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Kumar JK, Aronsson AC, Pilko G, Zupan M, Kumer K, Fabjan T, Osredkar J, Eriksson S. A clinical evaluation of the TK 210 ELISA in sera from breast cancer patients demonstrates high sensitivity and specificity in all stages of disease. Tumour Biol 2016; 37:11937-11945. [PMID: 27079872 PMCID: PMC5080325 DOI: 10.1007/s13277-016-5024-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 03/18/2016] [Indexed: 12/23/2022] Open
Abstract
Thymidine kinase (TK1) is an enzyme involved in DNA synthesis that leaks into the blood as a result of high cell turnover, particularly in the case of cancer. Serum TK1 activity has been used for prognosis and monitoring of leukemia and lymphoma patients for many years. Here, we describe the first clinical results with the newly developed TK 210 ELISA from AroCell AB. Sera from 124 breast cancer patients with known TNM classification along with sera from 53 healthy females were analyzed by TK 210 ELISA for TK1 protein and TK1 activity levels by the 3[H]-deoxythymidine (dThd) phosphorylation assay. The limit of detection for the TK 210 ELISA was 0.17 ng/ml, and 60 % of the sera from female blood donors were below this value. The median TK1 levels found in sera from breast cancer patients with T1 to T4 stage disease were 0.31, 0.46, 0.47, and 0.55 ng/ml, and these levels significantly differed from healthy controls. The median values of the biomarker CA 15-3 were also increased in patient sera from T1 to T4 patients (16, 34, 36, 40 U/ml, respectively). TK 210 ELISA showed significantly higher sensitivity for the T1 and T2 breast cancer patients compared to the TK activity assay. The combination of the TK1 ELISA and CA 15-3 biomarkers demonstrated a significant increase in sensitivity up to 15 % compared to each marker alone. This evaluation of the TK 210 ELISA strongly suggests that it can provide independent and complementary information for patients with breast cancer.
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Affiliation(s)
- J Kiran Kumar
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, VHC, PO Box 7011, SE 75007, Uppsala, Sweden. .,AroCell AB, Virdings Allé 32B, SE-754 50, Uppsala, Sweden.
| | - A C Aronsson
- AroCell AB, Virdings Allé 32B, SE-754 50, Uppsala, Sweden
| | - G Pilko
- Institute of Oncology, Ljubljana, Slovenia
| | - M Zupan
- Blood transfusion Centre, Ljubljana, Slovenia
| | - K Kumer
- Institute of Clinical Chemistry and Clinical Biochemistry, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - T Fabjan
- Institute of Clinical Chemistry and Clinical Biochemistry, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - J Osredkar
- Institute of Clinical Chemistry and Clinical Biochemistry, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - S Eriksson
- Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, VHC, PO Box 7011, SE 75007, Uppsala, Sweden.,AroCell AB, Virdings Allé 32B, SE-754 50, Uppsala, Sweden
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2
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Jagarlamudi KK, Moreau L, Westberg S, Rönnberg H, Eriksson S. A New Sandwich ELISA for Quantification of Thymidine Kinase 1 Protein Levels in Sera from Dogs with Different Malignancies Can Aid in Disease Management. PLoS One 2015; 10:e0137871. [PMID: 26366881 PMCID: PMC4569288 DOI: 10.1371/journal.pone.0137871] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 08/22/2015] [Indexed: 11/23/2022] Open
Abstract
Thymidine kinase 1 (TK1) is a DNA precursor enzyme whose expression is closely correlated with cell proliferation and cell turnover. Sensitive serum TK1 activity assays have been used for monitoring and prognosis of hematological malignancies in both humans and dogs. Here we describe the development of a specific sandwich TK1-ELISA for the quantification of TK1 protein levels in sera from dogs with different malignancies. A combination of rabbit polyclonal anti-dog TK1 antibody and a mouse monoclonal anti-human TK1 antibody was used. Different concentrations of recombinant canine TK1 was used as standard. Clinical evaluation of the ELISA was done by using sera from 42 healthy dogs, 43 dogs with hematological tumors and 55 with solid tumors. An established [3H]-dThd phosphorylation assay was used to determine the TK1 activity levels in the same sera. The mean TK1 activities in dogs with hematological tumors were significantly higher than those found in healthy dogs. In agreement with earlier studies, no significant difference was observed in serum TK1 activities between healthy dogs and dogs with solid tumors. However, the mean TK1 protein levels determined by new TK1-ELISA were significantly higher not only in hematological tumors but also in solid tumors compared to healthy dogs (mean ± SD = 1.30 ± 1.16, 0.67 ± 0.55 and 0.27± 0.10 ng/mL, respectively). Moreover, TK1-ELISA had significantly higher ability to distinguish lymphoma cases from healthy based on receiver operating characteristic analyses (area under the curve, AUC, of 0.96) to that of the activity assay (AUC, 0.84). Furthermore, fluctuations in TK1 protein levels during the course of chemotherapy in dogs with lymphoma closely associated with clinical outcome. Overall, the TK1-ELISA showed significant linear correlation with the TK1 activity assay (rs = 0.6, p<0.0001). Thus, the new TK1-ELISA has sufficient sensitivity and specificity for routine clinical use in veterinary oncology.
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Affiliation(s)
- Kiran Kumar Jagarlamudi
- Department of Anatomy, Physiology, and Biochemistry, Veterinary Medicine and Animal Science center, Swedish University of Agricultural Sciences, Uppsala, Sweden
- * E-mail:
| | - Laura Moreau
- Department of Anatomy, Physiology, and Biochemistry, Veterinary Medicine and Animal Science center, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Sara Westberg
- University Animal Hospital, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Henrik Rönnberg
- Center of Clinical Comparative Oncology (C3O), Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Staffan Eriksson
- Department of Anatomy, Physiology, and Biochemistry, Veterinary Medicine and Animal Science center, Swedish University of Agricultural Sciences, Uppsala, Sweden
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Sala R, Nguyen QD, Patel CBK, Mann D, Steinke JHG, Vilar R, Aboagye EO. Phosphorylation status of thymidine kinase 1 following antiproliferative drug treatment mediates 3'-deoxy-3'-[18F]-fluorothymidine cellular retention. PLoS One 2014; 9:e101366. [PMID: 25003822 PMCID: PMC4086825 DOI: 10.1371/journal.pone.0101366] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 06/05/2014] [Indexed: 12/29/2022] Open
Abstract
Background 3′-Deoxy-3′-[18F]-fluorothymidine ([18F]FLT) is being investigated as a Positron Emission Tomography (PET) proliferation biomarker. The mechanism of cellular [18F]FLT retention has been assigned primarily to alteration of the strict transcriptionally regulated S-phase expression of thymidine kinase 1 (TK1). This, however, does not explain how anticancer agents acting primarily through G2/M arrest affect [18F]FLT uptake. We investigated alternative mechanisms of [18F]FLT cellular retention involving post-translational modification of TK1 during mitosis. Methods [18F]FLT cellular retention was assessed in cell lines having different TK1 expression. Drug-induced phosphorylation of TK1 protein was evaluated by MnCl2-phos-tag gel electrophoresis and correlated with [18F]FLT cellular retention. We further elaborated the amino acid residues involved in TK1 phosphorylation by transient transfection of FLAG-pCMV2 plasmids encoding wild type or mutant variants of TK1 into TK1 negative cells. Results Baseline [18F]FLT cellular retention and TK1 protein expression were associated. S-phase and G2/M phase arrest caused greater than two-fold reduction in [18F]FLT cellular retention in colon cancer HCT116 cells (p<0.001). G2/M cell cycle arrest increased TK1 phosphorylation as measured by induction of at least one phosphorylated form of the protein on MnCl2-phos-tag gels. Changes in [18F]FLT cellular retention reflected TK1 phosphorylation and not expression of total protein, in keeping with the impact of phosphorylation on enzyme catalytic activity. Both Ser13 and Ser231 were shown to be involved in the TK1 phosphorylation-modulated [18F]FLT cellular retention; although the data suggested involvement of other amino-acid residues. Conclusion We have defined a regulatory role of TK1 phosphorylation in mediating [18F]FLT cellular retention and hence reporting of antiproliferative activity, with implications especially for drugs that induce a G2/M cell cycle arrest.
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Affiliation(s)
- Roberta Sala
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Quang-Dé Nguyen
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Chirag B. K. Patel
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, London, United Kingdom
| | - David Mann
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Joachim H. G. Steinke
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, London, United Kingdom
| | - Ramon Vilar
- Institute of Chemical Biology, Department of Chemistry, Imperial College London, London, United Kingdom
| | - Eric O. Aboagye
- Comprehensive Cancer Imaging Centre, Department of Surgery and Cancer, Imperial College London, London, United Kingdom
- * E-mail:
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Sharif H, Hagman R, Wang L, Eriksson S. Elevation of serum thymidine kinase 1 in a bacterial infection: Canine pyometra. Theriogenology 2013; 79:17-23. [DOI: 10.1016/j.theriogenology.2012.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 09/07/2012] [Accepted: 09/07/2012] [Indexed: 11/25/2022]
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Plotnik DA, McLaughlin LJ, Krohn KA, Schwartz JL. The effects of 5-fluoruracil treatment on 3'-fluoro-3'-deoxythymidine (FLT) transport and metabolism in proliferating and non-proliferating cultures of human tumor cells. Nucl Med Biol 2012; 39:970-6. [PMID: 22560972 DOI: 10.1016/j.nucmedbio.2012.03.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 02/21/2012] [Accepted: 03/20/2012] [Indexed: 01/19/2023]
Abstract
UNLABELLED 3'-Fluoro-3'-deoxythymidine (FLT) positron emission tomography (PET) has been proposed for imaging thymidylate synthase (TS) inhibition. Agents that target TS and shut down de novo synthesis of thymidine monophosphate increase the uptake and retention of FLT in vitro and in vivo because of a compensating increase in the salvage pathway. Increases in both thymidine kinase-1 (TK1) and the equilibrative nucleoside transporter hENT1 have been reported to underlie this effect. We examined whether the effects of one TS inhibitor, 5-fluorouracil (5FU), on FLT uptake require proliferating cells and whether the effects are limited to increasing TK1 activity. METHODS The effects of 5FU on FLT transport and metabolism, TK1 activity, and cell cycle progression were evaluated in the human tumor cell line, A549, maintained as either a proliferating or non-proliferating culture. RESULTS There were dose-dependent increases in FLT uptake that peaked after a 10 μM 5FU exposure and then declined to baseline levels or below at higher doses in both proliferating and non-proliferating cultures. The dose-dependence for FLT uptake was mirrored by changes in TK1 activity. S phase fraction did not correlate with FLT uptake in proliferating cultures. Chemical inhibition of hENT1 reduced overall levels of FLT uptake but did not affect the low dose increase in FLT uptake. CONCLUSIONS 5FU only affects FLT uptake in proliferating A549 cells and increases in FLT uptake are directly related to increased TK1 activity. Our studies did not support a role for hENT1 in the increased uptake of FLT after exposure to 5FU. Our studies with A549 cells support the suggestion that FLT-PET could provide a measure of TS inhibition in vivo.
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Affiliation(s)
- David A Plotnik
- Department of Radiation Oncology, University of Washington, Box 356069 Seattle, WA 98195, USA
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Sharif H, von Euler H, Westberg S, He E, Wang L, Eriksson S. A sensitive and kinetically defined radiochemical assay for canine and human serum thymidine kinase 1 (TK1) to monitor canine malignant lymphoma. Vet J 2012; 194:40-7. [PMID: 22516918 DOI: 10.1016/j.tvjl.2012.03.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 03/06/2012] [Accepted: 03/10/2012] [Indexed: 11/29/2022]
Abstract
Thymidine kinase 1 (TK1) is a cell cycle regulated enzyme with maximum expression during the S phase. Serum TK1 (S-TK1) is a unique biomarker for cell proliferation. Here, an optimized [(3)H]-thymidine (dThd) phosphorylation assay is described, which is as sensitive as the commercially available TK-REA and TK-Liaison assays for measurement of S-TK1 activity in dogs and humans. Serum samples from dogs (35 healthy, 32 with lymphoma, 2 with leukemia, and 35 with solid tumors) and humans (18 healthy, 9 with chronic lymphocytic leukemia, 10 with myelodysplastic syndrome) were analyzed using the [(3)H]-dThd assay. Mean S-TK1 activities were 1.11 ± 0.46 pmol/min/mL in healthy dogs and 1.15 ± 0.32 pmol/min/mL in healthy humans. S-TK1 activities in dogs with hematological malignancies were 24.2 ± 47.9 pmol/min/mL, and the receiver operating characteristic curve showed an area under the curve of 0.88. With a cut-off value of 1.9 pmol/min/mL (mean value ± 2 SD), the sensitivity was 0.94 and the specificity was 0.68. Very similar results were obtained with human samples (healthy and lymphoma cases). S-TK1 activities measured during chemotherapy of six dogs with lymphoma were drastically reduced. In one case, S-TK1 activity increased prior to relapse. S-TK1 levels in dogs with solid tumors did not differ from the healthy group. S-TK1 activities correlated with those determined with the TK-REA and TK-Liaison assays (r=0.92 and r=0.96, respectively). In conclusion, this optimized [(3)H]-dThd assay is fast, sensitive and economical for measuring S-TK1 activity and should increase its clinical use as biomarker.
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Affiliation(s)
- H Sharif
- Department of Anatomy, Swedish University of Agricultural Sciences, BMC, P.O. Box 575, S-751 23 Uppsala, Sweden
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Hu CM, Chang ZF. Mitotic control of dTTP pool: a necessity or coincidence? J Biomed Sci 2007; 14:491-7. [PMID: 17525869 DOI: 10.1007/s11373-007-9175-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Accepted: 02/27/2007] [Indexed: 10/23/2022] Open
Abstract
The fidelity of DNA replication in eukaryotic cells requires a balanced dNTP supply in the S phase. During the cell cycle progression, the production of dTTP is highly regulated to coordinate with DNA replication. Intracellular thymidine is salvaged to dTTP by cytosolic thymidine kinase (TK1) and thymidylate kinase (TMPK), both of which expression increase in the G1/S transition and diminish in the mitotic phase via proteolytic destruction. Anaphase promoting complex/cyclosome (APC/C)-mediated ubiquitination targets TK1 and TMPK to undergo proteasomal degradation in mitosis, by which dTTP pool is minimized in the early G1 phase of the next cell cycle. In this review, we will focus on regulation of TK1 in the post-S phase and the importance of mitotic proteolysis in controlling dNTP balance, replication stress and genomic stability. Finally, we discuss how thymidine pool and oligomeric forms of TK1 can affect mitotic control of dTTP.
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Affiliation(s)
- Chun-Mei Hu
- Graduate Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, No. 1, Section 1, Jen-Ai Road, Taipei, 100, Taiwan
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Hsu JM, Lee YCG, Yu CTR, Huang CYF. Fbx7 functions in the SCF complex regulating Cdk1-cyclin B-phosphorylated hepatoma up-regulated protein (HURP) proteolysis by a proline-rich region. J Biol Chem 2004; 279:32592-602. [PMID: 15145941 DOI: 10.1074/jbc.m404950200] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
F-box proteins, components of SCF ubiquitin-ligase complexes, are believed to be responsible for substrate recognition and recruitment in SCF-mediated proteolysis. F-box proteins that have been identified to function in the SCF complexes to date mostly have substrate-binding motifs, such as WD repeats or leucine-rich repeats in their C termini. However, many F-box proteins lack recognizable substrate-binding modules; whether they can function in the SCF complexes remains unclear. We show here that Fbx7, an F-box protein without WD repeats and leucine-rich repeats, is required for the proteasome-mediated proteolysis of the hepatoma up-regulated protein (HURP). Depletion of Fbx7 by small interfering RNA leads to depression of HURP ubiquitination and accumulation of HURP abundance. In the SCF(Fbx7) complex, Fbx7 recruits HURP through its C-terminal proline-rich region in a Cdk1-cyclin B-phosphorylation dependent manner. Mutation of the multiple Cdk1-cyclin B phosphorylation sites on HURP or the proline-rich region of Fbx7 abolishes the association between Fbx7 and HURP. Thus, Fbx7 is a functional adaptor of the SCF complex with a proline-rich region as the substrate-binding module. In addition to Fbx7, data base analyses reveal two putative mammalian proline-rich region-containing F-box proteins, KIAA1783 and RIKEN cDNA 2410015K21. Taken together, these findings further expound the diverse substrate-recognition abilities of the SCF complexes.
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MESH Headings
- Amino Acid Motifs
- Amino Acid Sequence
- Binding Sites
- Blotting, Western
- CDC2 Protein Kinase/metabolism
- Carcinoma, Hepatocellular/metabolism
- Cell Cycle
- Cell Line
- Cyclin B/metabolism
- Cycloheximide/pharmacology
- DNA, Complementary/metabolism
- Databases as Topic
- Electrophoresis, Polyacrylamide Gel
- Enzyme Inhibitors/pharmacology
- F-Box Proteins/metabolism
- F-Box Proteins/physiology
- Genetic Vectors
- Humans
- Microscopy, Fluorescence
- Mitosis
- Models, Biological
- Models, Genetic
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Mutation
- Neoplasm Proteins/metabolism
- Nocodazole/pharmacology
- Phosphoproteins/chemistry
- Phosphorylation
- Precipitin Tests
- Proline/chemistry
- Protein Binding
- Protein Biosynthesis
- Protein Structure, Tertiary
- Protein Synthesis Inhibitors/pharmacology
- RNA, Small Interfering/metabolism
- Recombinant Proteins/chemistry
- Recombination, Genetic
- Sequence Homology, Amino Acid
- Stem Cell Factor/metabolism
- Substrate Specificity
- Temperature
- Time Factors
- Transfection
- Ubiquitin/metabolism
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Affiliation(s)
- Jung-Mao Hsu
- Division of Molecular and Genomic Medicine, National Health Research Institutes, Taipei 115, Taiwan
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Ke PY, Chang ZF. Mitotic degradation of human thymidine kinase 1 is dependent on the anaphase-promoting complex/cyclosome-CDH1-mediated pathway. Mol Cell Biol 2004; 24:514-26. [PMID: 14701726 PMCID: PMC343798 DOI: 10.1128/mcb.24.2.514-526.2004] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The expression of human thymidine kinase 1 (hTK1) is highly dependent on the growth states and cell cycle stages in mammalian cells. The amount of hTK1 is significantly increased in the cells during progression to the S and M phases, and becomes barely detectable in the early G(1) phase by a proteolytic control during mitotic exit. This tight regulation is important for providing the correct pool of dTTP for DNA synthesis at the right time in the cell cycle. Here, we investigated the mechanism responsible for mitotic degradation of hTK1. We show that hTK1 is degraded via a ubiquitin-proteasome pathway in mammalian cells and that anaphase-promoting complex/cyclosome (APC/C) activator Cdh1 is not only a necessary but also a rate-limiting factor for mitotic degradation of hTK1. Furthermore, a KEN box sequence located in the C-terminal region of hTK1 is required for its mitotic degradation and interaction capability with Cdh1. By in vitro ubiquitinylation assays, we demonstrated that hTK1 is targeted for degradation by the APC/C-Cdh1 ubiquitin ligase dependent on this KEN box motif. Taken together, we concluded that activation of the APC/C-Cdh1 complex during mitotic exit controls timing of hTK1 destruction, thus effectively minimizing dTTP formation from the salvage pathway in the early G(1) phase of the cell cycle in mammalian cells.
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Affiliation(s)
- Po-Yuan Ke
- Graduate Institute of Biochemistry and Molecular Biology, National Taiwan University College of Medicine, No. 1, Section 1 Jen-Ai Road, Taipei 100, Taiwan, Republic of China
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Li CL, Lu CY, Ke PY, Chang ZF. Perturbation of ATP-induced tetramerization of human cytosolic thymidine kinase by substitution of serine-13 with aspartic acid at the mitotic phosphorylation site. Biochem Biophys Res Commun 2004; 313:587-93. [PMID: 14697231 DOI: 10.1016/j.bbrc.2003.11.147] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Human cytosolic thymidine kinase (TK1) is tightly regulated in the cell cycle by multiple mechanisms. Our laboratory has previously shown that in mitotic-arrested cells human TK1 is phosphorylated at serine-13, accompanied by a decrease in catalytic efficiency. In this study we investigated whether serine-13 phosphorylation regulated TK1 activity and found that substitution of serine-13 with aspartic acid (S13D), which mimics phosphorylation, not only diminished the ATP-activating effect on the enzyme, but also decreased its thymidine substrate affinity. Our experimental results further showed that the S13D mutation perturbed ATP-induced tetramerization of TK1. Given that the dimeric form of TK1 is less active than the tetrameric, we propose that mitotic phosphorylation of serine-13 is of physiological importance, in that it may counteract ATP-dependent activation of TK1 by affecting its quaternary structure, thus attenuating its enzymatic function at the G2/M phase.
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Affiliation(s)
- Chia-Lung Li
- Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, No 1 Jen Ai Road First Section, Taipei, Taiwan ROC
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