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Kawamukai M. Regulation of sexual differentiation initiation in Schizosaccharomyces pombe. Biosci Biotechnol Biochem 2024; 88:475-492. [PMID: 38449372 DOI: 10.1093/bbb/zbae019] [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: 01/16/2024] [Accepted: 02/05/2024] [Indexed: 03/08/2024]
Abstract
The fission yeast Schizosaccharomyces pombe is an excellent model organism to explore cellular events owing to rich tools in genetics, molecular biology, cellular biology, and biochemistry. Schizosaccharomyces pombe proliferates continuously when nutrients are abundant but arrests in G1 phase upon depletion of nutrients such as nitrogen and glucose. When cells of opposite mating types are present, cells conjugate, fuse, undergo meiosis, and finally form 4 spores. This sexual differentiation process in S. pombe has been studied extensively. To execute sexual differentiation, the glucose-sensing cAMP-PKA (cyclic adenosine monophosphate-protein kinase A) pathway, nitrogen-sensing TOR (target of rapamycin) pathway, and SAPK (stress-activating protein kinase) pathway are crucial, and the MAPK (mitogen-activating protein kinase) cascade is essential for pheromone sensing. These signals regulate ste11 at the transcriptional and translational levels, and Ste11 is modified in multiple ways. This review summarizes the initiation of sexual differentiation in S. pombe based on results I have helped to obtain, including the work of many excellent researchers.
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Affiliation(s)
- Makoto Kawamukai
- D epartment of Life Sciences, Faculty of Life and Environmental Sciences, Shimane University, Nishikawatsu, Matsue, Japan
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2
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Canete JA, Andrés S, Muñoz S, Zamarreño J, Rodríguez S, Díaz-Cuervo H, Bueno A, Sacristán MP. Fission yeast Cdc14-like phosphatase Flp1/Clp1 modulates the transcriptional response to oxidative stress. Sci Rep 2023; 13:14677. [PMID: 37674027 PMCID: PMC10482896 DOI: 10.1038/s41598-023-41869-w] [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: 01/12/2023] [Accepted: 09/01/2023] [Indexed: 09/08/2023] Open
Abstract
Reactive oxygen species (ROS) are an important source of cellular damage. When ROS intracellular levels increase, oxidative stress takes place affecting DNA stability and metabolic functions. To prevent these effects, stress-activated protein kinases (SAPKs) delay cell cycle progression and induce a transcriptional response that activates antioxidant mechanisms ensuring cell adaptation and survival. Fission yeast Cdc14-like phosphatase Flp1 (also known as Clp1) has a well-established role in cell cycle regulation. Moreover, Flp1 contributes to checkpoint activation during replication stress. Here, we show that Flp1 has a role in fine-tuning the cellular oxidative stress response. Phosphorylation-dependent nucleolar release of Flp1 in response to oxidative stress conditions plays a role in the cellular transcriptional response. Thus, Flp1 ablation increases the transcriptional response to oxidative stress, in both intensity and duration, upregulating both Atf1/Pcr1- and Pap1-dependent stress induced genes. Remarkably, we found that Flp1 interacts with the Atf1/Pcr1 complex with Pcr1 acting as a direct substrate. Our results provide evidence that Flp1 modulates the oxidative stress response by limiting the Atf1/Pcr1-mediated transcription.
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Affiliation(s)
- Juan A Canete
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007, Salamanca, Spain
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Sonia Andrés
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007, Salamanca, Spain
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Sofía Muñoz
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007, Salamanca, Spain
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Javier Zamarreño
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007, Salamanca, Spain
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Sergio Rodríguez
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007, Salamanca, Spain
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain
| | - Helena Díaz-Cuervo
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007, Salamanca, Spain
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain
- Axentiva Solutions SL, 08036, Barcelona, Spain
| | - Avelino Bueno
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007, Salamanca, Spain.
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain.
| | - María P Sacristán
- Instituto de Biología Molecular y Celular del Cáncer (IBMCC), Universidad de Salamanca-CSIC, Campus Miguel de Unamuno, 37007, Salamanca, Spain.
- Departamento de Microbiología y Genética, Universidad de Salamanca, Campus Miguel de Unamuno, 37007, Salamanca, Spain.
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Alao JP, Legon L, Rallis C. Crosstalk between the mTOR and DNA Damage Response Pathways in Fission Yeast. Cells 2021; 10:cells10020305. [PMID: 33540829 PMCID: PMC7913062 DOI: 10.3390/cells10020305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 01/27/2021] [Accepted: 01/28/2021] [Indexed: 12/14/2022] Open
Abstract
Cells have developed response systems to constantly monitor environmental changes and accordingly adjust growth, differentiation, and cellular stress programs. The evolutionarily conserved, nutrient-responsive, mechanistic target of rapamycin signaling (mTOR) pathway coordinates basic anabolic and catabolic cellular processes such as gene transcription, protein translation, autophagy, and metabolism, and is directly implicated in cellular and organismal aging as well as age-related diseases. mTOR mediates these processes in response to a broad range of inputs such as oxygen, amino acids, hormones, and energy levels, as well as stresses, including DNA damage. Here, we briefly summarize data relating to the interplays of the mTOR pathway with DNA damage response pathways in fission yeast, a favorite model in cell biology, and how these interactions shape cell decisions, growth, and cell-cycle progression. We, especially, comment on the roles of caffeine-mediated DNA-damage override. Understanding the biology of nutrient response, DNA damage and related pharmacological treatments can lead to the design of interventions towards improved cellular and organismal fitness, health, and survival.
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Affiliation(s)
- John-Patrick Alao
- ZEAB Therapeutic, University of East London, Stratford Campus, Water Lane, Stratford, London E15 4LZ, UK;
| | - Luc Legon
- School of Health, Sport and Bioscience, University of East London, Stratford Campus, Water Lane, Stratford, London E15 4LZ, UK;
| | - Charalampos Rallis
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
- Correspondence:
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4
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Ghosal A, Sarkar P, Sundaram G. Communication between Cyclin-dependent kinase Cdc2 and the Wis1-Spc1 MAPK pathway determines mitotic timing in Schizosaccharomyces pombe. Biol Open 2020; 9:bio053322. [PMID: 32554481 PMCID: PMC7390630 DOI: 10.1242/bio.053322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 05/26/2020] [Indexed: 11/20/2022] Open
Abstract
Checkpoint activation and gene expression modulation represent key determinants of cellular survival in adverse conditions. The former is regulated by cyclin-dependent kinases (CDKs) while the latter can be controlled by mitogen-activated protein kinases (MAPKs). Association between cell-cycle progression and MAPK-dependent gene expression exists in cells growing in optimal environments. While MAPK-mediated regulation of the cell cycle is well characterised, the reciprocal influence of mitotic CDK on stress response is not well studied. We present evidence that CDK activity can regulate the extent of MAPK activation in Schizosaccharomyces pombe cells. We show that increasing or decreasing mitotic CDK (Cdc2) activity in S. pombe cells can affect the activation of stress responsive MAPK (Spc1) even in the absence of stress stimuli. Our results indicate that the strong correlation between Cdc2 activity and Spc1 MAPK-activity in S. pombe is important in regulating mitotic timing.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Agamani Ghosal
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, WB, India
| | - Priyanka Sarkar
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, WB, India
| | - Geetanjali Sundaram
- Department of Biochemistry, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, 700019, WB, India
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Byrne DP, Shrestha S, Galler M, Cao M, Daly LA, Campbell AE, Eyers CE, Veal EA, Kannan N, Eyers PA. Aurora A regulation by reversible cysteine oxidation reveals evolutionarily conserved redox control of Ser/Thr protein kinase activity. Sci Signal 2020; 13:eaax2713. [PMID: 32636306 DOI: 10.1126/scisignal.aax2713] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Reactive oxygen species (ROS) are physiological mediators of cellular signaling and play potentially damaging roles in human diseases. In this study, we found that the catalytic activity of the Ser/Thr kinase Aurora A was inhibited by the oxidation of a conserved cysteine residue (Cys290) that lies adjacent to Thr288, a critical phosphorylation site in the activation segment. Cys is present at the equivalent position in ~100 human Ser/Thr kinases, a residue that we found was important not only for the activity of human Aurora A but also for that of fission yeast MAPK-activated kinase (Srk1) and PKA (Pka1). Moreover, the presence of this conserved Cys predicted biochemical redox sensitivity among a cohort of human CAMK, AGC, and AGC-like kinases. Thus, we predict that redox modulation of the conserved Cys290 of Aurora A may be an underappreciated regulatory mechanism that is widespread in eukaryotic Ser/Thr kinases. Given the key biological roles of these enzymes, these findings have implications for understanding physiological and pathological responses to ROS and highlight the importance of protein kinase regulation through multivalent modification of the activation segment.
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Affiliation(s)
- Dominic P Byrne
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
| | - Safal Shrestha
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Martin Galler
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Min Cao
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Leonard A Daly
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
- Centre for Proteome Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Amy E Campbell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
- Centre for Proteome Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Claire E Eyers
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
- Centre for Proteome Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Elizabeth A Veal
- Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Natarajan Kannan
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Patrick A Eyers
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK.
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Alao JP, Sunnerhagen P. Caffeine as a tool for investigating the integration of Cdc25 phosphorylation, activity and ubiquitin-dependent degradation in Schizosaccharomyces pombe. Cell Div 2020; 15:10. [PMID: 32612670 PMCID: PMC7322915 DOI: 10.1186/s13008-020-00066-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 06/08/2020] [Indexed: 12/27/2022] Open
Abstract
The evolutionarily conserved Cdc25 phosphatase is an essential protein that removes inhibitory phosphorylation moieties on the mitotic regulator Cdc2. Together with the Wee1 kinase, a negative regulator of Cdc2 activity, Cdc25 is thus a central regulator of cell cycle progression in Schizosaccharomyces pombe. The expression and activity of Cdc25 is dependent on the activity of the Target of Rapamycin Complex 1 (TORC1). TORC1 inhibition leads to the activation of Cdc25 and repression of Wee1, leading to advanced entry into mitosis. Withdrawal of nitrogen leads to rapid Cdc25 degradation via the ubiquitin- dependent degradation pathway by the Pub1 E3- ligase. Caffeine is believed to mediate the override of DNA damage checkpoint signalling, by inhibiting the activity of the ataxia telangiectasia mutated (ATM)/Rad3 homologues. This model remains controversial, as TORC1 appears to be the preferred target of caffeine in vivo. Recent studies suggest that caffeine induces DNA damage checkpoint override by inducing the nuclear accumulation of Cdc25 in S. pombe. Caffeine may thus modulate Cdc25 activity and stability via inhibition of TORC1. A clearer understanding of the mechanisms by which caffeine stabilises Cdc25, may provide novel insights into how TORC1 and DNA damage signalling is integrated.
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Affiliation(s)
- John P Alao
- School of Health, Sports and Bioscience, University of East London, Stratford Campus, London, E15 4LZ UK.,Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, Gothenburg, SE- 405 30 Sweden
| | - Per Sunnerhagen
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, Gothenburg, SE- 405 30 Sweden
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7
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Sjölander JJ, Tarczykowska A, Picazo C, Cossio I, Redwan IN, Gao C, Solano C, Toledano MB, Grøtli M, Molin M, Sunnerhagen P. A Redox-Sensitive Thiol in Wis1 Modulates the Fission Yeast Mitogen-Activated Protein Kinase Response to H 2O 2 and Is the Target of a Small Molecule. Mol Cell Biol 2020; 40:e00346-19. [PMID: 31932483 PMCID: PMC7076255 DOI: 10.1128/mcb.00346-19] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 09/23/2019] [Accepted: 01/03/2020] [Indexed: 12/17/2022] Open
Abstract
Oxidation of a highly conserved cysteine (Cys) residue located in the kinase activation loop of mitogen-activated protein kinase kinases (MAPKK) inactivates mammalian MKK6. This residue is conserved in the fission yeast Schizosaccharomyces pombe MAPKK Wis1, which belongs to the H2O2-responsive MAPK Sty1 pathway. Here, we show that H2O2 reversibly inactivates Wis1 through this residue (C458) in vitro We found that C458 is oxidized in vivo and that serine replacement of this residue significantly enhances Wis1 activation upon addition of H2O2 The allosteric MAPKK inhibitor INR119, which binds in a pocket next to the activation loop and C458, prevented the inhibition of Wis1 by H2O2in vitro and significantly increased Wis1 activation by low levels of H2O2in vivo We propose that oxidation of C458 inhibits Wis1 and that INR119 cancels out this inhibitory effect by binding close to this residue. Kinase inhibition through the oxidation of a conserved Cys residue in MKK6 (C196) is thus conserved in the S. pombe MAPKK Wis1.
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Affiliation(s)
- Johanna J Sjölander
- University of Gothenburg, Department of Chemistry and Molecular Biology, Gothenburg, Sweden
| | - Agata Tarczykowska
- University of Gothenburg, Department of Chemistry and Molecular Biology, Gothenburg, Sweden
| | - Cecilia Picazo
- University of Gothenburg, Department of Chemistry and Molecular Biology, Gothenburg, Sweden
- Chalmers University of Technology, Department of Biology and Biological Engineering, Gothenburg, Sweden
| | - Itziar Cossio
- University of Gothenburg, Department of Chemistry and Molecular Biology, Gothenburg, Sweden
| | - Itedale Namro Redwan
- University of Gothenburg, Department of Chemistry and Molecular Biology, Gothenburg, Sweden
| | - Chunxia Gao
- University of Gothenburg, Department of Chemistry and Molecular Biology, Gothenburg, Sweden
| | - Carlos Solano
- University of Gothenburg, Department of Chemistry and Molecular Biology, Gothenburg, Sweden
| | - Michel B Toledano
- Oxidative Stress and Cancer Laboratory, Integrative Biology and Molecular Genetics Unit, CEA Saclay, Gif-sur-Yvette, France
| | - Morten Grøtli
- University of Gothenburg, Department of Chemistry and Molecular Biology, Gothenburg, Sweden
| | - Mikael Molin
- University of Gothenburg, Department of Chemistry and Molecular Biology, Gothenburg, Sweden
- Chalmers University of Technology, Department of Biology and Biological Engineering, Gothenburg, Sweden
| | - Per Sunnerhagen
- University of Gothenburg, Department of Chemistry and Molecular Biology, Gothenburg, Sweden
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8
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Morigasaki S, Chin LC, Hatano T, Emori M, Iwamoto M, Tatebe H, Shiozaki K. Modulation of TOR complex 2 signaling by the stress-activated MAPK pathway in fission yeast. J Cell Sci 2019; 132:jcs.236133. [PMID: 31477575 DOI: 10.1242/jcs.236133] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Accepted: 08/28/2019] [Indexed: 01/27/2023] Open
Abstract
Sin1 is a substrate-binding subunit of target of rapamycin complex 2 (TORC2), an evolutionarily conserved protein kinase complex. In fission yeast, Sin1 has also been identified as a protein that interacts with Spc1 (also known as Sty1) in the stress-activated protein kinase (SAPK) pathway. Therefore, this study examined the relationship between TORC2 and Spc1 signaling. We found that the common docking (CD) domain of Spc1 interacts with a cluster of basic amino acid residues in Sin1. Although diminished TORC2 activity in the absence of the functional Spc1 cascade suggests positive regulation of TORC2 by Spc1, such regulation appears to be independent of the Sin1-Spc1 interaction. Hyperosmotic stress transiently inhibits TORC2, and its swift recovery is dependent on Spc1, the transcription factor Atf1, and the glycelrol-3-phosphate dehydrogenase Gpd1, whose expression is induced upon osmostress by the Spc1-Atf1 pathway. Thus, cellular adaptation to osmostress seems important for TORC2 reactivation, though Spc1 and Atf1 contribute to TORC2 activation also in the absence of osmostress. These results indicate coordinated actions of the SAPK and TORC2 pathways, both of which are essential for fission yeast cells to survive environmental stress.
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Affiliation(s)
- Susumu Morigasaki
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan.,Okinawa Institute of Science and Technology Graduate University, Onna-son, Okinawa 904-0495, Japan
| | - Lit Chein Chin
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Tomoyuki Hatano
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Midori Emori
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Mika Iwamoto
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Hisashi Tatebe
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Kazuhiro Shiozaki
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan .,Department of Microbiology and Molecular Genetics, University of California, Davis, CA 95616, USA
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9
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Day AM, Quinn J. Stress-Activated Protein Kinases in Human Fungal Pathogens. Front Cell Infect Microbiol 2019; 9:261. [PMID: 31380304 PMCID: PMC6652806 DOI: 10.3389/fcimb.2019.00261] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/04/2019] [Indexed: 11/28/2022] Open
Abstract
The ability of fungal pathogens to survive hostile environments within the host depends on rapid and robust stress responses. Stress-activated protein kinase (SAPK) pathways are conserved MAPK signaling modules that promote stress adaptation in all eukaryotic cells, including pathogenic fungi. Activation of the SAPK occurs via the dual phosphorylation of conserved threonine and tyrosine residues within a TGY motif located in the catalytic domain. This induces the activation and nuclear accumulation of the kinase and the phosphorylation of diverse substrates, thus eliciting appropriate cellular responses. The Hog1 SAPK has been extensively characterized in the model yeast Saccharomyces cerevisiae. Here, we use this a platform from which to compare SAPK signaling mechanisms in three major fungal pathogens of humans, Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans. Despite the conservation of SAPK pathways within these pathogenic fungi, evidence is emerging that their role and regulation has significantly diverged. However, consistent with stress adaptation being a common virulence trait, SAPK pathways are important pathogenicity determinants in all these major human pathogens. Thus, the development of drugs which target fungal SAPKs has the exciting potential to generate broad-acting antifungal treatments.
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Affiliation(s)
- Alison M Day
- Faculty of Medicine, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Janet Quinn
- Faculty of Medicine, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle Upon Tyne, United Kingdom
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10
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Yang JY, Fang YL, Wang P, Ye JR, Huang L. Pleiotropic Roles of ChSat4 in Asexual Development, Cell Wall Integrity Maintenance, and Pathogenicity in Colletotrichum higginsianum. Front Microbiol 2018; 9:2311. [PMID: 30405539 PMCID: PMC6208185 DOI: 10.3389/fmicb.2018.02311] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 09/10/2018] [Indexed: 01/31/2023] Open
Abstract
Potassium has an important role to play in multiple cellular processes. In Saccharomyces cerevisiae, the serine/threonine (S/T) kinase Sat4/Hal4 is required for potassium accumulation, and thus, regulates the resistance to sodium salts and helps in the stabilization of other plasma membrane transporters. However, the functions of Sat4 in filamentous phytopathogenic fungi are largely unknown. In this study, ChSat4, the yeast Sat4p homolog in Colletotrichum higginsianum, has been identified. Target deletion of ChSAT4 resulted in defects in mycelial growth and sporulation. Intracellular K+ accumulation was significantly decreased in the ChSAT4 deletion mutant. Additionally, the ΔChsat4 mutant showed defects in cell wall integrity, hyperoxide stress response, and pathogenicity. Localization pattern analysis indicated ChSat4 was localized in the cytoplasm. Furthermore, ChSat4 showed high functional conservation with the homolog FgSat4 in Fusarium graminearum. Taken together, our data indicated that ChSat4 was important for intracellular K+ accumulation and infection morphogenesis in C. higginsianum.
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Affiliation(s)
- Ji-Yun Yang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Yu-Lan Fang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Ping Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Jian-Ren Ye
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Lin Huang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
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11
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Paul M, Ghosal A, Bandyopadhyay S, G P, Selvam U, Rai N, Sundaram G. The fission yeast MAPK Spc1 senses perturbations in Cdc25 and Wee1 activities and targets Rad24 to restore this balance. Yeast 2017; 35:261-271. [PMID: 29065217 DOI: 10.1002/yea.3289] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 10/11/2017] [Accepted: 10/12/2017] [Indexed: 12/15/2022] Open
Abstract
Mitogen-activated protein kinases (MAPKs) play vital roles in multiple cellular processes and represent prominently pursued targets for development of therapeutic regimes. The MAPK Spc1 (p38 homologue) is known to be very important for both mitotic promotion and delay in Schizosaccharomyces pombe. However, the mechanism responsible for mitotic inhibition has remained elusive. Cdc25 (Cdc2 activator) and Wee1 (Cdc2 inhibtor) are important determinants of mitotic timing in all eukaryotes. Our results show that Spc1 can sense the perturbations in the balance of Cdc25 and Wee1 activities in S. pombe and that its function as a mitotic inhibitor is very important for controlling the same. An Spc1-Srk1-Rad24-dependent pathway for mitotic inhibition has been reported earlier.Here we report the presence of an alternative mechanism wherein Spc1 targets the 14-3-3 protein, Rad24, independently of Srk1, leading to relocalization of Cdc25 and mitotic inhibition. Our observations suggest that this pathway can serve as a backup mechanism for Cdc2 inactivation in the absence of Wee1.
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Affiliation(s)
- Madhurima Paul
- Department of Biochemistry and Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, 35, Ballygunje Circular Road, Kolkata, 700019, WB, India
| | - Agamani Ghosal
- Department of Biochemistry and Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, 35, Ballygunje Circular Road, Kolkata, 700019, WB, India
| | - Sushobhana Bandyopadhyay
- Department of Biochemistry and Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, 35, Ballygunje Circular Road, Kolkata, 700019, WB, India
| | - Prakadeeswari G
- Department of Biochemistry and Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, 35, Ballygunje Circular Road, Kolkata, 700019, WB, India
| | - Upasna Selvam
- Department of Biochemistry and Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, 35, Ballygunje Circular Road, Kolkata, 700019, WB, India
| | - Neeraj Rai
- Department of Biochemistry and Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, 35, Ballygunje Circular Road, Kolkata, 700019, WB, India
| | - Geetanjali Sundaram
- Department of Biochemistry and Centre for Research in Nanoscience and Nanotechnology, University of Calcutta, 35, Ballygunje Circular Road, Kolkata, 700019, WB, India
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12
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Opalko HE, Moseley JB. Dynamic regulation of Cdr1 kinase localization and phosphorylation during osmotic stress. J Biol Chem 2017; 292:18457-18468. [PMID: 28924043 DOI: 10.1074/jbc.m117.793034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 09/14/2017] [Indexed: 11/06/2022] Open
Abstract
Environmental conditions modulate cell cycle progression in many cell types. A key component of the eukaryotic cell cycle is the protein kinase Wee1, which inhibits the cyclin-dependent kinase Cdk1 in yeast through human cells. In the fission yeast Schizosaccharomyces pombe, the protein kinase Cdr1 is a mitotic inducer that promotes mitotic entry by phosphorylating and inhibiting Wee1. Cdr1 and Wee1 both localize to punctate structures, termed nodes, on the medial cortex, but it has been unknown whether node localization can be altered by physiological signals. Here we investigated how environmental conditions regulate Cdr1 signaling for cell division. Osmotic stress induced hyperphosphorylation of the mitotic inducer Cdr1 for several hours, and cells delayed division for the same time period. This stress-induced hyperphosphorylation required both Cdr1 autophosphorylation and the stress-activated protein kinase Sty1. During osmotic stress, Cdr1 exited cortical nodes and localized in the cytoplasm. Using a series of truncation mutants, we mapped a C-terminal domain that is necessary and sufficient for Cdr1 node localization and found that Sty1 directly phosphorylates this domain in vitro Sty1 was not required for Cdr1 exit from nodes, indicating the existence of additional regulatory signals. Both Cdr1 phosphorylation and node localization returned to basal levels when cells adapted to osmotic conditions and resumed cell cycle progression. In summary, we identified a mechanism that prevents Cdr1 colocalization with its inhibitory target Wee1 during osmotic stress. Dynamic regulation of protein localization to cortical nodes might represent a strategy to modulate entry into mitosis under differing environmental conditions.
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Affiliation(s)
- Hannah E Opalko
- From the Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
| | - James B Moseley
- From the Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755
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Glucose Starvation Alters Heat Shock Response, Leading to Death of Wild Type Cells and Survival of MAP Kinase Signaling Mutant. PLoS One 2016; 11:e0165980. [PMID: 27870869 PMCID: PMC5117620 DOI: 10.1371/journal.pone.0165980] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 10/20/2016] [Indexed: 12/31/2022] Open
Abstract
A moderate heat shock induces Neurospora crassa to synthesize large quantities of heat shock proteins that are protective against higher, otherwise lethal temperatures. However, wild type cells do not survive when carbohydrate deprivation is added to heat shock. In contrast, a mutant strain defective in a stress-activated protein kinase does survive the combined stresses. In order to understand the basis for this difference in survival, we have determined the relative levels of detected proteins in the mutant and wild type strain during dual stress, and we have identified gene transcripts in both strains whose quantities change in response to heat shock or dual stress. These data and supportive experimental evidence point to reasons for survival of the mutant strain. By using alternative respiratory mechanisms, these cells experience less of the oxidative stress that proves damaging to wild type cells. Of central importance, mutant cells recycle limited resources during dual stress by undergoing autophagy, a process that we find utilized by both wild type and mutant cells during heat shock. Evidence points to inappropriate activation of TORC1, the central metabolic regulator, in wild type cells during dual stress, based upon behavior of an additional signaling mutant and inhibitor studies.
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Abstract
Schizosaccharomyces pombe is a popular model eukaryotic organism to study diverse aspects of mammalian biology, including responses to cellular stress triggered by redox imbalances within its compartments. The review considers the current knowledge on the signaling pathways that govern the transcriptional response of fission yeast cells to elevated levels of hydrogen peroxide. Particular attention is paid to the mechanisms that yeast cells employ to promote cell survival in conditions of intermediate and acute oxidative stress. The role of the Sty1/Spc1/Phh1 mitogen-activated protein kinase in regulating gene expression at multiple levels is discussed in detail.
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Affiliation(s)
- Manos A Papadakis
- a Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark , Lyngby , Denmark
| | - Christopher T Workman
- a Center for Biological Sequence Analysis, Department of Systems Biology, Technical University of Denmark , Lyngby , Denmark
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Gómez-Hierro A, Lambea E, Giménez-Zaragoza D, López-Avilés S, Yance-Chávez T, Montserrat M, Pujol MJ, Bachs O, Aligue R. Ssp1 CaMKK: A Sensor of Actin Polarization That Controls Mitotic Commitment through Srk1 in Schizosaccharomyces pombe. PLoS One 2015; 10:e0143037. [PMID: 26575035 PMCID: PMC4648557 DOI: 10.1371/journal.pone.0143037] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/29/2015] [Indexed: 11/18/2022] Open
Abstract
Background Calcium/calmodulin-dependent protein kinase kinase (CaMKK) is required for diverse cellular functions. Mammalian CaMKK activates CaMKs and also the evolutionarily-conserved AMP-activated protein kinase (AMPK). The fission yeast Schizosaccharomyces pombe CaMKK, Ssp1, is required for tolerance to limited glucose through the AMPK, Ssp2, and for the integration of cell growth and division through the SAD kinase Cdr2. Results Here we report that Ssp1 controls the G2/M transition by regulating the activity of the CaMK Srk1. We show that inhibition of Cdc25 by Srk1 is regulated by Ssp1; and also that restoring growth polarity and actin localization of ssp1-deleted cells by removing the actin-monomer-binding protein, twinfilin, is sufficient to suppress the ssp1 phenotype. Conclusions These findings demonstrate that entry into mitosis is mediated by a network of proteins, including the Ssp1 and Srk1 kinases. Ssp1 connects the network of components that ensures proper polarity and cell size with the network of proteins that regulates Cdk1-cyclin B activity, in which Srk1 plays an inhibitory role.
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Affiliation(s)
- Alba Gómez-Hierro
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Catalunya, Spain
| | - Eva Lambea
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Catalunya, Spain
| | - David Giménez-Zaragoza
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Catalunya, Spain
| | | | - Tula Yance-Chávez
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Catalunya, Spain
| | - Marta Montserrat
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Catalunya, Spain
| | - M. Jesús Pujol
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Catalunya, Spain
| | - Oriol Bachs
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Catalunya, Spain
| | - Rosa Aligue
- Departament de Biologia Cellular, Immunologia i Neurociències, Facultat de Medicina, Universitat de Barcelona, Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Barcelona, Catalunya, Spain
- * E-mail:
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Převorovský M, Oravcová M, Tvarůžková J, Zach R, Folk P, Půta F, Bähler J. Fission Yeast CSL Transcription Factors: Mapping Their Target Genes and Biological Roles. PLoS One 2015; 10:e0137820. [PMID: 26366556 PMCID: PMC4569565 DOI: 10.1371/journal.pone.0137820] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 08/24/2015] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Cbf11 and Cbf12, the fission yeast CSL transcription factors, have been implicated in the regulation of cell-cycle progression, but no specific roles have been described and their target genes have been only partially mapped. METHODOLOGY/PRINCIPAL FINDINGS Using a combination of transcriptome profiling under various conditions and genome-wide analysis of CSL-DNA interactions, we identify genes regulated directly and indirectly by CSL proteins in fission yeast. We show that the expression of stress-response genes and genes that are expressed periodically during the cell cycle is deregulated upon genetic manipulation of cbf11 and/or cbf12. Accordingly, the coordination of mitosis and cytokinesis is perturbed in cells with genetically manipulated CSL protein levels, together with other specific defects in cell-cycle progression. Cbf11 activity is nutrient-dependent and Δcbf11-associated defects are mitigated by inactivation of the protein kinase A (Pka1) and stress-activated MAP kinase (Sty1p38) pathways. Furthermore, Cbf11 directly regulates a set of lipid metabolism genes and Δcbf11 cells feature a stark decrease in the number of storage lipid droplets. CONCLUSIONS/SIGNIFICANCE Our results provide a framework for a more detailed understanding of the role of CSL proteins in the regulation of cell-cycle progression in fission yeast.
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Affiliation(s)
- Martin Převorovský
- Research Department of Genetics, Evolution & Environment and UCL Cancer Institute, University College London, London, United Kingdom
- Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Martina Oravcová
- Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jarmila Tvarůžková
- Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Róbert Zach
- Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Petr Folk
- Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - František Půta
- Department of Cell Biology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jürg Bähler
- Research Department of Genetics, Evolution & Environment and UCL Cancer Institute, University College London, London, United Kingdom
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17
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The SrkA Kinase Is Part of the SakA Mitogen-Activated Protein Kinase Interactome and Regulates Stress Responses and Development in Aspergillus nidulans. EUKARYOTIC CELL 2015; 14:495-510. [PMID: 25820520 DOI: 10.1128/ec.00277-14] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/20/2015] [Indexed: 02/02/2023]
Abstract
Fungi and many other eukaryotes use specialized mitogen-activated protein kinases (MAPK) of the Hog1/p38 family to transduce environmental stress signals. In Aspergillus nidulans, the MAPK SakA and the transcription factor AtfA are components of a central multiple stress-signaling pathway that also regulates development. Here we characterize SrkA, a putative MAPK-activated protein kinase, as a novel component of this pathway. ΔsrkA and ΔsakA mutants share a derepressed sexual development phenotype. However, ΔsrkA mutants are not sensitive to oxidative stress, and in fact, srkA inactivation partially suppresses the sensitivity of ΔsakA mutant conidia to H2O2, tert-butyl-hydroperoxide (t-BOOH), and menadione. In the absence of stress, SrkA shows physical interaction with nonphosphorylated SakA in the cytosol. We show that H2O2 induces a drastic change in mitochondrial morphology consistent with a fission process and the relocalization of SrkA to nuclei and mitochondria, depending on the presence of SakA. SakA-SrkA nuclear interaction is also observed during normal asexual development in dormant spores. Using SakA and SrkA S-tag pulldown and purification studies coupled to mass spectrometry, we found that SakA interacts with SrkA, the stress MAPK MpkC, the PPT1-type phosphatase AN6892, and other proteins involved in cell cycle regulation, DNA damage response, mRNA stability and protein synthesis, mitochondrial function, and other stress-related responses. We propose that oxidative stress induces DNA damage and mitochondrial fission and that SakA and SrkA mediate cell cycle arrest and regulate mitochondrial function during stress. Our results provide new insights into the mechanisms by which SakA and SrkA regulate the remodelling of cell physiology during oxidative stress and development.
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18
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Alao JP, Sjölander JJ, Baar J, Özbaki-Yagan N, Kakoschky B, Sunnerhagen P. Caffeine stabilizes Cdc25 independently of Rad3 in Schizosaccharomyces pombe contributing to checkpoint override. Mol Microbiol 2014; 92:777-96. [PMID: 24666325 PMCID: PMC4235345 DOI: 10.1111/mmi.12592] [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] [Accepted: 03/24/2014] [Indexed: 01/31/2023]
Abstract
Cdc25 is required for Cdc2 dephosphorylation and is thus essential for cell cycle progression. Checkpoint activation requires dual inhibition of Cdc25 and Cdc2 in a Rad3-dependent manner. Caffeine is believed to override activation of the replication and DNA damage checkpoints by inhibiting Rad3-related proteins in both S chizosaccharomyces pombe and mammalian cells. In this study, we have investigated the impact of caffeine on Cdc25 stability, cell cycle progression and checkpoint override. Caffeine induced Cdc25 accumulation in S . pombe independently of Rad3. Caffeine delayed cell cycle progression under normal conditions but advanced mitosis in cells treated with replication inhibitors and DNA-damaging agents. In the absence of Cdc25, caffeine inhibited cell cycle progression even in the presence of hydroxyurea or phleomycin. Caffeine induces Cdc25 accumulation in S . pombe by suppressing its degradation independently of Rad3. The induction of Cdc25 accumulation was not associated with accelerated progression through mitosis, but rather with delayed progression through cytokinesis. Caffeine-induced Cdc25 accumulation appears to underlie its ability to override cell cycle checkpoints. The impact of Cdc25 accumulation on cell cycle progression is attenuated by Srk1 and Mad2. Together our findings suggest that caffeine overrides checkpoint enforcement by inducing the inappropriate nuclear localization of Cdc25.
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Affiliation(s)
- John P Alao
- Department of Chemistry and Molecular Biology, Lundberg Laboratory, University of Gothenburg, Box 462, SE-405 30, Göteborg, Sweden
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19
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Chang M, Kang HJ, Baek IJ, Kang CM, Park YS, Yun CW. Rck1 up-regulates Hog1 activity by down-regulating Slt2 activity in Saccharomyces cerevisiae. Biochem Biophys Res Commun 2013; 440:119-24. [DOI: 10.1016/j.bbrc.2013.09.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 09/08/2013] [Indexed: 10/26/2022]
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20
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Quinn J, Malakasi P, Smith DA, Cheetham J, Buck V, Millar JBA, Morgan BA. Two-component mediated peroxide sensing and signal transduction in fission yeast. Antioxid Redox Signal 2011; 15:153-65. [PMID: 20919928 DOI: 10.1089/ars.2010.3345] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Two-component related proteins play a major role in regulating the oxidative stress response in the fission yeast, Schizosaccharomyces pombe. For example, the peroxide-sensing Mak2 and Mak3 histidine kinases regulate H(2)O(2)-induced activation of the Sty1 stress-activated protein kinase pathway, and the Skn7-related response regulator transcription factor, Prr1, is essential for activation of the core oxidative stress response genes. Here, we investigate the mechanism by which the S. pombe two-component system senses H(2)O(2), and the potential role of two-component signaling in the regulation of Prr1. Significantly, we demonstrate that PAS and GAF domains present in the Mak2 histidine kinase are essential for redox-sensing and activation of Sty1. In addition, we find that Prr1 is required for the transcriptional response to a wide range of H(2)O(2) concentrations and, furthermore, that two-component regulation of Prr1 is specifically required for the response of cells to high levels of H(2)O(2). Significantly, this provides the first demonstration that the conserved two-component phosphorylation site on Skn7-related proteins influences resistance to oxidative stress and oxidative stress-induced gene expression. Collectively, these data provide new insights into the two-component mediated sensing and signaling mechanisms underlying the response of S. pombe to oxidative stress.
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Affiliation(s)
- Janet Quinn
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom.
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21
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Kaneko K, Sugiyama Y, Yamada Y, Sueyoshi N, Watanabe A, Asada Y, Ishida A, Kameshita I. CoPK32 is a novel stress-responsive protein kinase in the mushroom Coprinopsis cinerea. Biochim Biophys Acta Gen Subj 2011; 1810:620-9. [DOI: 10.1016/j.bbagen.2011.03.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 03/07/2011] [Accepted: 03/24/2011] [Indexed: 10/18/2022]
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22
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Kim SY, Ko YJ, Jung KW, Strain A, Nielsen K, Bahn YS. Hrk1 plays both Hog1-dependent and -independent roles in controlling stress response and antifungal drug resistance in Cryptococcus neoformans. PLoS One 2011; 6:e18769. [PMID: 21533251 PMCID: PMC3076434 DOI: 10.1371/journal.pone.0018769] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Accepted: 03/18/2011] [Indexed: 11/18/2022] Open
Abstract
The HOG (High Osmolarity Glycerol response) pathway plays a central role in controlling stress response, ergosterol biosynthesis, virulence factor production, and differentiation of Cryptococcus neoformans, which causes fatal fungal meningoencephalitis. Recent transcriptome analysis of the HOG pathway discovered a Hog1-regulated gene (CNAG_00130.2), encoding a putative protein kinase orthologous to Rck1/2 in Saccharomyces cerevisiae and Srk1 in Schizosaccharomyces pombe. Its function is not known in C. neoformans. The present study functionally characterized the role of Hrk1 in C. neoformans. Northern blot analysis confirmed that HRK1 expression depends on the Hog1 MAPK. Similar to the hog1Δ mutant, the hrk1Δ mutant exhibited almost complete resistance to fludioxonil, which triggers glycerol biosynthesis via the HOG pathway. Supporting this, the hrk1Δ mutant showed reduced intracellular glycerol accumulation and swollen cell morphology in response to fludioxonil, further suggesting that Hrk1 works downstream of the HOG pathway. However, Hrk1 also appeared to have Hog1-independent functions. Mutation of HRK1 not only further increased osmosensitivity of the hog1Δ mutant, but also suppressed increased azole-resistance of the hog1Δ mutant in an Erg11-independent manner. Furthermore, unlike the hog1Δ mutant, Hrk1 was not involved in capsule biosynthesis. Hrk1 was slightly involved in melanin production but dispensable for virulence of C. neoformans. These findings suggest that Hrk1 plays both Hog1-dependent and –independent roles in stress and antifungal drug susceptibility and virulence factor production in C. neoformans. Particularly, the finding that inhibition of Hrk1 substantially increases azole drug susceptibility provides a novel strategy for combination antifungal therapy.
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Affiliation(s)
- Seo-Young Kim
- Department of Biotechnology, College of Life Science and Biotechnology, Center for Fungal Pathogenesis, Yonsei University, Seoul, Korea
| | - Young-Joon Ko
- Department of Biotechnology, College of Life Science and Biotechnology, Center for Fungal Pathogenesis, Yonsei University, Seoul, Korea
| | - Kwang-Woo Jung
- Department of Biotechnology, College of Life Science and Biotechnology, Center for Fungal Pathogenesis, Yonsei University, Seoul, Korea
| | - Anna Strain
- Department of Microbiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Kirsten Nielsen
- Department of Microbiology, Medical School, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Yong-Sun Bahn
- Department of Biotechnology, College of Life Science and Biotechnology, Center for Fungal Pathogenesis, Yonsei University, Seoul, Korea
- * E-mail:
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23
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Purtill FS, Whitehall SK, Williams ES, McInerny CJ, Sharrocks AD, Morgan BA. A homeodomain transcription factor regulates the DNA replication checkpoint in yeast. Cell Cycle 2011; 10:664-70. [PMID: 21304269 DOI: 10.4161/cc.10.4.14824] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Checkpoints monitor the successful completion of cell cycle processes, such as DNA replication, and also regulate the expression of cell cycle-dependent genes that are required for responses. In the model yeast Schizosaccharomyces pombe G 1/S phase-specific gene expression is regulated by the MBF (also known as DSC1) transcription factor complex and is also activated by the mammalian ATM/ATR-related Rad3 DNA replication checkpoint. Here, we show that the Yox1 homeodomain transcription factor acts to co-ordinate the expression of MBF-regulated genes during the cell division cycle. Moreover, our data suggests that Yox1 is inactivated by the Rad3 DNA replication checkpoint via phosphorylation by the conserved Cds1 checkpoint kinase. Collectively, our data has implications for understanding the mechanisms underlying the coordination of cell cycle processes in eukaryotes.
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Affiliation(s)
- Frances S Purtill
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon tyne, UK
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24
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Sun W, Wang Z, Jiang H, Zhang J, Bähler J, Chen D, Murchie AIH. A novel function of the mitochondrial transcription factor Mtf1 in fission yeast; Mtf1 regulates the nuclear transcription of srk1. Nucleic Acids Res 2010; 39:2690-700. [PMID: 21138961 PMCID: PMC3074130 DOI: 10.1093/nar/gkq1179] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
In eukaryotic cells, Mtf1 and its homologues function as mitochondrial transcription factors for the mitochondrial RNA polymerase in the mitochondrion. Here we show that in fission yeast Mtf1 exerts a non-mitochondrial function as a nuclear factor that regulates transcription of srk1, which is a kinase involved in the stress response and cell cycle progression. We first found Mtf1 expression in the nucleus. A ChIP-chip approach identified srk1 as a putative Mtf1 target gene. Over expression of Mtf1 induced transcription of the srk1 gene and Mtf1 deletion led to a reduction in transcription of the srk1 gene in vivo. Mtf1 overexpression causes cell elongation in a srk1 dependent manner. Mtf1 overexpression can cause cytoplasmic accumulation of Cdc25. We also provide biochemical evidence that Mtf1 binds to the upstream sequence of srk1. This is the first evidence that a mitochondrial transcription factor Mtf1 can regulate a nuclear gene. Mtf1 may also have a role in cell cycle progression.
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Affiliation(s)
- Wenxia Sun
- Institute of Biomedical Science, Fudan University, Yi Xue Yuan Road 138, 200032 Shanghai, China
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25
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Abstract
For decades, the fission yeast Schizosaccharomyces pombe has been used as an excellent model with which to explore how cellular growth is coordinated with the division cycle, a yet-unanswered question in biology. New studies in this organism show that TOR (target of rapamycin) kinase and stress-responsive MAPK (mitogen-activated protein kinase) form a signaling pathway that readjusts the timing of mitotic onset in response to poor nutrient conditions. Nutritional environment appears to be translated into graded activity of the protein kinases that influence the activation of Cdc2, a cyclin-dependent kinase driving cell-cycle progression.
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Affiliation(s)
- Kazuhiro Shiozaki
- Department of Microbiology, University of California, Davis, CA 95616, USA.
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Alao JP, Olesch J, Sunnerhagen P. Inhibition of type I histone deacetylase increases resistance of checkpoint-deficient cells to genotoxic agents through mitotic delay. Mol Cancer Ther 2009; 8:2606-15. [PMID: 19723888 DOI: 10.1158/1535-7163.mct-09-0218] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Histone deacetylase (HDAC) inhibitors potently inhibit tumor growth and are currently being evaluated for their efficacy as chemosensitizers and radiosensitizers. This efficacy is likely to be limited by the fact that HDAC inhibitors also induce cell cycle arrest. Deletion of the class I HDAC Rpd3 has been shown to specifically suppress the sensitivity of Saccharomyces cerevisiae DNA damage checkpoint mutants to UV and hydroxyurea. We show that in the fission yeast Schizosaccharomyces pombe, inhibition of the homologous class I HDAC specifically suppresses the DNA damage sensitivity of checkpoint mutants. Importantly, the prototype HDAC inhibitor Trichostatin A also suppressed the sensitivity of DNA damage checkpoint but not of DNA repair mutants to UV and HU. TSA suppressed DNA damage activity independently of the mitogen-activated protein kinase-dependent and spindle checkpoint pathways. We show that TSA delays progression into mitosis and propose that this is the main mechanism for suppression of the DNA damage sensitivity of S. pombe checkpoint mutants, partially compensating for the loss of the G(2) checkpoint pathway. Our studies also show that the ability of HDAC inhibitors to suppress DNA damage sensitivity is not species specific. Class I HDACs are the major target of HDAC inhibitors and cancer cells are often defective in checkpoint activation. Effective use of these agents as chemosensitizers and radiosensitizers may require specific treatment schedules that circumvent their inhibition of cell cycle progression.
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Affiliation(s)
- John P Alao
- Department of Cell and Molecular Biology, Lundberg Laboratory, University of Gothenburg, S-405 30 Göteborg, Sweden
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28
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Hartmuth S, Petersen J. Fission yeast Tor1 functions as part of TORC1 to control mitotic entry through the stress MAPK pathway following nutrient stress. J Cell Sci 2009; 122:1737-46. [PMID: 19417002 DOI: 10.1242/jcs.049387] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
TOR signalling coordinates growth and division to control cell size. Inhibition of Schizosaccharomyces pombe Tor1, in response to a reduction in the quality of the nitrogen source (nutrient stress), promotes mitotic onset through activation of the mitogen-activated protein kinase (MAPK) Sty1 (also known as Spc1). Here we show that ;nutrient starvation' (complete withdrawal of nitrogen or leucine) blocks mitotic commitment by altering Sty1 signalling and that different degrees of Sty1 activation determine these differences in mitotic commitment decisions. Mammals contain one TOR kinase, whereas yeasts contain two. In each case, they comprise two distinct complexes: TORC1 and TORC2. We find that nutrient-stress-induced control of mitotic onset, through Tor1, is regulated through changes in TORC1 signalling. In minimal medium, Tor1 interacts with the TORC1 component Mip1 (raptor), and overexpression of tor1+ generates growth defects reminiscent of TORC1 mutants. Strains lacking the TORC2-specific components Sin1 and Ste20 (rictor) still advance mitotic onset in response to nutrient stress. By contrast, Mip1 and the downstream effector Gad8 (a S6K kinase homologue), like Tor1, are essential for nutrient stress to advance mitotic onset. We conclude that S. pombe Tor1 and Tor2 can both act in TORC1. However, it is the inhibition of Tor1 as part of TORC1 that promotes mitosis following nutrient stress.
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Affiliation(s)
- Sonya Hartmuth
- University of Manchester, Faculty of Life Sciences, C.4255 Michael Smith Building, Oxford Road, Manchester M13 9PT, UK
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29
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Master and commander in fungal pathogens: the two-component system and the HOG signaling pathway. EUKARYOTIC CELL 2008; 7:2017-36. [PMID: 18952900 DOI: 10.1128/ec.00323-08] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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30
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Udagawa T, Nemoto N, Wilkinson CRM, Narashimhan J, Jiang L, Watt S, Zook A, Jones N, Wek RC, Bähler J, Asano K. Int6/eIF3e promotes general translation and Atf1 abundance to modulate Sty1 MAPK-dependent stress response in fission yeast. J Biol Chem 2008; 283:22063-75. [PMID: 18502752 PMCID: PMC2494926 DOI: 10.1074/jbc.m710017200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2007] [Revised: 05/22/2008] [Indexed: 11/06/2022] Open
Abstract
int-6 is one of the frequent integration sites for mouse mammary tumor viruses. Although its product is the e-subunit of translation initiation factor eIF3, other evidence indicates that it interacts with proteasomes or other proteins to regulate protein stability. Here we report that the fission yeast int6(+) is required for overcoming stress imposed by histidine starvation, using the drug 3-aminotriazole (3AT). Microarray and complementary Northern studies using wild-type, int6Delta or gcn2Delta mutants indicate that 3AT-treated wild-type yeast induces core environmental stress response (CESR) genes in addition to typical general amino acid control (GAAC) genes whose transcription depends on the eIF2 kinase, Gcn2. In agreement with this, Sty1 MAPK and its target transcription factor Atf1, which signal the CESR, are required for overcoming 3AT-induced starvation. We find that Int6 is required for maintaining the basal level of Atf1 and for rapid transcriptional activation of the CESR on 3AT-insult. Pulse labeling experiments indicate that int6Delta significantly slows down de novo protein synthesis. Moreover, Atf1 protein half-life was reduced in int6Delta cells. These effects would account for the compromised Atf1 activity on 3AT-induced stress. Thus, the robust protein synthesis promoted by intact eIF3 appears to be a part of the requisites for sound Sty1 MAPK-dependent signaling governed by the activity of the Atf1 transcription factor.
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Affiliation(s)
- Tsuyoshi Udagawa
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
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Alao JP, Sunnerhagen P. Rad3 and Sty1 function in Schizosaccharomyces pombe: an integrated response to DNA damage and environmental stress? Mol Microbiol 2008; 68:246-54. [DOI: 10.1111/j.1365-2958.2008.06147.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Huard S, Elder RT, Liang D, Li G, Zhao RY. Human immunodeficiency virus type 1 Vpr induces cell cycle G2 arrest through Srk1/MK2-mediated phosphorylation of Cdc25. J Virol 2008; 82:2904-17. [PMID: 18160429 PMCID: PMC2259012 DOI: 10.1128/jvi.01098-07] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Accepted: 11/28/2007] [Indexed: 02/06/2023] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) Vpr induces cell cycle G(2) arrest in fission yeast (Schizosaccharomyces pombe) and mammalian cells, suggesting the cellular pathway(s) targeted by Vpr is conserved among eukaryotes. Our previous studies in fission yeast demonstrated that Vpr induces G(2) arrest in part through inhibition of Cdc25, a Cdc2-specific phosphatase that promotes G(2)/M transition. The goal of this study was to further elucidate molecular mechanism underlying the inhibitory effect of Vpr on Cdc25. We show here that, similar to the DNA checkpoint controls, expression of vpr promotes subcellular relocalization of Cdc25 from nuclear to cytoplasm and thereby prevents activation of Cdc2 by Cdc25. Vpr-induced nuclear exclusion of Cdc25 appears to depend on the serine/threonine phosphorylation of Cdc25 and the presence of Rad24/14-3-3 protein, since amino acid substitutions of the nine possible phosphorylation sites of Cdc25 with Ala (9A) or deletion of the rad24 gene abolished nuclear exclusion induced by Vpr. Interestingly, Vpr is still able to promote Cdc25 nuclear export in mutants defective in the checkpoints (rad3 and chk1/cds1), the kinases that are normally required for Cdc25 phosphorylation and nuclear exclusion of Cdc25, suggesting that others kinase(s) might modulate phosphorylation of Cdc25 for the Vpr-induced G(2) arrest. We report here that this kinase is Srk1. Deletion of the srk1 gene blocks the nuclear exclusion of Cdc25 caused by Vpr. Overexpression of srk1 induces cell elongation, an indication of cell cycle G(2) delay, in a similar fashion to Vpr; however, no additive effect of cell elongation was observed when srk1 and vpr were coexpressed, indicating Srk1 and Vpr are likely affecting the cell cycle G(2)/M transition through the same cellular pathway. Immunoprecipitation further shows that Vpr and Srk1 are part of the same protein complex. Consistent with our findings in fission yeast, depletion of the MK2 gene, a human homologue of Srk1, either by small interfering RNA or an MK2 inhibitor suppresses Vpr-induced cell cycle G(2) arrest in mammalian cells. Collectively, our data suggest that Vpr induces cell cycle G(2) arrest at least in part through a Srk1/MK2-mediated mechanism.
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Affiliation(s)
- Sylvain Huard
- Department of Pathology, University of Maryland School of Medicine, 10 South Pine Street, MSTF700A, Baltimore, MD 21201, USA
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López-Avilés S, Lambea E, Moldón A, Grande M, Fajardo A, Rodríguez-Gabriel MA, Hidalgo E, Aligue R. Activation of Srk1 by the mitogen-activated protein kinase Sty1/Spc1 precedes its dissociation from the kinase and signals its degradation. Mol Biol Cell 2008; 19:1670-9. [PMID: 18272791 DOI: 10.1091/mbc.e07-07-0639] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Control of cell cycle progression by stress-activated protein kinases (SAPKs) is essential for cell adaptation to extracellular stimuli. The Schizosaccharomyces pombe SAPK Sty1/Spc1 orchestrates general changes in gene expression in response to diverse forms of cytotoxic stress. Here we show that Sty1/Spc1 is bound to its target, the Srk1 kinase, when the signaling pathway is inactive. In response to stress, Sty1/Spc1 phosphorylates Srk1 at threonine 463 of the regulatory domain, inducing both activation of Srk1 kinase, which negatively regulates cell cycle progression by inhibiting Cdc25, and dissociation of Srk1 from the SAPK, which leads to Srk1 degradation by the proteasome.
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Affiliation(s)
- Sandra López-Avilés
- Departament de Biologia Cellular, Universitat de Barcelona. Institut d'Investigacions Biomèdiques August Pi i Sunyer, 08036 Barcelona, Catalunya, Spain
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Chen D, Wilkinson CR, Watt S, Penkett CJ, Toone WM, Jones N, Bähler J. Multiple pathways differentially regulate global oxidative stress responses in fission yeast. Mol Biol Cell 2008; 19:308-17. [PMID: 18003976 PMCID: PMC2174203 DOI: 10.1091/mbc.e07-08-0735] [Citation(s) in RCA: 156] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Revised: 10/24/2007] [Accepted: 11/01/2007] [Indexed: 01/01/2023] Open
Abstract
Cellular protection against oxidative damage is relevant to ageing and numerous diseases. We analyzed the diversity of genome-wide gene expression programs and their regulation in response to various types and doses of oxidants in Schizosaccharomyces pombe. A small core gene set, regulated by the AP-1-like factor Pap1p and the two-component regulator Prr1p, was universally induced irrespective of oxidant and dose. Strong oxidative stresses led to a much larger transcriptional response. The mitogen-activated protein kinase (MAPK) Sty1p and the bZIP factor Atf1p were critical for the response to hydrogen peroxide. A newly identified zinc-finger protein, Hsr1p, is uniquely regulated by all three major regulatory systems (Sty1p-Atf1p, Pap1p, and Prr1p) and in turn globally supports gene expression in response to hydrogen peroxide. Although the overall transcriptional responses to hydrogen peroxide and t-butylhydroperoxide were similar, to our surprise, Sty1p and Atf1p were less critical for the response to the latter. Instead, another MAPK, Pmk1p, was involved in surviving this stress, although Pmk1p played only a minor role in regulating the transcriptional response. These data reveal a considerable plasticity and differential control of regulatory pathways in distinct oxidative stress conditions, providing both specificity and backup for protection from oxidative damage.
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Affiliation(s)
- Dongrong Chen
- *Cancer Research UK Fission Yeast Functional Genomics Group, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1HH, United Kingdom; and
- Paterson Institute for Cancer Research, University of Manchester, Manchester M20 4BX, United Kingdom
| | - Caroline R.M. Wilkinson
- Paterson Institute for Cancer Research, University of Manchester, Manchester M20 4BX, United Kingdom
| | - Stephen Watt
- *Cancer Research UK Fission Yeast Functional Genomics Group, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1HH, United Kingdom; and
| | - Christopher J. Penkett
- *Cancer Research UK Fission Yeast Functional Genomics Group, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1HH, United Kingdom; and
| | - W. Mark Toone
- Paterson Institute for Cancer Research, University of Manchester, Manchester M20 4BX, United Kingdom
| | - Nic Jones
- Paterson Institute for Cancer Research, University of Manchester, Manchester M20 4BX, United Kingdom
| | - Jürg Bähler
- *Cancer Research UK Fission Yeast Functional Genomics Group, Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1HH, United Kingdom; and
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Fission yeast mitogen-activated protein kinase Sty1 interacts with translation factors. EUKARYOTIC CELL 2007; 7:328-38. [PMID: 18065650 DOI: 10.1128/ec.00358-07] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Signaling by stress-activated mitogen-activated protein kinase (MAPK) pathways influences translation efficiency in mammalian cells and budding yeast. We have investigated the stress-activated MAPK from fission yeast, Sty1, and its downstream protein kinase, Mkp1/Srk1, for physically associated proteins using tandem affinity purification tagging. We find Sty1, but not Mkp1, to bind to the translation elongation factor eukaryotic elongation factor 2 (eEF2) and the translation initiation factor eukaryotic initiation factor 3a (eIF3a). The Sty1-eIF3a interaction is weakened under oxidative or hyperosmotic stress, whereas the Sty1-eEF2 interaction is stable. Nitrogen deprivation causes a transient strengthening of both the Sty1-eEF2 and the Sty1-Mkp1 interactions, overlapping with the time of maximal Sty1 activation. Analysis of polysome profiles from cells under oxidative stress, or after hyperosmotic shock or nitrogen deprivation, shows that translation in sty1 mutant cells recovers considerably less efficiently than that in the wild type. Cells lacking the Sty1-regulated transcription factor Atf1 are deficient in maintaining and recovering translational activity after hyperosmotic shock but not during oxidative stress or nitrogen starvation. In cells lacking Sty1, eIF3a levels are decreased, and phosphorylation of eIF3a is reduced. Taken together, our data point to a central role in translational adaptation for the stress-activated MAPK pathway in fission yeast similar to that in other investigated eukaryotes, with the exception that fission yeast MAPK-activated protein kinases seem not to be directly involved in this process.
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36
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Miklos I, Szilagyi Z, Watt S, Zilahi E, Batta G, Antunovics Z, Enczi K, Bähler J, Sipiczki M. Genomic expression patterns in cell separation mutants of Schizosaccharomyces pombe defective in the genes sep10 ( + ) and sep15 ( + ) coding for the Mediator subunits Med31 and Med8. Mol Genet Genomics 2007; 279:225-38. [PMID: 17922236 DOI: 10.1007/s00438-007-0296-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2007] [Accepted: 09/19/2007] [Indexed: 11/26/2022]
Abstract
Cell division is controlled by a complex network involving regulated transcription of genes and postranslational modification of proteins. The aim of this study is to demonstrate that the Mediator complex, a general regulator of transcription, is involved in the regulation of the second phase (cell separation) of cell division of the fission yeast Schizosaccharomyces pombe. In previous studies we have found that the fission yeast cell separation genes sep10 ( + ) and sep15 ( + ) code for proteins (Med31 and Med8) associated with the Mediator complex. Here, we show by genome-wide gene expression profiling of mutants defective in these genes that both Med8 and Med31 control large, partially overlapping sets of genes scattered over the entire genome and involved in diverse biological functions. Six cell separation genes controlled by the transcription factors Sep1 and Ace2 are among the target genes. Since neither sep1 ( + ) nor ace2 ( + ) is affected in the mutant cells, we propose that the Med8 and Med31 proteins act as coactivators of the Sep1-Ace2-dependent cell separation genes. The results also indicate that the subunits of Mediator may contribute to the coordination of cellular processes by fine-tuning of the expression of larger sets of genes.
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Affiliation(s)
- Ida Miklos
- Department of Genetics and Applied Microbiology, University of Debrecen, Debrecen, Hungary
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37
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Miranda-Saavedra D, Stark MJR, Packer JC, Vivares CP, Doerig C, Barton GJ. The complement of protein kinases of the microsporidium Encephalitozoon cuniculi in relation to those of Saccharomyces cerevisiae and Schizosaccharomyces pombe. BMC Genomics 2007; 8:309. [PMID: 17784954 PMCID: PMC2078597 DOI: 10.1186/1471-2164-8-309] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2007] [Accepted: 09/04/2007] [Indexed: 12/02/2022] Open
Abstract
Background Microsporidia, parasitic fungi-related eukaryotes infecting many cell types in a wide range of animals (including humans), represent a serious health threat in immunocompromised patients. The 2.9 Mb genome of the microsporidium Encephalitozoon cuniculi is the smallest known of any eukaryote. Eukaryotic protein kinases are a large superfamily of enzymes with crucial roles in most cellular processes, and therefore represent potential drug targets. We report here an exhaustive analysis of the E. cuniculi genomic database aimed at identifying and classifying all protein kinases of this organism with reference to the kinomes of two highly-divergent yeast species, Saccharomyces cerevisiae and Schizosaccharomyces pombe. Results A database search with a multi-level protein kinase family hidden Markov model library led to the identification of 29 conventional protein kinase sequences in the E. cuniculi genome, as well as 3 genes encoding atypical protein kinases. The microsporidian kinome presents striking differences from those of other eukaryotes, and this minimal kinome underscores the importance of conserved protein kinases involved in essential cellular processes. ~30% of its kinases are predicted to regulate cell cycle progression while another ~28% have no identifiable homologues in model eukaryotes and are likely to reflect parasitic adaptations. E. cuniculi lacks MAP kinase cascades and almost all protein kinases that are involved in stress responses, ion homeostasis and nutrient signalling in the model fungi S. cerevisiae and S. pombe, including AMPactivated protein kinase (Snf1), previously thought to be ubiquitous in eukaryotes. A detailed database search and phylogenetic analysis of the kinomes of the two model fungi showed that the degree of homology between their kinomes of ~85% is much higher than that previously reported. Conclusion The E. cuniculi kinome is by far the smallest eukaryotic kinome characterised to date. The difficulty in assigning clear homology relationships for nine out of the twentynine microsporidian conventional protein kinases despite its compact genome reflects the phylogenetic distance between microsporidia and other eukaryotes. Indeed, the E. cuniculi genome presents a high proportion of genes in which evolution has been accelerated by up to four-fold. There are no orthologues of the protein kinases that constitute MAP kinase pathways and many other protein kinases with roles in nutrient signalling are absent from the E. cuniculi kinome. However, orthologous kinases can nonetheless be identified that correspond to members of the yeast kinomes with roles in some of the most fundamental cellular processes. For example, E. cuniculi has clear orthologues of virtually all the major conserved protein kinases that regulate the core cell cycle machinery (Aurora, Polo, DDK, CDK and Chk1). A comprehensive comparison of the homology relationships between the budding and fission yeast kinomes indicates that, despite an estimated 800 million years of independent evolution, the two model fungi share ~85% of their protein kinases. This will facilitate the annotation of many of the as yet uncharacterised fission yeast kinases, and also those of novel fungal genomes.
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Affiliation(s)
- Diego Miranda-Saavedra
- College of Life Sciences, University of Dundee, Dow St, Dundee DD1 5EH, Scotland, UK
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY, UK
| | - Michael JR Stark
- College of Life Sciences, University of Dundee, Dow St, Dundee DD1 5EH, Scotland, UK
| | - Jeremy C Packer
- Division of Advanced Technologies, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064, USA
| | - Christian P Vivares
- Laboratoire de Parasitologie Moléculaire et Cellulaire. UMR CNRS 6023, Université Blaise Pascal, Aubière, France
| | - Christian Doerig
- INSERM U609, Wellcome Centre for Molecular Parasitology, Glasgow Biomedical Research Centre, 120 University Place, Glasgow G12 8TA, Scotland, UK
| | - Geoffrey J Barton
- College of Life Sciences, University of Dundee, Dow St, Dundee DD1 5EH, Scotland, UK
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Penkett CJ, Birtle ZE, Bähler J. Simplified primer design for PCR-based gene targeting and microarray primer database: two web tools for fission yeast. Yeast 2007; 23:921-8. [PMID: 17072893 PMCID: PMC2964512 DOI: 10.1002/yea.1422] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PCR-based gene targeting is a popular method for manipulating yeast genes in their normal chromosomal locations. The manual design of primers, however, can be cumbersome and error-prone. We have developed a straightforward web-based tool that applies user-specified inputs to automate and simplify the task of primer selection for deletion, tagging and/or regulated expression of genes in Schizosaccharomyces pombe. This tool, named PPPP (for Pombe PCR Primer Programs), is available at http://www.sanger.ac.uk/PostGenomics/S_pombe/software/. We also present a searchable Microarray Primer Database to retrieve the sequences and accompanying information for primers and PCR products used to build our in-house Sz. pombe microarrays. This database contains information on both coding and intergenic regions to provide context for the microarray data, and it should be useful also for other applications, such as quantitative PCR. The database can be accessed at http://www.sanger.ac.uk/PostGenomics/S_pombe/microarray/. Copyright © 2006 John Wiley & Sons, Ltd.
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Affiliation(s)
| | | | - Jürg Bähler
- *Correspondence to: Jürg Bähler,Cancer Research UK Fission Yeast Functional Genomics Group, Wellcome Trust Sanger Institute, Cambridge CB10 1HH, UK. E-mail:
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39
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Sunnerhagen P. Cytoplasmatic post-transcriptional regulation and intracellular signalling. Mol Genet Genomics 2007; 277:341-55. [PMID: 17333280 DOI: 10.1007/s00438-007-0221-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2006] [Accepted: 02/06/2007] [Indexed: 02/05/2023]
Abstract
Studies of intracellular signalling have traditionally focused on regulation at the levels of initiation of transcription on one hand, and post-translational regulation on the other. More recently, it is becoming apparent that the post-transcriptional level of gene expression is also subject to regulation by signalling pathways. The emphasis in this review is on short-term regulation of mRNAs at the levels of degradation and frequency of translation. Interplay between the mRNA translation and degradation machineries and mainly the TOR, stress-induced MAP kinase (SAPK), and DNA damage checkpoint pathways is discussed. Since a large fraction of the molecular mechanisms has been dissected using molecular genetics methods in yeast, most of the examples in this review are from budding and fission yeast. Some parallels are drawn to plant and animal cells. This review is intended for those more familiar with intracellular signalling, and who realise that post-transcriptional regulation may be an underemphasised level of signalling output.
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Affiliation(s)
- Per Sunnerhagen
- Department of Cell and Molecular Biology, Lundberg Laboratory, Göteborg University, P.O. Box 462, 405 30, Göteborg, Sweden.
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40
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Xie Y, Wang F, Puscheck EE, Rappolee DA. Pipetting causes shear stress and elevation of phosphorylated stress-activated protein kinase/jun kinase in preimplantation embryos. Mol Reprod Dev 2007; 74:1287-94. [PMID: 17492777 DOI: 10.1002/mrd.20563] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Shear stress at 1.2 dynes/cm(2) induces stress-activated protein kinase/jun kinase phosphorylation that precedes and causes apoptosis in embryos (Xie et al., 2006b, Biol Reprod). Pipetting embryos is necessary for many protocols, from in vitro fertilization to collecting embryos prior to analyzing gene expression by microarrays. We sought to determine if pipetting upregulates phosphorylated MAPK8/9 (formerly known as stress-activated protein kinase/jun kinase/SAPK/JNK1, 2). We found that phosphorylated MAPK8/9, a marker of MAPK8/9 activation, is upregulated in a dose-dependent manner by pipetting. Whereas embryos with the zona pellucida removed were more sensitive to stress-induced lethality mediated by 1.2 dynes/cm(2) shear force, phosphorylated MAPK8/9 was induced at lower numbers of pipet triturations in hatched embryos at E4.5. E4.5 embryos were more sensitive to induction of MAPK8/9 than unhatched embryos at E2.5 or E3.5. E3.5 embryos also showed a pipetting dose-dependent induction of FOS protein (formerly known as c-fos), a marker of shear stress in many cell types. Phosphorylated MAPK8/9 measured in ex vivo embryos from E1.5 to E4.5 were expressed at low levels. Embryos that had been pipetted sufficiently to induce phosphorylated MAPK8/9 and FOS had the same number of cells as untreated embryos 24 hr later. This suggests that rapid phosphorylation of MAPK8/9 due to transient shear stress does not mediate long-term negative biological outcomes. But, it is possible that techniques requiring multiple handling events would induce MAPK8/9 and cause biological outcomes or that other biological outcomes are affected by low amounts of transient shear stress. This study suggests that embryo handling prior to experimental measurement of signal transduction phosphoproteins, proteins and mRNA should be performed with care. Indeed, it is likely that shear stress may cause rapid transient changes in hundreds of proteins and mRNA.
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Affiliation(s)
- Y Xie
- CS Mott Center for Human Growth and Development of Ob/Gyn, Wayne State University School of Medicine, Detroit, Michigan, USA
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41
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Vivancos AP, Jara M, Zuin A, Sansó M, Hidalgo E. Oxidative stress in Schizosaccharomyces pombe: different H2O2 levels, different response pathways. Mol Genet Genomics 2006; 276:495-502. [PMID: 17043891 DOI: 10.1007/s00438-006-0175-z] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Accepted: 09/20/2006] [Indexed: 01/27/2023]
Abstract
Schizosaccharomyces pombe triggers different signalling pathways depending on the severity of the oxidative stress exerted, the main ones being the Pap1 and the Sty1 pathways. The Pap1 transcription factor is more sensitive to hydrogen peroxide (H(2)O(2)) than the MAP kinase Sty1 pathway, and is designed to induce adaptation, rather than survival, responses. The peroxiredoxin Tpx1 acts as a H(2)O(2) sensor and the upstream activator of the Pap1 pathway. Therefore, sensitivity to H(2)O(2) depends on this thioredoxin peroxidase. In order to achieve maximal activation of the MAP kinase pathway, the concentration of H(2)O(2) needs to be at least fivefold higher than that to fully activate Pap1. Tpx1 is a H(2)O(2) scavenger, thus its peroxidase activity is essential for aerobic growth. As described for other eukaryotic peroxiredoxins, high doses of H(2)O(2) temporarily inactivate Tpx1 and delay Pap1 activation, whereas the Sty1 pathway remains fully functional under these conditions. As part of the Sty1-dependent transcriptional response, the expression of Srx1 is induced and this reductase re-activates the over-oxidised Tpx1. Therefore, the antioxidant pathways of the fission yeast are perfectly designed so that the transcriptional programs triggered by the different signalling pathways never overlap.
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Affiliation(s)
- Ana P Vivancos
- Cell Signalling Unit, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, C/Dr. Aiguader 80, Barcelona, 08003, Spain
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Karlsson-Rosenthal C, Millar JBA. Cdc25: mechanisms of checkpoint inhibition and recovery. Trends Cell Biol 2006; 16:285-92. [PMID: 16682204 DOI: 10.1016/j.tcb.2006.04.002] [Citation(s) in RCA: 191] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Accepted: 04/07/2006] [Indexed: 12/01/2022]
Abstract
Members of the eukaryotic Cdc25 phosphatase family are key targets of the Chk1 and Chk2 checkpoint kinases, which inactivate Cdc25 to halt cell cycle progression when DNA is damaged or incompletely replicated. Now, new kinases that phosphorylate and inactivate Cdc25 are being discovered, including MAPKAP kinase-2, a component of the p38 stress-activated MAP kinase pathway. The roles of other kinases, such as cyclin-dependent kinase, Polo and Aurora A kinase, in controlling the localization or the activation of Cdc25, are controversial. Here, we discuss new data that suggests that different Cdc25 isoforms and regulators of Cdc25 are differentially required for normal cell cycle progression and recovery from checkpoint arrest.
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43
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Rodríguez-Gabriel MA, Russell P. Distinct signaling pathways respond to arsenite and reactive oxygen species in Schizosaccharomyces pombe. EUKARYOTIC CELL 2005; 4:1396-402. [PMID: 16087744 PMCID: PMC1214538 DOI: 10.1128/ec.4.8.1396-1402.2005] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Exposure to certain metal and metalloid species, such as arsenic, cadmium, chromium, and nickel, has been associated with an increased risk of cancer in humans. The biological effects of these metals are thought to result from induction of reactive oxygen species (ROS) and inhibition of DNA repair enzymes, although alterations in signal transduction pathways may also be involved in tumor development. To better understand metal toxicity and its connection to ROS, we have compared the effects of arsenite and hydrogen peroxide in wild-type and mutant strains of the fission yeast Schizosaccharomyces pombe. An atf1Delta pap1Delta strain, which is defective in two transcription factors that control stress responses, is extremely sensitive to hydrogen peroxide but not to arsenite. A strain that lacks the transcription factor Zip1 has the opposite relationship. Spc1 (Sty1) mitogen-activated protein kinase (MAPK), a homologue of mammalian p38 MAPK, and the upstream MAPK kinase (MAPKK) Wis1 are essential for survival of both arsenite and hydrogen peroxide. Inactivation of two MAPKK kinases, Win1 and Wis4, almost completely eliminates Spc1 activation by arsenite, yet these cells survive arsenite treatment. The two-component phosphorelay protein Mcs4, which acts upstream of Win1 and Wis4 and is required for Spc1 activation in response to oxidative stress, is not required for Spc1 activation in response to arsenite. We conclude that the toxic effects of arsenic are not strongly connected to oxidative stress and that although Spc1 is activated by arsenic exposure, the basal activity of Spc1 is largely sufficient for the survival of arsenic.
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Affiliation(s)
- Miguel A Rodríguez-Gabriel
- Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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44
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Swaminathan S, Masek T, Molin C, Pospisek M, Sunnerhagen P. Rck2 is required for reprogramming of ribosomes during oxidative stress. Mol Biol Cell 2005; 17:1472-82. [PMID: 16381815 PMCID: PMC1382333 DOI: 10.1091/mbc.e05-07-0632] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Rck2 is a mitogen-activated protein kinase-activated protein kinase in yeast implicated in translational regulation. rck2Delta mutants are mildly sensitive to oxidative stress, a condition that causes dissociation of actively translating ribosomes (polysomes). In rck2Delta cells, polysomes are lost to an even higher degree than in the wild-type upon stress. Cells overexpressing the catalytically inactive rck2-kd allele are highly sensitive to oxidative stress. In such cells, dissociation of polysomes upon stress was instead greatly delayed. The protein synthesis rate decreased to a similar degree as in wild-type cells, however, indicating that in rck2-kd cells, the polysome complexes were inactive. Array analyses of total and polysome-associated mRNAs revealed major deregulation of the translational machinery in rck2 mutant cells. This involves transcripts for cytosolic ribosomal proteins and for processing and assembly of ribosomes. In rck2Delta cells, weakly transcribed mRNAs associate more avidly with polysomes than in wild-type cells, whereas the opposite holds true for rck2-kd cells. This is consistent with perturbed regulation of translation elongation, which is predicted to alter the ratio between mRNAs with and without strong entry sites at ribosomes. We infer that imbalances in the translational apparatus are a major reason for the inability of these cells to respond to stress.
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Affiliation(s)
- Swarna Swaminathan
- Department of Cell and Molecular Biology, Lundberg Laboratory, Göteborg University, S-405 30 Göteborg, Sweden
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Enjalbert B, Smith DA, Cornell MJ, Alam I, Nicholls S, Brown AJP, Quinn J. Role of the Hog1 stress-activated protein kinase in the global transcriptional response to stress in the fungal pathogen Candida albicans. Mol Biol Cell 2005; 17:1018-32. [PMID: 16339080 PMCID: PMC1356608 DOI: 10.1091/mbc.e05-06-0501] [Citation(s) in RCA: 288] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The resistance of Candida albicans to many stresses is dependent on the stress-activated protein kinase (SAPK) Hog1. Hence we have explored the role of Hog1 in the regulation of transcriptional responses to stress. DNA microarrays were used to characterize the global transcriptional responses of HOG1 and hog1 cells to three stress conditions that activate the Hog1 SAPK: osmotic stress, oxidative stress, and heavy metal stress. This revealed both stress-specific transcriptional responses and a core transcriptional response to stress in C. albicans. The core transcriptional response was characterized by a subset of genes that responded in a stereotypical manner to all of the stresses analyzed. Inactivation of HOG1 significantly attenuated transcriptional responses to osmotic and heavy metal stresses, but not to oxidative stress, and this was reflected in the role of Hog1 in the regulation of C. albicans core stress genes. Instead, the Cap1 transcription factor plays a key role in the oxidative stress regulation of C. albicans core stress genes. Our data show that the SAPK network in C. albicans has diverged from corresponding networks in model yeasts and that the C. albicans SAPK pathway functions in parallel with other pathways to regulate the core transcriptional response to stress.
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Affiliation(s)
- Brice Enjalbert
- Aberdeen Fungal Group, School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom
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Bulmer R, Pic-Taylor A, Whitehall SK, Martin KA, Millar JBA, Quinn J, Morgan BA. The forkhead transcription factor Fkh2 regulates the cell division cycle of Schizosaccharomyces pombe. EUKARYOTIC CELL 2005; 3:944-54. [PMID: 15302827 PMCID: PMC500873 DOI: 10.1128/ec.3.4.944-954.2004] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In eukaryotes the regulation of gene expression plays a key role in controlling cell cycle progression. Here, we demonstrate that a forkhead transcription factor, Fkh2, regulates the periodic expression of cdc15(+) and spo12(+) in the M and G(1) phases of the cell division cycle in the fission yeast Schizosaccharomyces pombe. We also show that Fkh2 is important for several cell cycle processes, including cell morphology and cell separation, nuclear structure and migration, and mitotic spindle function. We find that the expression of fkh2(+) is itself regulated in a cell cycle-dependent manner in G(1) coincident with the expression of cdc18(+), a Cdc10-regulated gene. However, fkh2(+) expression is independent of Cdc10 function. Fkh2 was found to be phosphorylated during the cell division cycle, with a timing that suggests that this posttranslational modification is important for cdc15(+) and spo12(+) expression. Related forkhead proteins regulate G(2) and M phase-specific gene expression in the evolutionarily distant Saccharomyces cerevisiae, suggesting that these proteins play conserved roles in regulating cell cycle processes in eukaryotes.
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Affiliation(s)
- Richard Bulmer
- Institute of Cell and Molecular Biosciences, Faculty of Medical Sciences, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom
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Bimbó A, Jia Y, Poh SL, Karuturi RKM, den Elzen N, Peng X, Zheng L, O'Connell M, Liu ET, Balasubramanian MK, Liu J. Systematic deletion analysis of fission yeast protein kinases. EUKARYOTIC CELL 2005; 4:799-813. [PMID: 15821139 PMCID: PMC1087820 DOI: 10.1128/ec.4.4.799-813.2005] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Eukaryotic protein kinases are key molecules mediating signal transduction that play a pivotal role in the regulation of various biological processes, including cell cycle progression, cellular morphogenesis, development, and cellular response to environmental changes. A total of 106 eukaryotic protein kinase catalytic-domain-containing proteins have been found in the entire fission yeast genome, 44% (or 64%) of which possess orthologues (or nearest homologues) in humans, based on sequence similarity within catalytic domains. Systematic deletion analysis of all putative protein kinase-encoding genes have revealed that 17 out of 106 were essential for viability, including three previously uncharacterized putative protein kinases. Although the remaining 89 protein kinase mutants were able to form colonies under optimal growth conditions, 46% of the mutants exhibited hypersensitivity to at least 1 of the 17 different stress factors tested. Phenotypic assessment of these mutants allowed us to arrange kinases into functional groups. Based on the results of this assay, we propose also the existence of four major signaling pathways that are involved in the response to 17 stresses tested. Microarray analysis demonstrated a significant correlation between the expression signature and growth phenotype of kinase mutants tested. Our complete microarray data sets are available at http://giscompute.gis.a-star.edu.sg/~gisljh/kinome.
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Affiliation(s)
- Andrea Bimbó
- Temasek Life Sciences Laboratory, 1 Research Link, NUS, Singapore 117604
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Wang LY, Shimada K, Morishita M, Shiozaki K. Response of fission yeast to toxic cations involves cooperative action of the stress-activated protein kinase Spc1/Sty1 and the Hal4 protein kinase. Mol Cell Biol 2005; 25:3945-55. [PMID: 15870269 PMCID: PMC1087739 DOI: 10.1128/mcb.25.10.3945-3955.2005] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Stress-activated protein kinases (SAPKs), members of a mitogen-activated protein kinase (MAPK) subfamily, are highly conserved among eukaryotes. Studies of yeasts demonstrated that SAPKs play pivotal roles in survival responses to high osmolarity, oxidative stress, and heat shock. Here we report a novel physiological role of the fission yeast Spc1 SAPK in cellular resistance to certain cations, such as Na(+), Li(+), and Ca(2+). Strains lacking Spc1 or its activator, Wis1 MAPK kinase, are hypersensitive to these cations. Spc1 positively regulates expression of sod2(+) encoding a Na(+)/H(+) antiporter through Atf1 and other transcription factors. In addition, we have identified a novel Spc1-interacting protein, Hal4, which is highly homologous to the budding yeast Sat4/Hal4 protein kinase. Like its budding yeast counterpart, the fission yeast Hal4 kinase is essential for cellular resistance to Na(+), Li(+), and Ca(2+). The hal4-null phenotype is complemented by overexpression of the Trk1 potassium transporter or increased K(+) in the growth medium, suggesting that Hal4 promotes K(+) uptake, which consequently increases cellular resistance to other cations. Interestingly, the Spc1-Hal4 interaction appears to be required for cellular resistance to Ca(2+) but not Na(+) and Li(+). We propose that Spc1 SAPK and Hal4 kinase cooperatively function to protect cells from the toxic cations.
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Affiliation(s)
- Ling-Yu Wang
- Section of Microbiology, Division of Biological Sciences, University of California, Davis, CA 95616, USA
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Swaminathan S, Sunnerhagen P. Degradation of Saccharomyces cervisiae Rck2 upon exposure of cells to high levels of zinc is dependent on Pep4. Mol Genet Genomics 2005; 273:433-9. [PMID: 15887030 DOI: 10.1007/s00438-005-1151-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Accepted: 03/30/2005] [Indexed: 10/25/2022]
Abstract
In undisturbed cells, the MAPK-activated protein kinase Rck2 of Saccharomyces cerevisiae is a stable protein with a turnover time exceeding 60 min. However, we have found that Rck2 is subject to intracellular degradation after exposure of cells to Zn2+ concentrations of 5 mM or more. In high-zinc medium, most of the Rck2 pool is degraded within 5 min. This degradation is blocked by inhibiting the vacuolar proteolytic pathway with the protease inhibitor phenyl methyl sulphonyl fluoride or by mutation of the PEP4 gene. By contrast, blocking the proteasomal pathway with the inhibitor MG132 does not prevent Rck2 degradation upon addition of Zn2+, nor is degradation inhibited in the proteasomal mutations pre1 pre2, cim3, or cim5. The stability of Rck2 is not affected by any of the other stress conditions examined, or by growth rate. Possible mechanisms of the degradation of Rck2 under high zinc conditions, and its physiological significance, are discussed.
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Affiliation(s)
- Swarna Swaminathan
- Lundberg Laboratory, Department of Cell and Molecular Biology, Göteborg University, P.O. Box 462, 405 30, Goteborg, Sweden
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Weeks ME, Sinclair J, Jacob RJ, Saxton MJ, Kirby S, Jones J, Waterfield MD, Cramer R, Timms JF. Stress-induced changes in theSchizosaccharomyces pombe proteome using two-dimensional difference gel electrophoresis, mass spectrometry and a novel integrated robotics platform. Proteomics 2005; 5:1669-85. [PMID: 15789347 DOI: 10.1002/pmic.200401241] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Robotic and manual methods have been used to obtain identification of significantly changing proteins regulated when Schizosaccharomyces pombe is exposed to oxidative stress. Differently treated S. pombe cells were lysed, labelled with CyDye and analysed by two-dimensional difference gel electrophoresis. Gel images analysed off-line, using the DeCyder image analysis software [GE Healthcare, Amersham, UK] allowed selection of significantly regulated proteins. Proteins displaying differential expression were excised robotically for manual digestion and identified by matrix-assisted laser desorption/ionisation - mass spectrometry (MALDI-MS). Additionally the same set of proteins displaying differential expression were automatically cut and digested using a prototype robotic platform. Automated MALDI-MS, peak label assignment and database searching were utilised to identify as many proteins as possible. The results achieved by the robotic system were compared to manual methods. The identification of all significantly altered proteins provides an annotated peroxide stress-related proteome that can be used as a base resource against which other stress-induced proteomic changes can be compared.
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Affiliation(s)
- Mark E Weeks
- Ludwig Institute for Cancer Research, Gower Street, London, UK.
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