1
|
Hu G, Lan X, Peng B, Liao J, Xiong Y. Water resistant, biodegradable and flexible corn starch/carboxymethyl cellulose composite film for slow-release fertilizer coating materials. Int J Biol Macromol 2024; 260:129476. [PMID: 38232878 DOI: 10.1016/j.ijbiomac.2024.129476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 01/06/2024] [Accepted: 01/11/2024] [Indexed: 01/19/2024]
Abstract
The inherent limitations of Cornstarch (CS) and Carboxymethyl Cellulose (CMC) membranes, such as brittleness, fragility, and water solubility, limit their use in controlled-release fertilizers. This study reports on the synthesis of crosslinked CMC/CS-20-E composite membranes using the casting technique, with epichlorohydrin (ECH) as the crosslinking agent in an acidic environment to crosslink CS and CMC. The synthesized composite film demonstrates remarkable water resistance, as evidenced by the insignificant alteration in its morphology and structure post 72 h of water immersion. Its flexibility is reflected in its capacity to endure knotting and bending, with an elongation at break reaching 78.1 %. Moreover, the degradation rate surpasses 90 % within a span of seven days. The CMC/CS-20-E-x-urea controlled-release fertilizer was subsequently produced using a layer-by-layer self-assembly technique, where urea particles were incorporated into the crosslinked composite solution. This CMC/CS-20-E-x-urea controlled-release fertilizer displayed superior controlled-release performance over a duration of seven days when juxtaposed with pure urea. In particular, the CMC/CS-20-E-3 %-urea controlled-release fertilizer showed a cumulative release rate of 84 % by the seventh day. The controlled-release fertilizers developed in this study offer a promising strategy for creating eco-friendly options that are crucial for fertilizing crops with short growth cycles.
Collapse
Affiliation(s)
- Guirong Hu
- Department of Polymer Materials and Engineering, College of Materials and Metallurgy, Guizhou University, Guiyang, 550025, China
| | - Xianyu Lan
- Department of Polymer Materials and Engineering, College of Materials and Metallurgy, Guizhou University, Guiyang, 550025, China
| | - Baolin Peng
- Guiyang Kai Phosphorus Fertilizer Co., Guiyang 551109, China
| | - Jixing Liao
- Guiyang Kai Phosphorus Fertilizer Co., Guiyang 551109, China
| | - Yuzhu Xiong
- Department of Polymer Materials and Engineering, College of Materials and Metallurgy, Guizhou University, Guiyang, 550025, China.
| |
Collapse
|
2
|
Pantiora PD, Georgakis ND, Premetis GE, Labrou NE. Metagenomic analysis of hot spring soil for mining a novel thermostable enzybiotic. Appl Microbiol Biotechnol 2024; 108:163. [PMID: 38252132 PMCID: PMC10803476 DOI: 10.1007/s00253-023-12979-2] [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: 08/17/2023] [Revised: 12/06/2023] [Accepted: 12/20/2023] [Indexed: 01/23/2024]
Abstract
The misuse and overuse of antibiotics have contributed to a rapid emergence of antibiotic-resistant bacterial pathogens. This global health threat underlines the urgent need for innovative and novel antimicrobials. Endolysins derived from bacteriophages or prophages constitute promising new antimicrobials (so-called enzybiotics), exhibiting the ability to break down bacterial peptidoglycan (PG). In the present work, metagenomic analysis of soil samples, collected from thermal springs, allowed the identification of a prophage-derived endolysin that belongs to the N-acetylmuramoyl-L-alanine amidase type 2 (NALAA-2) family and possesses a LysM (lysin motif) region as a cell wall binding domain (CWBD). The enzyme (Ami1) was cloned and expressed in Escherichia coli, and its bactericidal and lytic activity was characterized. The results indicate that Ami1 exhibits strong bactericidal and antimicrobial activity against a broad range of bacterial pathogens, as well as against isolated peptidoglycan (PG). Among the examined bacterial pathogens, Ami1 showed highest bactericidal activity against Staphylococcus aureus sand Staphylococcus epidermidis cells. Thermostability analysis revealed a melting temperature of 64.2 ± 0.6 °C. Overall, these findings support the potential that Ami1, as a broad spectrum antimicrobial agent, could be further assessed as enzybiotic for the effective treatment of bacterial infections. KEY POINTS: • Metagenomic analysis allowed the identification of a novel prophage endolysin • The endolysin belongs to type 2 amidase family with lysin motif region • The endolysin displays high thermostability and broad bactericidal spectrum.
Collapse
Affiliation(s)
- Panagiota D Pantiora
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855, Athens, Greece
| | - Nikolaos D Georgakis
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855, Athens, Greece
| | - Georgios E Premetis
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855, Athens, Greece
| | - Nikolaos E Labrou
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Applied Biology and Biotechnology, Agricultural University of Athens, 75 Iera Odos Street, GR-11855, Athens, Greece.
| |
Collapse
|
3
|
Frenett ML, Weis K, Cole MJ, Vargas JCC, Ramsay A, Huang J, Gentry MS, Vander Kooi CW, Raththagala M. Differential activity of glucan phosphatase starch EXcess4 orthologs from agronomic crops. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2022. [DOI: 10.1016/j.bcab.2022.102479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
4
|
Murphy RD, Chen T, Lin J, He R, Wu L, Pearson CR, Sharma S, Vander Kooi CD, Sinai AP, Zhang ZY, Vander Kooi CW, Gentry MS. The Toxoplasma glucan phosphatase TgLaforin utilizes a distinct functional mechanism that can be exploited by therapeutic inhibitors. J Biol Chem 2022; 298:102089. [PMID: 35640720 PMCID: PMC9254107 DOI: 10.1016/j.jbc.2022.102089] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/21/2022] [Accepted: 05/23/2022] [Indexed: 01/19/2023] Open
Abstract
Toxoplasma gondii is an intracellular parasite that generates amylopectin granules (AGs), a polysaccharide associated with bradyzoites that define chronic T. gondii infection. AGs are postulated to act as an essential energy storage molecule that enable bradyzoite persistence, transmission, and reactivation. Importantly, reactivation can result in the life-threatening symptoms of toxoplasmosis. T. gondii encodes glucan dikinase and glucan phosphatase enzymes that are homologous to the plant and animal enzymes involved in reversible glucan phosphorylation and which are required for efficient polysaccharide degradation and utilization. However, the structural determinants that regulate reversible glucan phosphorylation in T. gondii are unclear. Herein, we define key functional aspects of the T. gondii glucan phosphatase TgLaforin (TGME49_205290). We demonstrate that TgLaforin possesses an atypical split carbohydrate-binding-module domain. AlphaFold2 modeling combined with hydrogen-deuterium exchange mass spectrometry and differential scanning fluorimetry also demonstrate the unique structural dynamics of TgLaforin with regard to glucan binding. Moreover, we show that TgLaforin forms a dual specificity phosphatase domain-mediated dimer. Finally, the distinct properties of the glucan phosphatase catalytic domain were exploited to identify a small molecule inhibitor of TgLaforin catalytic activity. Together, these studies define a distinct mechanism of TgLaforin activity, opening up a new avenue of T. gondii bradyzoite biology as a therapeutic target.
Collapse
Affiliation(s)
- Robert D Murphy
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA; Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Tiantian Chen
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Jianping Lin
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA
| | - Rongjun He
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA
| | - Li Wu
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA
| | - Caden R Pearson
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Savita Sharma
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Carl D Vander Kooi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Anthony P Sinai
- Department of Microbiology, Immunology, and Molecular Genetics, College of Medicine, University of Kentucky, Lexington, Kentucky, USA
| | - Zhong-Yin Zhang
- Departments of Medicinal Chemistry and Molecular Pharmacology and of Chemistry, Purdue Institute for Drug Discovery, Purdue University, West Lafayette, Indiana, USA.
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA.
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, Kentucky, USA.
| |
Collapse
|
5
|
An empirical pipeline for personalized diagnosis of Lafora disease mutations. iScience 2021; 24:103276. [PMID: 34755096 PMCID: PMC8564118 DOI: 10.1016/j.isci.2021.103276] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/14/2021] [Accepted: 10/12/2021] [Indexed: 11/23/2022] Open
Abstract
Lafora disease (LD) is a fatal childhood dementia characterized by progressive myoclonic epilepsy manifesting in the teenage years, rapid neurological decline, and death typically within ten years of onset. Mutations in either EPM2A, encoding the glycogen phosphatase laforin, or EPM2B, encoding the E3 ligase malin, cause LD. Whole exome sequencing has revealed many EPM2A variants associated with late-onset or slower disease progression. We established an empirical pipeline for characterizing the functional consequences of laforin missense mutations in vitro using complementary biochemical approaches. Analysis of 26 mutations revealed distinct functional classes associated with different outcomes that were supported by clinical cases. For example, F321C and G279C mutations have attenuated functional defects and are associated with slow progression. This pipeline enabled rapid characterization and classification of newly identified EPM2A mutations, providing clinicians and researchers genetic information to guide treatment of LD patients. Lafora disease (LD) patients present with varying clinical progression LD missense mutations differentially affect laforin function An empirical in vitro pipeline is used to classify laforin missense mutations Patient progression can be predicted based on mutation class
Collapse
|
6
|
Mak CA, Weis K, Henao T, Kuchtova A, Chen T, Sharma S, Meekins DA, Thalmann M, Vander Kooi CW, Raththagala M. Cooperative Kinetics of the Glucan Phosphatase Starch Excess4. Biochemistry 2021; 60:2425-2435. [PMID: 34319705 DOI: 10.1021/acs.biochem.1c00307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glucan phosphatases are members of a functionally diverse family of dual-specificity phosphatase (DSP) enzymes. The plant glucan phosphatase Starch Excess4 (SEX4) binds and dephosphorylates glucans, contributing to processive starch degradation in the chloroplast at night. Little is known about the complex kinetics of SEX4 when acting on its complex physiologically relevant glucan substrate. Therefore, we explored the kinetics of SEX4 against both insoluble starch and soluble amylopectin glucan substrates. SEX4 displays robust activity and a unique sigmoidal kinetic response to amylopectin, characterized by a Hill coefficient of 2.77 ± 0.63, a signature feature of cooperativity. We investigated the basis for this positive kinetic cooperativity and determined that the SEX4 carbohydrate-binding module (CBM) dramatically influences the binding cooperativity and substrate transformation rates. These findings provide insights into a previously unknown but important regulatory role for SEX4 in reversible starch phosphorylation and further advances our understanding of atypical kinetic mechanisms.
Collapse
Affiliation(s)
- Claudia A Mak
- Department of Chemistry, Skidmore College, Saratoga Springs, New York 12866, United States
| | - Kenyon Weis
- Department of Chemistry, Skidmore College, Saratoga Springs, New York 12866, United States
| | - Tiffany Henao
- Department of Chemistry, Skidmore College, Saratoga Springs, New York 12866, United States
| | - Andrea Kuchtova
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40506, United States
| | - Tiantian Chen
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40506, United States
| | - Savita Sharma
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40506, United States
| | - David A Meekins
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40506, United States
| | - Matthias Thalmann
- The John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, Kentucky 40506, United States
| | - Madushi Raththagala
- Department of Chemistry, Skidmore College, Saratoga Springs, New York 12866, United States
| |
Collapse
|
7
|
Simmons ZR, Sharma S, Wayne J, Li S, Vander Kooi CW, Gentry MS. Generation and characterization of a laforin nanobody inhibitor. Clin Biochem 2021; 93:80-89. [PMID: 33831386 PMCID: PMC8217207 DOI: 10.1016/j.clinbiochem.2021.03.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/05/2021] [Accepted: 03/29/2021] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Mutations in the gene encoding the glycogen phosphatase laforin result in the fatal childhood dementia Lafora disease (LD). A cellular hallmark of LD is cytoplasmic, hyper-phosphorylated, glycogen-like aggregates called Lafora bodies (LBs) that form in nearly all tissues and drive disease progression. Additional tools are needed to define the cellular function of laforin, understand the pathological role of laforin in LD, and determine the role of glycogen phosphate in glycogen metabolism. In this work, we present the generation and characterization of laforin nanobodies, with one being a laforin inhibitor. DESIGN AND METHODS We identify multiple classes of specific laforin-binding nanobodies and determine their binding epitopes using hydrogen deuterium exchange (HDX) mass spectrometry. Using para-nitrophenyl phosphate (pNPP) and a malachite gold-based assay specific for glucan phosphatase activity, we assess the inhibitory effect of one nanobody on laforin's catalytic activity. RESULTS Six families of laforin nanobodies are characterized and their epitopes mapped. One nanobody is identified and characterized that serves as an inhibitor of laforin's phosphatase activity. CONCLUSIONS The six generated and characterized laforin nanobodies, with one being a laforin inhibitor, are an important set of tools that open new avenues to define unresolved glycogen metabolism questions.
Collapse
Affiliation(s)
- Zoe R Simmons
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY 40536, United States
| | - Savita Sharma
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY 40536, United States
| | - Jeremiah Wayne
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY 40536, United States
| | - Sheng Li
- Department of Medicine, University of California at San Diego, La Jolla, CA 92093, United States
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY 40536, United States; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, KY 40536, United States
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, University of Kentucky College of Medicine, Lexington, KY 40536, United States; Lafora Epilepsy Cure Initiative, University of Kentucky College of Medicine, Lexington, KY 40536, United States.
| |
Collapse
|
8
|
Bheri M, Mahiwal S, Sanyal SK, Pandey GK. Plant protein phosphatases: What do we know about their mechanism of action? FEBS J 2020; 288:756-785. [PMID: 32542989 DOI: 10.1111/febs.15454] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/27/2020] [Accepted: 06/09/2020] [Indexed: 12/30/2022]
Abstract
Protein phosphorylation is a major reversible post-translational modification. Protein phosphatases function as 'critical regulators' in signaling networks through dephosphorylation of proteins, which have been phosphorylated by protein kinases. A large understanding of their working has been sourced from animal systems rather than the plant or the prokaryotic systems. The eukaryotic protein phosphatases include phosphoprotein phosphatases (PPP), metallo-dependent protein phosphatases (PPM), protein tyrosine (Tyr) phosphatases (PTP), and aspartate (Asp)-dependent phosphatases. The PPP and PPM families are serine(Ser)/threonine(Thr)-specific phosphatases (STPs), while PTP family is Tyr specific. Dual-specificity phosphatases (DsPTPs/DSPs) dephosphorylate Ser, Thr, and Tyr residues. PTPs lack sequence homology with STPs, indicating a difference in catalytic mechanisms, while the PPP and PPM families share a similar structural fold indicating a common catalytic mechanism. The catalytic cysteine (Cys) residue in the conserved HCX5 R active site motif of the PTPs acts as a nucleophile during hydrolysis. The PPP members require metal ions, which coordinate the phosphate group of the substrate, followed by a nucleophilic attack by a water molecule and hydrolysis. The variable holoenzyme assembly of protein phosphatase(s) and the overlap with other post-translational modifications like acetylation and ubiquitination add to their complexity. Though their functional characterization is extensively reported in plants, the mechanistic nature of their action is still being explored by researchers. In this review, we exclusively overview the plant protein phosphatases with an emphasis on their mechanistic action as well as structural characteristics.
Collapse
Affiliation(s)
- Malathi Bheri
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Swati Mahiwal
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Sibaji K Sanyal
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Girdhar K Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| |
Collapse
|
9
|
Carrillo JB, Torresi F, Morales LL, Ricordi M, Gomez-Casati DF, Busi MV, Martín M. Identification and characterization of ChlreSEX4, a novel glucan phosphatase from Chlamydomonas reinhardtii green alga. Arch Biochem Biophys 2020; 680:108235. [PMID: 31877265 DOI: 10.1016/j.abb.2019.108235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/18/2019] [Accepted: 12/20/2019] [Indexed: 11/16/2022]
Abstract
Chlamydomonas reinhardtii is the best known unicellular green alga model which has long been used to investigate all kinds of cellular processes, including starch metabolism. Here we identified and characterized a novel enzyme, ChlreSEX4, orthologous to glucan phosphatase SEX4 from Arabidopsis thaliana, that is capable of binding and dephosphorylating amylopectin in vitro. We also reported that cysteine 224 and tryptophan 305 residues are critical for enzyme catalysis and substrate binding. Furthermore, we verified that ChlreSEX4 gene is expressed in vivo and that glucan phosphatase activity is measurable in Chlamydomonas protein extracts. In view of the results presented, we suggest ChlreSEX4 as a functional phosphoglucan phosphatase from C. reinhardtii. Our data obtained so far contribute to understanding the phosphoglucan phosphatases evolutionary process in the green lineage and their role in starch reversible phosphorylation. In addition, this allows to position Chlamydomonas as a potential tool to obtain starches with different degrees of phosphorylation for industrial or biotechnological purposes.
Collapse
Affiliation(s)
- Julieta B Carrillo
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina
| | - Florencia Torresi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina
| | - Luisina L Morales
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina
| | - Micaela Ricordi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina
| | - Diego F Gomez-Casati
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina
| | - Maria V Busi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina.
| | - Mariana Martín
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Suipacha 531, S2002LRK Rosario, 2000, Rosario, Santa Fe, Argentina.
| |
Collapse
|
10
|
Schreier TB, Umhang M, Lee SK, Lue WL, Shen Z, Silver D, Graf A, Müller A, Eicke S, Stadler-Waibel M, Seung D, Bischof S, Briggs SP, Kötting O, Moorhead GBG, Chen J, Zeeman SC. LIKE SEX4 1 Acts as a β-Amylase-Binding Scaffold on Starch Granules during Starch Degradation. THE PLANT CELL 2019; 31:2169-2186. [PMID: 31266901 PMCID: PMC6751131 DOI: 10.1105/tpc.19.00089] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/17/2019] [Accepted: 06/26/2019] [Indexed: 05/23/2023]
Abstract
In Arabidopsis (Arabidopsis thaliana) leaves, starch is synthesized during the day and degraded at night to fuel growth and metabolism. Starch is degraded primarily by β-amylases, liberating maltose, but this activity is preceded by glucan phosphorylation and is accompanied by dephosphorylation. A glucan phosphatase family member, LIKE SEX4 1 (LSF1), binds starch and is required for normal starch degradation, but its exact role is unclear. Here, we show that LSF1 does not dephosphorylate glucans. The recombinant dual specificity phosphatase (DSP) domain of LSF1 had no detectable phosphatase activity. Furthermore, a variant of LSF1 mutated in the catalytic cysteine of the DSP domain complemented the starch-excess phenotype of the lsf1 mutant. By contrast, a variant of LSF1 with mutations in the carbohydrate binding module did not complement lsf1 Thus, glucan binding, but not phosphatase activity, is required for the function of LSF1 in starch degradation. LSF1 interacts with the β-amylases BAM1 and BAM3, and the BAM1-LSF1 complex shows amylolytic but not glucan phosphatase activity. Nighttime maltose levels are reduced in lsf1, and genetic analysis indicated that the starch-excess phenotype of lsf1 is dependent on bam1 and bam3 We propose that LSF1 binds β-amylases at the starch granule surface, thereby promoting starch degradation.
Collapse
Affiliation(s)
- Tina B Schreier
- Institute of Molecular Plant Biology, ETH Zurich, CH-8092 Zurich, Switzerland
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, United Kingdom
| | - Martin Umhang
- Institute of Molecular Plant Biology, ETH Zurich, CH-8092 Zurich, Switzerland
| | - Sang-Kyu Lee
- Institute of Molecular Plant Biology, ETH Zurich, CH-8092 Zurich, Switzerland
| | - Wei-Ling Lue
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Zhouxin Shen
- Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093-0380
| | - Dylan Silver
- University of Calgary, Department of Biological Sciences, Calgary, Alberta T2N 1N4, Canada
| | - Alexander Graf
- John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom
| | - Antonia Müller
- Institute of Molecular Plant Biology, ETH Zurich, CH-8092 Zurich, Switzerland
| | - Simona Eicke
- Institute of Molecular Plant Biology, ETH Zurich, CH-8092 Zurich, Switzerland
| | | | - David Seung
- Institute of Molecular Plant Biology, ETH Zurich, CH-8092 Zurich, Switzerland
| | - Sylvain Bischof
- Institute of Molecular Plant Biology, ETH Zurich, CH-8092 Zurich, Switzerland
| | - Steven P Briggs
- Division of Biological Sciences, University of California, San Diego, La Jolla, California 92093-0380
| | - Oliver Kötting
- Institute of Molecular Plant Biology, ETH Zurich, CH-8092 Zurich, Switzerland
| | - Greg B G Moorhead
- University of Calgary, Department of Biological Sciences, Calgary, Alberta T2N 1N4, Canada
| | - Jychian Chen
- Institute of Molecular Biology, Academia Sinica, Taipei 115, Taiwan
| | - Samuel C Zeeman
- Institute of Molecular Plant Biology, ETH Zurich, CH-8092 Zurich, Switzerland
| |
Collapse
|
11
|
Austin GL, Simmons ZR, Klier JE, Rondon A, Hodges BL, Shaffer R, Aziz NM, McKnight TR, Pauly JR, Armstrong DD, Vander Kooi CW, Gentry MS. Central Nervous System Delivery and Biodistribution Analysis of an Antibody-Enzyme Fusion for the Treatment of Lafora Disease. Mol Pharm 2019; 16:3791-3801. [PMID: 31329461 DOI: 10.1021/acs.molpharmaceut.9b00396] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Lafora disease (LD) is a fatal juvenile epilepsy characterized by the accumulation of aberrant glucan aggregates called Lafora bodies (LBs). Delivery of protein-based therapeutics to the central nervous system (CNS) for the clearance of LBs remains a unique challenge in the field. Recently, a humanized antigen-binding fragment (hFab) derived from a murine systemic lupus erythematosus DNA autoantibody (3E10) has been shown to mediate cell penetration and proposed as a broadly applicable carrier to mediate cellular targeting and uptake. We report studies on the efficacy and CNS delivery of VAL-0417, an antibody-enzyme fusion composed of the 3E10 hFab and human pancreatic α-amylase, in a mouse model of LD. An enzyme-linked immunosorbent assay has been developed to detect VAL-0417 post-treatment as a measure of delivery efficacy. We demonstrate the robust and sensitive detection of the fusion protein in multiple tissue types. Using this method, we measured biodistribution in different methods of delivery. We found that intracerebroventricular administration provided robust CNS delivery when compared to intrathecal administration. These data define critical steps in the translational pipeline of VAL-0417 for the treatment of LD.
Collapse
Affiliation(s)
| | | | | | | | - Brad L Hodges
- Valerion Therapeutics , Concord , Massachusetts 01742 , United States
| | - Robert Shaffer
- Valerion Therapeutics , Concord , Massachusetts 01742 , United States
| | - Nadine M Aziz
- Valerion Therapeutics , Concord , Massachusetts 01742 , United States
| | - Tracy R McKnight
- Valerion Therapeutics , Concord , Massachusetts 01742 , United States
| | - James R Pauly
- Department of Pharmaceutical Sciences , University of Kentucky College of Pharmacy , Lexington , Kentucky 40536 , United States
| | | | | | | |
Collapse
|
12
|
Brewer MK, Gentry MS. Brain Glycogen Structure and Its Associated Proteins: Past, Present and Future. ADVANCES IN NEUROBIOLOGY 2019; 23:17-81. [PMID: 31667805 PMCID: PMC7239500 DOI: 10.1007/978-3-030-27480-1_2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
This chapter reviews the history of glycogen-related research and discusses in detail the structure, regulation, chemical properties and subcellular distribution of glycogen and its associated proteins, with particular focus on these aspects in brain tissue.
Collapse
Affiliation(s)
- M Kathryn Brewer
- Department of Molecular and Cellular Biochemistry, Epilepsy and Brain Metabolism Center, Lafora Epilepsy Cure Initiative, and Center for Structural Biology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, Epilepsy and Brain Metabolism Center, Lafora Epilepsy Cure Initiative, and Center for Structural Biology, University of Kentucky College of Medicine, Lexington, KY, USA.
| |
Collapse
|
13
|
Sharma S, Vander Kooi CD, Gentry MS, Vander Kooi CW. Oligomerization and carbohydrate binding of glucan phosphatases. Anal Biochem 2018; 563:51-55. [PMID: 30291838 DOI: 10.1016/j.ab.2018.10.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/20/2018] [Accepted: 10/02/2018] [Indexed: 11/24/2022]
Abstract
Glucan phosphatases are a unique subset of the phosphatase family that bind to and dephosphorylate carbohydrate substrates. Family members are found in diverse organisms ranging from single-cell red algae to humans. The nature of their functional oligomerization has been a source of considerable debate. We demonstrate that the human laforin protein behaves aberrantly when subjected to Size Exclusion Chromotography (SEC) analysis due to interaction with the carbohydrate-based matrix. This interaction complicates the analysis of laforin human disease mutations. Herein, we show that SEC with Multi-Angle static Light Scattering (SEC-MALS) provides a method to robustly define the oligomerization state of laforin and laforin variants. We further analyzed glucan phosphatases from photosynthetic organisms to define if this interaction was characteristic of all glucan phosphatases. Starch EXcess-four (SEX4) from green plants was found to lack significant interaction with the matrix and instead exists as a monomer. Conversely, Cm-laforin, from red algae, exists as a monomer in solution while still exhibiting significant interaction with the matrix. These data demonstrate a range of oligomerization behaviors of members of the glucan phosphatase family, and establish SEC-MALS as a robust methodology to quantify and compare oligomerization states between different proteins and protein variants in this family.
Collapse
Affiliation(s)
- Savita Sharma
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40536, USA
| | - Carl D Vander Kooi
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40536, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40536, USA
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40536, USA; Center for Structural Biology, University of Kentucky, Lexington, KY, 40536, USA.
| |
Collapse
|
14
|
Samodien E, Jewell JF, Loedolff B, Oberlander K, George GM, Zeeman SC, Damberger FF, van der Vyver C, Kossmann J, Lloyd JR. Repression of Sex4 and Like Sex Four2 Orthologs in Potato Increases Tuber Starch Bound Phosphate With Concomitant Alterations in Starch Physical Properties. FRONTIERS IN PLANT SCIENCE 2018; 9:1044. [PMID: 30083175 PMCID: PMC6064929 DOI: 10.3389/fpls.2018.01044] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 06/27/2018] [Indexed: 05/25/2023]
Abstract
To examine the roles of starch phosphatases in potatoes, transgenic lines were produced where orthologs of SEX4 and LIKE SEX FOUR2 (LSF2) were repressed using RNAi constructs. Although repression of either SEX4 or LSF2 inhibited leaf starch degradation, it had no effect on cold-induced sweetening in tubers. Starch amounts were unchanged in the tubers, but the amount of phosphate bound to the starch was significantly increased in all the lines, with phosphate bound at the C6 position of the glucosyl units increased in lines repressed in StSEX4 and in the C3 position in lines repressed in StLSF2 expression. This was accompanied by a reduction in starch granule size and an alteration in the constituent glucan chain lengths within the starch molecule, although no obvious alteration in granule morphology was observed. Starch from the transgenic lines contained fewer chains with a degree of polymerization (DP) of less than 17 and more with a DP between 17 and 38. There were also changes in the physical properties of the starches. Rapid viscoanalysis demonstrated that both the holding strength and the final viscosity of the high phosphate starches were increased indicating that the starches have increased swelling power due to an enhanced capacity for hydration.
Collapse
Affiliation(s)
- Ebrahim Samodien
- Department of Genetics, Institute for Plant Biotechnology, Stellenbosch University, Stellenbosch, South Africa
| | - Jonathan F. Jewell
- Department of Genetics, Institute for Plant Biotechnology, Stellenbosch University, Stellenbosch, South Africa
| | - Bianke Loedolff
- Department of Genetics, Institute for Plant Biotechnology, Stellenbosch University, Stellenbosch, South Africa
| | - Kenneth Oberlander
- Department of Conservation Ecology and Entomology, Stellenbosch University, Stellenbosch, South Africa
| | - Gavin M. George
- Institute of Molecular Plant Biology, ETH Zürich, Zürich, Switzerland
| | - Samuel C. Zeeman
- Institute of Molecular Plant Biology, ETH Zürich, Zürich, Switzerland
| | - Fred F. Damberger
- Institute of Molecular Biology and Biophysics, ETH Zürich, Zürich, Switzerland
- Biomolecular NMR Spectroscopy Platform, Department of Biology, ETH Zürich, Zürich, Switzerland
| | - Christell van der Vyver
- Department of Genetics, Institute for Plant Biotechnology, Stellenbosch University, Stellenbosch, South Africa
| | - Jens Kossmann
- Department of Genetics, Institute for Plant Biotechnology, Stellenbosch University, Stellenbosch, South Africa
| | - James R. Lloyd
- Department of Genetics, Institute for Plant Biotechnology, Stellenbosch University, Stellenbosch, South Africa
| |
Collapse
|
15
|
Garcia-Gimeno MA, Rodilla-Ramirez PN, Viana R, Salas-Puig X, Brewer MK, Gentry MS, Sanz P. A novel EPM2A mutation yields a slow progression form of Lafora disease. Epilepsy Res 2018; 145:169-177. [PMID: 30041081 DOI: 10.1016/j.eplepsyres.2018.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/11/2018] [Accepted: 07/13/2018] [Indexed: 12/19/2022]
Abstract
Lafora disease (LD, OMIM 254780) is a rare disorder characterized by epilepsy and neurodegeneration leading patients to a vegetative state and death, usually within the first decade from the onset of the first symptoms. In the vast majority of cases LD is related to mutations in either the EPM2A gene (encoding the glucan phosphatase laforin) or the EPM2B gene (encoding the E3-ubiquitin ligase malin). In this work, we characterize the mutations present in the EPM2A gene in a patient displaying a slow progression form of the disease. The patient is compound heterozygous with Y112X and N163D mutations in the corresponding alleles. In primary fibroblasts obtained from the patient, we analyzed the expression of the mutated alleles by quantitative real time PCR and found slightly lower levels of expression of the EPM2A gene respect to control cells. However, by Western blotting we were unable to detect endogenous levels of the protein in crude extracts from patient fibroblasts. The Y112X mutation would render a truncated protein lacking the phosphatase domain and likely degraded. Since minute amounts of laforin-N163D might still play a role in cell physiology, we analyzed the biochemical characteristics of the N163D mutation. We found that recombinant laforin N163D protein was as stable as wild type and exhibited near wild type phosphatase activity towards biologically relevant substrates. On the contrary, it showed a severe impairment in the interaction profile with previously identified laforin binding partners. These results lead us to conclude that the slow progression of the disease present in this patient could be either due to the specific biochemical properties of laforin N163D or to the presence of alternative genetic modifying factors separate from pathogenicity.
Collapse
Affiliation(s)
| | | | - Rosa Viana
- IBV-CSIC. Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Xavier Salas-Puig
- Epilepsy Unit, Neurology Dept., Hospital Vall Hebron, Barcelona, Spain
| | - M Kathryn Brewer
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, USA; Lafora Epilepsy Cure Initiative, USA
| | - Pascual Sanz
- IBV-CSIC. Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain; CIBERER. Centro de Investigación Biomédica en Red de Enfermedades Raras, Valencia, Spain; Lafora Epilepsy Cure Initiative, USA.
| |
Collapse
|
16
|
Gentry MS, Guinovart JJ, Minassian BA, Roach PJ, Serratosa JM. Lafora disease offers a unique window into neuronal glycogen metabolism. J Biol Chem 2018; 293:7117-7125. [PMID: 29483193 DOI: 10.1074/jbc.r117.803064] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Lafora disease (LD) is a fatal, autosomal recessive, glycogen-storage disorder that manifests as severe epilepsy. LD results from mutations in the gene encoding either the glycogen phosphatase laforin or the E3 ubiquitin ligase malin. Individuals with LD develop cytoplasmic, aberrant glycogen inclusions in nearly all tissues that more closely resemble plant starch than human glycogen. This Minireview discusses the unique window into glycogen metabolism that LD research offers. It also highlights recent discoveries, including that glycogen contains covalently bound phosphate and that neurons synthesize glycogen and express both glycogen synthase and glycogen phosphorylase.
Collapse
Affiliation(s)
- Matthew S Gentry
- Lafora Epilepsy Cure Initiative, Lexington, Kentucky 40503; Department of Biochemistry and Molecular Biology, Lexington, Kentucky 40503; University of Kentucky Epilepsy Research Center (EpiC), University of Kentucky, Lexington, Kentucky 40503.
| | - Joan J Guinovart
- Lafora Epilepsy Cure Initiative, Lexington, Kentucky 40503; Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology, 08028 Barcelona, Spain; Biomedical Research Networking Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), 28029 Madrid, Spain; Department of Biochemistry and Molecular Biomedicine, University of Barcelona, 08028 Barcelona, Spain
| | - Berge A Minassian
- Lafora Epilepsy Cure Initiative, Lexington, Kentucky 40503; Department of Pediatrics and Dallas Children's Medical Center, University of Texas Southwestern, Dallas, Texas 75390-9063; Department of Pediatrics, The Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario M5G 0A4, Canada
| | - Peter J Roach
- Lafora Epilepsy Cure Initiative, Lexington, Kentucky 40503; Department of Biochemistry and Molecular Biology, Center for Diabetes and Metabolic Diseases and Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Jose M Serratosa
- Lafora Epilepsy Cure Initiative, Lexington, Kentucky 40503; Laboratory of Neurology, IIS-Jimenez Diaz Foundation, UAM, 28045 Madrid, Spain; Biomedical Research Networking Center on Rare Diseases (CIBERER), 28029 Madrid, Spain
| |
Collapse
|
17
|
Carrillo JB, Gomez-Casati DF, Martín M, Busi MV. Identification and analysis of OsttaDSP, a phosphoglucan phosphatase from Ostreococcus tauri. PLoS One 2018; 13:e0191621. [PMID: 29360855 PMCID: PMC5779698 DOI: 10.1371/journal.pone.0191621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/08/2018] [Indexed: 11/18/2022] Open
Abstract
Ostreococcus tauri, the smallest free-living (non-symbiotic) eukaryote yet described, is a unicellular green alga of the Prasinophyceae family. It has a very simple cellular organization and presents a unique starch granule and chloroplast. However, its starch metabolism exhibits a complexity comparable to higher plants, with multiple enzyme forms for each metabolic reaction. Glucan phosphatases, a family of enzymes functionally conserved in animals and plants, are essential for normal starch or glycogen degradation in plants and mammals, respectively. Despite the importance of O. tauri microalgae in evolution, there is no information available concerning the enzymes involved in reversible phosphorylation of starch. Here, we report the molecular cloning and heterologous expression of the gene coding for a dual specific phosphatase from O. tauri (OsttaDSP), homologous to Arabidopsis thaliana LSF2. The recombinant enzyme was purified to electrophoretic homogeneity to characterize its oligomeric and kinetic properties accurately. OsttaDSP is a homodimer of 54.5 kDa that binds and dephosphorylates amylopectin. Also, we also determined that residue C162 is involved in catalysis and possibly also in structural stability of the enzyme. Our results could contribute to better understand the role of glucan phosphatases in the metabolism of starch in green algae.
Collapse
Affiliation(s)
- Julieta B. Carrillo
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Diego F. Gomez-Casati
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
| | - Mariana Martín
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
- * E-mail: (MM); (MVB)
| | - Maria V. Busi
- Centro de Estudios Fotosintéticos y Bioquímicos (CEFOBI-CONICET), Universidad Nacional de Rosario, Rosario, Santa Fe, Argentina
- * E-mail: (MM); (MVB)
| |
Collapse
|
18
|
White-Gloria C, Johnson JJ, Marritt K, Kataya A, Vahab A, Moorhead GB. Protein Kinases and Phosphatases of the Plastid and Their Potential Role in Starch Metabolism. FRONTIERS IN PLANT SCIENCE 2018; 9:1032. [PMID: 30065742 PMCID: PMC6056723 DOI: 10.3389/fpls.2018.01032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/25/2018] [Indexed: 05/03/2023]
Abstract
Phospho-proteomic studies have confirmed that phosphorylation is a common mechanism to regulate protein function in the chloroplast, including the enzymes of starch metabolism. In addition to the photosynthetic machinery protein kinases (STN7 and STN8) and their cognate protein phosphatases PPH1 (TAP38) and PBCP, multiple other protein kinases and phosphatases have now been localized to the chloroplast. Here, we build a framework for understanding protein kinases and phosphatases, their regulation, and potential roles in starch metabolism. We also catalog mapped phosphorylation sites on proteins of chloroplast starch metabolism to illustrate the potential and mostly unknown roles of protein phosphorylation in the regulation of starch biology.
Collapse
Affiliation(s)
- Chris White-Gloria
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Jayde J. Johnson
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Kayla Marritt
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Amr Kataya
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
- Department of Chemistry and Biosciences, University of Stavanger, Stavanger, Norway
| | - Ahmad Vahab
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Greg B. Moorhead
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
- *Correspondence: Greg B. Moorhead,
| |
Collapse
|
19
|
Gentry MS, Brewer MK, Vander Kooi CW. Structural biology of glucan phosphatases from humans to plants. Curr Opin Struct Biol 2016; 40:62-69. [PMID: 27498086 PMCID: PMC5161650 DOI: 10.1016/j.sbi.2016.07.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2016] [Revised: 07/11/2016] [Accepted: 07/21/2016] [Indexed: 02/07/2023]
Abstract
Glucan phosphatases are functionally conserved at the enzymatic level, dephosphorylating glycogen in animals and starch in plants. The human glucan phosphatase laforin is the founding member of the family and it is comprised of a carbohydrate binding module (CBM) domain followed by a dual specificity phosphatase (DSP) domain. Plants encode two glucan phosphatases: Starch EXcess4 (SEX4) and Like Sex Four2 (LSF2). SEX4 contains a DSP domain followed by a CBM domain, while LSF2 contains a DSP domain and lacks a CBM. This review demonstrates how glucan phosphatase function is conserved and highlights how each family member employs a unique mechanism to bind and dephosphorylate glucan substrates.
Collapse
Affiliation(s)
- Matthew S Gentry
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40536, United States.
| | - M Kathryn Brewer
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40536, United States
| | - Craig W Vander Kooi
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40536, United States.
| |
Collapse
|
20
|
Emanuelle S, Brewer MK, Meekins DA, Gentry MS. Unique carbohydrate binding platforms employed by the glucan phosphatases. Cell Mol Life Sci 2016; 73:2765-2778. [PMID: 27147465 PMCID: PMC4920694 DOI: 10.1007/s00018-016-2249-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 04/22/2016] [Indexed: 12/19/2022]
Abstract
Glucan phosphatases are a family of enzymes that are functionally conserved at the enzymatic level in animals and plants. These enzymes bind and dephosphorylate glycogen in animals and starch in plants. While the enzymatic function is conserved, the glucan phosphatases employ distinct mechanisms to bind and dephosphorylate glycogen or starch. The founding member of the family is a bimodular human protein called laforin that is comprised of a carbohydrate binding module 20 (CBM20) followed by a dual specificity phosphatase domain. Plants contain two glucan phosphatases: Starch EXcess4 (SEX4) and Like Sex Four2 (LSF2). SEX4 contains a chloroplast targeting peptide, dual specificity phosphatase (DSP) domain, a CBM45, and a carboxy-terminal motif. LSF2 is comprised of simply a chloroplast targeting peptide, DSP domain, and carboxy-terminal motif. SEX4 employs an integrated DSP-CBM glucan-binding platform to engage and dephosphorylate starch. LSF2 lacks a CBM and instead utilizes two surface binding sites to bind and dephosphorylate starch. Laforin is a dimeric protein in solution and it utilizes a tetramodular architecture and cooperativity to bind and dephosphorylate glycogen. This chapter describes the biological role of glucan phosphatases in glycogen and starch metabolism and compares and contrasts their ability to bind and dephosphorylate glucans.
Collapse
Affiliation(s)
- Shane Emanuelle
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40536 USA
| | - M. Kathryn Brewer
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40536 USA
| | - David A. Meekins
- Division of Biology, Kansas State University, Manhattan, KS 66506 USA
| | - Matthew S. Gentry
- Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40536 USA
| |
Collapse
|
21
|
Zhao P, Sokolov LN, Ye J, Tang CY, Shi J, Zhen Y, Lan W, Hong Z, Qi J, Lu GH, Pandey GK, Yang YH. The LIKE SEX FOUR2 regulates root development by modulating reactive oxygen species homeostasis in Arabidopsis. Sci Rep 2016; 6:28683. [PMID: 27349915 PMCID: PMC4923905 DOI: 10.1038/srep28683] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 06/08/2016] [Indexed: 01/22/2023] Open
Abstract
Maintaining reactive oxygen species (ROS) homeostasis plays a central role in plants, and is also critical for plant root development. Threshold levels of ROS act as signals for elongation and differentiation of root cells. The protein phosphatase LIKE SEX FOUR2 (LSF2) has been reported to regulate starch metabolism in Arabidopsis, but little is known about the mechanism how LSF2 affect ROS homeostasis. Here, we identified that LSF2 function as a component modulating ROS homeostasis in response to oxidative stress and, thus regulate root development. Compared with wild type Arabidopsis, lsf2-1 mutant exhibited reduced rates of superoxide generation and higher levels of hydrogen peroxide upon oxidative stress treatments. The activities of several antioxidant enzymes, including superoxide dismutase, catalase, and ascorbate peroxidase, were also affected in lsf2-1 mutant under these oxidative stress conditions. Consequently, lsf2-1 mutant exhibited the reduced root growth but less inhibition of root hair formation compared to wild type Arabidopsis plants. Importantly, protein phosphatase LSF2 interacted with mitogen-activated protein kinase 8 (MPK8), a known component of ROS homeostasis pathways in the cytoplasm. These findings indicated the novel function of LSF2 that controls ROS homeostasis to regulate root development.
Collapse
Affiliation(s)
- Pingzhi Zhao
- NJU-NJFU Joint Institute for Plant Molecular Biology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Lubomir N Sokolov
- NJU-NJFU Joint Institute for Plant Molecular Biology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Jian Ye
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Cheng-Yi Tang
- NJU-NJFU Joint Institute for Plant Molecular Biology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Jisen Shi
- NJU-NJFU Joint Institute for Plant Molecular Biology, MOE Key Laboratory of Forest Genetics and Biotechnology, Nanjing Forestry University, Nanjing 210037, China
| | - Yan Zhen
- NJU-NJFU Joint Institute for Plant Molecular Biology, MOE Key Laboratory of Forest Genetics and Biotechnology, Nanjing Forestry University, Nanjing 210037, China
| | - Wenzhi Lan
- NJU-NJFU Joint Institute for Plant Molecular Biology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Zhi Hong
- NJU-NJFU Joint Institute for Plant Molecular Biology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Jinliang Qi
- NJU-NJFU Joint Institute for Plant Molecular Biology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Gui-Hua Lu
- NJU-NJFU Joint Institute for Plant Molecular Biology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Girdhar K Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi 110021, India
| | - Yong-Hua Yang
- NJU-NJFU Joint Institute for Plant Molecular Biology, State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China
| |
Collapse
|
22
|
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] [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.
Collapse
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
| |
Collapse
|