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Dąbala M, Świder M, Kasela T, Buda P, Grabarek BO. Variances in the Expression Profile of DUSP1-7 and miRNAs Regulating Their Expression in the Hacat Line Under LPS and Cyclosporine A. Curr Pharm Biotechnol 2023:CPB-EPUB-130784. [PMID: 37032503 DOI: 10.2174/1389201024666230407122254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 01/11/2023] [Accepted: 01/20/2023] [Indexed: 04/11/2023]
Abstract
INTRODUCTION Cyclosporin A (CsA) treats moderate to severe psoriasis vulgaris. Psoriasis is a chronic inflammatory disease in which hyperproliferation of keratinocytes occurs. One of the most relevant signaling cascades in the development of psoriasis is the mitogen-activated protein kinase (MAPK) signaling pathway. It has been observed that dual-specificity phosphatases (DUSPs) dephosphorylate signaling molecules, such as MAPKs. AIMS This study aims to determine changes in the expression pattern of Dual Activity Protein Phosphatase (DUSP1-7) and micro RNAs (miRNAs), potentially regulating their expression in the human adult, low-calcium, high-temperature keratinocytes cell line (HaCaT) cultures exposed to lipopolysaccharide A (LPS)-induced inflammation, followed by CsA. METHODS HaCaT cell line was exposed for 8 hours to 1 μg/mL LPS and then to 100 ng/mL CsA for 2, 8, and 24 hours compared to cultures not exposed to LPS and the drug. The molecular analysis included determining the DUSP1-7 expression and the miRNAs potentially regulating it using an expression microarray technique. An enzyme-linked immunosorbent assay (ELISA) was also performed to assess the concentration of DUSP1-7 in the culture medium. Statistical evaluation was performed assuming a statistical significance threshold (p) of < 0.05. RESULTS Statistically significant differences were found in the expression of DUSP1-7 mRNAs and the miRNAs that regulate their expression. The most significant changes in expression were observed for DUSP1 and DUSP5, with the differences being most pronounced during the eight-hour incubation period of the cells, with the drug predictive analysis showing that miR-34 potentially regulates the expression of DUSP1-4,7, miR-1275: DUSP2, mir-3188:DUSP4, miR-382: DUSP4, miR-27a and miR-27b: DUSP5,6 and miR-16: DUSP7. No expression of DUSP1-7 was demonstrated at the protein level in CsA-exposed cultures. CONCLUSION Our evaluation of the efficacy of CsA therapy on an in vitro model of HaCaT indicates that treatment with this drug is effective, resulting in changes in the expression of DUSP1-7 and, potentially, the miRNAs that regulate their expression. We also confirmed that the different expression pattern of mRNA and protein encoded by a given transcript is not only due to the regulatory role of miRNAs but also the lack of synchronization between transcription and translation processes.
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Affiliation(s)
- Maciej Dąbala
- Department of Histology, Cytophysiology and Embryology, Faculty of Medicine in Zabrze, Academy of Silesia, 41800 Zabrze, Poland
- Dabala Ortodoncja, Francuska 102/u3, 40-507 Katowice, Poland
| | - Magdalena Świder
- Department of Histology, Cytophysiology and Embryology, Faculty of Medicine in Zabrze, Academy of Silesia, 41800 Zabrze, Poland
| | - Tomasz Kasela
- Department of Histology, Cytophysiology and Embryology, Faculty of Medicine in Zabrze, Academy of Silesia, 41800 Zabrze, Poland
- Gyncentrum, Laboratory of Molecular Biology and Virology, 40851 Katowice, Poland
| | - Paulina Buda
- Department of Histology, Cytophysiology and Embryology, Faculty of Medicine in Zabrze, Academy of Silesia, 41800 Zabrze, Poland
| | - Beniamin Oskar Grabarek
- Department of Histology, Cytophysiology and Embryology, Faculty of Medicine in Zabrze, Academy of Silesia, 41800 Zabrze, Poland
- Gyncentrum, Laboratory of Molecular Biology and Virology, 40851 Katowice, Poland
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Liu S, Gong X, Ma J, Wang S, Guo M. MoMih1 is indispensable for asexual development, cell wall integrity, and pathogenicity of Magnaporthe oryzae. Front Plant Sci 2023; 14:1146915. [PMID: 36998683 PMCID: PMC10044144 DOI: 10.3389/fpls.2023.1146915] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 02/27/2023] [Indexed: 06/19/2023]
Abstract
Asexual spore serves as essential inoculum of rice blast during the disease cycle, and differentiation of young conidium from conidiophore is intimately regulated by cell cycle. Mih1 encodes a dual-specificity phosphatase that involved in the G2/M transition of the mitotic cell cycle by regulating the Cdk1 activity in eukaryotes. Till now, the roles of Mih1 homologue, however, remain unclear in Magnaporthe oryzae. We here functionally characterized the Mih1 homologue MoMih1 in M. oryzae. MoMih1 is localized to both the cytoplasm and nucleus and can physically interact with the CDK protein MoCdc28 in vivo. Loss of MoMih1 led to delayed nucleus division and a high level of Tyr15 phosphorylation of MoCdc28. The MoMih1 mutants showed retarded mycelial growth with a defective polar growth, less fungal biomass, and shorter distance between diaphragms, compared with the KU80. Asexual reproduction altered in MoMih1 mutants, with both abnormal conidial morphogenesis and decreased conidiation. The MoMih1 mutants severely attenuated the virulence to host plants due to the impaired ability of penetration and biotrophic growth. The incapability of scavenging of host-derived reactive oxygen species, which was possibly ascribed to the severely decreased extracellular enzymes activities, were partially associated with deficiency of pathogenicity. Besides, the MoMih1 mutants displayed also improper localization of retromer protein MoVps26 and polarisome component MoSpa2, and defects of cell wall integrity (CWI), melanin pigmentation, chitin synthesis, and hydrophobicity. In conclusion, our results demonstrate that MoMih1 plays pleiotropic roles during fungal development and plant infection of M. oryzae.
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Affiliation(s)
- Shiyi Liu
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, Hefei, China
- College of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Xinli Gong
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, Hefei, China
- College of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Ji Ma
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, Hefei, China
- College of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Shuaishuai Wang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, Hefei, China
- College of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Min Guo
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, Anhui Agricultural University, Hefei, China
- College of Plant Protection, Anhui Agricultural University, Hefei, China
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Thompson EM, Patel V, Rajeeve V, Cutillas PR, Stoker AW. The cytotoxic action of BCI is not dependent on its stated DUSP1 or DUSP6 targets in neuroblastoma cells. FEBS Open Bio 2022; 12:1388-1405. [PMID: 35478300 PMCID: PMC9249316 DOI: 10.1002/2211-5463.13418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 04/04/2022] [Accepted: 04/26/2022] [Indexed: 12/04/2022] Open
Abstract
Neuroblastoma (NB) is a heterogeneous cancer of the sympathetic nervous system, which accounts for 7-10% of paediatric malignancies worldwide. Due to the lack of targetable molecular aberrations in NB, most treatment options remain relatively nonspecific. Here, we investigated the therapeutic potential of BCI, an inhibitor of DUSP1 and DUSP6, in cultured NB cells. BCI was cytotoxic in a range of NB cell lines and induced a short-lived activation of the AKT and stress-inducible MAP kinases, although ERK phosphorylation was unaffected. Furthermore, a phosphoproteomic screen identified significant upregulation of JNK signalling components and suppression in mTOR and R6K signalling. To assess the specificity of BCI, CRISPR-Cas9 was employed to introduce insertions and deletions in the DUSP1 and DUSP6 genes. Surprisingly, BCI remained fully cytotoxic in NB cells with complete loss of DUSP6 and partial depletion of DUSP1, suggesting that BCI exerts cytotoxicity in NB cells through a complex mechanism that is unrelated to these phosphatases. Overall, these data highlight the risk of using an inhibitor such as BCI as supposedly specific DUSP1/6, without understanding its full range of targets in cancer cells.
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Affiliation(s)
- Elliott M. Thompson
- Developmental Biology & Cancer Research and Teaching DepartmentUCL Great Ormond Street Institute of Child HealthLondonUK
| | - Vruti Patel
- Developmental Biology & Cancer Research and Teaching DepartmentUCL Great Ormond Street Institute of Child HealthLondonUK
- Present address:
Current Address: Discovery Research MRL UKMSDThe London Bioscience Innovation Centre (LBIC)LondonUK
| | - Vinothini Rajeeve
- Mass Spectrometry LaboratoryBarts Cancer InstituteQueen Mary University of LondonUK
| | - Pedro R Cutillas
- Mass Spectrometry LaboratoryBarts Cancer InstituteQueen Mary University of LondonUK
| | - Andrew W. Stoker
- Developmental Biology & Cancer Research and Teaching DepartmentUCL Great Ormond Street Institute of Child HealthLondonUK
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Ayatollahi Z, Kazanaviciute V, Shubchynskyy V, Kvederaviciute K, Schwanninger M, Rozhon W, Stumpe M, Mauch F, Bartels S, Ulm R, Balazadeh S, Mueller-Roeber B, Meskiene I, Schweighofer A. Dual control of MAPK activities by AP2C1 and MKP1 MAPK phosphatases regulates defence responses in Arabidopsis. J Exp Bot 2022; 73:2369-2384. [PMID: 35088853 PMCID: PMC9015810 DOI: 10.1093/jxb/erac018] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/25/2022] [Indexed: 06/14/2023]
Abstract
Mitogen-activated protein kinase (MAPK) cascades transmit environmental signals and induce stress and defence responses in plants. These signalling cascades are negatively controlled by specific Ser/Thr protein phosphatases of the type 2C (PP2C) and dual-specificity phosphatase (DSP) families that inactivate stress-induced MAPKs; however, the interplay between phosphatases of these different types has remained unknown. This work reveals that different Arabidopsis MAPK phosphatases, the PP2C-type AP2C1 and the DSP-type MKP1, exhibit both specific and overlapping functions in plant stress responses. Each single mutant, ap2c1 and mkp1, and the ap2c1 mkp1 double mutant displayed enhanced stress-induced activation of the MAPKs MPK3, MPK4, and MPK6, as well as induction of a set of transcription factors. Moreover, ap2c1 mkp1 double mutants showed an autoimmune-like response, associated with increased levels of the stress hormones salicylic acid and ethylene, and of the phytoalexin camalexin. This phenotype was reduced in the ap2c1 mkp1 mpk3 and ap2c1 mkp1 mpk6 triple mutants, suggesting that the autoimmune-like response is due to MAPK misregulation. We conclude that the evolutionarily distant MAPK phosphatases AP2C1 and MKP1 contribute crucially to the tight control of MAPK activities, ensuring appropriately balanced stress signalling and suppression of autoimmune-like responses during plant growth and development.
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Affiliation(s)
- Zahra Ayatollahi
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Dr.-Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Vaiva Kazanaviciute
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Dr.-Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Volodymyr Shubchynskyy
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Dr.-Bohr-Gasse 9, A-1030 Vienna, Austria
| | - Kotryna Kvederaviciute
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Sauletekio al. 7, LT-10257 Vilnius, Lithuania
| | - Manfred Schwanninger
- Department of Chemistry, University of Natural Resources and Applied Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Wilfried Rozhon
- Department of Agriculture, Ecotrophology, and Landscape Development, Anhalt University of Applied Sciences, Strenzfelder Allee 28, D-06406 Bernburg, Germany
| | - Michael Stumpe
- Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Felix Mauch
- Department of Biology, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland
| | - Sebastian Bartels
- Faculty of Biology, Institute of Biology II, University of Freiburg, Schänzlestraße 1, D-79104 Freiburg, Germany
| | - Roman Ulm
- Department of Botany and Plant Biology, Section of Biology, Faculty of Sciences, University of Geneva, 30 Quai E. Ansermet, CH-1211 Geneva, Switzerland
| | - Salma Balazadeh
- Max-Planck-Institute of Molecular Plant Physiology (MPIMP), Am Mühlenberg 1, D-14476 Potsdam, Germany
- University of Potsdam, Karl-Liebknecht-Straße 24, D-14476 Potsdam, Germany
- Institute of Biology Leiden (IBL), Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Bernd Mueller-Roeber
- Max-Planck-Institute of Molecular Plant Physiology (MPIMP), Am Mühlenberg 1, D-14476 Potsdam, Germany
- University of Potsdam, Karl-Liebknecht-Straße 24, D-14476 Potsdam, Germany
- Center of Plant Systems Biology and Biotechnology (CPSBB), Ruski 139 Blvd., Plovdiv 4000, Bulgaria
| | - Irute Meskiene
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Dr.-Bohr-Gasse 9, A-1030 Vienna, Austria
- Department of Functional and Evolutionary Ecology, University of Vienna, Djerassiplatz 1, A-1030 Vienna, Austria
| | - Alois Schweighofer
- Max Perutz Labs, University of Vienna, Vienna BioCenter, Dr.-Bohr-Gasse 9, A-1030 Vienna, Austria
- Department of Functional and Evolutionary Ecology, University of Vienna, Djerassiplatz 1, A-1030 Vienna, Austria
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Gehring K, Kozlov G, Yang M, Fakih R. The double lives of phosphatases of regenerating liver: A structural view of their catalytic and noncatalytic activities. J Biol Chem 2021; 298:101471. [PMID: 34890645 PMCID: PMC8728433 DOI: 10.1016/j.jbc.2021.101471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 11/18/2022] Open
Abstract
Phosphatases of regenerating liver (PRLs) are protein phosphatases involved in the control of cell growth and migration. They are known to promote cancer metastasis but, despite over 20 years of study, there is still no consensus about their mechanism of action. Recent work has revealed that PRLs lead double lives, acting both as catalytically active enzymes and as pseudophosphatases. The three known PRLs belong to the large family of cysteine phosphatases that form a phosphocysteine intermediate during catalysis. Uniquely to PRLs, this intermediate is stable, with a lifetime measured in hours. As a consequence, PRLs have very little phosphatase activity. Independently, PRLs also act as pseudophosphatases by binding CNNM membrane proteins to regulate magnesium homeostasis. In this function, an aspartic acid from CNNM inserts into the phosphatase catalytic site of PRLs, mimicking a substrate–enzyme interaction. The delineation of PRL pseudophosphatase and phosphatase activities in vivo was impossible until the recent identification of PRL mutants defective in one activity or the other. These mutants showed that CNNM binding was sufficient for PRL oncogenicity in one model of metastasis, but left unresolved its role in other contexts. As the presence of phosphocysteine prevents CNNM binding and CNNM-binding blocks catalytic activity, these two activities are inherently linked. Additional studies are needed to untangle the intertwined catalytic and noncatalytic functions of PRLs. Here, we review the current understanding of the structure and biophysical properties of PRL phosphatases.
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Affiliation(s)
- Kalle Gehring
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montreal, Quebec, Canada.
| | - Guennadi Kozlov
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montreal, Quebec, Canada
| | - Meng Yang
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montreal, Quebec, Canada
| | - Rayan Fakih
- Department of Biochemistry and Centre de Recherche en Biologie Structurale, McGill University, Montreal, Quebec, Canada
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Khoubai FZ, Grosset CF. DUSP9, a Dual-Specificity Phosphatase with a Key Role in Cell Biology and Human Diseases. Int J Mol Sci 2021; 22:ijms222111538. [PMID: 34768967 PMCID: PMC8583968 DOI: 10.3390/ijms222111538] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 12/14/2022] Open
Abstract
Mitogen-activated protein kinases (MAPKs) are essential for proper cell functioning as they regulate many molecular effectors. Careful regulation of MAPKs is therefore required to avoid MAPK pathway dysfunctions and pathologies. The mammalian genome encodes about 200 phosphatases, many of which dephosphorylate the MAPKs and bring them back to an inactive state. In this review, we focus on the normal and pathological functions of dual-specificity phosphatase 9 (DUSP9)/MAP kinase phosphatases-4 (MKP-4). This cytoplasmic phosphatase, which belongs to the threonine/tyrosine dual-specific phosphatase family and was first described in 1997, is known to dephosphorylate ERK1/2, p38, JNK and ASK1, and thereby to control various MAPK pathway cascades. As a consequence, DUSP9 plays a major role in human pathologies and more specifically in cardiac dysfunction, liver metabolic syndromes, diabetes, obesity and cancer including drug response and cell stemness. Here, we recapitulate the mechanism of action of DUSP9 in the cell, its levels of regulation and its roles in the most frequent human diseases, and discuss its potential as a therapeutic target.
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Grabarek BO, Dąbala M, Kasela T, Gralewski M, Gładysz D. Changes in the expression pattern of DUSP1-7 and miRNA regulating their expression in the keratinocytes treated with LPS and adalimumab. Curr Pharm Biotechnol 2021; 23:873-881. [PMID: 34342258 DOI: 10.2174/1389201022666210802102508] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/13/2021] [Accepted: 05/19/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Increased levels of phosphorylated ERK and p38 MAPK proteins have been observed in psoriatic skin biopsies compared to controls, which may be associated with an impaired expression pattern of dual activity protein phosphatase (DUSP). OBJECTIVE The purpose of this study was to assess changes in the expression profile of mRNA DUSP 1-7 and miRNA regulating their expression in human keratinocyte cells (HaCaT) had exposed to the liposaccharide A (LPS). METHODS HaCaT was exposed to 1 µg/ml LPS and next adalimumab by 2,8,24h compared to untreated cells. The microarray method was used to analyze expression pattern of mRNAs, miRNAs, and ELISA to evaluate changes in the level of the proteins. RTqPCR was used to validate the microarray data. Transcriptome Analysis Console and Statistica Software 13 PL were used in statistical analysis (p<0.05). RESULTS The highest changes in expression was observed for DUSP2 (FC +11.12) and DUSP5 (FC +5.53) in HaCaT culture after 2 hours exposition on adalimumab. It was observed that miR-1275 (FC -2.39) and miR-34a (FC +6.52) might regulate level of DUSP2, and miR-27a (FC +3.55), miR-27b (FC +2.87) are involved in DUSP5 expression. CONCLUSION The results obtained suggest that DUSP2 and DUSP5 may be considered as complementary molecular markers in the diagnosis and monitoring of the effectiveness of psoriasis therapy. It was confirmed that hsa-miR-34a, hsa-miR-1275, hsa-miR-3188, hsa-miR-382, hsa-miR-27a, hsa-miR-27b, hsa-miR-16 have the highest influence on the expression pattern of DUSP1-7.
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Affiliation(s)
- Beniamin Oskar Grabarek
- Department of Histology, Cytophysiology, and Embryology in Zabrze, Faculty of Medicine in Zabrze, The University of Technology in Katowice, 41-800 Zabrze. Poland
| | - Maciej Dąbala
- "Dabala Ortodoncja", Francuska 102/u3, 40-507 Katowice. Poland
| | - Tomasz Kasela
- European Center of Aestheticsin Katowice, 40-055 Katowice. Poland
| | - Marcin Gralewski
- Department of Histology, Cytophysiology, and Embryology in Zabrze, Faculty of Medicine in Zabrze, The University of Technology in Katowice, 41-800 Zabrze. Poland
| | - Dorian Gładysz
- Department of Histology, Cytophysiology, and Embryology in Zabrze, Faculty of Medicine in Zabrze, The University of Technology in Katowice, 41-800 Zabrze. Poland
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Kanda Y, Mizuno A, Takasaki T, Satoh R, Hagihara K, Masuko T, Endo Y, Tanabe G, Sugiura R. Down-regulation of dual-specificity phosphatase 6, a negative regulator of oncogenic ERK signaling, by ACA-28 induces apoptosis in NIH/3T3 cells overexpressing HER2/ErbB2. Genes Cells 2020; 26:109-116. [PMID: 33249692 DOI: 10.1111/gtc.12823] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 11/20/2020] [Accepted: 11/21/2020] [Indexed: 12/15/2022]
Abstract
Dual-specificity phosphatase 6 (DUSP6) is a key negative feedback regulator of the member of the RAS-ERK MAPK signaling pathway that is associated with cellular proliferation and differentiation. Deterioration of DUSP6 expression could therefore result in deregulated growth activity. We have previously discovered ACA-28, a novel anticancer compound with a unique property to stimulate ERK phosphorylation and induce apoptosis in ERK-active melanoma cells. However, the mechanism of cancer cell-specific-apoptosis by ACA-28 remains obscure. Here, we investigated the involvement of DUSP6 in the mechanisms of the ACA-28-mediated apoptosis by using the NIH/3T3 cells overexpressing HER2/ErbB2 (A4-15 cells), as A4-15 exhibited higher ERK phosphorylation and are more susceptible to ACA-28 than NIH/3T3. We showed that A4-15 exhibited high DUSP6 protein levels, which require ERK activation. Notably, the silencing of the DUDSP6 gene by siRNA inhibited proliferation and induced apoptosis in A4-15, but not in NIH/3T3, indicating that A4-15 requires high DUSP6 expression for growth. Importantly, ACA-28 preferentially down-regulated the DUSP6 protein and proliferation in A4-15 via the proteasome, while it stimulated ERK phosphorylation. Collectively, the up-regulation of DUSP6 may exert a growth-promoting role in cancer cells overexpressing HER2. DUSP6 down-regulation in ERK-active cancer cells might have the potential as a novel cancer measure.
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Affiliation(s)
- Yuki Kanda
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Kindai University, Higashi-Osaka, Japan
| | - Ayami Mizuno
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Kindai University, Higashi-Osaka, Japan
| | - Teruaki Takasaki
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Kindai University, Higashi-Osaka, Japan
| | - Ryosuke Satoh
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Kindai University, Higashi-Osaka, Japan
| | - Kanako Hagihara
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Kindai University, Higashi-Osaka, Japan
| | - Takashi Masuko
- Laboratory of Natural Drug Resources, Department of Pharmaceutical Sciences, Kindai University, Higashi-Osaka, Japan
| | - Yuichi Endo
- Laboratory of Natural Drug Resources, Department of Pharmaceutical Sciences, Kindai University, Higashi-Osaka, Japan
| | - Genzoh Tanabe
- Laboratory of Organic Chemistry, Department of Pharmacy, Kindai University, Higashi-Osaka, Japan
| | - Reiko Sugiura
- Laboratory of Molecular Pharmacogenomics, Department of Pharmaceutical Sciences, Kindai University, Higashi-Osaka, Japan.,Pharmaceutical Research and Technology Institute, Kindai University, Higashi-Osaka, Japan
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Hinton SD. Pseudophosphatase MK-STYX: the atypical member of the MAP kinase phosphatases. FEBS J 2020; 287:4221-4231. [PMID: 32472731 DOI: 10.1111/febs.15426] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 04/25/2020] [Accepted: 05/26/2020] [Indexed: 01/03/2023]
Abstract
The regulation of the phosphorylation of mitogen-activated protein kinases (MAPKs) is essential for cellular processes such as proliferation, differentiation, survival, and death. Mutations within the MAPK signaling cascades are implicated in diseases such as cancer, neurodegenerative disorders, arthritis, obesity, and diabetes. MAPK phosphorylation is controlled by an intricate balance between MAPK kinases (enzymes that add phosphate groups) and MAPK phosphatases (MKPs) (enzymes that remove phosphate groups). MKPs are complex negative regulators of the MAPK pathway that control the amplitude and spatiotemporal regulation of MAPKs. MK-STYX (MAPK phosphoserine/threonine/tyrosine-binding protein) is a member of the MKP subfamily, which lacks the critical histidine and nucleophilic cysteine residues in the active site required for catalysis. MK-STYX does not influence the phosphorylation status of MAPK, but even so it adds to the complexity of signal transduction cascades as a signaling regulator. This review highlights the function of MK-STYX, providing insight into MK-STYX as a signal regulating molecule in the stress response, HDAC 6 dynamics, apoptosis, and neurite differentiation.
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Affiliation(s)
- Shantá D Hinton
- Department of Biology, Integrated Science Center, William & Mary, Williamsburg, VA, USA
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Ha J, Kang E, Seo J, Cho S. Phosphorylation Dynamics of JNK Signaling: Effects of Dual-Specificity Phosphatases (DUSPs) on the JNK Pathway. Int J Mol Sci 2019; 20:E6157. [PMID: 31817617 DOI: 10.3390/ijms20246157] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/30/2019] [Accepted: 12/04/2019] [Indexed: 02/06/2023] Open
Abstract
Protein phosphorylation affects conformational change, interaction, catalytic activity, and subcellular localization of proteins. Because the post-modification of proteins regulates diverse cellular signaling pathways, the precise control of phosphorylation states is essential for maintaining cellular homeostasis. Kinases function as phosphorylating enzymes, and phosphatases dephosphorylate their target substrates, typically in a much shorter time. The c-Jun N-terminal kinase (JNK) signaling pathway, a mitogen-activated protein kinase pathway, is regulated by a cascade of kinases and in turn regulates other physiological processes, such as cell differentiation, apoptosis, neuronal functions, and embryonic development. However, the activation of the JNK pathway is also implicated in human pathologies such as cancer, neurodegenerative diseases, and inflammatory diseases. Therefore, the proper balance between activation and inactivation of the JNK pathway needs to be tightly regulated. Dual specificity phosphatases (DUSPs) regulate the magnitude and duration of signal transduction of the JNK pathway by dephosphorylating their substrates. In this review, we will discuss the dynamics of phosphorylation/dephosphorylation, the mechanism of JNK pathway regulation by DUSPs, and the new possibilities of targeting DUSPs in JNK-related diseases elucidated in recent studies.
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Wu F, McCuaig RD, Sutton CR, Tan AHY, Jeelall Y, Bean EG, Dai J, Prasanna T, Batham J, Malik L, Yip D, Dahlstrom JE, Rao S. Nuclear-Biased DUSP6 Expression is Associated with Cancer Spreading Including Brain Metastasis in Triple-Negative Breast Cancer. Int J Mol Sci 2019; 20:E3080. [PMID: 31238530 DOI: 10.3390/ijms20123080] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/20/2019] [Accepted: 06/22/2019] [Indexed: 12/18/2022] Open
Abstract
DUSP6 is a dual-specificity phosphatase (DUSP) involved in breast cancer progression, recurrence, and metastasis. DUSP6 is predominantly cytoplasmic in HER2+ primary breast cancer cells, but the expression and subcellular localization of DUSPs, especially DUSP6, in HER2-positive circulating tumor cells (CTCs) is unknown. Here we used the DEPArray system to identify and isolate CTCs from metastatic triple negative breast cancer (TNBC) patients and performed single-cell NanoString analysis to quantify cancer pathway gene expression in HER2-positive and HER2-negative CTC populations. All TNBC patients contained HER2-positive CTCs. HER2-positive CTCs were associated with increased ERK1/ERK2 expression, which are direct DUSP6 targets. DUSP6 protein expression was predominantly nuclear in breast CTCs and the brain metastases but not pleura or lung metastases of TNBC patients. Therefore, nuclear DUSP6 may play a role in the association with cancer spreading in TNBC patients, including brain metastasis.
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12
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Chen HF, Chuang HC, Tan TH. Regulation of Dual-Specificity Phosphatase (DUSP) Ubiquitination and Protein Stability. Int J Mol Sci 2019; 20:E2668. [PMID: 31151270 DOI: 10.3390/ijms20112668] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 12/21/2022] Open
Abstract
Mitogen-activated protein kinases (MAPKs) are key regulators of signal transduction and cell responses. Abnormalities in MAPKs are associated with multiple diseases. Dual-specificity phosphatases (DUSPs) dephosphorylate many key signaling molecules, including MAPKs, leading to the regulation of duration, magnitude, or spatiotemporal profiles of MAPK activities. Hence, DUSPs need to be properly controlled. Protein post-translational modifications, such as ubiquitination, phosphorylation, methylation, and acetylation, play important roles in the regulation of protein stability and activity. Ubiquitination is critical for controlling protein degradation, activation, and interaction. For DUSPs, ubiquitination induces degradation of eight DUSPs, namely, DUSP1, DUSP4, DUSP5, DUSP6, DUSP7, DUSP8, DUSP9, and DUSP16. In addition, protein stability of DUSP2 and DUSP10 is enhanced by phosphorylation. Methylation-induced ubiquitination of DUSP14 stimulates its phosphatase activity. In this review, we summarize the knowledge of the regulation of DUSP stability and ubiquitination through post-translational modifications.
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13
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Cho SSL, Han J, James SJ, Png CW, Weerasooriya M, Alonso S, Zhang Y. Dual-Specificity Phosphatase 12 Targets p38 MAP Kinase to Regulate Macrophage Response to Intracellular Bacterial Infection. Front Immunol 2017; 8:1259. [PMID: 29062315 PMCID: PMC5640881 DOI: 10.3389/fimmu.2017.01259] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 09/21/2017] [Indexed: 12/24/2022] Open
Abstract
The mitogen-activated protein kinase (MAPK) cascades are activated in innate immune cells such as macrophages upon the detection of microbial infection, critically regulating the expression of proinflammatory cytokines and chemokines such as TNF-α, IL-6, and MCP-1. As a result, activation of MAPKs is tightly regulated to ensure appropriate and adequate immune responses. Dual-specificity phosphatases (DUSPs) are a family of proteins which specifically dephosphorylates threonine and tyrosine residues essential for MAPK activation to negatively regulate their activation. DUSP12 is a member of atypical DUSPs that lack MAPK-binding domain. Its substrate and function in immune cells are unknown. In this study, we demonstrated that DUSP12 is able to interact with all the three groups of MAPKs, including extracellular signal-regulated protein kinase, JNK, and p38. To investigate the function of DUSP12 in macrophages in response to TLR activation and microbial infection, we established RAW264.7 cell lines stably overexpressing DUSP12 and found that overexpression of DUSP12 inhibited proinflammatory cytokine and chemokine production in response to TLR4 activation, heat-inactivated Mycobacterium tuberculosis stimulation as well as infections by intracellular bacteria including Listeria moncytogenesis and Mycobacterium bovis BCG by specifically inhibiting p38 and JNK. In addition, a scaffold protein known as signal transducing adaptor protein 2 (STAP2), was found to mediate the interaction between DUSP12 and p38. Thus, DUSP12 is a bona fide MAPK phosphatase, playing an important role in MAPK-regulated responses to bacterial infection. Our study provides a model where atypical DUSPs regulate MAPKs via scaffold, thereby regulating immune responses to microbial infection.
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Affiliation(s)
- Sharol Su Lei Cho
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Jian Han
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Sharmy J James
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Chin Wen Png
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Madhushanee Weerasooriya
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Sylvie Alonso
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
| | - Yongliang Zhang
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, Singapore, Singapore.,Immunology Programme, Life Science Institute, National University of Singapore, Singapore, Singapore
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14
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Liang KL, Paredes R, Carmody R, Eyers PA, Meyer S, McCarthy TV, Keeshan K. Human TRIB2 Oscillates during the Cell Cycle and Promotes Ubiquitination and Degradation of CDC25C. Int J Mol Sci 2016; 17:E1378. [PMID: 27563873 DOI: 10.3390/ijms17091378] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 08/04/2016] [Accepted: 08/18/2016] [Indexed: 12/13/2022] Open
Abstract
Tribbles homolog 2 (TRIB2) is a member of the mammalian Tribbles family of serine/threonine pseudokinases (TRIB1-3). Studies of TRIB2 indicate that many of the molecular interactions between the single Drosophila Tribbles (Trbl) protein and interacting partners are evolutionary conserved. In this study, we examined the relationship between TRIB2 and cell division cycle 25 (CDC25) family of dual-specificity protein phosphatases (mammalian homologues of Drosophila String), which are key physiological cell cycle regulators. Using co-immunoprecipitation we demonstrate that TRIB2 interacts with CDC25B and CDC25C selectively. Forced overexpression of TRIB2 caused a marked decrease in total CDC25C protein levels. Following inhibition of the proteasome, CDC25C was stabilized in the nuclear compartment. This implicates TRIB2 as a regulator of nuclear CDC25C turnover. In complementary ubiquitination assays, we show that TRIB2-mediated degradation of CDC25C is associated with lysine-48-linked CDC25C polyubiquitination driven by the TRIB2 kinase-like domain. A cell cycle associated role for TRIB2 is further supported by the cell cycle regulated expression of TRIB2 protein levels. Our findings reveal mitotic CDC25C as a new target of TRIB2 that is degraded via the ubiquitin proteasome system. Inappropriate CDC25C regulation could mechanistically underlie TRIB2 mediated regulation of cellular proliferation in neoplastic cells.
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15
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Liu R, van Berlo JH, York AJ, Vagnozzi RJ, Maillet M, Molkentin JD. DUSP8 Regulates Cardiac Ventricular Remodeling by Altering ERK1/2 Signaling. Circ Res 2016; 119:249-60. [PMID: 27225478 DOI: 10.1161/circresaha.115.308238] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 05/25/2016] [Indexed: 01/05/2023]
Abstract
RATIONALE Mitogen-activated protein kinase (MAPK) signaling regulates the growth response of the adult myocardium in response to increased cardiac workload or pathological insults. The dual-specificity phosphatases (DUSPs) are critical effectors, which dephosphorylate the MAPKs to control the basal tone, amplitude, and duration of MAPK signaling. OBJECTIVE To examine DUSP8 as a regulator of MAPK signaling in the heart and its impact on ventricular and cardiac myocyte growth dynamics. METHODS AND RESULTS Dusp8 gene-deleted mice and transgenic mice with inducible expression of DUSP8 in the heart were used here to investigate how this MAPK-phosphatase might regulate intracellular signaling and cardiac growth dynamics in vivo. Dusp8 gene-deleted mice were mildly hypercontractile at baseline with a cardiac phenotype of concentric ventricular remodeling, which protected them from progressing towards heart failure in 2 surgery-induced disease models. Cardiac-specific overexpression of DUSP8 produced spontaneous eccentric remodeling and ventricular dilation with heart failure. At the cellular level, adult cardiac myocytes from Dusp8 gene-deleted mice were thicker and shorter, whereas DUSP8 overexpression promoted cardiac myocyte lengthening with a loss of thickness. Mechanistically, activation of extracellular signal-regulated kinases 1/2 were selectively increased in Dusp8 gene-deleted hearts at baseline and following acute pathological stress stimulation, whereas p38 MAPK and c-Jun N-terminal kinases were mostly unaffected. CONCLUSIONS These results indicate that DUSP8 controls basal and acute stress-induced extracellular signal-regulated kinases 1/2 signaling in adult cardiac myocytes that then alters the length-width growth dynamics of individual cardiac myocytes, which further alters contractility, ventricular remodeling, and disease susceptibility.
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Affiliation(s)
- Ruijie Liu
- From the Department of Pediatrics, University of Cincinnati (R.L., J.H.v.B., A.J.Y., R.J.V., M.M., J.D.M.) and Howard Hughes Medical Institute (J.D.M.), Cincinnati Children's Hospital Medical Center, Cincinnati, OH; and Division of Cardiology, Department of Medicine, Lillehei Heart Institute, University of Minnesota, St. Paul (J.H.v.B.)
| | - Jop H van Berlo
- From the Department of Pediatrics, University of Cincinnati (R.L., J.H.v.B., A.J.Y., R.J.V., M.M., J.D.M.) and Howard Hughes Medical Institute (J.D.M.), Cincinnati Children's Hospital Medical Center, Cincinnati, OH; and Division of Cardiology, Department of Medicine, Lillehei Heart Institute, University of Minnesota, St. Paul (J.H.v.B.)
| | - Allen J York
- From the Department of Pediatrics, University of Cincinnati (R.L., J.H.v.B., A.J.Y., R.J.V., M.M., J.D.M.) and Howard Hughes Medical Institute (J.D.M.), Cincinnati Children's Hospital Medical Center, Cincinnati, OH; and Division of Cardiology, Department of Medicine, Lillehei Heart Institute, University of Minnesota, St. Paul (J.H.v.B.)
| | - Ronald J Vagnozzi
- From the Department of Pediatrics, University of Cincinnati (R.L., J.H.v.B., A.J.Y., R.J.V., M.M., J.D.M.) and Howard Hughes Medical Institute (J.D.M.), Cincinnati Children's Hospital Medical Center, Cincinnati, OH; and Division of Cardiology, Department of Medicine, Lillehei Heart Institute, University of Minnesota, St. Paul (J.H.v.B.)
| | - Marjorie Maillet
- From the Department of Pediatrics, University of Cincinnati (R.L., J.H.v.B., A.J.Y., R.J.V., M.M., J.D.M.) and Howard Hughes Medical Institute (J.D.M.), Cincinnati Children's Hospital Medical Center, Cincinnati, OH; and Division of Cardiology, Department of Medicine, Lillehei Heart Institute, University of Minnesota, St. Paul (J.H.v.B.)
| | - Jeffery D Molkentin
- From the Department of Pediatrics, University of Cincinnati (R.L., J.H.v.B., A.J.Y., R.J.V., M.M., J.D.M.) and Howard Hughes Medical Institute (J.D.M.), Cincinnati Children's Hospital Medical Center, Cincinnati, OH; and Division of Cardiology, Department of Medicine, Lillehei Heart Institute, University of Minnesota, St. Paul (J.H.v.B.).
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16
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Meekins DA, Vander Kooi CW, Gentry MS. Structural mechanisms of plant glucan phosphatases in starch metabolism. FEBS J 2016; 283:2427-47. [PMID: 26934589 DOI: 10.1111/febs.13703] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Revised: 01/31/2016] [Accepted: 02/29/2016] [Indexed: 01/12/2023]
Abstract
Glucan phosphatases are a recently discovered class of enzymes that dephosphorylate starch and glycogen, thereby regulating energy metabolism. Plant genomes encode two glucan phosphatases, called Starch EXcess4 (SEX4) and Like Sex Four2 (LSF2), that regulate starch metabolism by selectively dephosphorylating glucose moieties within starch glucan chains. Recently, the structures of both SEX4 and LSF2 were determined, with and without phosphoglucan products bound, revealing the mechanism for their unique activities. This review explores the structural and enzymatic features of the plant glucan phosphatases, and outlines how they are uniquely adapted to perform their cellular functions. We outline the physical mechanisms used by SEX4 and LSF2 to interact with starch glucans: SEX4 binds glucan chains via a continuous glucan-binding platform comprising its dual-specificity phosphatase domain and carbohydrate-binding module, while LSF2 utilizes surface binding sites. SEX4 and LSF2 both contain a unique network of aromatic residues in their catalytic dual-specificity phosphatase domains that serve as glucan engagement platforms and are unique to the glucan phosphatases. We also discuss the phosphoglucan substrate specificities inherent to SEX4 and LSF2, and outline structural features within the active site that govern glucan orientation. This review defines the structural mechanism of the plant glucan phosphatases with respect to phosphatases, starch metabolism and protein-glucan interaction, thereby providing a framework for their application in both agricultural and industrial settings.
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Affiliation(s)
- David A Meekins
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY, USA.,Division of Biology, Kansas State University, Manhattan, KS, USA
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY, USA
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17
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Lountos GT, Austin BP, Tropea JE, Waugh DS. Structure of human dual-specificity phosphatase 7, a potential cancer drug target. Acta Crystallogr F Struct Biol Commun 2015; 71:650-6. [PMID: 26057789 DOI: 10.1107/s2053230x1500504x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 03/12/2015] [Indexed: 11/10/2022]
Abstract
Human dual-specificity phosphatase 7 (DUSP7/Pyst2) is a 320-residue protein that belongs to the mitogen-activated protein kinase phosphatase (MKP) subfamily of dual-specificity phosphatases. Although its precise biological function is still not fully understood, previous reports have demonstrated that DUSP7 is overexpressed in myeloid leukemia and other malignancies. Therefore, there is interest in developing DUSP7 inhibitors as potential therapeutic agents, especially for cancer. Here, the purification, crystallization and structure determination of the catalytic domain of DUSP7 (Ser141-Ser289/C232S) at 1.67 Å resolution are reported. The structure described here provides a starting point for structure-assisted inhibitor-design efforts and adds to the growing knowledge base of three-dimensional structures of the dual-specificity phosphatase family.
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Affiliation(s)
- George T Lountos
- Basic Science Program, Leidos Biomedical Research Inc., Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Brian P Austin
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, PO Box B, Frederick, MD 21702, USA
| | - Joseph E Tropea
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, PO Box B, Frederick, MD 21702, USA
| | - David S Waugh
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute at Frederick, PO Box B, Frederick, MD 21702, USA
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18
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Silver DM, Kötting O, Moorhead GBG. Phosphoglucan phosphatase function sheds light on starch degradation. Trends Plant Sci 2014; 19:471-8. [PMID: 24534096 DOI: 10.1016/j.tplants.2014.01.008] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/09/2014] [Accepted: 01/14/2014] [Indexed: 05/07/2023]
Abstract
Phosphoglucan phosphatases are novel enzymes that remove phosphates from complex carbohydrates. In plants, these proteins are vital components in the remobilization of leaf starch at night. Breakdown of starch is initiated through reversible glucan phosphorylation to disrupt the semi-crystalline starch structure at the granule surface. The phosphoglucan phosphatases starch excess 4 (SEX4) and like-SEX4 2 (LSF2) dephosphorylate glucans to provide access for amylases that release maltose and glucose from starch. Another phosphatase, LSF1, is a putative inactive scaffold protein that may act as regulator of starch degradative enzymes at the granule surface. Absence of these phosphatases disrupts starch breakdown, resulting in plants accumulating excess starch. Here, we describe recent advances in understanding the biochemical and structural properties of each of these starch phosphatases.
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Affiliation(s)
- Dylan M Silver
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Oliver Kötting
- Institute for Agricultural Sciences, ETH Zürich, Zürich, Switzerland
| | - Greg B G Moorhead
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada.
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19
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Roces L, Knowles PP, Fox G, Juanhuix J, Scaplehorn N, Way M, McDonald NQ. Crystallization and preliminary X-ray diffraction analysis of vaccinia virus H1L phosphatase. Acta Crystallogr Sect F Struct Biol Cryst Commun 2008; 64:190-2. [PMID: 18323605 PMCID: PMC2374156 DOI: 10.1107/s1744309108003680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2007] [Accepted: 02/02/2008] [Indexed: 11/10/2022]
Abstract
The cysteine-based protein phosphatase H1L was the first reported dual-specificity protein phosphatase. H1L is encapsidated within the vaccinia virus and is required for successful host infection and for the production of viable vaccinia progeny. H1L has therefore been proposed as a target candidate for antiviral compounds. Recombinant H1L has been expressed in a catalytically inactive form using an Escherichia coli host, leading to purification and crystallization by the microbatch method. The crystals diffract to 2.1 A resolution using synchrotron radiation. These crystals belong to space group P422, with unit-cell parameters a = b = 98.31, c = 169.15 A, and are likely to contain four molecules in the asymmetric unit. A sulfur SAD data set was collected to 2.8 A resolution on beamline BM14 at the ESRF to facilitate structure determination. Attempts to derivatize these crystals with xenon gas changed the space group to I422, with unit-cell parameters a = b = 63.28, c = 169.68 A and a single molecule in the asymmetric unit. The relationship between these two crystal forms is discussed.
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Affiliation(s)
- Laura Roces
- Departamento de Química Física y Analítica, Universidad de Oviedo, Julián Clavería 8, 33006 Oviedo, Spain
- Structural Biology Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln’s Inn Fields, London WC2A 3PX, England
| | - Phillip P. Knowles
- Structural Biology Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln’s Inn Fields, London WC2A 3PX, England
| | - Gavin Fox
- ESRF, 6 Rue Jules Horowitz, 38043 Grenoble CEDEX 9, France
| | - Jordi Juanhuix
- ESRF, 6 Rue Jules Horowitz, 38043 Grenoble CEDEX 9, France
| | - Nicki Scaplehorn
- Cell Motility Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln’s Inn Fields, London WC2A 3PX, England
| | - Michael Way
- Cell Motility Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln’s Inn Fields, London WC2A 3PX, England
| | - Neil Q. McDonald
- Structural Biology Laboratory, London Research Institute, Cancer Research UK, 44 Lincoln’s Inn Fields, London WC2A 3PX, England
- School of Crystallography, Birkbeck College, Malet Street, London WC1E 7HX, England
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