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Jeon J, Lee S, Park JM, Lee TH, Kang TH. Circadian control of cisplatin-DNA adduct repair and apoptosis in culture cells. Int J Biochem Cell Biol 2023; 162:106454. [PMID: 37574041 DOI: 10.1016/j.biocel.2023.106454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 07/02/2023] [Accepted: 08/09/2023] [Indexed: 08/15/2023]
Abstract
Cisplatin, a widely prescribed chemotherapeutic agent for treating solid tumors, induces DNA adducts and activates cellular defense mechanisms, including DNA repair, cell cycle checkpoint control, and apoptosis. Considering the circadian rhythmicity displayed by most chemotherapeutic agents and their varying therapeutic efficacy based on treatment timing, our study aimed to investigate whether the circadian clock system influences the DNA damage responses triggered by cisplatin in synchronized cells. We examined the DNA damage responses in circadian-synchronized wild-type mouse embryonic fibroblasts (WT-MEF; clock-proficient cells), cryptochrome1 and 2 double knock-out MEF (CRYDKO; clock-deficient cells), and mouse hepatocarcinoma Hepa1c1c7 cells. Varying the treatment time resulted in a significant difference in the rate of platinum-DNA adduct removal specifically in circadian-synchronized WT-MEF, while CRYDKO did not exhibit such variation. Moreover, diurnal variation in other DNA damage responses, such as cell cycle checkpoint activity indicated by p53 phosphorylation status and apoptosis measured by DNA break frequency, was observed only in circadian-synchronized WT-MEF, not in CRYDKO or mouse hepatocarcinoma Hepa1c1c7 cells. These findings highlight that the DNA damage responses triggered by cisplatin are indeed governed by circadian control exclusively in clock-proficient cells. This outcome bears potential implications for enhancing or devising chronotherapy approaches for cancer patients.
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Affiliation(s)
- Jeseok Jeon
- Department of Biomedical Sciences, Dong-A University, Busan 49315, Republic of Korea
| | - Sanggon Lee
- Department of Biomedical Sciences, Dong-A University, Busan 49315, Republic of Korea
| | - Jeong-Min Park
- Department of Stem Cell Transplantation Research, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Tae-Hee Lee
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Tae-Hong Kang
- Department of Biomedical Sciences, Dong-A University, Busan 49315, Republic of Korea.
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2
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Yang S, Johnson AN. The serine/threonine kinase Back seat driver prevents cell fusion to maintain cell identity. Dev Biol 2023; 495:35-41. [PMID: 36528051 PMCID: PMC11088746 DOI: 10.1016/j.ydbio.2022.12.004] [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: 07/25/2022] [Revised: 11/23/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
Cell fate specification is essential for every major event of embryogenesis, and subsequent cell maturation ensures individual cell types acquire specialized functions. The mechanisms that regulate cell fate specification have been studied exhaustively, and each technological advance in developmental biology ushers in a new era of studies aimed at uncovering the most fundamental processes by which cells acquire unique identities. What is less appreciated is that mechanisms are in place to ensure cell identity is maintained throughout the life of the organism. The body wall musculature in the Drosophila embryo is a well-established model to study cell fate specification, as each hemisegment in the embryo generates and maintains thirty muscles with distinct identities. Once specified, the thirty body wall muscles fuse with mononucleate muscle precursors that lack a specific identity to form multinucleate striated muscles. Multinucleate body wall muscles do not fuse with each other, which maintains a diversification of muscle cell identities. Here we show the serine/threonine kinase Back seat driver (Bsd) prevents inappropriate muscle fusion to maintain cell identity. Thus, the regulation of cell fusion is one mechanism that maintains cell identity.
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Affiliation(s)
- Shuo Yang
- Department of Developmental Biology Washington University School of Medicine St. Louis, MO 63110
| | - Aaron N. Johnson
- Department of Developmental Biology Washington University School of Medicine St. Louis, MO 63110
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3
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Ojaghi M, Varghese J, Kastelic JP, Thundathil JC. Characterization of the Testis-Specific Angiotensin Converting Enzyme (tACE)-Interactome during Bovine Sperm Capacitation. Curr Issues Mol Biol 2022; 44:449-469. [PMID: 35723410 PMCID: PMC8928970 DOI: 10.3390/cimb44010031] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/22/2021] [Accepted: 01/12/2022] [Indexed: 12/29/2022] Open
Abstract
A comprehensive understanding of molecular and biochemical changes during sperm capacitation is critical to the success of assisted reproductive technologies. We reported involvement of the testis-specific isoform of Angiotensin Converting Enzyme (tACE) in bovine sperm capacitation. The objective of this study was to characterize the tACE interactome in fresh and heparin-capacitated bovine sperm through immunoprecipitation coupled with mass spectrometry. These interactions were validated by co-localization of tACE with beta-tubulin as an identified interactome constituent. Although interactions between tACE and several proteins remained unchanged in fresh and capacitated sperm, mitochondrial aldehyde dehydrogenase 2 (ALDH2), inactive serine/threonine protein-kinase 3 (VRK3), tubulin-beta-4B chain (TUBB4B), and tubulin-alpha-8 chain (TUBA8) were recruited during capacitation, with implications for cytoskeletal and membrane reorganization, vesicle-mediated transport, GTP-binding, and redox regulation. A proposed tACE interactional network with identified interactome constituents was generated. Despite tACE function being integral to capacitation, the relevance of interactions with its binding partners during capacitation and subsequent events leading to fertilization remains to be elucidated.
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4
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Han SH, Kim KT. RNF144a induces ERK-dependent cell death under oxidative stress via downregulation of vaccinia-related kinase 3. J Cell Sci 2020; 133:jcs247304. [PMID: 33067254 DOI: 10.1242/jcs.247304] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 09/17/2020] [Indexed: 08/31/2023] Open
Abstract
Vaccinia-related kinase 3 (VRK3) has been reported to be a negative regulator of ERK (ERK1 and ERK2; also known as MAPK3 and MAPK1, respectively) that protects cells from persistent ERK activation and inhibits ERK-dependent apoptosis. Here we report that the E3 ubiquitin-protein ligase RNF144a promotes the degradation of VRK3 via polyubiquitylation and thus affects VRK3-mediated ERK activity. Under oxidative stress, VRK3 migrates from the nucleus to the cytoplasm, which increases its chance of interacting with RNF144a, thereby promoting the degradation of VRK3. Overexpression of RNF144a increases ERK activity via downregulation of VRK3 and promotes ERK-dependent apoptosis. In contrast, depletion of RNF144a increases the protein level of VRK3 and protects cells from excessive ERK activity. These findings suggest that VRK3 protects cells by suppressing oxidative stress-induced ERK, and that RNF144a sensitively regulates this process.
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Affiliation(s)
- Seung Hyun Han
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
| | - Kyong-Tai Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 37673, Republic of Korea
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5
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Sears RM, Roux KJ. Diverse cellular functions of barrier-to-autointegration factor and its roles in disease. J Cell Sci 2020; 133:133/16/jcs246546. [PMID: 32817163 DOI: 10.1242/jcs.246546] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Barrier-to-autointegration factor (BAF; encoded by BANF1) is a small highly conserved, ubiquitous and self-associating protein that coordinates with numerous binding partners to accomplish several key cellular processes. By interacting with double-stranded DNA, histones and various other nuclear proteins, including those enriched at the nuclear envelope, BAF appears to be essential for replicating cells to protect the genome and enable cell division. Cellular processes, such as innate immunity, post-mitotic nuclear reformation, repair of interphase nuclear envelope rupture, genomic regulation, and the DNA damage and repair response have all been shown to depend on BAF. This Review focuses on the regulation of the numerous interactions of BAF, which underlie the mechanisms by which BAF accomplishes its essential cellular functions. We will also discuss how perturbation of BAF function may contribute to human disease.
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Affiliation(s)
- Rhiannon M Sears
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD 57104, USA.,Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069, USA
| | - Kyle J Roux
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD 57104, USA .,Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57069, USA
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6
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Zhang Q, Liu W, Liu C, Lin SY, Guo AY. SEGtool: a specifically expressed gene detection tool and applications in human tissue and single-cell sequencing data. Brief Bioinform 2019; 19:1325-1336. [PMID: 28981576 DOI: 10.1093/bib/bbx074] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Indexed: 12/20/2022] Open
Abstract
Different tissues and diseases have distinct transcriptional profilings with specifically expressed genes (SEGs). So, the identification of SEGs is an important issue in the studies of gene function, biological development, disease mechanism and biomarker discovery. However, few accurate and easy-to-use tools are available for RNA sequencing (RNA-seq) data to detect SEGs. Here, we presented SEGtool, a tool based on fuzzy c-means, Jaccard index and greedy annealing method for SEG detection automatically and self-adaptively ignoring data distribution. Testing result showed that our SEGtool outperforms the existing tools, which was mainly developed for microarray data. By applying SEGtool to Genotype-Tissue Expression (GTEx) human tissue data set, we detected 3181 SEGs with tissue-related functions. Regulatory networks reveal tissue-specific transcription factors regulating many SEGs, such as ETV2 in testis, HNF4A in liver and NEUROD1 in brain. Applied to a case study of single-cell sequencing (SCS) data from embryo cells, we identified many SEGs in specific stages of human embryogenesis. Notably, SEGtool is suitable for RNA-seq data and even SCS data with high specificity and accuracy. An implementation of SEGtool R package is freely available at http://bioinfo.life.hust.edu.cn/SEGtool/.
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Affiliation(s)
- Qiong Zhang
- Huazhong University of Science and Technology, China
| | - Wei Liu
- Huazhong University of Science and Technology, China
| | - Chunjie Liu
- Huazhong University of Science and Technology, China
| | - Sheng-Yan Lin
- Huazhong University of Science and Technology, China
| | - An-Yuan Guo
- Huazhong University of Science and Technology, China
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7
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Ryu HG, Kim S, Lee S, Lee E, Kim HJ, Kim DY, Kim KT. HNRNP Q suppresses polyglutamine huntingtin aggregation by post-transcriptional regulation of vaccinia-related kinase 2. J Neurochem 2019; 149:413-426. [PMID: 30488434 DOI: 10.1111/jnc.14638] [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] [Received: 10/09/2018] [Revised: 11/20/2018] [Accepted: 11/22/2018] [Indexed: 12/22/2022]
Abstract
Misfolded proteins with abnormal polyglutamine (polyQ) expansion cause neurodegenerative disorders, including Huntington's disease. Recently, it was found that polyQ aggregates accumulate as a result of vaccinia-related kinase 2 (VRK2)-mediated degradation of TCP-1 ring complex (TRiC)/chaperonin-containing TCP-1 (CCT), which has an essential role in the prevention of polyQ protein aggregation and cytotoxicity. The levels of VRK2 are known to be much higher in actively proliferating cells but are maintained at a low level in the brain via an unknown mechanism. Here, we found that basal levels of neuronal cell-specific VRK2 mRNA are maintained by post-transcriptional, rather than transcriptional, regulation. Moreover, heterogeneous nuclear ribonucleoprotein Q (HNRNP Q) specifically binds to the 3'untranslated region of VRK2 mRNA in neuronal cells to reduce the mRNA stability. As a result, we found a dramatic decrease in CCT4 protein levels in response to a reduction in HNRNP Q levels, which was followed by an increase in polyQ aggregation in human neuroblastoma cells and mouse cortical neurons. Taken together, these results provide new insights into how neuronal HNRNP Q decreases VRK2 mRNA stability and contributes to the prevention of Huntington's disease, while also identifying new prognostic markers of HD.
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Affiliation(s)
- Hye Guk Ryu
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Korea
| | - Sangjune Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Korea.,Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Baltimore, Maryland, USA.,Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Saebom Lee
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Korea.,Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Baltimore, Maryland, USA.,Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Eunju Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Korea.,Advanced Bio Convergence Center, Pohang Technopark, Pohang, Korea
| | - Hyo-Jin Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Korea.,SL BIGEN, Seongnam, Korea
| | - Do-Yeon Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Korea.,Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, Korea.,Brain Science & Engineering Institute, Kyungpook National University, Daegu, Korea
| | - Kyong-Tai Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang, Korea.,Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Pohang, Korea
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8
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Park CH, Ryu HG, Kim SH, Lee D, Song H, Kim KT. Presumed pseudokinase VRK3 functions as a BAF kinase. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1738-48. [PMID: 25899223 DOI: 10.1016/j.bbamcr.2015.04.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 04/04/2015] [Accepted: 04/10/2015] [Indexed: 11/29/2022]
Abstract
Vaccinia-related kinase 3 (VRK3) is known as a pseudokinase that is catalytically inactive due to changes in motifs that are essential for kinase activity. Although VRK3 has been regarded as a genuine pseudokinase from structural and biochemical studies, recent reports suggest that VRK3 acts as an active kinase as well as a signaling scaffold in cells. Here, we demonstrate that VRK3 phosphorylates the nuclear envelope protein barrier-to-autointegration factor (BAF) on Ser4. Interestingly, VRK3 kinase activity is dependent upon its N-terminal regulatory region, which is excluded from the determination of its crystal structure. Furthermore, the kinase activity of VRK3 is involved in the regulation of the cell cycle. VRK3 expression levels increase during interphase, whereas VRK1 is enriched in late G2 and early M phase. Ectopic expression of VRK3 induces the translocation of BAF from the nucleus to the cytoplasm. In addition, depletion of VRK3 decreases the population of proliferating cells. These data suggest that VRK3-mediated phosphorylation of BAF may facilitate DNA replication or gene expression by facilitating the dissociation of nuclear envelope proteins and chromatin during interphase.
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Affiliation(s)
- Choon-Ho Park
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology(POSTECH), Hyoja Dong, San 31, Pohang 790-784, Republic of Korea
| | - Hye Guk Ryu
- Department of Life Sciences, Pohang University of Science and Technology(POSTECH), Hyoja Dong, San 31, Pohang 790-784, Republic of Korea
| | - Seong-Hoon Kim
- Department of Life Sciences, Pohang University of Science and Technology(POSTECH), Hyoja Dong, San 31, Pohang 790-784, Republic of Korea
| | - Dohyun Lee
- Department of Life Sciences, Pohang University of Science and Technology(POSTECH), Hyoja Dong, San 31, Pohang 790-784, Republic of Korea
| | - Haengjin Song
- Department of Life Sciences, Pohang University of Science and Technology(POSTECH), Hyoja Dong, San 31, Pohang 790-784, Republic of Korea
| | - Kyong-Tai Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology(POSTECH), Hyoja Dong, San 31, Pohang 790-784, Republic of Korea; Department of Life Sciences, Pohang University of Science and Technology(POSTECH), Hyoja Dong, San 31, Pohang 790-784, Republic of Korea.
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9
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Kang TH, Leem SH. Modulation of ATR-mediated DNA damage checkpoint response by cryptochrome 1. Nucleic Acids Res 2014; 42:4427-34. [PMID: 24489120 PMCID: PMC3985666 DOI: 10.1093/nar/gku094] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mammalian cryptochromes (Crys) are essential circadian clock factors implicated in diverse clock-independent physiological functions, including DNA damage responses. Here we show that Cry1 modulates the ATR-mediated DNA damage checkpoint (DDC) response by interacting with Timeless (Tim) in a time-of-day-dependent manner. The DDC capacity in response to UV irradiation showed a circadian rhythm. Interestingly, clock-deficient Cry1 and Cry2 double knockout (CryDKO) cells retained substantial DDC capacity compared with clock-proficient wild-type cells, although the Cry1-modulated oscillation of the DDC capacity was abolished in CryDKO cells. We found temporal interaction of Cry1 and Tim in the nucleus. When Cry1 was expressed in the nucleus, it was critical for circadian ATR activity. We regenerated rhythmic DDC responses by ectopically expressing Cry1 in CryDKO cells. In addition, we also investigated the DDC capacity in the liver of mice that were intraperitoneally injected with cisplatin at different circadian times (CT). When mice were injected at CT20, about 2-fold higher expression of phosphorylated minichromosome maintenance protein 2 (p-MCM2) was detected compared with mice injected at CT08, which consequently affected the removal rate of cisplatin-DNA adducts from genomic DNA. Taken together, our data demonstrate the intimate interaction between the circadian clock and the DDC system during genotoxic stress in clock-ticking cells.
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Affiliation(s)
- Tae-Hong Kang
- Department of Biological Science, Dong-A University, Hadan2-dong, Saha-gu, Busan 604-714, South Korea
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10
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Lacroix J, Schlund F, Leuchs B, Adolph K, Sturm D, Bender S, Hielscher T, Pfister SM, Witt O, Rommelaere J, Schlehofer JR, Witt H. Oncolytic effects of parvovirus H-1 in medulloblastoma are associated with repression of master regulators of early neurogenesis. Int J Cancer 2013; 134:703-16. [PMID: 23852775 PMCID: PMC4232887 DOI: 10.1002/ijc.28386] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 06/24/2013] [Indexed: 12/31/2022]
Abstract
Based on extensive pre-clinical studies, the oncolytic parvovirus H-1 (H-1PV) is currently applied to patients with recurrent glioblastoma in a phase I/IIa clinical trial (ParvOryx01, NCT01301430). Cure rates of about 40% in pediatric high-risk medulloblastoma (MB) patients also indicate the need of new therapeutic approaches. In order to prepare a future application of oncolytic parvovirotherapy to MB, the present study preclinically evaluates the cytotoxic efficacy of H-1PV on MB cells in vitro and characterizes cellular target genes involved in this effect. Six MB cell lines were analyzed by whole genome oligonucleotide microarrays after treatment and the results were matched to known molecular and cytogenetic risk factors. In contrast to non-transformed infant astrocytes and neurons, in five out of six MB cell lines lytic H-1PV infection and efficient viral replication could be demonstrated. The cytotoxic effects induced by H-1PV were observed at LD50s below 0.05 p. f. u. per cell indicating high susceptibility. Gene expression patterns in the responsive MB cell lines allowed the identification of candidate target genes mediating the cytotoxic effects of H-1PV. H-1PV induced down-regulation of key regulators of early neurogenesis shown to confer poor prognosis in MB such as ZIC1, FOXG1B, MYC, and NFIA. In MB cell lines with genomic amplification of MYC, expression of MYC was the single gene most significantly repressed after H-1PV infection. H-1PV virotherapy may be a promising treatment approach for MB since it targets genes of functional relevance and induces cell death at very low titers of input virus.
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Affiliation(s)
- Jeannine Lacroix
- Division of Tumor Virology, Program Infection and Cancer, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 242, Heidelberg, Germany; Department of Pediatric Hematology, Oncology and Immunology, Heidelberg University Hospital, Im Neuenheimer Feld 430, Heidelberg, Germany
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11
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Krementsov DN, Katchy A, Case LK, Carr FE, Davis B, Williams C, Teuscher C. Studies in experimental autoimmune encephalomyelitis do not support developmental bisphenol a exposure as an environmental factor in increasing multiple sclerosis risk. Toxicol Sci 2013; 135:91-102. [PMID: 23798566 DOI: 10.1093/toxsci/kft141] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Multiple sclerosis (MS), a demyelinating immune-mediated central nervous system disease characterized by increasing female penetrance, is the leading cause of disability in young adults in the developed world. Epidemiological data strongly implicate an environmental factor, acting at the population level during gestation, in the increasing incidence of female MS observed over the last 50 years, yet the identity of this factor remains unknown. Gestational exposure to bisphenol A (BPA), an endocrine disruptor used in the manufacture of polycarbonate plastics since the 1950s, has been reported to alter a variety of physiological processes in adulthood. BPA has estrogenic activity, and we hypothesized that increased gestational exposure to environmental BPA may therefore contribute to the increasing female MS risk. To test this hypothesis, we utilized two different mouse models of MS, experimental autoimmune encephalomyelitis (EAE) in C57BL/6J mice (chronic progressive) and in SJL/J mice (relapsing-remitting). Dams were exposed to physiologically relevant levels of BPA in drinking water starting 2 weeks prior to mating and continuing until weaning of offspring. EAE was induced in adult offspring. No significant changes in EAE incidence, progression, or severity were observed with BPA exposure, despite changes in cytokine production by autoreactive T cells. However, endocrine disruption was evidenced by changes in testes development, and transcriptomic profiling revealed that BPA exposure altered the expression of several genes important for testes development, including Pdgfa, which was downregulated. Overall, our results do not support gestational BPA exposure as a significant contributor to the increasing female MS risk.
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Affiliation(s)
- Dimitry N Krementsov
- Department of Medicine, Immunobiology Program, University of Vermont, Burlington, Vermont 05405, USA
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12
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Lee TH, Park JM, Leem SH, Kang TH. Coordinated regulation of XPA stability by ATR and HERC2 during nucleotide excision repair. Oncogene 2012. [PMID: 23178497 DOI: 10.1038/onc.2012.539] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
ATR (ATM and Rad3-related) is an essential regulator of the nucleotide excision repair (NER) mechanism. For NER activation, ATR phosphorylates XPA, the rate-limiting factor in the NER pathway. However, the role of XPA phosphorylation at serine 196 by ATR has been elusive. Here we show that ATR-mediated XPA phosphorylation enhances XPA stability by inhibiting HERC2-mediated ubiquitination and subsequent degradation. We analyzed stabilization of XPA with substitutions of Ser 196 either to aspartate (S196D), a phosphomimetic mutation, or to alanine (S196A), a phosphodeficient mutation. Upon ultraviolet damage, ATR facilitated HERC2 dissociation from the XPA complex to induce XPA stabilization. However, this regulation was abrogated in S196A-complemented XPA-deficient cells due to persistent association of HERC2 with this XPA complex, resulting in enhanced ubiquitination of S196A. Conversely, the S196D substitution showed delayed degradation kinetics compared with the wild-type and less binding with HERC2, resulting in reduced ubiquitination of S196D. We also found that XPA phosphorylation enhanced the chromatin retention of XPA, the interaction with its binding partners following DNA damage. Taken together, our study presents a novel control mechanism in the NER pathway by regulating the steady-state level of XPA through posttranslational modifications by which ATR-mediated phosphorylation induces XPA stabilization by antagonizing HERC2-catalyzed XPA ubiquitination.
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Affiliation(s)
- T-H Lee
- Department of Biological Science, Dong-A University, Busan, Republic of Korea
| | - J-M Park
- Department of Biological Science, Dong-A University, Busan, Republic of Korea
| | - S-H Leem
- Department of Biological Science, Dong-A University, Busan, Republic of Korea
| | - T-H Kang
- Department of Biological Science, Dong-A University, Busan, Republic of Korea
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13
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Fernández IF, Pérez-Rivas LG, Blanco S, Castillo-Dominguez AA, Lozano J, Lazo PA. VRK2 anchors KSR1-MEK1 to endoplasmic reticulum forming a macromolecular complex that compartmentalizes MAPK signaling. Cell Mol Life Sci 2012; 69:3881-93. [PMID: 22752157 PMCID: PMC11114894 DOI: 10.1007/s00018-012-1056-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 05/16/2012] [Accepted: 06/11/2012] [Indexed: 12/30/2022]
Abstract
The spatial and temporal regulation of intracellular signaling is determined by the spatial and temporal organization of complexes assembled on scaffold proteins, which can be modulated by their interactions with additional proteins as well as subcellular localization. The scaffold KSR1 protein interacts with MAPK forming a complex that conveys a differential signaling in response to growth factors. The aim of this work is to determine the unknown mechanism by which VRK2A downregulates MAPK signaling. We have characterized the multiprotein complex formed by KSR1 and the Ser-Thr kinase VRK2A. VRK2A is a protein bound to the endoplasmic reticulum (ER) and retains a fraction of KSR1 complexes on the surface of this organelle. Both proteins, VRK2A and KSR1, directly interact by their respective C-terminal regions. In addition, MEK1 is also incorporated in the basal complex. MEK1 independently interacts with the CA5 region of KSR1 and with the N-terminus of VRK2A. Thus, VRK2A can form a high molecular size (600-1,000 kDa) stable complex with both MEK1 and KSR1. Knockdown of VRK2A resulted in disassembly of these high molecular size complexes. Overexpression of VRK2A increased the amount of KSR1 in the particulate fraction and prevented the incorporation of ERK1/2 into the complex after stimulation with EGF. Neither VRK2A nor KSR1 interact with the VHR, MKP1, MKP2, or MKP3 phosphatases. The KSR1 complex assembled and retained by VRK2A in the ER can have a modulatory effect on the signal mediated by MAPK, thus locally affecting the magnitude of its responses, and can explain differential responses depending on cell type.
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Affiliation(s)
- Isabel F. Fernández
- Experimental Therapeutics and Translational Oncology Program, Instituto de Biología Molecular y Celular del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Luis G. Pérez-Rivas
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Malaga, Spain
- Laboratorio de Oncología Molecular, Fundación IMABIS, Hospital Clínico Universitario Virgen de la Victoria, Malaga, Spain
| | - Sandra Blanco
- Experimental Therapeutics and Translational Oncology Program, Instituto de Biología Molecular y Celular del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Adrián A. Castillo-Dominguez
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Malaga, Spain
- Laboratorio de Oncología Molecular, Fundación IMABIS, Hospital Clínico Universitario Virgen de la Victoria, Malaga, Spain
| | - José Lozano
- Departamento de Biología Molecular y Bioquímica, Facultad de Ciencias, Universidad de Málaga, Malaga, Spain
- Laboratorio de Oncología Molecular, Fundación IMABIS, Hospital Clínico Universitario Virgen de la Victoria, Malaga, Spain
| | - Pedro A. Lazo
- Experimental Therapeutics and Translational Oncology Program, Instituto de Biología Molecular y Celular del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
- Instituto de Investigación Biomédica de Salamanca (IBSAL), Hospital Universitario de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
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14
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Zhang H, Photiou A, Grothey A, Stebbing J, Giamas G. The role of pseudokinases in cancer. Cell Signal 2012; 24:1173-84. [PMID: 22330072 DOI: 10.1016/j.cellsig.2012.01.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 01/27/2012] [Indexed: 01/12/2023]
Abstract
Kinases play a critical role in regulating many cellular functions including development, differentiation and proliferation. To date, over 518 proteins with kinase activity, comprising ~2-3% of total cellular proteins, have been identified from within the human kinome. Interestingly, approximately 10% of kinases are categorised as pseudokinases since they lack one or more conserved catalytic residues within their kinase domain and were originally thought to have no enzymatic activity. Recently, there has been strong evidence to suggest that some pseudokinsases can not only function as scaffold proteins, but may also possess kinase activity leading to modulation of cell signalling pathways. Altered activity of these pseudokinases can result in impaired cellular function, particularly in malignancies. In this review we are discussing recent evidence that apart from a scaffolding role, pseudokinases also orchestrate cellular processes as active kinases per se in signalling pathways of malignant cells.
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Affiliation(s)
- Hua Zhang
- Department of Cancer and Surgery, Imperial College, Hammersmith Hospital Campus, Du Cane Road, London, W12 ONN, UK
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15
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Zeqiraj E, van Aalten DMF. Pseudokinases-remnants of evolution or key allosteric regulators? Curr Opin Struct Biol 2010; 20:772-81. [PMID: 21074407 PMCID: PMC3014569 DOI: 10.1016/j.sbi.2010.10.001] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 10/05/2010] [Accepted: 10/08/2010] [Indexed: 11/18/2022]
Abstract
Protein kinases provide a platform for the integration of signal transduction networks. A key feature of transmitting these cellular signals is the ability of protein kinases to activate one another by phosphorylation. A number of kinases are predicted by sequence homology to be incapable of phosphoryl group transfer due to degradation of their catalytic motifs. These are termed pseudokinases and because of the assumed lack of phosphoryltransfer activity their biological role in cellular transduction has been mysterious. Recent structure-function studies have uncovered the molecular determinants for protein kinase inactivity and have shed light to the biological functions and evolution of this enigmatic subset of the human kinome. Pseudokinases act as signal transducers by bringing together components of signalling networks, as well as allosteric activators of active protein kinases.
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Affiliation(s)
- Elton Zeqiraj
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Room 1090, Toronto, Ontario M5G 1X5, Canada
- MRC Protein Phosphorylation Unit, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
| | - Daan MF van Aalten
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom
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16
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Wiebe MS, Nichols RJ, Molitor TP, Lindgren JK, Traktman P. Mice deficient in the serine/threonine protein kinase VRK1 are infertile due to a progressive loss of spermatogonia. Biol Reprod 2009; 82:182-93. [PMID: 19696012 DOI: 10.1095/biolreprod.109.079095] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The VRK1 protein kinase has been implicated as a pro-proliferative factor. Genetic analyses of mutant alleles of the Drosophila and Caenorhabditis elegans VRK1 homologs have revealed phenotypes ranging from embryonic lethality to mitotic and meiotic defects with resultant sterility. Herein, we describe the first genetic analysis of murine VRK1. Two lines of mice containing distinct gene-trap integrations into the Vrk1 locus were established. Insertion into intron 12 (GT12) spared VRK1 function, enabling the examination of VRK1 expression in situ. Insertion into intron 3 (GT3) disrupted VRK1 function, but incomplete splicing to the gene trap rendered this allele hypomorphic (approximately 15% of wild-type levels of VRK1 remain). GT3/GT3 mice are viable, but both males and females are infertile. In testes, VRK1 is expressed in Sertoli cells and spermatogonia. The infertility of GT3/GT3 male mice results from a progressive defect in spermatogonial proliferation or differentiation, culminating in the absence of mitotic and meiotic cells in adult testis. These data demonstrate an important role for VRK1 in cell proliferation and confirm that the need for VRK1 during gametogenesis is evolutionarily conserved.
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Affiliation(s)
- Matthew S Wiebe
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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17
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Scheeff ED, Eswaran J, Bunkoczi G, Knapp S, Manning G. Structure of the pseudokinase VRK3 reveals a degraded catalytic site, a highly conserved kinase fold, and a putative regulatory binding site. Structure 2009; 17:128-38. [PMID: 19141289 PMCID: PMC2639636 DOI: 10.1016/j.str.2008.10.018] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 10/15/2008] [Accepted: 10/21/2008] [Indexed: 01/19/2023]
Abstract
About 10% of all protein kinases are predicted to be enzymatically inactive pseudokinases, but the structural details of kinase inactivation have remained unclear. We present the first structure of a pseudokinase, VRK3, and that of its closest active relative, VRK2. Profound changes to the active site region underlie the loss of catalytic activity, and VRK3 cannot bind ATP because of residue substitutions in the binding pocket. However, VRK3 still shares striking structural similarity with VRK2, and appears to be locked in a pseudoactive conformation. VRK3 also conserves residue interactions that are surprising in the absence of enzymatic function; these appear to play important architectural roles required for the residual functions of VRK3. Remarkably, VRK3 has an "inverted" pattern of sequence conservation: although the active site is poorly conserved, portions of the molecular surface show very high conservation, suggesting that they form key interactions that explain the evolutionary retention of VRK3.
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Affiliation(s)
- Eric D Scheeff
- Razavi Newman Center for Bioinformatics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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18
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Sanz-García M, López-Sánchez I, Lazo PA. Proteomics identification of nuclear Ran GTPase as an inhibitor of human VRK1 and VRK2 (vaccinia-related kinase) activities. Mol Cell Proteomics 2008; 7:2199-214. [PMID: 18617507 PMCID: PMC2577208 DOI: 10.1074/mcp.m700586-mcp200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Human vaccinia-related kinase (VRK) 1 is a novel serine-threonine kinase that regulates several transcription factors, nuclear envelope assembly, and chromatin condensation and is also required for cell cycle progression. The regulation of this kinase family is unknown. Mass spectrometry has permitted the identification of Ran as an interacting and regulatory protein of the VRK serine-threonine kinase activities. The stable interaction has been validated by pulldown of endogenous proteins as well as by reciprocal immunoprecipitations. The three members of the VRK family stably interact with Ran, and the interaction was not affected by the bound nucleotide, GDP or GTP. The interaction was stronger with the RanT24N that is locked in its inactive conformation and cannot bind nucleotides. None of the kinases phosphorylated Ran or RCC1. VRK1 does not directly interact with RCC1, but if Ran is present they can be isolated as a complex. The main effect of the interaction of inactive RanGDP with VRK1 is the inhibition of its kinase activity, which was detected by a reduction in VRK1 autophosphorylation and a reduction in phosphorylation of histone H3 in residues Thr-3 and Ser-10. The kinase activity inhibition can be relieved by the interaction with the constitutively active RanGTP or RanL43E, which locks Ran in its GTP-bound active conformation. In this complex, the interaction with VRK proteins does not alter the effect of its guanine exchange factor, RCC1. Ran is a novel negative regulator of nuclear VRK1 and VRK2 kinase activity, which may vary in different subcellular localizations generating an asymmetric intracellular distribution of kinase activity depending on local protein interactions.
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Affiliation(s)
- Marta Sanz-García
- Programa de Oncología Translacional, Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca E-37007, Spain
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