1
|
Daras G, Templalexis D, Avgeri F, Tsitsekian D, Karamanou K, Rigas S. Updating Insights into the Catalytic Domain Properties of Plant Cellulose synthase ( CesA) and Cellulose synthase-like ( Csl) Proteins. Molecules 2021; 26:molecules26144335. [PMID: 34299608 PMCID: PMC8306620 DOI: 10.3390/molecules26144335] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/15/2021] [Accepted: 07/15/2021] [Indexed: 11/24/2022] Open
Abstract
The wall is the last frontier of a plant cell involved in modulating growth, development and defense against biotic stresses. Cellulose and additional polysaccharides of plant cell walls are the most abundant biopolymers on earth, having increased in economic value and thereby attracted significant interest in biotechnology. Cellulose biosynthesis constitutes a highly complicated process relying on the formation of cellulose synthase complexes. Cellulose synthase (CesA) and Cellulose synthase-like (Csl) genes encode enzymes that synthesize cellulose and most hemicellulosic polysaccharides. Arabidopsis and rice are invaluable genetic models and reliable representatives of land plants to comprehend cell wall synthesis. During the past two decades, enormous research progress has been made to understand the mechanisms of cellulose synthesis and construction of the plant cell wall. A plethora of cesa and csl mutants have been characterized, providing functional insights into individual protein isoforms. Recent structural studies have uncovered the mode of CesA assembly and the dynamics of cellulose production. Genetics and structural biology have generated new knowledge and have accelerated the pace of discovery in this field, ultimately opening perspectives towards cellulose synthesis manipulation. This review provides an overview of the major breakthroughs gathering previous and recent genetic and structural advancements, focusing on the function of CesA and Csl catalytic domain in plants.
Collapse
|
2
|
Inhibition of cell expansion enhances cortical microtubule stability in the root apex of Arabidopsis thaliana. ACTA ACUST UNITED AC 2021; 28:13. [PMID: 34082808 PMCID: PMC8173746 DOI: 10.1186/s40709-021-00143-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 05/18/2021] [Indexed: 12/04/2022]
Abstract
Background Cortical microtubules regulate cell expansion by determining cellulose microfibril orientation in the root apex of Arabidopsis thaliana. While the regulation of cell wall properties by cortical microtubules is well studied, the data on the influence of cell wall to cortical microtubule organization and stability remain scarce. Studies on cellulose biosynthesis mutants revealed that cortical microtubules depend on Cellulose Synthase A (CESA) function and/or cell expansion. Furthermore, it has been reported that cortical microtubules in cellulose-deficient mutants are hypersensitive to oryzalin. In this work, the persistence of cortical microtubules against anti-microtubule treatment was thoroughly studied in the roots of several cesa mutants, namely thanatos, mre1, any1, prc1-1 and rsw1, and the Cellulose Synthase Interacting 1 protein (csi1) mutant pom2-4. In addition, various treatments with drugs affecting cell expansion were performed on wild-type roots. Whole mount tubulin immunolabeling was applied in the above roots and observations were performed by confocal microscopy. Results Cortical microtubules in all mutants showed statistically significant increased persistence against anti-microtubule drugs, compared to those of the wild-type. Furthermore, to examine if the enhanced stability of cortical microtubules was due to reduced cellulose biosynthesis or to suppression of cell expansion, treatments of wild-type roots with 2,6-dichlorobenzonitrile (DCB) and Congo red were performed. After these treatments, cortical microtubules appeared more resistant to oryzalin, than in the control. Conclusions According to these findings, it may be concluded that inhibition of cell expansion, irrespective of the cause, results in increased microtubule stability in A. thaliana root. In addition, cell expansion does not only rely on cortical microtubule orientation but also plays a regulatory role in microtubule dynamics, as well. Various hypotheses may explain the increased cortical microtubule stability under decreased cell expansion such as the role of cell wall sensors and the presence of less dynamic cortical microtubules. Supplementary Information The online version contains supplementary material available at 10.1186/s40709-021-00143-8.
Collapse
|
3
|
Alaguero-Cordovilla A, Gran-Gómez FJ, Jadczak P, Mhimdi M, Ibáñez S, Bres C, Just D, Rothan C, Pérez-Pérez JM. A quick protocol for the identification and characterization of early growth mutants in tomato. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 301:110673. [PMID: 33218638 DOI: 10.1016/j.plantsci.2020.110673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/03/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
Root system architecture (RSA) manipulation may improve water and nutrient capture by plants under normal and extreme climate conditions. With the aim of initiating the genetic dissection of RSA in tomato, we established a defined ontology that allowed the curated annotation of the observed phenotypes on 12 traits at four consecutive growth stages. In addition, we established a quick approach for the molecular identification of the mutations associated with the trait-of-interest by using a whole-genome sequencing approach that does not require the building of an additional mapping population. As a proof-of-concept, we screened 4543 seedlings from 300 tomato M3 lines (Solanum lycopersicum L. cv. Micro-Tom) generated by chemical mutagenesis with ethyl methanesulfonate. We studied the growth and early development of both the root system (primary and lateral roots) and the aerial part of the seedlings as well as the wound-induced adventitious roots emerging from the hypocotyl. We identified 659 individuals (belonging to 203 M3 lines) whose early seedling and RSA phenotypes differed from those of their reference background. We confirmed the genetic segregation of the mutant phenotypes affecting primary root length, seedling viability and early RSA in 31 M4 families derived from 15 M3 lines selected in our screen. Finally, we identified a missense mutation in the SlCESA3 gene causing a seedling-lethal phenotype with short roots. Our results validated the experimental approach used for the identification of tomato mutants during early growth, which will allow the molecular identification of the genes involved.
Collapse
Affiliation(s)
| | | | - Paula Jadczak
- Instituto de Bioingeniería, Universidad Miguel Hernández, 03202, Elche, Alicante, Spain.
| | - Mariem Mhimdi
- Instituto de Bioingeniería, Universidad Miguel Hernández, 03202, Elche, Alicante, Spain.
| | - Sergio Ibáñez
- Instituto de Bioingeniería, Universidad Miguel Hernández, 03202, Elche, Alicante, Spain.
| | - Cécile Bres
- INRAE and University of Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, F-33140, Villenave d'Ornon, France.
| | - Daniel Just
- INRAE and University of Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, F-33140, Villenave d'Ornon, France.
| | - Christophe Rothan
- INRAE and University of Bordeaux, UMR 1332 Biologie du Fruit et Pathologie, F-33140, Villenave d'Ornon, France.
| | | |
Collapse
|
4
|
Mazarei M, Baxter HL, Li M, Biswal AK, Kim K, Meng X, Pu Y, Wuddineh WA, Zhang JY, Turner GB, Sykes RW, Davis MF, Udvardi MK, Wang ZY, Mohnen D, Ragauskas AJ, Labbé N, Stewart CN. Functional Analysis of Cellulose Synthase CesA4 and CesA6 Genes in Switchgrass ( Panicum virgatum) by Overexpression and RNAi-Mediated Gene Silencing. FRONTIERS IN PLANT SCIENCE 2018; 9:1114. [PMID: 30127793 PMCID: PMC6088197 DOI: 10.3389/fpls.2018.01114] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/10/2018] [Indexed: 05/11/2023]
Abstract
Switchgrass (Panicum virgatum L.) is a leading lignocellulosic bioenergy feedstock. Cellulose is a major component of the plant cell walls and the primary substrate for saccharification. Accessibility of cellulose to enzymatic breakdown into fermentable sugars is limited by the presence of lignin in the plant cell wall. In this study, putatively novel switchgrass secondary cell wall cellulose synthase PvCesA4 and primary cell wall PvCesA6 genes were identified and their functional role in cellulose synthesis and cell wall composition was examined by overexpression and knockdown of the individual genes in switchgrass. The endogenous expression of PvCesA4 and PvCesA6 genes varied among including roots, leaves, stem, and reproductive tissues. Increasing or decreasing PvCesA4 and PvCesA6 expression to extreme levels in the transgenic lines resulted in decreased biomass production. PvCesA6-overexpressing lines had reduced lignin content and syringyl/guaiacyl lignin monomer ratio accompanied by increased sugar release efficiency, suggesting an impact of PvCesA6 expression levels on lignin biosynthesis. Cellulose content and cellulose crystallinity were decreased, while xylan content was increased in PvCesA4 and PvCesA6 overexpression or knockdown lines. The increase in xylan content suggests that the amount of non-cellulosic cell wall polysaccharide was modified in these plants. Taken together, the results show that the manipulation of the cellulose synthase genes alters the cell wall composition and availability of cellulose as a bioprocessing substrate.
Collapse
Affiliation(s)
- Mitra Mazarei
- Department of Plant Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Holly L. Baxter
- Department of Plant Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Mi Li
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Biosciences Division, Joint Institute for Biological Science, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Ajaya K. Biswal
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Keonhee Kim
- Center for Renewable Carbon, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Xianzhi Meng
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Yunqiao Pu
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Biosciences Division, Joint Institute for Biological Science, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Wegi A. Wuddineh
- Department of Plant Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| | - Ji-Yi Zhang
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Noble Research Institute, Ardmore, OK, United States
| | - Geoffrey B. Turner
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- National Renewable Energy Laboratory, Golden, CO, United States
| | - Robert W. Sykes
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- National Renewable Energy Laboratory, Golden, CO, United States
| | - Mark F. Davis
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- National Renewable Energy Laboratory, Golden, CO, United States
| | - Michael K. Udvardi
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Noble Research Institute, Ardmore, OK, United States
| | - Zeng-Yu Wang
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Noble Research Institute, Ardmore, OK, United States
| | - Debra Mohnen
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Arthur J. Ragauskas
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Biosciences Division, Joint Institute for Biological Science, Oak Ridge National Laboratory, Oak Ridge, TN, United States
- Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Nicole Labbé
- Center for Renewable Carbon, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - C. Neal Stewart
- Department of Plant Sciences, University of Tennessee, Knoxville, Knoxville, TN, United States
- BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN, United States
| |
Collapse
|
5
|
Hill JL, Josephs C, Barnes WJ, Anderson CT, Tien M. Longevity in vivo of primary cell wall cellulose synthases. PLANT MOLECULAR BIOLOGY 2018; 96:279-289. [PMID: 29388029 DOI: 10.1007/s11103-017-0695-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 12/11/2017] [Indexed: 05/10/2023]
Abstract
Our work focuses on understanding the lifetime and thus stability of the three main cellulose synthase (CESA) proteins involved in primary cell wall synthesis of Arabidopsis. It had long been thought that a major means of CESA regulation was via their rapid degradation. However, our studies here have uncovered that AtCESA proteins are not rapidly degraded. Rather, they persist for an extended time in the plant cell. Plant cellulose is synthesized by membrane-embedded cellulose synthase complexes (CSCs). The CSC is composed of cellulose synthases (CESAs), of which three distinct isozymes form the primary cell wall CSC and another set of three isozymes form the secondary cell wall CSC. We determined the stability over time of primary cell wall (PCW) CESAs in Arabidopsis thaliana seedlings, using immunoblotting after inhibiting protein synthesis with cycloheximide treatment. Our work reveals very slow turnover for the Arabidopsis PCW CESAs in vivo. Additionally, we show that the stability of all three CESAs within the PCW CSC is altered by mutations in individual CESAs, elevated temperature, and light conditions. Together, these results suggest that CESA proteins are very stable in vivo, but that their lifetimes can be modulated by intrinsic and environmental cues.
Collapse
Affiliation(s)
- Joseph Lee Hill
- The Center for Lignocellulose Structure and Formation, The Pennsylvania State University, University Park, USA
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, USA
- Department of Horticulture, Michigan State University, East Lansing, MI, 48824, USA
| | - Cooper Josephs
- The Center for Lignocellulose Structure and Formation, The Pennsylvania State University, University Park, USA
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, USA
| | - William J Barnes
- The Center for Lignocellulose Structure and Formation, The Pennsylvania State University, University Park, USA
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Charles T Anderson
- The Center for Lignocellulose Structure and Formation, The Pennsylvania State University, University Park, USA
- Department of Biology, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Ming Tien
- The Center for Lignocellulose Structure and Formation, The Pennsylvania State University, University Park, USA.
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, USA.
- , 305 S. Frear, University Park, PA, 16802, USA.
| |
Collapse
|
6
|
Merz D, Richter J, Gonneau M, Sanchez-Rodriguez C, Eder T, Sormani R, Martin M, Hématy K, Höfte H, Hauser MT. T-DNA alleles of the receptor kinase THESEUS1 with opposing effects on cell wall integrity signaling. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4583-4593. [PMID: 28981771 PMCID: PMC5853656 DOI: 10.1093/jxb/erx263] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 07/04/2017] [Indexed: 05/21/2023]
Abstract
Perturbation of cellulose synthesis in plants triggers stress responses, including growth retardation, mediated by the cell wall integrity-sensing receptor-like kinase (RLK) THESEUS1 (THE1). The analysis of two alleles carrying T-DNA insertions at comparable positions has led to conflicting conclusions concerning the impact of THE1 signaling on growth. Here we confirm that, unlike the1-3 and other the1 alleles in which cellular responses to genetic or pharmacological inhibition of cellulose synthesis are attenuated, the1-4 showed enhanced responses, including growth inhibition, ectopic lignification, and stress gene expression. Both the1-3 and the1-4 express a transcript encoding a predicted membrane-associated truncated protein lacking the kinase domain. However, the1-3, in contrast to the1-4, strongly expresses antisense transcripts, which are expected to prevent the expression of the truncated protein as suggested by the genetic interactions between the two alleles. Seedlings overexpressing such a truncated protein react to isoxaben treatment similarly to the1-4 and the full-length THE overexpressor. We conclude that the1-4 is a hypermorphic allele; that THE1 signaling upon cell wall damage has a negative impact on cell expansion; and that caution is required when interpreting the phenotypic effects of T-DNA insertions in RLK genes.
Collapse
Affiliation(s)
- David Merz
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Julia Richter
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Martine Gonneau
- Institut Jean-Pierre Bourgin, INRA, Centre National pour la Recherche Scientifique, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | | | - Tobias Eder
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Rodnay Sormani
- Institut Jean-Pierre Bourgin, INRA, Centre National pour la Recherche Scientifique, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | - Marjolaine Martin
- Institut Jean-Pierre Bourgin, INRA, Centre National pour la Recherche Scientifique, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | - Kian Hématy
- Institut Jean-Pierre Bourgin, INRA, Centre National pour la Recherche Scientifique, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | - Herman Höfte
- Institut Jean-Pierre Bourgin, INRA, Centre National pour la Recherche Scientifique, AgroParisTech, Université Paris-Saclay, Versailles Cedex, France
| | - Marie-Theres Hauser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna, Austria
- Corresponding author:
| |
Collapse
|
7
|
Rui Y, Anderson CT. Functional Analysis of Cellulose and Xyloglucan in the Walls of Stomatal Guard Cells of Arabidopsis. PLANT PHYSIOLOGY 2016; 170:1398-419. [PMID: 26729799 PMCID: PMC4775103 DOI: 10.1104/pp.15.01066] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 01/03/2016] [Indexed: 05/18/2023]
Abstract
Stomatal guard cells are pairs of specialized epidermal cells that control water and CO2 exchange between the plant and the environment. To fulfill the functions of stomatal opening and closure that are driven by changes in turgor pressure, guard cell walls must be both strong and flexible, but how the structure and dynamics of guard cell walls enable stomatal function remains poorly understood. To address this question, we applied cell biological and genetic analyses to investigate guard cell walls and their relationship to stomatal function in Arabidopsis (Arabidopsis thaliana). Using live-cell spinning disk confocal microscopy, we measured the motility of cellulose synthase (CESA)-containing complexes labeled by green fluorescent protein (GFP)-CESA3 and observed a reduced proportion of GFP-CESA3 particles colocalizing with microtubules upon stomatal closure. Imaging cellulose organization in guard cells revealed a relatively uniform distribution of cellulose in the open state and a more fibrillar pattern in the closed state, indicating that cellulose microfibrils undergo dynamic reorganization during stomatal movements. In cesa3(je5) mutants defective in cellulose synthesis and xxt1 xxt2 mutants lacking the hemicellulose xyloglucan, stomatal apertures, changes in guard cell length, and cellulose reorganization were aberrant during fusicoccin-induced stomatal opening or abscisic acid-induced stomatal closure, indicating that sufficient cellulose and xyloglucan are required for normal guard cell dynamics. Together, these results provide new insights into how guard cell walls allow stomata to function as responsive mediators of gas exchange at the plant surface.
Collapse
Affiliation(s)
- Yue Rui
- Department of Biology (Y.R., C.T.A.) and Center for Lignocellulose Structure and Formation (C.T.A.), Pennsylvania State University, University Park, Pennsylvania 16802
| | - Charles T Anderson
- Department of Biology (Y.R., C.T.A.) and Center for Lignocellulose Structure and Formation (C.T.A.), Pennsylvania State University, University Park, Pennsylvania 16802
| |
Collapse
|
8
|
Pysh LD. Two alleles of the AtCesA3 gene in Arabidopsis thaliana display intragenic complementation. AMERICAN JOURNAL OF BOTANY 2015; 102:1434-41. [PMID: 26391708 DOI: 10.3732/ajb.1500212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/13/2015] [Indexed: 05/03/2023]
Abstract
PREMISE OF THE STUDY Cellulose is the most abundant biomolecule on the planet, yet the mechanism by which it is synthesized by higher plants remains largely unknown. In Arabidopsis thaliana (L.) Heynh, synthesis of cellulose in the primary cell wall requires three different cellulose synthase genes (AtCesA1, AtCesA3, and AtCesA6-related genes [AtCesA2, AtCesA5, and AtCesA6]). The multiple response expansion1 (mre1) mutant contains a hypomorphic AtCesA3 allele that results in significantly shorter, expanded roots. Crosses between mre1 and another allele of AtCesA3 (constitutive expression of VSP1, cev1) yielded an F1 with roots considerably longer and thinner than either parent, suggesting intragenic complementation. The F2 generation resulting from self-crossing these F1 showed three different root phenotypes: roots like mre1, roots like cev1, and roots like the F1. METHODS The segregation patterns of the three root phenotypes in multiple F2 and F3 generations were determined. Multiple characteristics of the roots and shoots were analyzed both qualitatively and quantitatively at different developmental stages, both on plates and on soil. KEY RESULTS The trans-heterozygous plants differed significantly from the parental mre1 and cev1 lines. CONCLUSIONS The two alleles display intragenic complementation. A classic genetic interpretation of these results would suggest that cellulose synthesis requires homo-multimerization of cellulose synthase monomers.
Collapse
Affiliation(s)
- Leonard D Pysh
- Roanoke College, Department of Biology, 221 College Lane, Salem, Virginia 24153 USA
| |
Collapse
|
9
|
Abstract
Cellulose is the most abundant biopolymer on Earth, and certain organisms from bacteria to plants and animals synthesize cellulose as an extracellular polymer for various biological functions. Humans have used cellulose for millennia as a material and an energy source, and the advent of a lignocellulosic fuel industry will elevate it to the primary carbon source for the burgeoning renewable energy sector. Despite the biological and societal importance of cellulose, the molecular mechanism by which it is synthesized is now only beginning to emerge. On the basis of recent advances in structural and molecular biology on bacterial cellulose synthases, we review emerging concepts of how the enzymes polymerize glucose molecules, how the nascent polymer is transported across the plasma membrane, and how bacterial cellulose biosynthesis is regulated during biofilm formation. Additionally, we review evolutionary commonalities and differences between cellulose synthases that modulate the nature of the cellulose product formed.
Collapse
Affiliation(s)
- Joshua T. McNamara
- Center for Membrane Biology, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
| | - Jacob L.W. Morgan
- Center for Membrane Biology, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
| | - Jochen Zimmer
- Center for Membrane Biology, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908
| |
Collapse
|
10
|
Slabaugh E, Sethaphong L, Xiao C, Amick J, Anderson CT, Haigler CH, Yingling YG. Computational and genetic evidence that different structural conformations of a non-catalytic region affect the function of plant cellulose synthase. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:6645-53. [PMID: 25262226 PMCID: PMC4246192 DOI: 10.1093/jxb/eru383] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The β-1,4-glucan chains comprising cellulose are synthesized by cellulose synthases in the plasma membranes of diverse organisms including bacteria and plants. Understanding structure-function relationships in the plant enzymes involved in cellulose synthesis (CESAs) is important because cellulose is the most abundant component in the plant cell wall, a key renewable biomaterial. Here, we explored the structure and function of the region encompassing transmembrane helices (TMHs) 5 and 6 in CESA using computational and genetic tools. Ab initio computational structure prediction revealed novel bi-modal structural conformations of the region between TMH5 and 6 that may affect CESA function. Here we present our computational findings on this region in three CESAs of Arabidopsis thaliana (AtCESA1, 3, and 6), the Atcesa3(ixr1-2) mutant, and a novel missense mutation in AtCESA1. A newly engineered point mutation in AtCESA1 (Atcesa1(F954L) ) that altered the structural conformation in silico resulted in a protein that was not fully functional in the temperature-sensitive Atcesa1(rsw1-1) mutant at the restrictive temperature. The combination of computational and genetic results provides evidence that the ability of the TMH5-6 region to adopt specific structural conformations is important for CESA function.
Collapse
Affiliation(s)
- Erin Slabaugh
- Department of Crop Science and Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Latsavongsakda Sethaphong
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Chaowen Xiao
- Department of Biology, the Pennsylvania State University, University Park, PA 16802, USA
| | - Joshua Amick
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Charles T Anderson
- Department of Biology, the Pennsylvania State University, University Park, PA 16802, USA
| | - Candace H Haigler
- Department of Crop Science and Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC 27695, USA
| | - Yaroslava G Yingling
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| |
Collapse
|
11
|
Li S, Bashline L, Lei L, Gu Y. Cellulose synthesis and its regulation. THE ARABIDOPSIS BOOK 2014; 12:e0169. [PMID: 24465174 PMCID: PMC3894906 DOI: 10.1199/tab.0169] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Cellulose, the most abundant biopolymer synthesized on land, is made of linear chains of ß (1-4) linked D-glucose. As a major structural component of the cell wall, cellulose is important not only for industrial use but also for plant growth and development. Cellulose microfibrils are tethered by other cell wall polysaccharides such as hemicellulose, pectin, and lignin. In higher plants, cellulose is synthesized by plasma membrane-localized rosette cellulose synthase complexes. Despite the recent advances using a combination of molecular genetics, live cell imaging, and spectroscopic tools, many aspects of the cellulose synthesis remain a mystery. In this chapter, we highlight recent research progress towards understanding the mechanism of cellulose synthesis in Arabidopsis.
Collapse
Affiliation(s)
- Shundai Li
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
| | - Logan Bashline
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
| | - Lei Lei
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
| | - Ying Gu
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802
- Address correspondence to
| |
Collapse
|
12
|
Abstract
A 3D atomistic model of a plant cellulose synthase (CESA) has remained elusive despite over forty years of experimental effort. Here, we report a computationally predicted 3D structure of 506 amino acids of cotton CESA within the cytosolic region. Comparison of the predicted plant CESA structure with the solved structure of a bacterial cellulose-synthesizing protein validates the overall fold of the modeled glycosyltransferase (GT) domain. The coaligned plant and bacterial GT domains share a six-stranded β-sheet, five α-helices, and conserved motifs similar to those required for catalysis in other GT-2 glycosyltransferases. Extending beyond the cross-kingdom similarities related to cellulose polymerization, the predicted structure of cotton CESA reveals that plant-specific modules (plant-conserved region and class-specific region) fold into distinct subdomains on the periphery of the catalytic region. Computational results support the importance of the plant-conserved region and/or class-specific region in CESA oligomerization to form the multimeric cellulose-synthesis complexes that are characteristic of plants. Relatively high sequence conservation between plant CESAs allowed mapping of known mutations and two previously undescribed mutations that perturb cellulose synthesis in Arabidopsis thaliana to their analogous positions in the modeled structure. Most of these mutation sites are near the predicted catalytic region, and the confluence of other mutation sites supports the existence of previously undefined functional nodes within the catalytic core of CESA. Overall, the predicted tertiary structure provides a platform for the biochemical engineering of plant CESAs.
Collapse
|