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Chitin Synthesis in Yeast: A Matter of Trafficking. Int J Mol Sci 2022; 23:ijms232012251. [PMID: 36293107 PMCID: PMC9603707 DOI: 10.3390/ijms232012251] [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: 09/22/2022] [Revised: 10/11/2022] [Accepted: 10/11/2022] [Indexed: 01/24/2023] Open
Abstract
Chitin synthesis has attracted scientific interest for decades as an essential part of fungal biology and for its potential as a target for antifungal therapies. While this interest remains, three decades ago, pioneering molecular studies on chitin synthesis regulation identified the major chitin synthase in yeast, Chs3, as an authentic paradigm in the field of the intracellular trafficking of integral membrane proteins. Over the years, researchers have shown how the intracellular trafficking of Chs3 recapitulates all the steps in the intracellular trafficking of integral membrane proteins, from their synthesis in the endoplasmic reticulum to their degradation in the vacuole. This trafficking includes specific mechanisms for sorting in the trans-Golgi network, regulated endocytosis, and endosomal recycling at different levels. This review summarizes the work carried out on chitin synthesis regulation, mostly focusing on Chs3 as a molecular model to study the mechanisms involved in the control of the intracellular trafficking of proteins.
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Abdel-Mohsen A, Abdel-Rahman R, Kubena I, Kobera L, Spotz Z, Zboncak M, Prikryl R, Brus J, Jancar J. Chitosan-glucan complex hollow fibers reinforced collagen wound dressing embedded with aloe vera. Part I: Preparation and characterization. Carbohydr Polym 2020; 230:115708. [DOI: 10.1016/j.carbpol.2019.115708] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 11/27/2019] [Accepted: 12/05/2019] [Indexed: 12/22/2022]
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Bogdanova OI, Chvalun SN. Polysaccharide-based natural and synthetic nanocomposites. POLYMER SCIENCE SERIES A 2018. [DOI: 10.1134/s0965545x16050047] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Bartnicki-Garcia S. The evolution of fungal morphogenesis, a personal account. Mycologia 2017; 108:475-84. [DOI: 10.3852/15-272] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/28/2016] [Indexed: 01/11/2023]
Affiliation(s)
- Salomon Bartnicki-Garcia
- Departamento de Microbiología, Centro de Investigación Científica y Educación Superior de Ensenada, CICESE, Ensenada B.C. 22860 Mexico
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Heterologous expression of an active chitin synthase from Rhizopus oryzae. Fungal Genet Biol 2016; 97:10-17. [PMID: 27777036 DOI: 10.1016/j.fgb.2016.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 10/13/2016] [Accepted: 10/20/2016] [Indexed: 11/21/2022]
Abstract
Chitin synthases are highly important enzymes in nature, where they synthesize structural components in species belonging to different eukaryotic kingdoms, including kingdom Fungi. Unfortunately, their structure and the molecular mechanism of synthesis of their microfibrilar product remain largely unknown, probably because no fungal active chitin synthases have been isolated, possibly due to their extreme hydrophobicity. In this study we have turned to the heterologous expression of the transcript from a small chitin synthase of Rhizopus oryzae (RO3G_00942, Chs1) in Escherichia coli. The enzyme was active, but accumulated mostly in inclusion bodies. High concentrations of arginine or urea solubilized the enzyme, but their dilution led to its denaturation and precipitation. Nevertheless, use of urea permitted the purification of small amounts of the enzyme. The properties of Chs1 (Km, optimum temperature and pH, effect of GlcNAc) were abnormal, probably because it lacks the hydrophobic transmembrane regions characteristic of chitin synthases. The product of the enzyme showed that, contrasting with chitin made by membrane-bound Chs's and chitosomes, was only partially in the form of short microfibrils of low crystallinity. This approach may lead to future developments to obtain active chitin synthases that permit understanding their molecular mechanism of activity, and microfibril assembly.
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Bartnicki-Garcia S. Manfred Girbardt and Charles Bracker: outstanding pioneers in fungal microscopy. Nat Rev Microbiol 2014; 13:52-7. [DOI: 10.1038/nrmicro3379] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Affiliation(s)
- Meritxell Riquelme
- Departamento de Microbiología, Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE), Ensenada, Baja California, Mexico 22860;
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PKC1 is essential for protection against both oxidative and nitrosative stresses, cell integrity, and normal manifestation of virulence factors in the pathogenic fungus Cryptococcus neoformans. EUKARYOTIC CELL 2008; 7:1685-98. [PMID: 18689526 DOI: 10.1128/ec.00146-08] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cell wall integrity is crucial for fungal growth, survival, and pathogenesis. Responses to environmental stresses are mediated by the highly conserved Pkc1 protein and its downstream components. In this study, we demonstrate that both oxidative and nitrosative stresses activate the PKC1 cell integrity pathway in wild-type cells, as measured by phosphorylation of Mpk1, the terminal protein in the PKC1 phosphorylation cascade. Furthermore, deletion of PKC1 shows that this gene is essential for defense against both oxidative and nitrosative stresses; however, other genes involved directly in the PKC1 pathway are dispensable for protection against these stresses. This suggests that Pkc1 may have multiple and alternative functions other than activating the mitogen-activated protein kinase cascade from a "top-down" approach. Deletion of PKC1 also causes osmotic instability, temperature sensitivity, severe sensitivity to cell wall-inhibiting agents, and alterations in capsule and melanin. Furthermore, the vital cell wall components chitin and its deacetylated form chitosan appear to be mislocalized in a pkc1Delta strain, although this mutant contains wild-type levels of both of these polymers. These data indicate that loss of Pkc1 has pleiotropic effects because it is central to many functions either dependent on or independent of PKC1 pathway activation. Notably, this is the first time that Pkc1 has been implicated in protection against nitrosative stress in any organism.
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Schönitzer V, Weiss IM. The structure of mollusc larval shells formed in the presence of the chitin synthase inhibitor Nikkomycin Z. BMC STRUCTURAL BIOLOGY 2007; 7:71. [PMID: 17986326 PMCID: PMC2241824 DOI: 10.1186/1472-6807-7-71] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Accepted: 11/06/2007] [Indexed: 11/10/2022]
Abstract
BACKGROUND Chitin self-assembly provides a dynamic extracellular biomineralization interface. The insoluble matrix of larval shells of the marine bivalve mollusc Mytilus galloprovincialis consists of chitinous material that is distributed and structured in relation to characteristic shell features. Mollusc shell chitin is synthesized via a complex transmembrane chitin synthase with an intracellular myosin motor domain. RESULTS Enzymatic mollusc chitin synthesis was investigated in vivo by using the small-molecule drug NikkomycinZ, a structural analogue to the sugar donor substrate UDP-N-acetyl-D-glucosamine (UDP-GlcNAc). The impact on mollusc shell formation was analyzed by binocular microscopy, polarized light video microscopy in vivo, and scanning electron microscopy data obtained from shell material formed in the presence of NikkomycinZ. The partial inhibition of chitin synthesis in vivo during larval development by NikkomycinZ (5 microM - 10 microM) dramatically alters the structure and thus the functionality of the larval shell at various growth fronts, such as the bivalve hinge and the shell's edges. CONCLUSION Provided that NikkomycinZ mainly affects chitin synthesis in molluscs, the presented data suggest that the mollusc chitin synthase fulfils an important enzymatic role in the coordinated formation of larval bivalve shells. It can be speculated that chitin synthesis bears the potential to contribute via signal transduction pathways to the implementation of hierarchical patterns into chitin mineral-composites such as prismatic, nacre, and crossed-lamellar shell types.
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Affiliation(s)
- Veronika Schönitzer
- Lehrstuhl Biochemie I, Universität Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
| | - Ingrid M Weiss
- Lehrstuhl Biochemie I, Universität Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany
- INM – Leibniz-Institut für Neue Materialien gGmbH, Campus D2 2, 66123 Saarbrücken, Germany
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Riquelme M, Bartnicki-García S, González-Prieto JM, Sánchez-León E, Verdín-Ramos JA, Beltrán-Aguilar A, Freitag M. Spitzenkorper localization and intracellular traffic of green fluorescent protein-labeled CHS-3 and CHS-6 chitin synthases in living hyphae of Neurospora crassa. EUKARYOTIC CELL 2007; 6:1853-64. [PMID: 17644657 PMCID: PMC2043383 DOI: 10.1128/ec.00088-07] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The subcellular location and traffic of two selected chitin synthases (CHS) from Neurospora crassa, CHS-3 and CHS-6, labeled with green fluorescent protein (GFP), were studied by high-resolution confocal laser scanning microscopy. While we found some differences in the overall distribution patterns and appearances of CHS-3-GFP and CHS-6-GFP, most features were similar and were observed consistently. At the hyphal apex, fluorescence congregated into a conspicuous single body corresponding to the location of the Spitzenkörper (Spk). In distal regions (beyond 40 microm from the apex), CHS-GFP revealed a network of large endomembranous compartments that was predominantly comprised of irregular tubular shapes, while some compartments were distinctly spherical. In the distal subapex (20 to 40 microm from the apex), fluorescence was observed in globular bodies that appeared to disintegrate into vesicles as they advanced forward until reaching the proximal subapex (5 to 20 microm from the apex). CHS-GFP was also conspicuously found delineating developing septa. Analysis of fluorescence recovery after photobleaching suggested that the fluorescence of the Spk originated from the advancing population of microvesicles (chitosomes) in the subapex. The inability of brefeldin A to interfere with the traffic of CHS-containing microvesicles and the lack of colocalization of CHS-GFP with the endoplasmic reticulum (ER)-Golgi body fluorescent dyes lend support to the idea that CHS proteins are delivered to the cell surface via an alternative route distinct from the classical ER-Golgi body secretory pathway.
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Affiliation(s)
- Meritxell Riquelme
- Department of Microbiology, Center for Scientific Research and Higher Education of Ensenada (CICESE), San Ysidro, CA 92143-0222, USA.
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Lai-Kee-Him J, Chanzy H, Müller M, Putaux JL, Imai T, Bulone V. In vitro versus in vivo cellulose microfibrils from plant primary wall synthases: structural differences. J Biol Chem 2002; 277:36931-9. [PMID: 12145282 DOI: 10.1074/jbc.m203530200] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Detergent extracts of microsomal fractions from suspension cultured cells of Rubus fruticosus (blackberry) were tested for their ability to synthesize in vitro sizable quantities of cellulose from UDP-glucose. Both Brij 58 and taurocholate were effective and yielded a substantial percentage of cellulose microfibrils together with (1-->3)-beta-d-glucan (callose). The taurocholate extracts, which did not require the addition of Mg(2+), were the most efficient, yielding roughly 20% of cellulose. This cellulose was characterized after callose removal by methylation analysis, electron microscopy, and electron and x-ray synchrotron diffractions; its resistance toward the acid Updegraff reagent was also evaluated. The cellulose microfibrils synthesized in vitro had the same diameter as the endogenous microfibrils isolated from primary cell walls. Both polymers diffracted as cellulose IV(I), a disorganized form of cellulose I. Besides these similarities, the in vitro microfibrils had a higher perfection and crystallinity as well as a better resistance toward the Updegraff reagent. These differences can be attributed to the mode of synthesis of the in vitro microfibrils that are able to grow independently in a neighbor-free environment, as opposed to the cellulose in the parent cell walls where new microfibrils have to interweave with the already laid polymers, with the result of a number of structural defects.
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Affiliation(s)
- Joséphine Lai-Kee-Him
- Centre de Recherches sur les Macromolécules Végétales (CERMAV-UPR CNRS 5301), Joseph Fourier University of Grenoble, B.P. 53, 38041 Grenoble cedex 9, France
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Sugiyama J, Boisset C, Hashimoto M, Watanabe T. Molecular directionality of beta-chitin biosynthesis. J Mol Biol 1999; 286:247-55. [PMID: 9931263 DOI: 10.1006/jmbi.1998.2458] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The molecular packing in beta-chitin unit cells was experimentally determined by a combination of unidirectional degradation by Bacillus circulans chitinase A1 and microdiffraction electron crystallography using highly crystalline beta-chitin microfibrils from the protective tubes secreted by Lamellibrachia satsuma. The mode of chain packing was found to be identical with that of the previously published crystal model for beta-chitin, despite a controversial definition of the unit cell parameters. Here, a "parallel-down" packing was determined, where the reducing ends of chains point in an opposite direction to the crystallographic c-axis. Microdiffraction analyses of nascent beta-chitin microfibrils generated from diatom Thalassiosira sp. showed that the c-axis of the crystal was directed toward the diatoms, and therefore the reducing end of a growing chain pointed away from the locus of biosynthesis. This mechanism agreed well with what we found recently in the cellulose biosynthesis system, and provides strong evidence that the polymerization by the processive glycosyl transferase takes place at the non-reducing end of the growing polysaccharide chains.
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Affiliation(s)
- J Sugiyama
- Wood Research Institute, Kyoto University, Uji, Kyoto, 611-0011, Japan.
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Ziman M, Chuang JS, Schekman RW. Chs1p and Chs3p, two proteins involved in chitin synthesis, populate a compartment of the Saccharomyces cerevisiae endocytic pathway. Mol Biol Cell 1996; 7:1909-19. [PMID: 8970154 PMCID: PMC276039 DOI: 10.1091/mbc.7.12.1909] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In Saccharomyces cerevisiae, the synthesis of chitin, a cell-wall polysaccharide, is temporally and spatially regulated with respect to the cell cycle and morphogenesis. Using immunological reagents, we found that steady-state levels of Chs1p and Chs3p, two chitin synthase enzymes, did not fluctuate during the cell cycle, indicating that they are not simply regulated by synthesis and degradation. Previous cell fractionation studies demonstrated that chitin synthase I activity (CSI) exists in a plasma membrane form and in intracellular membrane-bound particles called chitosomes. Chitosomes were proposed to act as a reservoir for regulated transport of chitin synthase enzymes to the division septum. We found that Chs1p and Chs3p resided partly in chitosomes and that this distribution was not cell cycle regulated. Pulse-chase cell fractionation experiments showed that chitosome production was blocked in an endocytosis mutant (end4-1), indicating that endocytosis is required for the formation or maintenance of chitosomes. Additionally, Ste2p, internalized by ligand-induced endocytosis, cofractionated with chitosomes, suggesting that these membrane proteins populate the same endosomal compartment. However, in contrast to Ste2p, Chs1p and Chs3p were not rapidly degraded, thus raising the possibility that the temporal and spatial regulation of chitin synthesis is mediated by the mobilization of an endosomal pool of chitin synthase enzymes.
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Affiliation(s)
- M Ziman
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, USA
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Abstract
Mucor dimorphism has interested microbiologists since the time of Pasteur. When deprived of oxygen, these fungi grow as spherical, multipolar budding yeasts. In the presence of oxygen, they propagate as branching coenocytic hyphae. The ease with which these morphologies can be manipulated in the laboratory, the diverse array of morphopoietic agents available, and the alternative developmental fates that can be elicited from a single cell type (the sporangiospore) make Mucor spp. a highly propitious system in which to study eukaryotic cellular morphogenesis. The composition and organization of the cell wall differ greatly in Mucor yeasts and hyphae. The deposition of new wall polymers is isodiametric in yeasts and apically polarized in hyphae. Current research has focused on the identity and control of enzymes participating in wall synthesis. An understanding of how the chitosome interacts with appropriate effectors, specific enzymes, and the plasma membrane to assemble chitin-chitosan microfibrils and to deposit them at the proper sites on the cell exterior will be critical to elucidating dimorphism. Several biochemical and physiological parameters have been reported to fluctuate in a manner that correlates with Mucor morphogenesis. The literature describing these has been reviewed critically with the intent of distinguishing between causal and casual connections. The advancement of molecular genetics has afforded powerful new tools that researchers have begun to exploit in the study of Mucor dimorphism. Several genes, some encoding products known to correlate with development in Mucor spp. or other fungi, have been cloned, sequenced, and examined for transcriptional activity during morphogenesis. Most have appeared in multiple copies displaying independent transcriptional control. Selective translation of stored mRNA molecules occurs during sporangiospore germination. Many other correlates of Mucor morphogenesis, presently described but not yet explained, should prove amenable to analysis by the emerging molecular technology.
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Affiliation(s)
- M Orlowski
- Department of Microbiology, Louisiana State University, Baton Rouge 70803
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Chitin synthetase from yeast-type cells ofMucor rouxii induced by malonic acid: a screen for antifungal agents and isolation of an active metabolite from an actinomycetes. World J Microbiol Biotechnol 1990; 6:163-70. [PMID: 24429989 DOI: 10.1007/bf01200937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/1989] [Accepted: 12/13/1989] [Indexed: 11/27/2022]
Abstract
In an aerobic medium malonic acid inducedMucor rouxii to produce yeast-type cells exclusively. Chitin synthetase in a cell-free extract from these yeast cells increased its activity upon standing at 28°C or when activated by trypsin. It was similar in stability to that from the yeast cells formed under an atmosphere of N2/CO2 (7∶3 v/v). By using the enzyme activity as a model screen, a competitive inhibitor of chitin synthetase has been isolated from the fermentation broth of an actinomycete isolate.
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Chitin. ACTA ACUST UNITED AC 1990. [DOI: 10.1016/b978-0-12-461012-5.50019-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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Ruiz-Herrera J, Sentandreu R. Fungal cell wall synthesis and assembly. CURRENT TOPICS IN MEDICAL MYCOLOGY 1989; 3:168-217. [PMID: 2688916 DOI: 10.1007/978-1-4612-3624-5_8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Lezica RP, Daleo GR, Dey PM. Lipid-Linked Sugars As Intermediates in The Biosynthesis of Complex Carbohydrates in Plants. Adv Carbohydr Chem Biochem 1987. [DOI: 10.1016/s0065-2318(08)60081-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Abstract
In this review, the cell envelope of the human pathogenic yeast Candida albicans includes the plasma membrane and the mannoproteins, enzymes, beta-glucans, and chitin of the wall. The organization of the wall is complex and ultrastructural studies show distinct "layers". Mannoprotein is distributed throughout the wall but is concentrated on the exterior surface and adjacent to the plasma membrane. The mannoproteins contain the antigenic determinants of the yeast cells. The major structural components of the wall are beta-1,3- and beta 1,6-glucans, and these two linkages are present in almost equal amounts. Chitin is concentrated at the bud scar, but small amounts are located over the entire wall where it appears to be linked to beta-1,6-glucan. Chemical bonding both within and between wall components confers rigidity on the wall and restricts movement of molecules into and out of the cell. Soluble enzymes are retained within the wall matrix, but a number of enzymes and proteins are excreted. The plasma membrane of C. albicans is similar to that isolated from other fungi and contains the proton pump ATPase and enzymes involved in biosynthesis of the wall such as chitin synthase and beta-1,3-glucan synthase.
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Affiliation(s)
- M G Shepherd
- Experimental Oral Biology Unit, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Martínez JP, Murgui A, Flores A, Sentandreu R. Subcellular fractionation of actively growing protoplasts of Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA 1984; 805:59-71. [PMID: 6383484 DOI: 10.1016/0167-4889(84)90037-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Cell homogenates obtained from partially regenerated Saccharomyces cerevisiae protoplasts were fractionated by a procedure using a combination of continuous and discontinuous sucrose gradients, under experimental conditions that minimize possible artifacts due to centrifugation and resuspension. At least five different membranous organelle fractions (plasma membrane, mitochondria, rough endoplasmic reticulum, smooth endoplasmic reticulum-like structures and small-sized particulated structures) were isolated. Subcellular fractions were characterized by assaying established marker enzymes. Radioactive labelled [(U-3H]uracil) ribosomes were also used as a further characterization criterion of the rough endoplasmic reticulum. Comparative SDS-polyacrylamide gel electrophoresis of the protein constituents of the isolated membrane-bound organelles suggest that the polypeptide pattern could also be used as an additional marker for some of these structures. Finally, subcellular distribution of chitin synthase was determined using this fractionation procedure, and two partially zymogenic enzyme pools (one inside the cell associated to particles which sediments at high speed, and the second one associated to the plasma membrane) were found.
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Berthe MC, Charpentier C, Lematre J, Bonaly R. Glucosamine and chitin accumulation in cell walls of the yeast Rhodotorula glutinis CBS 3044. Influence of culture conditions. Biochem Biophys Res Commun 1981; 100:1504-14. [PMID: 7197520 DOI: 10.1016/0006-291x(81)90689-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Abstract
Research on chitin as a marine resource is pointing to novel applications for this cellulose-like biopolymer. Discovery of nondegrading solvent systems has permitted the spinning of filaments, for example, for use as surgical sutures. New methods for preparing the bioactive alkyl glycoside of N-acetyl-D-glucosamine (the monomer unit of chitin) and a microcrystalline chitin has encouraged their use as promoters for growth of bifidobacteria and as an aid in digestion of high-lactose cheese whey by domestic animals. Chitin-protein complexes of several crustacean species show great variability in ratios of chitin to covalently bound protein and in residual protein in the "purified" chitins.
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Philippi ML, Parish RW. Changes in glucan synthetase activity and plasma membrane proteins during encystment of the cellular slime mold Polysphondylium pallidum. PLANTA 1981; 152:59-69. [PMID: 24302320 DOI: 10.1007/bf00384986] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/1980] [Accepted: 12/18/1980] [Indexed: 06/02/2023]
Abstract
The activity of glucan synthetase increased dramatically during encystment of Polysphondylium pallidum cells. The majority of activity was present in purified plasma membranes. Activity, measured as glucose incorporation from UDPG into NaOH-insoluble glucan, increased 30-40 fold in the membranes. Increases in activity within the cells preceded plasma membrane increases and the enzyme appeared to be rapidly transported to the plasma membrane. Intracellular activity was relatively low. When cells were incubated with UDPG and when phloretin was included to inhibit glucose uptake, no NaOH-insoluble glucan was synthesized. Hence, the UDPG-binding site was not exposed at the cell-surface. When the NaOH-insoluble glucan was digested with endo-β-1,4-glucanase the products were cellobiose and glucose. The glucan could also be precipitated from Schweizer's reagent with acetic acid. These results suggest that the glucan contained predominantly β-1,4-linkages and may be cellulose. Experiments with cycloheximide confirmed that protein synthesis was required for encystment. Labeling of cells with [1-(14)C]-acetate showed that the synthesis of certain plasma membrane proteins was developmentally regulated. A number of proteins (e.g., myosin heavy chains and actin) were synthesized during the lag phase and their synthesis was subsequently reduced or ceased altogether. Immediately prior to the commencement of cyst wall formation seven new plasma membrane proteins were synthesized. These proteins were not detected intracellularly, indicating rapid transfer to the plasma membrane. The possible relationship between the seven developmentally regulated proteins and a postulated "multi-enzyme-complex" involved in cellulose synthesis is discussed. Their synthesis may be related to the increase in particles in the outer leaflet of the plasma membrane observed during encystment with freeze-etching (G.W. Erdos and H.R. Hohl, 1980, Cytobios, 29, 7-16).
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Affiliation(s)
- M L Philippi
- Cytology, Plant Biology Institute, University of Zürich, Zollikerstraße 107, CH-8008, Zürich, Switzerland
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Barstow WE, Pommerville J. The ultrastructure of cell wall formation and of gamma particles during encystment of Allomyces macrogynus zoospores. Arch Microbiol 1980. [DOI: 10.1007/bf00406156] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Mayer RT, Chen AC, DeLoach JR. Characterization of a chitin synthase from the stable fly, Stomoxys calcitrans (L.). ACTA ACUST UNITED AC 1980. [DOI: 10.1016/0020-1790(80)90090-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Farach MC, Farach H, Mirkes PE. Control of development in Neurospora crassa: Nutrient requirements for conidial germ tube emergence, elongation, and metabolic activation. ACTA ACUST UNITED AC 1979. [DOI: 10.1016/s0147-5975(79)80049-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Herth W. The site of beta-chitin fibril formation in centric diatoms. II. The chitin-forming cytoplasmic structures. JOURNAL OF ULTRASTRUCTURE RESEARCH 1979; 68:16-27. [PMID: 458930 DOI: 10.1016/s0022-5320(79)90138-2] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Abstract
Purified, intact yeast plasma membranes were allowed to synthesize chitin, and the nascent chains of polysaccharide were observed either by the fluorescence produced with a brightener or by autoradiography. By both methods, it was concluded that the newly formed chitin emerged at many sites on each membrane. Thus, the synthetase that catalyzes chitin formation has a similar distribution. Since chitin synthetase is found mainly in a zymogen form, these results confirm the hypothesis that initiation of the chitinous primary septum of Saccharomyces occurs by localized activation of the uniformly distributed zymogen.
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37
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38
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Solubilization and partial purification of yeast chitin synthetase. Confirmation of the zymogenic nature of the enzyme. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)34736-1] [Citation(s) in RCA: 122] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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39
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Bartnicki-Garcia S, Bracker CE, Reyes E, Ruiz-Herrera J. Isolation of chitosomes from taxonomically diverse fungi and synthesis of chitin microfibrils in Vitro. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/s0147-5975(78)80031-0] [Citation(s) in RCA: 123] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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40
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Sensitivity of germinating spores of Mucor rouxii to chitosanase. Mycology 1977. [DOI: 10.1016/s0147-5975(77)80008-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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41
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Mares D, Vannini GL, Fasulo MP, Bruni A. Submicroscopic morphology of Trichophyton mentagrophytes grown at different temperatures. Mycopathologia 1977; 61:43-8. [PMID: 895831 DOI: 10.1007/bf00440757] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Several modifications were observed in Trichophyton mentagrophytes cultivated at 19 degrees and 37 degrees C, i.e. nine degrees below and above the optimum of 28 degrees C. The phenomena included inhibition of the growth rate, changes in the gross aspects of the cultures as well as of the microscopic and submicroscopic morphology of the hyphal cells. At the ultrastructural level, in particular, it was shown that, at the suboptimal temperature, although the organelle structure in both young and aged hyphal cells remained nearly unchanged, unusual bodies of probable storage significance and plasmalemmasomes were formed. At the supraoptimal temperature, the youngest cells showed a normal organization but were richer in glycogen clusters and enveloped by a cell wall thicker than the ones at the optimal condition. In the cells far from the apex, the endomembrane integrity was lost and consequently an autolytic activity occurred. Degradation phenomena were detectable also at cell wall level. The cytological changes observed were tentatively correlated with a possible different sensitivity of the membrane system at the experimented temperature conditions.
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42
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Ruiz-Herrera J, Lopez-Romero E, Bartnicki-Garcia S. Properties of chitin synthetase in isolated chitosomes from yeast cells of Mucor rouxii. J Biol Chem 1977. [DOI: 10.1016/s0021-9258(17)40394-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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43
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Herth W, Kuppel A, Schnepf E. Chitinous fibrils in the lorica of the flagellate chrysophyte Poteriochromonas stipitata (syn. Ochromonas malhamensis). J Biophys Biochem Cytol 1977; 73:311-21. [PMID: 858740 PMCID: PMC2109911 DOI: 10.1083/jcb.73.2.311] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Ordered microfibrils are formed on the membrane of the cytoplasmic tail of the alga Poteriochromonas after attachment to a substrate. The ultrastructure of native and extracted stalk fibrils was studied with electron microscope methods. In addition, the structural polysaccharide was characterized by hydrolyses, separation of the monomers by thin-layer chromatography, gas-liquid chromatography and amino acid analysis, and by X-ray diffraction. The alkali-resistant fibrils yielded mostly glucosamine upon extensive hydrolysis, and showed X-ray diffraction patterns similar to those of fugal chitin. It is concluded that the resistant core of the fibrils is chitinous.
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44
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Abstract
Phenethyl alcohol, m-cresol, and related compounds cause inhibition of germ tube formation in conidia of Neurospora crassa. Conidia continue to swell and form large spherical cells that are capable of multiple germ tube formation upon removal of inhibitor.
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45
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Bracker CE, Ruiz-Herrera J, Bartnicki-Garcia S. Structure and transformation of chitin synthetase particles (chitosomes) during microfibril synthesis in vitro. Proc Natl Acad Sci U S A 1976; 73:4570-4. [PMID: 1070006 PMCID: PMC431546 DOI: 10.1073/pnas.73.12.4570] [Citation(s) in RCA: 157] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The fine structure of isolated chitin synthetase (UDP-2-acetamido-2-deoxy-D-glucose:chitin 4-beta-acetamido-deoxyglucosyltransferase; EC 2-4-1-16) particles (chitosomes) from Mucor rouxii and the elaboration of chitin microfibrils were studied by electron microscopy. Chitosomes are spheroidal, but often polymorphic, structures, mostly 40-70 nm in diameter. Their appearance after negative staining varies. Some reveal internal granular structure enclosed by a shell measuring 6-12 nm thick; others do not show internal structure but have a pronounced depression of the external surface. In thin sections, isolated chitosomes appear as microvesicular structures with a tripartite shell 6.5-7.0 nm thick. Morphologically similar structures can be seen in intact cells of M. rouxii. Isolated chitosomes undergo a seemingly irreversible series of transformations when substrate and activators are added. The internal structure changes, and a coiled microfibril (fibroid) appears inside the chitosome. The shell of the chitosome is opened or shed, and an extended microfibril arises from the fibroid particle. During prolonged incubation, the fibroid coils become less common and extended microfibrils appear thicker. We regard the chitosome as the cytoplasmic container and conveyor of chitin synthetase en route to its destination at the cell surface. Isolated chitosomes are well suited for integrated ultrastructural-biochemical studies of microfibril biogenesis in vitro.
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46
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Wang MC, Bartnicki-Garcia S. Synthesis of beta-1,3-glucan microfibrils by a cell-free extract from Phytophthora cinnamomi. Arch Biochem Biophys 1976; 175:351-4. [PMID: 952521 DOI: 10.1016/0003-9861(76)90517-8] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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47
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López-Romero E, Ruiz-Herrara J. Synthesis of chitin by particulate preparations from Aspergillus flavus. Antonie Van Leeuwenhoek 1976; 42:261-76. [PMID: 10833 DOI: 10.1007/bf00394123] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell-free extracts from Aspergillus flavus catalyzed the synthesis of chitin from UDP-GlcNAc. Most of the activity was associated with membrane-rich fractions whereas no activity was detected in the cell walls. Chitin synthetase was activated by fungal acid proteases; animal and plant proteases destroyed it. Upon incubation at 0 C and 28 C chitin synthetase was inactivated, probably by the action of proteases present in the particulate preparations. Maximal activity was obtained at pH 6.6-7.1 and 15 C. Arrhenius plot showed a biphasic curve with the transition at 7 C. E values were 3300 Kcal/mole above this temperature and 15500 Kcal/mole below it. The enzyme was activated by GlcNAc and required a divalent metal, the most active being Mg++. By plotting v vs UDP-GlcNAc concentration a sigmoidal curve was obtained. Km calculated at high substrate concentrations was 20 mM. Chitin synthetase was competitively inhibited by polyoxin D (Ki 6.5 muM) and (Ki 1.35 mM), the latter giving complex kinetics.
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48
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Benítez T, Villa TG, Acha IG. Chemical and structural differences in mycelial and regeneration walls of trichoderma viride. Arch Microbiol 1975; 105:277-82. [PMID: 1190957 DOI: 10.1007/bf00447147] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
When incubated in Winge medium, protoplasts from Trichoderma viride obtained by treatment with Micromonospora chalcea or Streptomyces venezuelae RA lytic systems first synthesized an aberrant wall, different from the normal one; it was aseptate, larger and irregular in size and length. They then regenerated a new wall, similar to the original one from which they were liberated. Analysis showed that the wall polymers were mainly beta-(1-3) glucan, beta-(1-6) glucan and chitin in the normal walls, whereas chitin was absent in aberrant tubes. These results are discussed below together with electron micrographs of aberrant and normal walls.
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49
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Keenan TW, Morré DJ. Glycosyltransferases: do they exist on the surface membrane of mammalian cells? FEBS Lett 1975; 55:8-13. [PMID: 1095425 DOI: 10.1016/0014-5793(75)80944-6] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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50
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Ruiz-Herrera J, Sing VO, Van der Woude WJ, Bartnicki-Garcia S. Microfibril assembly by granules of chitin synthetase. Proc Natl Acad Sci U S A 1975; 72:2706-10. [PMID: 1058485 PMCID: PMC432839 DOI: 10.1073/pnas.72.7.2706] [Citation(s) in RCA: 77] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Purified preparations of chitin synthetase (EC 2.4.1.16; UDP-2-acetamido-2-deoxy-D-glucose:chitin 4-beta-acetamidodeoxyglucosyltransferase), capable of forming microfibrils in vitro, were isolated from yeast cells of Mucor rouxii. Chitin synthetase was obtained either by substrate-induced liberation of bound enzyme (54,000 x g pellet) or by isolation of unbound enzyme present in the 54,000 x g supernatant of a cell-free extract. Both preparations contained ellipsoidal granules from about 350 to 1000 A diameter. Many granules exhibited a marked depression. No typical unit membrane profiles appeared in thin sections of glutaraldehyde/OsO4-fixed samples. Upon incubation with substrate and activators, chitin microfibrils were produced. The microfibrils were often found intimately associated with granules. The most common configurations were: a microfibril with a granule at one end, or two microfibrils "arising" from the same granule. These findings lend support to the granule hypothesis for the elaboration of cell wall microfibrils by end-synthesis.
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