1
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Structural Insights into the Active Site Formation of DUSP22 in N-loop-containing Protein Tyrosine Phosphatases. Int J Mol Sci 2020; 21:ijms21207515. [PMID: 33053837 PMCID: PMC7589817 DOI: 10.3390/ijms21207515] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/07/2020] [Accepted: 10/09/2020] [Indexed: 02/07/2023] Open
Abstract
Cysteine-based protein tyrosine phosphatases (Cys-based PTPs) perform dephosphorylation to regulate signaling pathways in cellular responses. The hydrogen bonding network in their active site plays an important conformational role and supports the phosphatase activity. Nearly half of dual-specificity phosphatases (DUSPs) use three conserved residues, including aspartate in the D-loop, serine in the P-loop, and asparagine in the N-loop, to form the hydrogen bonding network, the D-, P-, N-triloop interaction (DPN-triloop interaction). In this study, DUSP22 is used to investigate the importance of the DPN-triloop interaction in active site formation. Alanine mutations and somatic mutations of the conserved residues, D57, S93, and N128 substantially decrease catalytic efficiency (kcat/KM) by more than 102-fold. Structural studies by NMR and crystallography reveal that each residue can perturb the three loops and induce conformational changes, indicating that the hydrogen bonding network aligns the residues in the correct positions for substrate interaction and catalysis. Studying the DPN-triloop interaction reveals the mechanism maintaining phosphatase activity in N-loop-containing PTPs and provides a foundation for further investigation of active site formation in different members of this protein class.
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2
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Kutty RG, Talipov MR, Bongard RD, Lipinski RAJ, Sweeney NL, Sem DS, Rathore R, Ramchandran R. Dual Specificity Phosphatase 5-Substrate Interaction: A Mechanistic Perspective. Compr Physiol 2017; 7:1449-1461. [PMID: 28915331 DOI: 10.1002/cphy.c170007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The mammalian genome contains approximately 200 phosphatases that are responsible for catalytically removing phosphate groups from proteins. In this review, we discuss dual specificity phosphatase 5 (DUSP5). DUSP5 belongs to the dual specificity phosphatase (DUSP) family, so named after the family members' abilities to remove phosphate groups from serine/threonine and tyrosine residues. We provide a comparison of DUSP5's structure to other DUSPs and, using molecular modeling studies, provide an explanation for DUSP5's mechanistic interaction and specificity toward phospho-extracellular regulated kinase, its only known substrate. We also discuss new insights from molecular modeling studies that will influence our current thinking of mitogen-activated protein kinase signaling. Finally, we discuss the lessons learned from identifying small molecules that target DUSP5, which might benefit targeting efforts for other phosphatases. © 2017 American Physiological Society. Compr Physiol 7:1449-1461, 2017.
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Affiliation(s)
- Raman G Kutty
- Department of Pediatrics, Division of Neonatology, Department of Obstetrics and Gynecology, Developmental Vascular Biology Program, Translational and Biomedical Research Center, Milwaukee, Wisconsin, USA
| | - Marat R Talipov
- New Mexico State University, Department of Chemistry and Biochemistry, Las Cruces, New Mexico, USA
| | - Robert D Bongard
- Center for Structure-based Drug Design and Development, Department of Pharmaceutical Sciences, Concordia University of Wisconsin, Mequon, Wisconsin, USA
| | - Rachel A Jones Lipinski
- Department of Pediatrics, Division of Neonatology, Department of Obstetrics and Gynecology, Developmental Vascular Biology Program, Translational and Biomedical Research Center, Milwaukee, Wisconsin, USA.,Department of Chemistry, Marquette University, Milwaukee, Wisconsin, USA
| | - Noreena L Sweeney
- Center for Structure-based Drug Design and Development, Department of Pharmaceutical Sciences, Concordia University of Wisconsin, Mequon, Wisconsin, USA
| | - Daniel S Sem
- Center for Structure-based Drug Design and Development, Department of Pharmaceutical Sciences, Concordia University of Wisconsin, Mequon, Wisconsin, USA
| | - Rajendra Rathore
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin, USA
| | - Ramani Ramchandran
- Department of Pediatrics, Division of Neonatology, Department of Obstetrics and Gynecology, Developmental Vascular Biology Program, Translational and Biomedical Research Center, Milwaukee, Wisconsin, USA
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3
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Baßler J, Ahmed YL, Kallas M, Kornprobst M, Calviño FR, Gnädig M, Thoms M, Stier G, Ismail S, Kharde S, Castillo N, Griesel S, Bastuck S, Bradatsch B, Thomson E, Flemming D, Sinning I, Hurt E. Interaction network of the ribosome assembly machinery from a eukaryotic thermophile. Protein Sci 2017; 26:327-342. [PMID: 27863450 DOI: 10.1002/pro.3085] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 10/24/2016] [Accepted: 11/08/2016] [Indexed: 12/30/2022]
Abstract
Ribosome biogenesis in eukaryotic cells is a highly dynamic and complex process innately linked to cell proliferation. The assembly of ribosomes is driven by a myriad of biogenesis factors that shape pre-ribosomal particles by processing and folding the ribosomal RNA and incorporating ribosomal proteins. Biochemical approaches allowed the isolation and characterization of pre-ribosomal particles from Saccharomyces cerevisiae, which lead to a spatiotemporal map of biogenesis intermediates along the path from the nucleolus to the cytoplasm. Here, we cloned almost the entire set (∼180) of ribosome biogenesis factors from the thermophilic fungus Chaetomium thermophilum in order to perform an in-depth analysis of their protein-protein interaction network as well as exploring the suitability of these thermostable proteins for structural studies. First, we performed a systematic screen, testing about 80 factors for crystallization and structure determination. Next, we performed a yeast 2-hybrid analysis and tested about 32,000 binary combinations, which identified more than 1000 protein-protein contacts between the thermophilic ribosome assembly factors. To exemplary verify several of these interactions, we performed biochemical reconstitution with the focus on the interaction network between 90S pre-ribosome factors forming the ctUTP-A and ctUTP-B modules, and the Brix-domain containing assembly factors of the pre-60S subunit. Our work provides a rich resource for biochemical reconstitution and structural analyses of the conserved ribosome assembly machinery from a eukaryotic thermophile.
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Affiliation(s)
- Jochen Baßler
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Yasar Luqman Ahmed
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Martina Kallas
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Markus Kornprobst
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Fabiola R Calviño
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Marén Gnädig
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Matthias Thoms
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Gunter Stier
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Sherif Ismail
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Satyavati Kharde
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Nestor Castillo
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Sabine Griesel
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Sonja Bastuck
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Bettina Bradatsch
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Emma Thomson
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Dirk Flemming
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Irmgard Sinning
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
| | - Ed Hurt
- Biochemistry Center Heidelberg BZH, University of Heidelberg, Heidelberg, 69120, Germany
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4
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Ghattas MA, Raslan N, Sadeq A, Al Sorkhy M, Atatreh N. Druggability analysis and classification of protein tyrosine phosphatase active sites. DRUG DESIGN DEVELOPMENT AND THERAPY 2016; 10:3197-3209. [PMID: 27757011 PMCID: PMC5053377 DOI: 10.2147/dddt.s111443] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Protein tyrosine phosphatases (PTP) play important roles in the pathogenesis of many diseases. The fact that no PTP inhibitors have reached the market so far has raised many questions about their druggability. In this study, the active sites of 17 PTPs were characterized and assessed for its ability to bind drug-like molecules. Consequently, PTPs were classified according to their druggability scores into four main categories. Only four members showed intermediate to very druggable pocket; interestingly, the rest of them exhibited poor druggability. Particularly focusing on PTP1B, we also demonstrated the influence of several factors on the druggability of PTP active site. For instance, the open conformation showed better druggability than the closed conformation, while the tight-bound water molecules appeared to have minimal effect on the PTP1B druggability. Finally, the allosteric site of PTP1B was found to exhibit superior druggability compared to the catalytic pocket. This analysis can prove useful in the discovery of new PTP inhibitors by assisting researchers in predicting hit rates from high throughput or virtual screening and saving unnecessary cost, time, and efforts via prioritizing PTP targets according to their predicted druggability.
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Affiliation(s)
- Mohammad A Ghattas
- College of Pharmacy, Al Ain University of Science and Technology, Al Ain, UAE
| | - Noor Raslan
- College of Pharmacy, Al Ain University of Science and Technology, Al Ain, UAE
| | - Asil Sadeq
- College of Pharmacy, Al Ain University of Science and Technology, Al Ain, UAE
| | - Mohammad Al Sorkhy
- College of Pharmacy, Al Ain University of Science and Technology, Al Ain, UAE
| | - Noor Atatreh
- College of Pharmacy, Al Ain University of Science and Technology, Al Ain, UAE
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5
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Phosphotyrosine Substrate Sequence Motifs for Dual Specificity Phosphatases. PLoS One 2015; 10:e0134984. [PMID: 26302245 PMCID: PMC4547750 DOI: 10.1371/journal.pone.0134984] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 07/13/2015] [Indexed: 12/19/2022] Open
Abstract
Protein tyrosine phosphatases dephosphorylate tyrosine residues of proteins, whereas, dual specificity phosphatases (DUSPs) are a subgroup of protein tyrosine phosphatases that dephosphorylate not only Tyr(P) residue, but also the Ser(P) and Thr(P) residues of proteins. The DUSPs are linked to the regulation of many cellular functions and signaling pathways. Though many cellular targets of DUSPs are known, the relationship between catalytic activity and substrate specificity is poorly defined. We investigated the interactions of peptide substrates with select DUSPs of four types: MAP kinases (DUSP1 and DUSP7), atypical (DUSP3, DUSP14, DUSP22 and DUSP27), viral (variola VH1), and Cdc25 (A-C). Phosphatase recognition sites were experimentally determined by measuring dephosphorylation of 6,218 microarrayed Tyr(P) peptides representing confirmed and theoretical phosphorylation motifs from the cellular proteome. A broad continuum of dephosphorylation was observed across the microarrayed peptide substrates for all phosphatases, suggesting a complex relationship between substrate sequence recognition and optimal activity. Further analysis of peptide dephosphorylation by hierarchical clustering indicated that DUSPs could be organized by substrate sequence motifs, and peptide-specificities by phylogenetic relationships among the catalytic domains. The most highly dephosphorylated peptides represented proteins from 29 cell-signaling pathways, greatly expanding the list of potential targets of DUSPs. These newly identified DUSP substrates will be important for examining structure-activity relationships with physiologically relevant targets.
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Lountos GT, Cherry S, Tropea JE, Waugh DS. Structural analysis of human dual-specificity phosphatase 22 complexed with a phosphotyrosine-like substrate. Acta Crystallogr F Struct Biol Commun 2015; 71:199-205. [PMID: 25664796 PMCID: PMC4321476 DOI: 10.1107/s2053230x15000217] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/06/2015] [Indexed: 02/08/2023] Open
Abstract
4-Nitrophenyl phosphate (p-nitrophenyl phosphate, pNPP) is widely used as a small molecule phosphotyrosine-like substrate in activity assays for protein tyrosine phosphatases. It is a colorless substrate that upon hydrolysis is converted to a yellow 4-nitrophenolate ion that can be monitored by absorbance at 405 nm. Therefore, the pNPP assay has been widely adopted as a quick and simple method to assess phosphatase activity and is also commonly used in assays to screen for inhibitors. Here, the first crystal structure is presented of a dual-specificity phosphatase, human dual-specificity phosphatase 22 (DUSP22), in complex with pNPP. The structure illuminates the molecular basis for substrate binding and may also facilitate the structure-assisted development of DUSP22 inhibitors.
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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
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Scott Cherry
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Joseph E. Tropea
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - David S. Waugh
- Macromolecular Crystallography Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
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7
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Jeong DG, Wei CH, Ku B, Jeon TJ, Chien PN, Kim JK, Park SY, Hwang HS, Ryu SY, Park H, Kim DS, Kim SJ, Ryu SE. The family-wide structure and function of human dual-specificity protein phosphatases. ACTA ACUST UNITED AC 2014; 70:421-35. [PMID: 24531476 DOI: 10.1107/s1399004713029866] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 10/31/2013] [Indexed: 11/10/2022]
Abstract
Dual-specificity protein phosphatases (DUSPs), which dephosphorylate both phosphoserine/threonine and phosphotyrosine, play vital roles in immune activation, brain function and cell-growth signalling. A family-wide structural library of human DUSPs was constructed based on experimental structure determination supplemented with homology modelling. The catalytic domain of each individual DUSP has characteristic features in the active site and in surface-charge distribution, indicating substrate-interaction specificity. The active-site loop-to-strand switch occurs in a subtype-specific manner, indicating that the switch process is necessary for characteristic substrate interactions in the corresponding DUSPs. A comprehensive analysis of the activity-inhibition profile and active-site geometry of DUSPs revealed a novel role of the active-pocket structure in the substrate specificity of DUSPs. A structure-based analysis of redox responses indicated that the additional cysteine residues are important for the protection of enzyme activity. The family-wide structures of DUSPs form a basis for the understanding of phosphorylation-mediated signal transduction and the development of therapeutics.
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Affiliation(s)
- Dae Gwin Jeong
- Medical Proteomics Research Center, KRIBB, Daejeon, Republic of Korea
| | - Chun Hua Wei
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Bonsu Ku
- Medical Proteomics Research Center, KRIBB, Daejeon, Republic of Korea
| | - Tae Jin Jeon
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Pham Ngoc Chien
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Jae Kwan Kim
- Department of Industrial Engineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - So Ya Park
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Hyun Sook Hwang
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Sun Young Ryu
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Hwangseo Park
- Department of Bioscience and Biotechnology, Sejong University, Seoul, Republic of Korea
| | - Deok-Soo Kim
- Department of Industrial Engineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
| | - Seung Jun Kim
- Medical Proteomics Research Center, KRIBB, Daejeon, Republic of Korea
| | - Seong Eon Ryu
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul, Republic of Korea
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8
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Jeong MS, Kim E, Kang HJ, Choi EJ, Cho AR, Chung SJ, Park SB. A selective Seoul-Fluor-based bioprobe, SfBP, for vaccinia H1-related phosphatase--a dual-specific protein tyrosine phosphatase. Chem Commun (Camb) 2012; 48:6553-5. [PMID: 22622190 DOI: 10.1039/c2cc31377d] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We report a Seoul-Fluor-based bioprobe, SfBP, for selective monitoring of protein tyrosine phosphatases (PTPs). A rational design based on the structures at the active site of dual-specific PTPs can enable SfBP to selectively monitor the activity of these PTPs with a 93-fold change in brightness. Moreover, screening results of SfBP against 30 classical PTPs and 35 dual-specific PTPs show that it is selective toward vaccinia H1-related (VHR) phosphatase, a dual-specific PTP (DUSP-3).
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Affiliation(s)
- Myeong Seon Jeong
- BioNanotechnology Research Center, KRIBB and NanoBio Major, UST, 111 Kwahangno, Yuseong, Daejeon 305-806, Korea
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9
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Gentry MS, Romá-Mateo C, Sanz P. Laforin, a protein with many faces: glucan phosphatase, adapter protein, et alii. FEBS J 2012; 280:525-37. [PMID: 22364389 DOI: 10.1111/j.1742-4658.2012.08549.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lafora disease (LD) is a rare, fatal neurodegenerative disorder characterized by the accumulation of glycogen-like inclusions in the cytoplasm of cells from most tissues of affected patients. One hundred years after the first description of these inclusions, the molecular bases underlying the processes involved in LD physiopathology are finally being elucidated. The main cause of the disease is related to the activity of two proteins, the dual-specificity phosphatase laforin and the E3-ubiquitin ligase malin, which form a functional complex. Laforin is unique in humans, as it is composed of a carbohydrate-binding module attached to a cysteine-based catalytic dual-specificity phosphatase domain. Laforin directly dephosphorylates glycogen, but other proteinaceous substrates, if they exist, have remained elusive. Recently, an emerging set of laforin-binding partners apart from malin have been described, suggestive of laforin roles unrelated to its catalytic activity. Further investigations based on different transgenic mouse models have shown that the laforin-malin complex is also involved in other cellular processes, such as response to endoplasmic reticulum stress and misfolded protein clearance by the lysosomal pathway. However, controversial data and some missing links still make it difficult to assess the concrete relationship between glycogen deregulation and neuronal damage leading to the fatal symptoms observed in LD patients, such as myoclonic seizures and epilepsy. Consequently, clinical treatments are far from being achieved. In the present review, we focus on the knowledge of laforin biology, not only as a glucan phosphatase, but also as an adaptor protein involved in several physiological pathways.
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Affiliation(s)
- Matthew S Gentry
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY, USA
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10
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Laforin, a dual-specificity phosphatase involved in Lafora disease, is phosphorylated at Ser25 by AMP-activated protein kinase. Biochem J 2011; 439:265-75. [PMID: 21728993 DOI: 10.1042/bj20110150] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Lafora progressive myoclonus epilepsy [LD (Lafora disease)] is a fatal autosomal recessive neurodegenerative disorder caused by loss-of-function mutations in either the EPM2A gene, encoding the dual-specificity phosphatase laforin, or the EPM2B gene, encoding the E3-ubiquitin ligase malin. Previously, we and others showed that laforin and malin form a functional complex that regulates multiple aspects of glycogen metabolism, and that the interaction between laforin and malin is enhanced by conditions activating AMPK (AMP-activated protein kinase). In the present study, we demonstrate that laforin is a phosphoprotein, as indicated by two-dimensional electrophoresis, and we identify Ser(25) as the residue involved in this modification. We also show that Ser(25) is phosphorylated both in vitro and in vivo by AMPK. Lastly, we demonstrate that this residue plays a critical role for both the phosphatase activity and the ability of laforin to interact with itself and with previously established binding partners. The results of the present study suggest that phosphorylation of laforin-Ser(25) by AMPK provides a mechanism to modulate the interaction between laforin and malin. Regulation of this complex is necessary to maintain normal glycogen metabolism. Importantly, Ser(25) is mutated in some LD patients (S25P), and our results begin to elucidate the mechanism of disease in these patients.
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11
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Li JP, Fu YN, Chen YR, Tan TH. JNK pathway-associated phosphatase dephosphorylates focal adhesion kinase and suppresses cell migration. J Biol Chem 2009; 285:5472-8. [PMID: 20018849 DOI: 10.1074/jbc.m109.060186] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
JNK pathway-associated phosphatase (JKAP, also named DUSP22) is expressed in various tissues, indicating that JKAP may have an important biological function. We showed that JKAP localized in the actin filament-enriched region. Expression of JKAP reduced cell migration, whereas a JKAP mutant lacking catalytic activity promoted cell motility. JKAP efficiently removed tyrosine phosphorylation of several proteins. We have identified focal adhesion kinase (FAK) as a substrate of JKAP. Overexpression of JKAP, but not JKAP mutant lacking catalytic activity, decreased FAK phosphorylation at tyrosines 397, 576, and 577 in H1299 cells. Consistent with these results, decreasing JKAP expression by RNA interference promoted cell migration and Src-induced FAK phosphorylation. Taken together, this study identified a new role for JKAP in the modulation of FAK phosphorylation and cell motility.
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Affiliation(s)
- Ju-Pi Li
- Immunology Research Center, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan
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Abstract
The large-scale structural biology projects that target human proteins focus predominantly on the catalytic domains of potential therapeutic targets and the domains of human proteins that mediate protein-protein and protein-small-molecule interactions. Their main scientific objective is to elucidate the molecular basis for specificity and selectivity of function within large protein families of therapeutic interest, such as kinases, phosphatases, and proteins involved in epigenetic regulation. Half of the unique human protein structures determined in the past three years derive from these initiatives.
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Affiliation(s)
- Aled Edwards
- Banting and Best Department of Medical Research, University of Toronto, Ontario M5G 1L6, Canada
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13
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Ogra Y, Kitaguchi T, Suzuki N, Suzuki KT. In vitro translation with [34S]-labeled methionine, selenomethionine, and telluromethionine. Anal Bioanal Chem 2007; 390:45-51. [PMID: 17846751 DOI: 10.1007/s00216-007-1546-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2007] [Revised: 08/01/2007] [Accepted: 08/06/2007] [Indexed: 12/18/2022]
Abstract
Heteroisotope and heteroatom tagging with [(34)S]-enriched methionine (Met), selenomethionine (SeMet), and telluromethionine (TeMet) was applied to in vitro translation. Green fluorescent protein (GFP) and JNK stimulatory phosphatase-1 (JSP-1) genes were translated with wheat germ extract (WGE) in the presence of Met derivatives. GFPs containing Met derivatives were subjected to HPLC coupled with treble detection, i.e., a photodiode array detector, a fluorescence detector, and an inductively coupled plasma mass spectrometer (ICP-MS). The activities of JSP-1-containing Met derivatives were also measured. GFP and JSP-1 containing [(34)S]-Met and SeMet showed comparable fluorescence intensities and enzyme activities to those containing naturally occurring Met. TeMet was unstable and decomposed in WGE, whereas SeMet was stable throughout the experimental period. Thus, although Te was the most sensitive to ICP-MS detection among S, Se, and Te, TeMet was less incorporated into the proteins than Met and SeMet. Finally, the potential of heteroisotope and heteroatom tagging of desired proteins in in vitro translation followed by ICP-MS detection was discussed. [figure: see text] TeMet was less incorporated into GFP than Met and SeMet due to its instability in WGE.
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Affiliation(s)
- Yasumitsu Ogra
- Graduate School of Pharmaceutical Sciences, Chiba University, Chuo, Chiba, 260-8675, Japan.
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14
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Zhang L, Qiu B, Xiong B, Li X, Li J, Wang X, Li J, Shen J. Quinoxalinylurea derivatives as a novel class of JSP-1 inhibitors. Bioorg Med Chem Lett 2007; 17:2118-22. [PMID: 17303416 DOI: 10.1016/j.bmcl.2007.01.094] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Revised: 01/26/2007] [Accepted: 01/30/2007] [Indexed: 11/26/2022]
Abstract
A series of quinoxalinylurea-based inhibitors are synthesized and shown to be the novel and potent inhibitors against Jnk Stimulatory Phosphatase-1 (JSP-1), which is a special member of dual-specificity protein phosphatase (DSP) family. Biological assay and computational modeling studies showed the compounds were reversible and noncompetitive inhibitors of JSP-1. JSP-1 inhibitors may be useful for the treatment of inflammatory, vascular, neurodegenerative, metabolic, and oncological diseases in humans associated with dysfunctional Jnk signaling.
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Affiliation(s)
- Li Zhang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203, PR China
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