here, we summarize the role of multifunctional kinases in cytokinesis with a special focus on those with a still scarcely defined function during cell cleavage. Moreover, we discuss their implication in cancer.
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3
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Wang G, Gao G, Yang X, Yang X, Ma P. Casein kinase CK2 structure and activities in plants. JOURNAL OF PLANT PHYSIOLOGY 2022; 276:153767. [PMID: 35841742 DOI: 10.1016/j.jplph.2022.153767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/10/2022] [Accepted: 07/10/2022] [Indexed: 06/15/2023]
Abstract
Casein kinase CK2 is a highly conserved serine/threonine protein kinase and exists in all eukaryotes. It has been demonstrated to be widely involved in the biological processes of plants. The CK2 holoenzyme is a heterotetramer consisting of two catalytic subunits (α and/or α') and two regulatory subunits (β). CK2 in plants is generally encoded by multiple genes, with monomeric and oligomeric forms present in the tissue. Various subunit genes of CK2 have been cloned and characterized from Arabidopsis thaliana, tobacco, maize, wheat, tomato, and other plants. This paper reviews the structural features of CK2, provides a clear classification of its physiological functions and mechanisms of action, and elaborates on the regulation of CK2 activity to provide a knowledge base for subsequent studies of CK2 in plants.
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Affiliation(s)
- Guanfeng Wang
- College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Geling Gao
- College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Xiangna Yang
- College of Life Sciences, Northwest A&F University, Yangling, 712100, China
| | - Xiangdong Yang
- Institute of Agricultural Biotechnology, Jilin Academy of Agricultural Sciences, Changchun, 130033, China.
| | - Pengda Ma
- College of Life Sciences, Northwest A&F University, Yangling, 712100, China.
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4
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Gyenis L, Menyhart D, Cruise ES, Jurcic K, Roffey SE, Chai DB, Trifoi F, Fess SR, Desormeaux PJ, Núñez de Villavicencio Díaz T, Rabalski AJ, Zukowski SA, Turowec JP, Pittock P, Lajoie G, Litchfield DW. Chemical Genetic Validation of CSNK2 Substrates Using an Inhibitor-Resistant Mutant in Combination with Triple SILAC Quantitative Phosphoproteomics. Front Mol Biosci 2022; 9:909711. [PMID: 35755813 PMCID: PMC9225150 DOI: 10.3389/fmolb.2022.909711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/02/2022] [Indexed: 11/16/2022] Open
Abstract
Casein Kinase 2 (CSNK2) is an extremely pleiotropic, ubiquitously expressed protein kinase involved in the regulation of numerous key biological processes. Mapping the CSNK2-dependent phosphoproteome is necessary for better characterization of its fundamental role in cellular signalling. While ATP-competitive inhibitors have enabled the identification of many putative kinase substrates, compounds targeting the highly conserved ATP-binding pocket often exhibit off-target effects limiting their utility for definitive kinase-substrate assignment. To overcome this limitation, we devised a strategy combining chemical genetics and quantitative phosphoproteomics to identify and validate CSNK2 substrates. We engineered U2OS cells expressing exogenous wild type CSNK2A1 (WT) or a triple mutant (TM, V66A/H160D/I174A) with substitutions at residues important for inhibitor binding. These cells were treated with CX-4945, a clinical-stage inhibitor of CSNK2, and analyzed using large-scale triple SILAC (Stable Isotope Labelling of Amino Acids in Cell Culture) quantitative phosphoproteomics. In contrast to wild-type CSNK2A1, CSNK2A1-TM retained activity in the presence of CX-4945 enabling identification and validation of several CSNK2 substrates on the basis of their increased phosphorylation in cells expressing CSNK2A1-TM. Based on high conservation within the kinase family, we expect that this strategy can be broadly adapted for identification of other kinase-substrate relationships.
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Affiliation(s)
- Laszlo Gyenis
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Daniel Menyhart
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Edward S Cruise
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Kristina Jurcic
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Scott E Roffey
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Darren B Chai
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Flaviu Trifoi
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Sam R Fess
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Paul J Desormeaux
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | | | - Adam J Rabalski
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Stephanie A Zukowski
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Jacob P Turowec
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Paula Pittock
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - Gilles Lajoie
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
| | - David W Litchfield
- Department of Biochemistry, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.,Department of Oncology, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada
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5
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Guerra B, Doktor TK, Frederiksen SB, Somyajit K, Andresen BS. Essential role of CK2α for the interaction and stability of replication fork factors during DNA synthesis and activation of the S-phase checkpoint. Cell Mol Life Sci 2022; 79:339. [PMID: 35661926 PMCID: PMC9166893 DOI: 10.1007/s00018-022-04374-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 05/09/2022] [Accepted: 05/12/2022] [Indexed: 11/25/2022]
Abstract
The ataxia telangiectasia mutated and Rad3-related (ATR)-CHK1 pathway is the major signalling cascade activated in response to DNA replication stress. This pathway is associated with the core of the DNA replication machinery comprising CDC45, the replicative MCM2-7 hexamer, GINS (altogether forming the CMG complex), primase-polymerase (POLε, -α, and -δ) complex, and additional fork protection factors such as AND-1, CLASPIN (CLSPN), and TIMELESS/TIPIN. In this study, we report that functional protein kinase CK2α is critical for preserving replisome integrity and for mounting S-phase checkpoint signalling. We find that CDC45, CLSPN and MCM7 are novel CK2α interacting partners and these interactions are particularly important for maintenance of stable MCM7-CDC45, ATRIP-ATR-MCM7, and ATR-CLSPN protein complexes. Consistently, cells depleted of CK2α and treated with hydroxyurea display compromised replisome integrity, reduced chromatin binding of checkpoint mediator CLSPN, attenuated ATR-mediated S-phase checkpoint and delayed recovery of stalled forks. In further support of this, differential gene expression analysis by RNA-sequencing revealed that down-regulation of CK2α accompanies global shutdown of genes that are implicated in the S-phase checkpoint. These findings add to our understanding of the molecular mechanisms involved in DNA replication by showing that the protein kinase CK2α is essential for maintaining the stability of the replisome machinery and for optimizing ATR-CHK1 signalling activation upon replication stress.
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Affiliation(s)
- Barbara Guerra
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
| | - Thomas K Doktor
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Sabrina B Frederiksen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Kumar Somyajit
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
| | - Brage S Andresen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
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6
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The Immune Regulatory Role of Protein Kinase CK2 and Its Implications for Treatment of Cancer. Biomedicines 2021; 9:biomedicines9121932. [PMID: 34944749 PMCID: PMC8698504 DOI: 10.3390/biomedicines9121932] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 01/15/2023] Open
Abstract
Protein Kinase CK2, a constitutively active serine/threonine kinase, fulfills its functions via phosphorylating hundreds of proteins in nearly all cells. It regulates a variety of cellular signaling pathways and contributes to cell survival, proliferation and inflammation. CK2 has been implicated in the pathogenesis of hematologic and solid cancers. Recent data have documented that CK2 has unique functions in both innate and adaptive immune cells. In this article, we review aspects of CK2 biology, functions of the major innate and adaptive immune cells, and how CK2 regulates the function of immune cells. Finally, we provide perspectives on how CK2 effects in immune cells, particularly T-cells, may impact the treatment of cancers via targeting CK2.
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Husain K, Williamson TT, Nelson N, Ghansah T. Protein kinase 2 (CK2): a potential regulator of immune cell development and function in cancer. Immunol Med 2020; 44:159-174. [PMID: 33164702 DOI: 10.1080/25785826.2020.1843267] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Protein kinase CK2, formally known as casein kinase II, is ubiquitously expressed and highly conserved serine/threonine or tyrosine kinase enzyme that regulates diverse signaling pathways responsible for cellular processes (i.e., cell proliferation and apoptosis) via interactions with over 500 known substrates. The enzyme's physiological interactions and cellular functions have been widely studied, most notably in the blood and solid malignancies. CK2 has intrinsic role in carcinogenesis as overexpression of CK2 subunits (α, α`, and β) and deregulation of its activity have been linked to various forms of cancers. CK2 also has extrinsic role in cancer stroma or in the tumor microenvironment (TME) including the immune cells. However, very few research studies have focused on extrinsic role of CK2 in regulating immune responses as a therapeutic alternative for cancer. The following review discusses CK2's regulation of key signaling events [Nuclear factor kappa B (NF-κB), Janus kinase/signal transducer and activators of transcription (JAK/STAT), Hypoxia inducible factor-1alpha (HIF-1α), Cyclooygenase-2 (COX-2), Extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK), Notch, Protein kinase B/AKT, Ikaros and Wnt] that can influence the development and function of immune cells in cancer. Potential clinical trials using potent CK2 inhibitors will facilitate and improve the treatment of human malignancies.
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Affiliation(s)
- Kazim Husain
- Department of Molecular Medicine, University of South Florida, Tampa, FL, USA
| | - Tanika T Williamson
- Department of Molecular Medicine, University of South Florida, Tampa, FL, USA
| | - Nadine Nelson
- Department of Molecular Medicine, University of South Florida, Tampa, FL, USA
| | - Tomar Ghansah
- Department of Molecular Medicine, University of South Florida, Tampa, FL, USA
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8
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Down-regulation of CK2α correlates with decreased expression levels of DNA replication minichromosome maintenance protein complex (MCM) genes. Sci Rep 2019; 9:14581. [PMID: 31601942 PMCID: PMC6787000 DOI: 10.1038/s41598-019-51056-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 06/12/2019] [Indexed: 11/12/2022] Open
Abstract
Protein kinase CK2 is a serine/threonine kinase composed of two catalytic subunits (CK2α and/or CK2α’) and two regulatory subunits (CK2β). It is implicated in every stage of the cell cycle and in the regulation of various intracellular pathways associated with health and disease states. The catalytic subunits have similar biochemical activity, however, their functions may differ significantly in cells and in vivo. In this regard, homozygous deletion of CK2α leads to embryonic lethality in mid-gestation potentially due to severely impaired cell proliferation. To determine the CK2α-dependent molecular mechanisms that control cell proliferation, we established a myoblast-derived cell line with inducible silencing of CK2α and carried out a comprehensive RNA-Seq analysis of gene expression. We report evidence that CK2α depletion causes delayed cell cycle progression through the S-phase and defective response to replication stress. Differential gene expression analysis revealed that the down-regulated genes were enriched in pathways implicated in cell cycle regulation, DNA replication and DNA damage repair. Interestingly, the genes coding for the minichromosome maintenance proteins (MCMs), which constitute the core of the replication origin recognition complex, were among the most significantly down-regulated genes. These findings were validated in cells and whole mouse embryos. Taken together, our study provides new evidence for a critical role of protein kinase CK2 in controlling DNA replication initiation and the expression levels of replicative DNA helicases, which ensure maintenance of proliferative potential and genome integrity in eukaryotic cells.
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Li Q, Li K, Zhang S, Zhou Y, Hong J, Zhou X, Li Z, Wu B, Wu G, Meng R. The effect of ionizing radiation on the subcellular localization and kinase activity of protein kinase CK2 in human non-small cell lung cancer cells. Int J Radiat Biol 2019; 95:1462-1471. [PMID: 31290713 DOI: 10.1080/09553002.2019.1642531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Protein kinase CK2 is a ubiquitously expressed kinase in eukaryotes, which is known to phosphorylate many protein substrates. Because CK2 is involved in the regulation of various signaling pathways, we wondered whether CK2 participated in the regulation of ionizing radiation (IR) induced biological process. In this study, we investigated the effect of IR on the subcellular localization and kinase activity in human non-small cell lung cancer (NSCLC) cells. Immunofluorescent results showed that CK2 subunits shuttle into the nucleus mostly beginning 1 h after IR and lasting more than 6 h. We also conducted in vitro kinase assay and observed an increase in CK2 kinase activity at 6 h after IR. Furthermore, an increase in S phase was observed at 6 h after IR. Colony formation assay results demonstrated that CK2 inhibitor CX-4945 significantly enhanced the effect of irradiation in NSCLC cells. These results indicated that CK2 may be implicated in the regulation of IR-induced biological process.
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Affiliation(s)
- Qianwen Li
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ke Li
- Pharmacy Department, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Sheng Zhang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yu Zhou
- Department of Nuclear Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiaxin Hong
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoshu Zhou
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhenyu Li
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bian Wu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gang Wu
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Rui Meng
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Franchin C, Borgo C, Cesaro L, Zaramella S, Vilardell J, Salvi M, Arrigoni G, Pinna LA. Re-evaluation of protein kinase CK2 pleiotropy: new insights provided by a phosphoproteomics analysis of CK2 knockout cells. Cell Mol Life Sci 2018; 75:2011-2026. [PMID: 29119230 PMCID: PMC11105740 DOI: 10.1007/s00018-017-2705-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/28/2017] [Accepted: 10/30/2017] [Indexed: 10/18/2022]
Abstract
CK2 denotes a ubiquitous and pleiotropic protein kinase whose holoenzyme is composed of two catalytic (α and/or α') and two regulatory β subunits. The CK2 consensus sequence, S/T-x-x-D/E/pS/pT is present in numerous phosphosites, but it is not clear how many of these are really generated by CK2. To gain information about this issue, advantage has been taken of C2C12 cells entirely deprived of both CK2 catalytic subunits by the CRISPR/Cas9 methodology. A comparative SILAC phosphoproteomics analysis reveals that, although about 30% of the quantified phosphosites do conform to the CK2 consensus, only one-third of these are substantially reduced in the CK2α/α'(-/-) cells, consistent with their generation by CK2. A parallel study with C2C12 cells deprived of the regulatory β subunit discloses a role of this subunit in determining CK2 targeting. We also find that phosphosites notoriously generated by CK2 are not fully abrogated in CK2α/α'(-/-) cells, while some phosphosites unrelated to CK2 are significantly altered. Collectively taken our data allow to conclude that the phosphoproteome generated by CK2 is not as ample and rigidly pre-determined as it was believed before. They also show that the lack of CK2 promotes phosphoproteomics perturbations attributable to kinases other than CK2.
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Affiliation(s)
- Cinzia Franchin
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy
- Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, Via G. Orus 2/B, Padua, Italy
| | - Christian Borgo
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy
| | - Luca Cesaro
- Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, Via G. Orus 2/B, Padua, Italy
| | - Silvia Zaramella
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy
- Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, Via G. Orus 2/B, Padua, Italy
| | - Jordi Vilardell
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy
| | - Mauro Salvi
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy.
| | - Giorgio Arrigoni
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy.
- Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, Via G. Orus 2/B, Padua, Italy.
| | - Lorenzo A Pinna
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58/B, Padua, Italy.
- CNR Institute of Neurosciences, Via U. Bassi 58/B, Padua, Italy.
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11
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Rabjerg M, Guerra B, Oliván-Viguera A, Mikkelsen MLN, Köhler R, Issinger OG, Marcussen N. Nuclear localization of the CK2α-subunit correlates with poor prognosis in clear cell renal cell carcinoma. Oncotarget 2018; 8:1613-1627. [PMID: 27906674 PMCID: PMC5352082 DOI: 10.18632/oncotarget.13693] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 11/11/2016] [Indexed: 01/01/2023] Open
Abstract
Protein kinase CK2α, one of the two catalytic isoforms of the protein kinase CK2 has been shown to contribute to tumor development, tumor proliferation and suppression of apoptosis in various malignancies. We conducted this study to investigate CK2 expression in different subtypes of Renal Cell Carcinoma (RCC) and in the benign oncocytoma. qRT-PCR, immunohistochemistry and Western blot analyses revealed that CK2α expression was significantly increased at the mRNA and protein levels in clear cell RCC (ccRCC). Also the kinase activity of CK2 was significantly increased in ccRCC compared to normal renal cortex. Nuclear protein expression of CK2α correlated in univariate analysis with poor Progression Free Survival (HR = 8.11, p = 0.016). Functional analyses (cell proliferation assay) revealed an inhibitory effect of Caki-2 cell growth following CK2 inhibition with CX-4945. Our results suggest that CK2α promotes migration and invasion of ccRCC and therefore could serve as a novel prognostic biomarker and molecular therapeutic target in this type of cancer.
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Affiliation(s)
- Maj Rabjerg
- Department of Pathology, Odense University Hospital, DK-5000 Odense, Denmark
| | - Barbara Guerra
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense, Denmark
| | - Aida Oliván-Viguera
- Aragon Agency for Research and Development (ARAID), IACS, IIS Aragon, 50009 Zaragoza, Spain
| | | | - Ralf Köhler
- Aragon Agency for Research and Development (ARAID), IACS, IIS Aragon, 50009 Zaragoza, Spain
| | - Olaf-Georg Issinger
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense, Denmark
| | - Niels Marcussen
- Department of Pathology, Odense University Hospital, DK-5000 Odense, Denmark
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12
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Rusin SF, Adamo ME, Kettenbach AN. Identification of Candidate Casein Kinase 2 Substrates in Mitosis by Quantitative Phosphoproteomics. Front Cell Dev Biol 2017; 5:97. [PMID: 29214152 PMCID: PMC5702644 DOI: 10.3389/fcell.2017.00097] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/06/2017] [Indexed: 12/30/2022] Open
Abstract
Protein phosphorylation is a crucial regulatory mechanism that controls many aspects of cellular signaling. Casein kinase 2 (CK2), a constitutively expressed and active kinase, plays key roles in an array of cellular events including transcription and translation, ribosome biogenesis, cell cycle progression, and apoptosis. CK2 is implicated in cancerous transformation and is a therapeutic target in anti-cancer therapy. The specific and selective CK2 ATP competitive inhibitor, CX-4945 (silmitaseratib), is currently in phase 2 clinical trials. While many substrates and interactors of CK2 have been identified, less is known about CK2 substrates in mitosis. In the present work, we utilize CX-4945 and quantitative phosphoproteomics to inhibit CK2 activity in mitotically arrested HeLa cells and determine candidate CK2 substrates. We identify 330 phosphorylation sites on 202 proteins as significantly decreased in abundance upon inhibition of CK2 activity. Motif analysis of decreased sites reveals a linear kinase motif with aspartic and glutamic amino acids downstream of the phosphorylated residues, which is consistent with known substrate preferences for CK2. To validate specific candidate CK2 substrates, we perform in vitro kinase assays using purified components. Furthermore, we identified CK2 interacting proteins by affinity purification-mass spectrometry (AP-MS). To investigate the biological processes regulated by CK2 in mitosis, we perform network analysis and identify an enrichment of proteins involved in chromosome condensation, chromatin organization, and RNA processing. We demonstrate that overexpression of CK2 in HeLa cells affects proper chromosome condensation. Previously, we found that phosphoprotein phosphatase 6 (PP6), but not phosphoprotein phosphatase 2A (PP2A), opposes CK2 phosphorylation of the condensin I complex, which is essential for chromosome condensation. Here, we extend this observation and demonstrate that PP6 opposition of CK2 is a more general cellular regulatory mechanism.
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Affiliation(s)
- Scott F Rusin
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Mark E Adamo
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
| | - Arminja N Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States.,Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH, United States
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Han B, Fang Y, Feng M, Hu H, Hao Y, Ma C, Huo X, Meng L, Zhang X, Wu F, Li J. Brain Membrane Proteome and Phosphoproteome Reveal Molecular Basis Associating with Nursing and Foraging Behaviors of Honeybee Workers. J Proteome Res 2017; 16:3646-3663. [DOI: 10.1021/acs.jproteome.7b00371] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Bin Han
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Yu Fang
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Mao Feng
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Han Hu
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Yue Hao
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Chuan Ma
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Xinmei Huo
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Lifeng Meng
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Xufeng Zhang
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Fan Wu
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
| | - Jianke Li
- Institute of Apicultural
Research/Key Laboratory of Pollinating Insect Biology, Ministry of
Agriculture, Chinese Academy of Agricultural Science, Beijing, China
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Chon HJ, Bae KJ, Lee Y, Kim J. The casein kinase 2 inhibitor, CX-4945, as an anti-cancer drug in treatment of human hematological malignancies. Front Pharmacol 2015; 6:70. [PMID: 25873900 PMCID: PMC4379896 DOI: 10.3389/fphar.2015.00070] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 03/16/2015] [Indexed: 12/20/2022] Open
Abstract
The casein kinase 2 (CK2) protein kinase is a pro-survival kinase and therapeutic target in treatment of various human cancers. CK2 overexpression has been demonstrated in hematological malignancies, including chronic lymphocytic leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, acute myeloid leukemia, and multiple myeloma. CX-4945, also known as Silmitasertib, is an orally administered, highly specific, ATP-competitive inhibitor of CK2. CX-4945 induces cytotoxicity and apoptosis and is currently being evaluated in clinical trials for treatment of many cancer types. In the past 2 years, the focus on the therapeutic potential of CX-4945 has shifted from solid tumors to hematological malignancies. CX-4945 exerts anti-proliferative effects in hematological tumors by downregulating CK2 expression and suppressing activation of CK2-mediated PI3K/Akt/mTOR signaling pathways. Furthermore, combination of CX-4945 with other inhibitors yielded synergistic effects in cell death induction. These new findings demonstrate that CK2 overexpression contributes to blood cancer cell survival and resistance to chemotherapy. Combinatorial use of CX-4945 is a promising therapeutic tool for treatment of hematological malignancies.
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Affiliation(s)
- Hae J Chon
- Department of Biomedical Laboratory Science, School of Medicine, Eulji University , Daejeon, South Korea
| | - Kyoung J Bae
- Department of Biomedical Laboratory Science, School of Medicine, Eulji University , Daejeon, South Korea
| | - Yura Lee
- Department of Biomedical Laboratory Science, School of Medicine, Eulji University , Daejeon, South Korea
| | - Jiyeon Kim
- Department of Biomedical Laboratory Science, School of Medicine, Eulji University , Daejeon, South Korea
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15
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Abstract
The term 'casein kinase' has been widely used for decades to denote protein kinases sharing the ability to readily phosphorylate casein in vitro. These fall into three main classes: two of them, later renamed as protein kinases CK1 (casein kinase 1, also known as CKI) and CK2 (also known as CKII), are pleiotropic members of the kinome functionally unrelated to casein, whereas G-CK, or genuine casein kinase, responsible for the phosphorylation of casein in the Golgi apparatus of the lactating mammary gland, has only been identified recently with Fam20C [family with sequence similarity 20C; also known as DMP-4 (dentin matrix protein-4)], a member of the four-jointed family of atypical protein kinases, being responsible for the phosphorylation of many secreted proteins. In hindsight, therefore, the term 'casein kinase' is misleading in every instance; in the case of CK1 and CK2, it is because casein is not a physiological substrate, and in the case of G-CK/Fam20C/DMP-4, it is because casein is just one out of a plethora of its targets, and a rather marginal one at that. Strikingly, casein kinases altogether, albeit representing a minimal proportion of the whole kinome, appear to be responsible for the generation of up to 40-50% of non-redundant phosphosites currently retrieved in human phosphopeptides database. In the present review, a short historical explanation will be provided accounting for the usage of the same misnomer to denote three unrelated classes of protein kinases, together with an update of our current knowledge of these pleiotropic enzymes, sharing the same misnomer while playing very distinct biological roles.
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Fas-associated factor (Faf1) is a novel CD40 interactor that regulates CD40-induced NF-κB activation via a negative feedback loop. Cell Death Dis 2014; 5:e1213. [PMID: 24810049 PMCID: PMC4047894 DOI: 10.1038/cddis.2014.172] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Revised: 02/03/2014] [Accepted: 02/13/2014] [Indexed: 12/24/2022]
Abstract
CD40-induced signalling through ligation with its natural ligand (CD40L/CD154) is dependent on recruitment of TRAF molecules to the cytoplasmic domain of the receptor. Here, we applied the yeast two-hybrid system to examine whether other proteins can interact with CD40. Fas-Associated Factor 1(FAF1) was isolated from a HeLa cDNA library using the CD40 cytoplasmic tail (216–278 aa) as a bait construct. FAF1 was able to interact with CD40 both in vitro and in vivo. The FAF1 N-terminal domain was sufficient to bind CD40 and required the TRAF6-binding domain within the cytoplasmic tail of CD40 for binding. CD40 ligation induced FAF1 expression in an NFκB-dependent manner. Knockdown of FAF1 prolonged CD40-induced NFκB, whereas overexpression of FAF1 suppressed CD40-induced NFκB activity and this required interaction of FAF1 with the CD40 receptor via its FID domain. Thus, we report a novel role for FAF1in regulating CD40-induced NFκB activation via a negative feedback loop. Loss of FAF1 function in certain human malignancies may contribute to oncogenesis through unchecked NFκB activation, and further understanding of this process may provide a biomarker of NFκB-targeted therapies for such malignancies.
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17
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Turowec JP, Vilk G, Gabriel M, Litchfield DW. Characterizing the convergence of protein kinase CK2 and caspase-3 reveals isoform-specific phosphorylation of caspase-3 by CK2α': implications for pathological roles of CK2 in promoting cancer cell survival. Oncotarget 2013; 4:560-71. [PMID: 23599180 PMCID: PMC3720604 DOI: 10.18632/oncotarget.948] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Protein kinase CK2 has emerged as a promising candidate for the treatment of a number of cancers. This enzyme is comprised of two catalytic subunits (CK2 and/or CK2α′) that form complexes with homodimers of regulatory CK2β subunits. While catalytic and regulatory CK2 subunits are generally expressed at similar levels to form tetrameric complexes, asymmetric expression of CK2 subunits has been associated with various forms of cancer and the enhanced survival of cancer cells. To elucidate mechanisms responsible for regulation of cancer cell survival by CK2, we recently employed computational and experimental strategies that revealed widespread overlap between sites for CK2 phosphorylation and caspase cleavage. Among candidates with overlapping CK2 and caspase cleavage sites was caspase-3 that is phosphorylated by CK2 to prevent its activation by upstream caspases. To elucidate the precise relationship between CK2 and caspase-3, we modulated expression of individual CK2 subunits and demonstrated that CK2α′ exhibits a striking preference for caspase-3 phosphorylation in cells as compared to CK2α and that CK2β exhibits the capacity to abolish caspase-3 phosphorylation. Since caspase-3 represents the first CK2 substrate selectively phosphorylated by CK2α′ in cells, our work highlights divergent functions of the different forms of CK2. Given the involvement of CK2 in a diverse series of biological events and its association with various cancers, this work has important implications for identifying pathological roles of distinct forms of CK2 that could instruct efforts to selectively target individual CK2 subunits for therapy.
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Affiliation(s)
- Jacob P Turowec
- Department of Biochemistry, Schulich School of Medicine, Western University, London, ON, Canada
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18
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Wairkar YP, Trivedi D, Natarajan R, Barnes K, Dolores L, Cho P. CK2α regulates the transcription of BRP in Drosophila. Dev Biol 2013; 384:53-64. [PMID: 24080510 DOI: 10.1016/j.ydbio.2013.09.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 09/18/2013] [Accepted: 09/20/2013] [Indexed: 01/26/2023]
Abstract
Development and plasticity of synapses are brought about by a complex interplay between various signaling pathways. Typically, either changing the number of synapses or strengthening an existing synapse can lead to changes during synaptic plasticity. Altering the machinery that governs the exocytosis of synaptic vesicles, which primarily fuse at specialized structures known as active zones on the presynaptic terminal, brings about these changes. Although signaling pathways that regulate the synaptic plasticity from the postsynaptic compartments are well defined, the pathways that control these changes presynaptically are poorly described. In a genetic screen for synapse development in Drosophila, we found that mutations in CK2α lead to an increase in the levels of Bruchpilot (BRP), a scaffolding protein associated with the active zones. Using a combination of genetic and biochemical approaches, we found that the increase in BRP in CK2α mutants is largely due to an increase in the transcription of BRP. Interestingly, the transcripts of other active zone proteins that are important for function of active zones were also increased, while the transcripts from some other synaptic proteins were unchanged. Thus, our data suggest that CK2α might be important in regulating synaptic plasticity by modulating the transcription of BRP. Hence, we propose that CK2α is a novel regulator of the active zone protein, BRP, in Drosophila.
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Affiliation(s)
- Yogesh P Wairkar
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch, 301 University Blvd., Rte#1045, Galveston, TX 77555, United States.
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19
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Activation of protein kinase CK2 attenuates FOXO3a functioning in a PML-dependent manner: implications in human prostate cancer. Cell Death Dis 2013; 4:e543. [PMID: 23492774 PMCID: PMC3613841 DOI: 10.1038/cddis.2013.63] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Protein kinase CK2 (also known as Caseine Kinase II) is an ubiquitous Ser/Thr protein kinase present in both the nucleus and cytoplasm of cells, targeting several key enzymes, growth factor receptors, transcription factors and cytoskeletal proteins. It is not only a key player in regulating cellular growth and proliferation, but also behaves as a potent suppressor of apoptosis. CK2 has been frequently found to be deregulated (mostly hyperactivated) in all cancers, prostate cancer being prominent of them. In the recent past, tumor suppressor PML (promyelocytic leukemia) has been shown to be a target of phosphorylation by CK2. This phosphorylation promotes the ubiquitin-mediated proteasomal degradation of PML thereby effectively curbing its role as a tumor suppressor. Among many others, PML has also been established to mediate its tumor suppressive role by mitigating the inactivation of active AKT (pAKT) inside the nucleus by assembling a dephosphorylating platform for nuclear pAKT. One of the immediate consequences, of this inactivation is the stabilization of FOXO3a, another well-established tumor suppressor, inside the nucleus and its downstream activities. Here, we propose a novel signaling axis apexed by deregulated CK2, dismantling the association of PML and PHLPP2 (we also report PHLPP2 to be a novel interacting partner of PML inside the nucleus), ultimately leading to the inactivation and nuclear exclusion of FOXO3a, thereby downregulating p21/p27/Bim in which degradation of PML and the concomitant stabilization of pAKT plays a cardinal part.
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20
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Nie J, Liu L, He F, Fu X, Han W, Zhang L. CKIP-1: a scaffold protein and potential therapeutic target integrating multiple signaling pathways and physiological functions. Ageing Res Rev 2013; 12:276-81. [PMID: 22878216 DOI: 10.1016/j.arr.2012.07.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 07/04/2012] [Accepted: 07/11/2012] [Indexed: 11/16/2022]
Abstract
The PH domain-containing casein kinase 2 interacting protein-1 (CKIP-1, also known as PLEKHO1) acts as a scaffold protein mediating interactions with multiple proteins, including CK2α, CPα, AP-1/c-Jun, Akt, ATM, IFP35/Nmi and Smurf1. CKIP-1 functions through different ways, such as plasma membrane recruitment, transcriptional activity modulation and posttranscriptional modification regulation. Moreover, the subcellular localization of CKIP-1 is determined by several key amino acids in a cell type dependent style, and the nucleus/plasma membrane shuttle of CKIP-1 is regulated by different cell stresses. As an adaptor protein, CKIP-1 is involved in various important signaling pathways, controlling cell growth, apoptosis, differentiation, cytoskeleton and bone formation. Strikingly, CKIP-1 has been recently demonstrated to be a promising target for treatment of osteoporosis in rat models. In addition, more evidences suggest that CKIP-1 might also function as a potential tumor suppressor.
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Affiliation(s)
- Jing Nie
- Department of Molecular Biology, Institute of Basic Medical Science, PLA General Hospital, Beijing, China
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21
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Al Quobaili F, Montenarh M. CK2 and the regulation of the carbohydrate metabolism. Metabolism 2012; 61:1512-7. [PMID: 22917893 DOI: 10.1016/j.metabol.2012.07.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 07/10/2012] [Accepted: 07/17/2012] [Indexed: 11/21/2022]
Abstract
Protein kinase CK2 was originally identified by analyzing carbohydrate metabolism. Now it is clear that life without CK2 is impossible. Moreover, CK2 activity was found elevated in rapidly proliferating cells when compared to slowly proliferating or resting cells. Proliferating cells have an elevated need for energy which is generated from an elevated carbohydrate metabolism. From early observations and the emerging role of CK2 in cellular regulation, it is not surprising that CK2 plays a role in hormonal regulation of carbohydrate metabolism as well as modulating activities of enzymes directly involved in carbohydrate storage and metabolism. The aim of the present review is to summarize the knowledge about the role of CK2 in the regulation of the carbohydrate metabolism.
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Affiliation(s)
- Faizeh Al Quobaili
- Department of Biochemistry and Microbiology, Damascus University, 6735 Damascus, Syria
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22
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Expansion and evolution of the X-linked testis specific multigene families in the melanogaster species subgroup. PLoS One 2012; 7:e37738. [PMID: 22649555 PMCID: PMC3359341 DOI: 10.1371/journal.pone.0037738] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2011] [Accepted: 04/23/2012] [Indexed: 11/19/2022] Open
Abstract
The testis specific X-linked genes whose evolution is traced here in the melanogaster species subgroup are thought to undergo fast rate of diversification. The CK2ßtes and NACβtes gene families encode the diverged regulatory β-subunits of protein kinase CK2 and the homologs of β-subunit of nascent peptide associated complex, respectively. We annotated the CK2βtes-like genes related to CK2ßtes family in the D. simulans and D. sechellia genomes. The ancestor CK2βtes-like genes preserved in D. simulans and D. sechellia are considered to be intermediates in the emergence of the D. melanogaster specific Stellate genes related to the CK2ßtes family. The CK2ßtes-like genes are more similar to the unique autosomal CK2ßtes gene than to Stellates, taking into account their peculiarities of polymorphism. The formation of a variant the CK2ßtes gene Stellate in D. melanogaster as a result of illegitimate recombination between a NACßtes promoter and a distinct polymorphic variant of CK2ßtes-like ancestor copy was traced. We found a close nonrandom proximity between the dispersed defective copies of DINE-1 transposons, the members of Helitron family, and the CK2βtes and NACβtes genes, suggesting an involvement of DINE-1 elements in duplication and amplification of these genes.
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Gyenis L, Duncan JS, Turowec JP, Bretner M, Litchfield DW. Unbiased functional proteomics strategy for protein kinase inhibitor validation and identification of bona fide protein kinase substrates: application to identification of EEF1D as a substrate for CK2. J Proteome Res 2011; 10:4887-901. [PMID: 21936567 PMCID: PMC3208357 DOI: 10.1021/pr2008994] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Protein kinases have emerged as attractive targets for treatment of several diseases prompting large-scale phosphoproteomics studies to elucidate their cellular actions and the design of novel inhibitory compounds. Current limitations include extensive reliance on consensus predictions to derive kinase-substrate relationships from phosphoproteomics data and incomplete experimental validation of inhibitors. To overcome these limitations in the case of protein kinase CK2, we employed functional proteomics and chemical genetics to enable identification of physiological CK2 substrates and validation of CK2 inhibitors including TBB and derivatives. By 2D electrophoresis and mass spectrometry, we identified the translational elongation factor EEF1D as a protein exhibiting CK2 inhibitor-dependent decreases in phosphorylation in (32)P-labeled HeLa cells. Direct phosphorylation of EEF1D by CK2 was shown by performing CK2 assays with EEF1D -FLAG from HeLa cells. Dramatic increases in EEF1D phosphorylation following λ-phosphatase treatment and phospho- EEF1D antibody recognizing EEF1D pS162 indicated phosphorylation at the CK2 site in cells. Furthermore, phosphorylation of EEF1D in the presence of TBB or TBBz is restored using CK2 inhibitor-resistant mutants. Collectively, our results demonstrate that EEF1D is a bona fide physiological CK2 substrate for CK2 phosphorylation. Furthermore, this validation strategy could be adaptable to other protein kinases and readily combined with other phosphoproteomic methods.
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Affiliation(s)
- Laszlo Gyenis
- Department of Biochemistry, The University of Western Ontario , London, Ontario, N6A 5C1, Canada
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Ström CE, Mortusewicz O, Finch D, Parsons JL, Lagerqvist A, Johansson F, Schultz N, Erixon K, Dianov GL, Helleday T. CK2 phosphorylation of XRCC1 facilitates dissociation from DNA and single-strand break formation during base excision repair. DNA Repair (Amst) 2011; 10:961-9. [PMID: 21840775 DOI: 10.1016/j.dnarep.2011.07.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 07/05/2011] [Accepted: 07/14/2011] [Indexed: 10/17/2022]
Abstract
CK2 phosphorylates the scaffold protein XRCC1, which is required for efficient DNA single-strand break (SSB) repair. Here, we express an XRCC1 protein (XRCC1(ckm)) that cannot be phosphorylated by CK2 in XRCC1 mutated EM9 cells and show that the role of this post-translational modification gives distinct phenotypes in SSB repair and base excision repair (BER). Interestingly, we find that fewer SSBs are formed during BER after treatment with the alkylating agent dimethyl sulfate (DMS) in EM9 cells expressing XRCC1(ckm) (CKM cells) or following inhibition with the CK2 inhibitor 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole (DMAT). We also show that XRCC1(ckm) protein has a higher affinity for DNA than wild type XRCC1 protein and resides in an immobile fraction on DNA, in particular after damage. We propose a model whereby the increased affinity for DNA sequesters XRCC1(ckm) and the repair enzymes associated with it, at the repair site, which retards kinetics of BER. In conclusion, our results indicate that phosphorylation of XRCC1 by CK2 facilitates the BER incision step, likely by promoting dissociation from DNA.
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Affiliation(s)
- Cecilia E Ström
- Department of Genetics, Microbiology and Toxicology, Stockholm University, S-106 91 Stockholm, Sweden
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Chen J, Liu H, Cai Y, Wang G, Liu H, Li J. Mutations in the exon 10 of prolactin receptor gene change the egg production performance in Wanjiang white goose. Mol Biol Rep 2011; 39:475-83. [PMID: 21559838 DOI: 10.1007/s11033-011-0761-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Accepted: 04/27/2011] [Indexed: 01/28/2023]
Abstract
To select the molecular genetic markers related to egg performance of Wanjiang white goose, prolactin receptor gene (PRLR) was adopted to be a candidate gene in our study. Five pairs of primers (P1-P5) were designed to detect the SNPs of PRLR gene by PCR-SSCP method. The results revealed that polymorphisms were discovered in the PCR products amplified with P4 primers in PRLR exon 10, three genotypes were found: AA, AB and AC. The sequence of AB genotype is the same as original sequence (DQ660982) in NCBI. There are five mutations in AA genotype: C→A at 840 bp, C→T at 862 bp, T→C at 875 bp, T→A at 963 bp, A→T at 989 bp, resulting in amino acid mutations: His→Asn, Thr→Ile, Asn→Lys, Thr→Ser, and synonymous mutation at 875 bp. Sequencing revealed five mutations in AC genotype: G→T at 816 bp, A→T at 861 bp, C→T at 862 bp, T→C at 875 bp, A→G at 948 bp, causing amino acid mutations of Val→Phe, Thr→Phe, synonymous mutations at 875 and 963 bp. Besides, there are an N-glycosylation site (NQSR), three casein kinase II phosphorylation sites including SIIE, SKTE, and SLMD in AA genotype; three casein kinase II phosphorylation sites including SIIE, SKTE, and TLMD in AB genotype; three casein kinase II phosphorylation sites including SIFE, SKTE, and TLMD in AC genotype. The annual egg yielding of AB genotype geese are significantly more than those of AA and AC genotype geese on the average (P<0.05). It is suggested for the first time that PRLR is a promising candidate gene that can affect egg performance in Wanjiang white goose.
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Affiliation(s)
- Jie Chen
- College of Life Sciences, Anhui Normal University, Wuhu, 241000, China
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26
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Taherian A, Krone PH, Ovsenek N. A comparison of Hsp90alpha and Hsp90beta interactions with cochaperones and substrates. Biochem Cell Biol 2009; 86:37-45. [PMID: 18364744 DOI: 10.1139/o07-154] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hsp90 chaperone complexes function in assembly, folding, and activation of numerous substrates. The 2 vertebrate homologues encoded by the genes hsp90a and hsp90b are differentially expressed in embryonic and adult tissues and during stress; however, it is not known whether they possess identical functional activities in chaperone complexes. This question was addressed by examining potential differences between the Hsp90 isoforms with respect to both cochaperone and substrate interactions. Epitope-tagged proteins were expressed in mammalian cells or Xenopus oocytes and subjected to immunoprecipitation with an array of co-chaperones. Both isoforms were shown to participate equally in multichaperone complexes, and no significant differences in cochaperone distribution were observed. The substrates Raf-1, HSF1, Cdc37, and MEK1 interacted with both Hsp90alpha and Hsp90beta, and the relative patterns of these interactions were not affected by heat shock. The substrate kinases c-Src, CKIIB, A-raf, and Erk interacted with both isoforms; however, significantly more Hsp90alpha was recovered after heat shock. The data demonstrate that Hsp90alpha and Hsp90beta exhibit similar interactions with co-chaperones, but significantly different behaviors with respect to substrate interactions under stress conditions. These results reveal both functional similarities and key functional differences in the individual members of this protein family.
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Affiliation(s)
- Aliakbar Taherian
- Department of Anatomy and Cell Biology, College of Medicine, University of Saskatchewan, 107 Wiggins Rd., Saskatoon, Saskatchewan, Canada
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27
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Grozav AG, Chikamori K, Kozuki T, Grabowski DR, Bukowski RM, Willard B, Kinter M, Andersen AH, Ganapathi R, Ganapathi MK. Casein kinase I delta/epsilon phosphorylates topoisomerase IIalpha at serine-1106 and modulates DNA cleavage activity. Nucleic Acids Res 2008; 37:382-92. [PMID: 19043076 PMCID: PMC2632902 DOI: 10.1093/nar/gkn934] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We previously reported that phosphorylation of topoisomerase (topo) IIα at serine-1106 (Ser-1106) regulates enzyme activity and sensitivity to topo II-targeted drugs. In this study we demonstrate that phosphorylation of Ser-1106, which is flanked by acidic amino acids, is regulated in vivo by casein kinase (CK) Iδ and/or CKIɛ, but not by CKII. The CKI inhibitors, CKI-7 and IC261, reduced Ser-1106 phosphorylation and decreased formation of etoposide-stabilized topo II–DNA cleavable complex. In contrast, the CKII inhibitor, 5,6-dichlorobenzimidazole riboside, did not affect etoposide-stabilized topo II–DNA cleavable complex formation. Since, IC261 specifically targets the Ca2+-regulated isozymes, CKIδ and CKIɛ, we examined the effect of down-regulating these enzymes on Ser-1106 phosphorylation. Down-regulation of these isozymes with targeted si-RNAs led to hypophosphorylation of the Ser-1106 containing peptide. However, si-RNA-mediated down-regulation of CKIIα and α′ did not alter Ser-1106 phosphorylation. Furthermore, reduced phosphorylation of Ser-1106, observed in HRR25 (CKIδ/ɛ homologous gene)-deleted Saccharomyces cerevisiae cells transformed with human topo IIα, was enhanced following expression of human CKIɛ. Down-regulation of CKIδ and CKIɛ also led to reduced formation of etoposide stabilized topo II–DNA cleavable complex. These results provide strong support for an essential role of CKIδ/ɛ in phosphorylating Ser-1106 in human topo IIα and in regulating enzyme function.
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Affiliation(s)
- Adrian G Grozav
- Clinical Pharmacology Program, Taussig Cancer Institute, Cleveland, OH 44195, USA
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28
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Marjuki H, Scholtissek C, Yen HL, Webster RG. CK2beta gene silencing increases cell susceptibility to influenza A virus infection resulting in accelerated virus entry and higher viral protein content. J Mol Signal 2008; 3:13. [PMID: 18651975 PMCID: PMC2494991 DOI: 10.1186/1750-2187-3-13] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2008] [Accepted: 07/23/2008] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Influenza A virus (IVA) exploits diverse cellular gene products to support its replication in the host. The significance of the regulatory (beta) subunit of casein kinase 2 (CK2beta) in various cellular mechanisms is well established, but less is known about its potential role in IVA replication. We studied the role of CK2beta in IVA-infected A549 human epithelial lung cells. RESULTS Activation of CK2beta was observed in A549 cells during virus binding and internalization but appeared to be constrained as replication began. We used small interfering RNAs (siRNAs) targeting CK2beta mRNA to silence CK2beta protein expression in A549 cells without affecting expression of the CK2alpha subunit. CK2beta gene silencing led to increased virus titers, consistent with the inhibition of CK2beta during IVA replication. Notably, virus titers increased significantly when CK2beta siRNA-transfected cells were inoculated at a lower multiplicity of infection. Virus titers also increased in cells treated with a specific CK2 inhibitor but decreased in cells treated with a CK2beta stimulator. CK2beta absence did not impair nuclear export of viral ribonucleoprotein complexes (6 h and 8 h after inoculation) or viral polymerase activity (analyzed in a minigenome system). The enhancement of virus titers by CK2beta siRNA reflects increased cell susceptibility to influenza virus infection resulting in accelerated virus entry and higher viral protein content. CONCLUSION This study demonstrates the role of cellular CK2beta protein in the viral biology. Our results are the first to demonstrate a functional link between siRNA-mediated inhibition of the CK2beta protein and regulation of influenza A virus replication in infected cells. Overall, the data suggest that expression and activation of CK2beta inhibits influenza virus replication by regulating the virus entry process and viral protein synthesis.
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Affiliation(s)
- Henju Marjuki
- Division of Virology, Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Christoph Scholtissek
- Division of Virology, Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Hui-Ling Yen
- Division of Virology, Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Robert G Webster
- Division of Virology, Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
- Department of Pathology, University of Tennessee, Memphis, TN 38105, USA
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29
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Vilk G, Weber JE, Turowec JP, Duncan JS, Wu C, Derksen DR, Zien P, Sarno S, Donella-Deana A, Lajoie G, Pinna LA, Li SSC, Litchfield DW. Protein kinase CK2 catalyzes tyrosine phosphorylation in mammalian cells. Cell Signal 2008; 20:1942-51. [PMID: 18662771 DOI: 10.1016/j.cellsig.2008.07.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Accepted: 07/03/2008] [Indexed: 10/21/2022]
Abstract
Protein kinase CK2 exhibits oncogenic activity in mice and is over-expressed in a number of tumors or leukemic cells. On the basis of its amino acid sequence and a wealth of experimental information, CK2 has traditionally been classified as a protein serine/threonine kinase. In contrast to this traditional view of CK2, recent evidence has shown that CK2 can also phosphorylate tyrosine residues under some circumstances in vitro and in yeast. In this study, we provide definitive evidence demonstrating that CK2 also exhibits tyrosine kinase activity in mammalian cells. Tyrosine phosphorylation of CK2 in cells and in CK2 immunoprecipitates is dependent on CK2 activity and is inhibited by the CK2 selective inhibitor 4,5,6,7-tetrabromobenzotriazole. Examination of phosphotyrosine profiles in cells reveals a number of proteins, including CK2 itself, which exhibit increased tyrosine phosphorylation when CK2 levels are increased. Peptide arrays to evaluate the specificity determinants for tyrosine phosphorylation by CK2 reveal that its specificity for tyrosine phosphorylation is distinct from its specificity for serine/threonine phosphorylation. Of particular note is the requirement for an aspartic acid immediately C-terminal to the phosphorylatable tyrosine residue. Collectively, these data provide conclusive evidence that CK2 catalyzes the phosphorylation of tyrosine residues in mammalian cells, a finding that adds a new level of complexity to the challenge of elucidating its cellular functions. Furthermore, these results raise the possibility that increased CK2 levels that frequently accompany transformation may contribute to the increased tyrosine phosphorylation that occurs in transformed cells.
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Affiliation(s)
- Greg Vilk
- Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
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30
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The emerging CK2 interactome: insights into the regulation and functions of CK2. Mol Cell Biochem 2008; 316:5-14. [PMID: 18553055 DOI: 10.1007/s11010-008-9830-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 05/29/2008] [Indexed: 10/22/2022]
Abstract
Protein kinase CK2 represents a small family of protein serine/threonine kinases implicated in a variety of biological processes including events relating to cell proliferation and survival. Notably, CK2 displays oncogenic activity in mice and exhibits altered expression in several types of cancer. Accordingly, a detailed understanding of the cellular functions of CK2 and elucidation of the mechanisms by which CK2 is regulated in cells is expected to contribute to understanding its role in tumorigenesis with the prospect of novel approaches to therapy. While CK2 has traditionally been viewed as a tetrameric complex composed of two catalytic and two regulatory subunits, mounting evidence suggests that its subunits may have functions independent of tetrameric CK2 complexes. In mammals, as is the case in the budding yeast Saccharomyces cerevisiae, there are two isozymic forms of CK2, adding additional heterogeneity to the CK2 family. Studies in yeast and in human cells demonstrate that the different forms of CK2 interact with a large number of cellular proteins. To reveal new insights regarding the regulation and functions of different forms of CK2, we have examined the emerging interactomes for each of the CK2 subunits. Analysis of these interactomes for both yeast and human CK2 reinforces the view that this family of enzymes participates in a broad spectrum of cellular events. Furthermore, while there is considerable overlap between the interactomes of the individual CK2 subunits, notable differences in each of the individual interactomes provides additional evidence for functional specialization for the individual forms of CK2.
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31
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Seeber S, Issinger OG, Holm T, Kristensen LP, Guerra B. Validation of protein kinase CK2 as oncological target. Apoptosis 2007; 10:875-85. [PMID: 16133877 DOI: 10.1007/s10495-005-0380-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Protein kinase CK2 is a highly conserved enzyme composed of two catalytic subunits alpha and/or alpha' and two regulatory subunits beta whose activity is elevated in diverse tumour types as well as in highly proliferating tissues. Several results suggest that the overexpression of either CK2 catalytic subunits or the CK2 holoenzyme contributes to cellular transformation. In a similar vein, experiments performed compromising the intracellular expression of CK2 has led to somehow contradictory results with respect to the ability of this enzyme to control survival and apoptosis. To better elucidate the role of CK2 in programmed cell death, we have depleted cells of CK2 catalytic subunits by the application of antisense oligodeoxynucleotides and siRNAs techniques, respectively. Our results indicate that protein kinase CK2 is characterized by an extremely high stability that might be due to its association with other intracellular proteins, enhanced half-life or lower vulnerability towards proteolytic degradation. In addition, we show that despite the effectiveness of the methods applied in lowering CK2 kinase activity in all cells investigated, CK2 might not by itself be sufficient to trigger enhanced drug-induced apoptosis in cells.
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Affiliation(s)
- S Seeber
- Roche Diagnostics GmbH, Pharma Research Penzberg, Nonnenwald 2, D-82377 Penzberg, Germany
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32
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Law FBF, Chen YW, Wong KY, Ying J, Tao Q, Langford C, Lee PY, Law S, Cheung RWL, Chui CH, Tsao GSW, Lam KY, Wong J, Srivastava G, Tang JCO. Identification of a novel tumor transforming gene GAEC1 at 7q22 which encodes a nuclear protein and is frequently amplified and overexpressed in esophageal squamous cell carcinoma. Oncogene 2007; 26:5877-88. [PMID: 17384685 PMCID: PMC2875854 DOI: 10.1038/sj.onc.1210390] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2005] [Revised: 01/15/2007] [Accepted: 02/07/2007] [Indexed: 12/13/2022]
Abstract
By comparative DNA fingerprinting, we identified a 357-bp DNA fragment frequently amplified in esophageal squamous cell carcinomas (ESCC). This fragment overlaps with an expressed sequence tag mapped to 7q22. Further 5' and 3'-rapid amplification of cDNA ends revealed that it is part of a novel, single-exon gene with full-length mRNA of 2052 bp and encodes a nuclear protein of 109 amino acids ( approximately 15 kDa). This gene, designated as gene amplified in esophageal cancer 1 (GAEC1), was located within a 1-2 Mb amplicon at 7q22.1 identified by high-resolution 1 Mb array-comparative genomic hybridization in 6/10 ESCC cell lines. GAEC1 was ubiquitously expressed in normal tissues including esophageal and gastrointestinal organs; with amplification and overexpression in 6/10 (60%) ESCC cell lines and 34/99 (34%) primary tumors. Overexpression of GAEC1 in 3T3 mouse fibroblasts caused foci formation and colony formation in soft agar, comparable to H-ras and injection of GAEC1-transfected 3T3 cells into athymic nude mice formed undifferentiated sarcoma in vivo, indicating that GAEC1 is a transforming oncogene. Although no significant correlation was observed between GAEC1 amplification and clinicopathological parameters and prognosis, our study demonstrated that overexpressed GAEC1 has tumorigenic potential and suggest that overexpressed GAEC1 may play an important role in ESCC pathogenesis.
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Affiliation(s)
- FBF Law
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - YW Chen
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - KY Wong
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - J Ying
- Cancer Epigenetics Laboratory, State Key Laboratory in Oncology in South China, Sir YK Pao Center for Cancer, Department of Clinical Oncology, Hong Kong Cancer Institute and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong
| | - Q Tao
- Cancer Epigenetics Laboratory, State Key Laboratory in Oncology in South China, Sir YK Pao Center for Cancer, Department of Clinical Oncology, Hong Kong Cancer Institute and Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong
| | | | - PY Lee
- Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - S Law
- Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - RWL Cheung
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - C. H. Chui
- Lo Ka Chung Centre for Natural Anti-Cancer Drug Development, The Hong Kong Polytechnic University, Hong Kong
| | - GSW Tsao
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - KY Lam
- Department of Pathology, Griffith University, Queensland, Australia
| | - J Wong
- Department of Surgery, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - G Srivastava
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
| | - Johnny CO Tang
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong
- Lo Ka Chung Centre for Natural Anti-Cancer Drug Development, The Hong Kong Polytechnic University, Hong Kong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong
- State Key Laboratory of Chinese Medicine and Molecular Pharmacology, Shenzhen, PR China
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33
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Iwai S, Thi Dieu Trang L, Sehadova H, Takeda M. Expression analyses of casein kinase 2alpha and casein kinase 2beta in the silkmoth, Bombyx mori. Comp Biochem Physiol B Biochem Mol Biol 2007; 149:38-46. [PMID: 17888702 DOI: 10.1016/j.cbpb.2007.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2007] [Revised: 08/01/2007] [Accepted: 08/07/2007] [Indexed: 11/27/2022]
Abstract
A period-timeless (per-tim) based feedback loop is considered to be essential in generating circadian rhythms in Drosophila melanogaster. In addition to transcriptional regulation, the post-transcriptional modification is essential to the circadian oscillation of core clock proteins in the circadian system. Here we present expression profiles of the catalytic subunit of casein kinase 2alpha (ck2alpha) and casein kinase 2beta (ck2beta) in Bombyx mori. Southern blot analyses showed that ck2alpha and ck2beta of B. mori were single copy genes. Northern blot analyses demonstrated that both subunits were expressed in eggs, larval heads, adult heads, testes and ovaries. In situ hybridization analyses indicated that subunits were expressed in brain neurons expressing PER-like protein. Surprisingly, antisense RNAs of ck2alpha and ck2beta were also detected in the putative clock neurons. Temporal expressions of ck2alpha and ck2beta mRNAs were constant in adult heads under LD12:12. The core clock genes per and tim showed daily fluctuations of mRNA abundance in the embryonic stage that is photoperiod sensitive period to determine egg diapause in the next generation whereas the expression of ck2alpha and ck2beta was constant. No evidence supports that ck2alpha and ck2beta of B. mori were transcriptionally regulated by circadian oscillation, but histological data show a close association of ck2alpha and ck2beta with circadian system in B. mori.
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Affiliation(s)
- Sachio Iwai
- Division of Molecular Science, Graduate School of Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe 657-8567, Japan
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34
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Chaar Z, O'reilly P, Gelman I, Sabourin LA. v-Src-dependent Down-regulation of the Ste20-like Kinase SLK by Casein Kinase II. J Biol Chem 2006; 281:28193-9. [PMID: 16837460 DOI: 10.1074/jbc.m605665200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have previously shown that the Ste20-like kinase SLK is a microtubule-associated protein inducing actin stress fiber disassembly. Here, we show that v-Src expression can down-regulate SLK activity. This down-regulation is independent of focal adhesion kinase but requires v-Src kinase activity and membrane translocation. SLK down-regulation by v-Src is indirect and is accompanied by SLK hyperphosphorylation on serine residues. Deletion analysis revealed that casein kinase II (CK2) sites at position 347/348 are critical for v-Src-dependent modulation of SLK activity. Further studies show that CK2 can directly phosphorylate SLK at these positions and that inhibition of CK2 in v-Src-transformed cells results in normal kinase activity. Finally, CK2 and SLK can be co-localized in fibroblasts spreading on fibronectin-coated substrates, suggesting a mechanism whereby SLK may be regulated at sites of actin remodeling, such as membrane lamellipodia and ruffles, through CK2.
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Affiliation(s)
- Ziad Chaar
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H8L6, Canada
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35
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Olsten MEK, Weber JE, Litchfield DW. CK2 interacting proteins: emerging paradigms for CK2 regulation? Mol Cell Biochem 2006; 274:115-24. [PMID: 16335533 DOI: 10.1007/s11010-005-3072-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Protein kinase CK2 represents a small family of highly conserved protein kinases involved in a complex series of cellular events. Furthermore, CK2 has been localised to many discrete cellular sites and has an extensive and diverse array of substrates and interaction partners in cells. Despite considerable investigation, the precise mechanism(s) of regulation of CK2 in cells remains poorly understood. In consideration of the prospect that cells contain many distinct sub-populations of CK2 that are distinguished on the basis of localisation and/or interactions with other cellular components, one possibility is that there may be differential regulation of specific sub-populations of CK2. With this in mind, some of the individual sub-populations of CK2 may be regulated through particular protein-protein interactions that may play a role in recruiting CK2 into the vicinity of its substrates and/or modulating its ability to phosphorylate specific cellular targets. In this respect, here we examine two CK2-interacting proteins, namely Pin1 and CKIP-1 that have been shown to participate in the modulation of CK2 specificity or the subcellular localisation of CK2, respectively. One aspect of this work has been focused on the prospect that Pin1 interacts with CK2 in response to UV stimulation in a manner analogous to the phosphorylation-dependent interactions of CK2 that occur following the mitotic phosphorylation of CK2. A second aspect of this work involves an examination of the structural basis for interactions between CK2 and CKIP-1 with emphasis on a putative HIKE domain in CK2.
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Affiliation(s)
- Mary Ellen K Olsten
- Department of Biochemistry, Siebens-Drake Research Institute, University of Western Ontario, London, Ontario, Canada N6A 5CI
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36
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Shinozuka H, Hisano H, Ponting RC, Cogan NOI, Jones ES, Forster JW, Yamada T. Molecular cloning and genetic mapping of perennial ryegrass casein protein kinase 2 alpha-subunit genes. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2005; 112:167-77. [PMID: 16240106 DOI: 10.1007/s00122-005-0119-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2005] [Accepted: 09/15/2005] [Indexed: 05/04/2023]
Abstract
The alpha-subunit of the casein protein kinase CK2 has been implicated in both light-regulated and circadian rhythm-controlled plant gene expression, including control of the flowering time. Two putative CK2alpha genes of perennial ryegrass (Lolium perenne L.) have been obtained from a cDNA library constructed with mRNA isolated from cold-acclimated crown tissue. The genomic organisation of the two genes was determined by Southern hybridisation analysis. Primer designs to the Lpck2a-1 and Lpck2a-2 cDNA sequences permitted the amplification of genomic products containing large intron sequences. Amplicon sequence analysis detected single nucleotide polymorphisms (SNPs) within the p150/112 reference mapping population. Validated SNPs, within diagnostic restriction enzyme sites, were used to design cleaved amplified polymorphic sequence (CAPS) assays. The Lpck2a-1 CAPS marker was assigned to perennial ryegrass linkage group (LG) 4 and the Lpck2a-2 CAPS marker was assigned to LG2. The location of the Lpck2a-1 gene locus supports the previous conclusion of conserved synteny between perennial ryegrass LG4, the Triticeae homoeologous group 5L chromosomes and the corresponding segment of rice chromosome 3. Allelic variation at the Lpck2a-1 and Lpck2a-2 gene loci was correlated with phenotypic variation for heading date and winter survival, respectively. SNP polymorphism may be used for the further study of the role of CK2alpha genes in the initiation of reproductive development and winter hardiness in grasses.
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Affiliation(s)
- H Shinozuka
- Field Science Center for Northern Biosphere, Hokkaido University, Kita 11, Nishi 10, Kita, Sapporo 060-0811, Japan
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37
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Canton DA, Litchfield DW. The shape of things to come: an emerging role for protein kinase CK2 in the regulation of cell morphology and the cytoskeleton. Cell Signal 2005; 18:267-75. [PMID: 16126370 DOI: 10.1016/j.cellsig.2005.07.008] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2005] [Revised: 07/04/2005] [Accepted: 07/18/2005] [Indexed: 01/24/2023]
Abstract
Protein kinase CK2 is a highly conserved, pleiotropic, protein serine/threonine kinase that is essential for life in eukaryotes. CK2 has been implicated in diverse cellular processes such as cell cycle regulation, circadian rhythms, apoptosis, transformation and tumorigenesis. In addition, there is increasing evidence that CK2 is involved in the maintenance of cell morphology and cell polarity, and in the regulation of the actin and tubulin cytoskeletons. Accordingly, this review will highlight published evidence in experimental models ranging from yeast to mammals documenting the emerging roles of protein kinase CK2 in the regulation of cell polarity, cell morphology and the cytoskeleton.
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Affiliation(s)
- David A Canton
- Regulatory Biology and Functional Genomics Group, Siebens-Drake Medical Research Institute, Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
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Olsten MEK, Litchfield DW. Order or chaos? An evaluation of the regulation of protein kinase CK2. Biochem Cell Biol 2005; 82:681-93. [PMID: 15674436 DOI: 10.1139/o04-116] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
CK2 is a highly conserved, ubiquitously expressed protein serine/threonine kinase present in all eukaryotes. Circumscribed as having a vast array of substrates located in a number of cellular compartments, CK2 has been implicated in critical cellular processes such as proliferation, apoptosis, differentiation, and transformation. Despite advances in elucidating its substrates and involvement in cellular regulation, its precise mode of regulation remains poorly defined. In this respect, there are currently conflicting views as to whether CK2 is constitutively active or modulated in response to specific stimuli. Perhaps an important consideration in resolving these apparent discrepancies is recognition of the existence of many discrete CK2 subpopulations that are distinguished from one another by localization or association with distinct cellular components. The existence of these subpopulations brings to light the possibility of each population being regulated independently rather than the entire cellular CK2 content being regulated globally. Logically, each local population may then be regulated in a distinct manner to carry out its precise function(s). This review will examine those mechanisms including regulated expression and assembly of CK2 subunits, phosphorylation of CK2, and interactions with small molecules or cellular proteins that could contribute to the local regulation of distinct CK2 populations.
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Affiliation(s)
- Mary Ellen K Olsten
- Department of Biochemistry, Siebens-Drake Research Institute, University of Western Ontario, London, ON N6A 5C1, Canada
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39
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Abstract
Protein kinase CK2 has diverse links to gene control and cell cycle. Comparative genome-wide expression profiling of CK2 mutants of the budding yeast Saccharomyces cerevisiae at cell cycle entry has revealed that a significant proportion of cell-cycle genes are affected by CK2. Here, we examine how CK2 realizes this effect. We show that the CK2 action may be directed to gene promoters causing genes with promoter homologies to respond comparably to CK2 perturbation. Examples are metabolic pathway and nutrition supply genes such as the PHO and MET regulon genes, responsible for phosphate maintenance and methionine biosynthesis, respectively. CK2 perturbation affects both regulons permanently and both via repression of a central transcription factor, but with different mechanisms: In the PHO regulon, the gene encoding the central transcription factor Pho4 is repressed and, in addition, Pho4 and/or the cyclin-dependent kinase of the regulon's control complex may be affected by CK2 phosphorylation. In the MET regulon, the repression of the central transcription factor Met4 occurs not by expression inhibition, but rather by availability tuning via a CK2-mediated phosphorylation of a degradation complex. On the other hand, the CK2 action may be directed to the chromatin regulon, thus affecting globally the expression of genes, i.e., the CK2 perturbation results either in comparable responses of genes which have no promoter homologies or in deviating responses despite promoter homologies. The effect is rather transient and concerns aside various cell cycle control genes a notable number of genes encoding chromatin remodeling and modification proteins with functions in chromatin assembly and (anti-)silencing as well as in histone (de-)acetylation, and frequently are also substrates of CK2, suggesting additional tuning at protein level. In line with these findings, we observe in human cells sequence-independent but cell-cycle-dependent CK2 associations with promoters of cell-cycle-regulated genes at periods of extensive gene expression alterations, including cell cycle entry. Our observations are compatible with the idea that the gene control by CK2 is achieved via different mechanisms and at different levels of organization and includes a global role in transcription-related chromatin remodelling and modification.
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Affiliation(s)
- Walter Pyerin
- Biochemische Zellphysiologie (A135), Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
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Bibby AC, Litchfield DW. The multiple personalities of the regulatory subunit of protein kinase CK2: CK2 dependent and CK2 independent roles reveal a secret identity for CK2beta. Int J Biol Sci 2005; 1:67-79. [PMID: 15951851 PMCID: PMC1142214 DOI: 10.7150/ijbs.1.67] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Accepted: 02/01/2005] [Indexed: 12/01/2022] Open
Abstract
Protein kinase CK2 (formerly casein kinase II), an enzyme that participates in a wide variety of cellular processes, has traditionally been classified as a stable tetrameric complex consisting of two catalytic CK2α or CK2α' subunits and two regulatory CK2β subunits. While consideration of CK2 as a tetrameric complex remains relevant, significant evidence has emerged to challenge the view that its individual subunits exist exclusively within these complexes. This review will summarize biochemical and genetic evidence indicating that the regulatory CK2β subunit exists and performs functions independently of CK2 tetramers. For example, unbalanced expression of catalytic and regulatory CK2 subunits has been observed in a variety of tissues and tumors. Furthermore, localization studies including live cell imaging have demonstrated that while the catalytic and regulatory subunits of CK2 exhibit extensive co-localization, independent mobility of the individual CK2 subunits can also be observed within cells. Identification of proteins that interact with CK2β in the absence of catalytic CK2 subunits reinforces the notion that CK2β has functions distinct from CK2 and begins to offer insights into these CK2-independent functions. In this respect, the discovery that CK2β can interact with and modulate the activity of a number of other serine/threonine protein kinases including A-Raf, c-Mos and Chk1 is particularly striking. This review will discuss the interactions between CK2β and these protein kinases with special emphasis on the properties of CK2β that mediate these interactions and on the implications of these interactions in yielding new prospects for elucidation of the cellular functions of CK2β.
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Zhang L, Xing G, Tie Y, Tang Y, Tian C, Li L, Sun L, Wei H, Zhu Y, He F. Role for the pleckstrin homology domain-containing protein CKIP-1 in AP-1 regulation and apoptosis. EMBO J 2005; 24:766-78. [PMID: 15706351 PMCID: PMC549613 DOI: 10.1038/sj.emboj.7600532] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2004] [Accepted: 12/03/2004] [Indexed: 11/08/2022] Open
Abstract
The oncogenic transcription factor c-Jun plays an important role in cell proliferation, transformation and differentiation. All identified c-Jun-interacting proteins are localized to the nucleus or cytoplasm and function in their intact forms. Here we show that the pleckstrin homology domain-containing protein CKIP-1 (casein kinase 2-interacting protein-1) functions as a plasma membrane-bound AP-1 regulator. During apoptosis, CKIP-1 is cleaved by caspase-3 and translocated to the cytoplasm and then to the nucleus. C-terminal fragments of cleaved CKIP-1 strongly repress AP-1 activity. Importantly, CKIP-1 overexpression promotes apoptosis by forming a positive feedback loop between CKIP-1 and caspase-3. RNA interference of CKIP-1 or overexpression of c-Jun attenuates the sensitivity to apoptosis, indicating a novel role of CKIP-1 in apoptosis. CKIP-1 is the first case of a c-Jun-interacting protein that regulates AP-1 activity via caspase-3-dependent cleavage and translocation.
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Affiliation(s)
- Lingqiang Zhang
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese Human Genome Center of Beijing, Beijing, PR China
| | - Guichun Xing
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese Human Genome Center of Beijing, Beijing, PR China
| | - Yi Tie
- Department of Biochemistry and Molecular Biology, Beijing Institute of Radiation Medicine, Chinese Human Genome Center of Beijing, Beijing, PR China
| | - Ying Tang
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese Human Genome Center of Beijing, Beijing, PR China
| | - Chunyan Tian
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese Human Genome Center of Beijing, Beijing, PR China
| | - Li Li
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese Human Genome Center of Beijing, Beijing, PR China
| | - Libo Sun
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese Human Genome Center of Beijing, Beijing, PR China
| | - Handong Wei
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese Human Genome Center of Beijing, Beijing, PR China
| | - Yunping Zhu
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese Human Genome Center of Beijing, Beijing, PR China
| | - Fuchu He
- Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese Human Genome Center of Beijing, Beijing, PR China
- Institutes of Biomedical Sciences, Fudan University, Shanghai, PR China
- Beijing Institute of Radiation Medicine, 27 Taiping Road, Beijing 100850, PR China. Tel./Fax: +86 10 681 712 08; E-mail:
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de Oliveira FMB, da Silva ICDA, Rumjanek FD, Valadão AF, Franco GR, Mesquita RD, da Silva-Neto MAC, Fantappié MR. Functional properties of Schistosoma mansoni single-stranded DNA-binding protein SmPUR-alpha. Description of the interaction between SmPUR-alpha and SMYB1. Mol Biochem Parasitol 2005; 135:21-30. [PMID: 15287583 DOI: 10.1016/j.molbiopara.2003.12.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
PUR-alpha is a highly conserved protein in eukaryotes belonging to the family of single-stranded DNA-binding proteins. Because PUR-alpha is a multifunctional protein that participates in several regulatory events at the level of gene transcription, it became relevant to investigate the structural features of Schistosoma mansoni PUR-alpha (SmPUR-alpha) that could be correlated to its mode of action. Using deletion constructs on a dot blot assay we mapped the domains of GST-SmPUR-alpha fusion protein involved in the interactions with DNA and RNA. Individually, the N-terminal amino acid residues 1-26 and the C-terminal residues 196-276 of GST-SmPUR-alpha which did not contain nucleic acid-binding domains, did not bind ssDNA or RNA. In contrast, domains encompassing the N-terminal and Class I and C-terminal plus Class I exhibited the highest binding affinity. Seemingly, the latter (GST-SmPUR-alpha 174-276) played a major role in nucleic acid interaction as judged by affinity alone. Other combinations of the deletion constructs displayed either intermediary or no binding affinity to the DNA or RNA probes. Gel shift competition assay showed that GST-SmPUR-alpha bound to ssDNA with higher affinity than to RNA. Because SmPUR-alpha contains two putative phosphorylation sites the protein was tested as a substrate to casein kinase II. GST-SmPUR-alpha could be phosphorylated in vitro by casein kinase II at both, the N- and C-terminus of the protein. The multifunctional nature of SmPUR-alpha was demonstrated by experiments measuring the physical interaction between SmPUR-alpha and the transcription factor SMYB1. This was determined in vivo (yeast two hybrid) and in vitro (GST-pull down). Furthermore, we showed that SmPUR-alpha and SMYB1 acted synergistically to bind preferentially to pyrimidine-rich sequences.
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Grasselli E, Tomati V, Bernasconi MV, Nicolini C, Vergani L. C-terminal region of protein kinase CK2 alpha: How the structure can affect function and stability of the catalytic subunit. J Cell Biochem 2005; 92:270-84. [PMID: 15108354 DOI: 10.1002/jcb.20049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A novel mutant of the catalytic alpha subunit of human protein kinase CK2 (CK2 alpha) was designed in an attempt to clarify the role of the carboxylic-terminal segment characteristic of vertebrates, excluding fish. Starting from the sequence alignments, we constructed a phylogenetic tree of the primary structure of CK2 alpha. On this basis, we substituted two distal prolines with alanines (PA 382-384). Theoretical calculations and spectropolarimetry measurements, performed both on native and mutant subunits, indicate an increased content of alpha-helix after this double amino acidic substitution. In order to clarify the structure/function relationship of the C-terminal region, we verified if the structural change affects the catalytic activity of CK2 alpha. The mutant exhibits slightly increased phosphorylation efficiency, but reduced ability to transfer phosphate in comparison with the native subunit. At last, we compared the thermal stability of the mutant with respect to the native subunit and we tested the proteolytic degradability. The observation that the PA 382-384 mutant exhibits an increased thermal and proteolytic stability suggests that this mutant could be employed to solve the three-dimensional (3D) structure of human CK2 alpha and to overcome difficulties in crystallizing the native form.
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Affiliation(s)
- Elena Grasselli
- Department of Biophysical Sciences and Technologies M&O, School of Medicine, University of Genova, Genoa, Italy
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44
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Abstract
Regulation of protein synthesis is an important aspect of growth control. RNA polymerase (pol) III plays a key role in this process by catalysing production of tRNA and 5 S rRNA. Growth factors trigger a rapid increase in pol III activity and this is essential for cell proliferation. The transcription factor TFIIIB plays a key role in controlling pol III activity and is a target for regulation by a number of mechanisms. This review will focus on how TFIIIB is targeted by these proteins in response to mitogen stimulation.
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Affiliation(s)
- E Mauger
- Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, Davidson Building, University of Glasgow, Glasgow G12 8QQ, UK
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45
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Abstract
RNA polymerase (pol) III synthesizes a range of essential products, including tRNA, 5S rRNA and 7SL RNA, which are required for protein synthesis and trafficking. High rates of pol III transcription are necessary for cells to sustain growth. A wide range of transformed and tumour cell types have been shown to express elevated levels of pol III products. This review will summarize what is known about the mechanisms responsible for this deregulation. Some transforming agents have been shown to stimulate expression of the pol III-specific transcription factors TFIIIB or TFIIIC2. In addition, TFIIIB is bound and activated by several oncogenic proteins, including c-Myc. Conversely, TFIIIB interacts in healthy cells with the tumour suppressors RB and p53. Indeed, the ability to limit pol III transcription through TFIIIB may contribute to their growth-suppression capacities. The function of p53 and/or RB is compromised in most if not all transformed cells; the resultant derepression of TFIIIB may provide an almost universal route to deregulate pol III transcription in cancers. In addition to effects on protein synthesis and growth, there is a precedent for a pol III product having oncogenic activity.
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Affiliation(s)
- Robert J White
- Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Davidson Building, Glasgow G12 8QQ, UK.
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46
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Patel SK, Ma N, Monks TJ, Lau SS. Changes in gene expression during chemical-induced nephrocarcinogenicity in the Eker rat. Mol Carcinog 2003; 38:141-54. [PMID: 14587099 DOI: 10.1002/mc.10153] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hydroquinone (HQ) is a rodent carcinogen and a potential human carcinogen. Glutathione conjugation of HQ enhances its biological reactivity, and 2,3,5-tris-(glutathion-S-yl)hydroquinone (TGHQ) is a potent nephrotoxicant and nephrocarcinogen in the Eker rat. Moreover, a single exposure of primary epithelial cells derived from Eker rat kidneys to TGHQ transforms these cells into an immortalized phenotype (quinol-thioether transformed rat renal epithelial (QT-RRE) cells). The Eker rat bears a mutation in one allele of the tuberous sclerosis-2 (Tsc-2) tumor suppressor gene, which predisposes the animals to the development of spontaneous and chemical-induced renal cell carcinoma. Thus, the Eker rat provides a unique model for elucidating the mechanisms of renal tubular epithelial carcinogeneisis. cDNA microarray analysis of QT-RRE3 cells and of tumor tissue derived from the kidneys of Eker rats treated with TGHQ revealed alterations (by threefold or greater) in the expression of a total of 80 genes. Fifteen percent of these genes exhibited similar expression patterns in both QT-RRE cells and tumor tissue. The differentially expressed genes primarily participate in three major areas: (1) signal transduction or in the regulation of signal transduction (extracellular signal regulated kinase 2 (ERK2); protein kinase CK2; protein kinase B; c-jun; NF-kappaB; ras-related GTPases; annexins), (2) stress response, tissue remodeling, and DNA repair (glutathione-S-transferases; procollagen c proteinase enhancer; plasminogen activator; tissue inhibitor of metalloprotease 3; apurinic/apyrimidic endonuclease), and (3) electron transport and energy homeostasis (cytochrome c oxidase subunits). The changes in the expression of many of these genes was confirmed by reverse transcription (RT)-polymerase chain reactions (PCR) using primers specific for the differentially expressed genes. As an example, the annexin I and II genes, implicated in signal transduction, were highly induced in tumor tissue and also in dysplastic lesions isolated from the kidneys of rats treated chronically with TGHQ. The annexin I and II proteins were also upregulated in tumor tissue, which probably play an important role in TGHQ-induced nephrocarcinogenesis. Moreover, in the present study, a tumorigenicity assay using athymic nude mice revealed that QT-RRE cell lines formed tumors when injected in the subcutis of nude mice, providing evidence that the cells are malignantly transformed. Histopathological analysis further indicated that the tumors were composed of neoplastic cells, resembling renal carcinoma cells with varying degrees of atypia, with the presence of apoptotic and mitotic figures.
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Affiliation(s)
- Sonal K Patel
- Center for Molecular and Cellular Toxicology, Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, Texas, USA
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Escalier D, Silvius D, Xu X. Spermatogenesis of mice lacking CK2alpha': failure of germ cell survival and characteristic modifications of the spermatid nucleus. Mol Reprod Dev 2003; 66:190-201. [PMID: 12950107 DOI: 10.1002/mrd.10346] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Csnk2a2 encodes the CK2alpha'catalytic subunit of CK2 that is predominantly expressed in testis. Male mice in which Csnk2a2 has been disrupted were infertile and displayed oligozoospermia with an abnormal shape of the spermatid nucleus. In this study, Csnk2a2 null testes revealed extensive germ cell degenerative processes at all stages of spermatogenesis, including the first spermatogenesis wave. Nuclear envelope (NE) protrusions with loss of nuclear pores, swelling of the outer membrane, and disruption of the inner membrane were observed in cells ranging from spermatogonia to early spermatids. Most early round spermatids were depleted, and DNA-specific fluorescent dyes showed a large chromatin-free nuclear domain near the chromocenter. Spermatids that were not eliminated retained NE defects that could explain the acrosomal and nuclear abnormalities of Csnk2a2 null spermatozoa. Data suggest that CK2alpha' deficiency could impair the phosphorylation of nuclear proteins of male germ cells leading to a particular cell-death pathway characterized by NE protrusions and an unusual pattern of chromatin modifications in spermatids.
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Affiliation(s)
- Denise Escalier
- Histologie Fonctionnelle et Moléculaire, Université Paris 5, Paris, France.
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Grasselli E, Noviello G, Rando C, Nicolini C, Vergani L. Expression, purification and characterisation of a novel mutant of the human protein kinase CK2. Mol Biol Rep 2003; 30:97-106. [PMID: 12841580 DOI: 10.1023/a:1023934805326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The recombinant catalytic subunit of human protein kinase CK2 bas been mutagenised at the C-terminal region in an attempt to induce this tail to fold. We suppose in fact that this unstructured C-terminus just might be responsible for the high degradability of the human enzyme. On the basis of theoretical calculations we choose to substitute two distal prolines with alanines (PA 382-384). The mutant bas been purified to the electrophoretic homogeneity by means of three chromatographic steps. By circular dichroism Spectroscopy we verified if the double amino acids substitution reflected on the secondary structure of the recombinant a subunit. According to our theoretical predictions, we observed that the alpha-helix content of the protein increased when the two distal prolines were substituted by alanines. Moreover the mutant catalytic subunit shows a reduced ability to bind a classical inhibitor such as heparin.
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Affiliation(s)
- Elena Grasselli
- Department of Biophysical Sciences and Technologies M.&O., School of Medicine, University of Genova, Genova, Italy
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Wang H, Yu S, Davis AT, Ahmed K. Cell cycle dependent regulation of protein kinase CK2 signaling to the nuclear matrix. J Cell Biochem 2003; 88:812-22. [PMID: 12577315 DOI: 10.1002/jcb.10438] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Protein kinase CK2 is a ubiquitous protein serine/threonine kinase that is involved in cell growth and proliferation as well as suppression of apoptosis. Several studies have suggested that the kinase plays a role in cell cycle progression; however, changes in enzyme activity during phases of cell cycle have not been detected. Nuclear matrix is a key locus for CK2 signaling in the nucleus. We therefore examined CK2 signaling to the nuclear matrix in distinct phases of cell cycle by employing synchronized ALVA-41 prostate cancer cells. Removal of serum from the culture medium resulted in G0/G1 arrest, and a reduction in the nuclear matrix-associated CK2 activity which was rapidly reversed on addition of serum. Arresting the cells in G(0)/G(1) phase with hydroxyurea and subsequent release to S phase by serum gave similar results. Cells arrested in the G(2)/M phase by treatment with nocodazole demonstrated an extensive reduction in the nuclear matrix-associated CK2 which was reversed rapidly on addition of serum. Changes in the immunoreactive CK2 protein were concordant with the activity data reflecting a dynamic trafficking of the kinase in distinct phases of cell cycle. Under the same conditions, CK2 activity in total cellular lysate remained essentially unaltered. These results provide the first direct evidence of discrete modulations of CK2 in the nuclear matrix during the cell cycle progression. Inducible overexpression of CK2 in CHO cells yielded only a modest increase in CK2 activity even though a significant increase in expression was apparent at the level of CK2 alpha-specific message. Stably transfected ALVA-41 cells, however, did not show a significant change in CK2 levels despite increased expression at the message level. Not surprisingly, both types of the stably transfected cells failed to show any alteration in cell cycle progression. Distribution of the CK2 activity in the cytosolic versus nuclear matrix fractions in normal cells appears to be different from that in the cancer cells such that the ratio of nuclear matrix to cytosolic activity is much higher in the latter. Considering that nuclear matrix is central to several nuclear functions, this pattern of intracellular distribution of CK2 may have implications for its role in the oncogenic process. Published 2003 Wiley-Liss, Inc.
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Affiliation(s)
- Huamin Wang
- Cellular and Molecular Biochemistry Research Laboratory (151), Minneapolis Veterans Affairs Medical Center and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota 55417, USA
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50
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Xu YJ, Rathi SS, Chapman DC, Arneja AS, Dhalla NS. Mechanisms of lysophosphatidic acid-induced DNA synthesis in vascular smooth muscle cells. J Cardiovasc Pharmacol 2003; 41:381-7. [PMID: 12605016 DOI: 10.1097/00005344-200303000-00006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In order to investigate the signal transduction mechanisms of lysophosphatidic acid (LPA)-induced vascular smooth muscle (VSM) DNA synthesis, rat aortic A10 cells were used as an experimental model and [ H]-thymidine incorporation was used as an index of DNA synthesis. LPA caused dose- and time-dependent increase in DNA synthesis in A10 VSM cells. LPA (10 microM) also stimulated the activity of casein kinase II (CKII) in a time-dependent manner. The inhibitors of CKII, daidzein and 5,6-dichlorobenzimidazole riboside, diminished the LPA-induced increase in CKII activity and DNA synthesis. The LPA-stimulated activities of extracellularly regulated kinases (ERK) and p38 kinases as well as the stimulatory effects of LPA on DNA synthesis were blocked by ERK inhibitor, PD98059, and p38 kinase inhibitor, SB203580. The LPA-induced increase in intracellular free Ca and the LPA-induced DNA synthesis were not affected by Ca channel blockers, verapamil and diltiazem, as well as a Ca -dependent protein phosphatase (calcineurin) inhibitor, cyclosporine A. These data suggest that the LPA-induced DNA synthesis in VSM cells may be mediated by a signal transduction mechanism involving CKII, ERK, and p38 K.
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Affiliation(s)
- Yan-Jun Xu
- Institute of Cardiovascular Sciences, St Boniface General Hospital Research Center, Departments of Physiology and Internal Medicine, University of Manitoba, Winnipeg, Canada
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