scholarly journals The Importance of the Enzyme Sucrose Synthase for Cell Wall Synthesis in Plants

1994 ◽  
Author(s):  
Deborah P. Delmer ◽  
Prem S. Chourey
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Cotton Seed ◽  
Sucrose Synthase ◽  
Starch Synthesis ◽  
Endosperm Development ◽  
Current Evidence ◽  
Cell Wall Synthesis ◽  
Maize Endosperm ◽  
Callose Deposition

The goal of this work was to understand the role of the enzyme sucrose synthase (SuSy) in synthesis of cellulose and callose in plants. The work resulting from the this grant leads to a number of conclusions. SuSy clearly plays diverse roles in carbon metabolism. It can associate with the plasma membrane of cells undergoing rapid cellulose deposition, such as cotton fibers, developing maize endosperm, gravistimulated pulvini, and transfer cells of the cotton seed. It is also concentrated at sites of high callose deposition (tapetal cells; cell plates). When SuSy levels are lowered by mutation or by anti-sense technology, cell walls undergo degeneration (maize endosperm) and show reduced levels of cellulose (potato tubers). In sum, our evidence has very much strengthened the concept that SuSy does function in the plasma membrane to channel carbon from sucrose via UDP-glucose to glucan synthase complexes. Soluble SuSy also clearly plays a role in providing carbon for starch synthesis and respiration. Surprisingly, we found that the cotton seed is one unique case where SuSy apparently does not play a role in starch synthesis. Current evidence in sum suggests that no specific SuSy gene encodes the membrane-associated form, although in maize the SS 1 form of SuSy may be most important for cell wall synthesis in the early stages of endosperm development. Work is still in progress to determine what does control membrane localization - and the current evidence we have favors a role for Ca2+, and possibly also protein phosphorylation by differentially regulated protein kinases. Finally, we have discovered for the first time, a major new family of genes that encode the catalytic subunit of the cellulose synthase of plants - a result that has been widely cited and opens many new approaches for the study of this important plant function.

scholarly journals Analysis of Phenotypic Characteristics and Sucrose Metabolism in the Roots of Raphanus sativus L.

2021 ◽  
Vol 12 ◽  
Author(s):  
Ji-Nam Kang ◽  
Jung Sun Kim ◽  
Si Myung Lee ◽  
So Youn Won ◽  
Mi-Suk Seo ◽  
...  
Keyword(s):  
Cell Wall ◽  
Raphanus Sativus ◽  
Sugar Content ◽  
Starch Synthesis ◽  
Sucrose Metabolism ◽  
Sucrose Content ◽  
Cell Wall Synthesis ◽  
Genes Encoding ◽  
Apoplastic Pathway ◽  
Positive Correlation Coefficient

The taproot of radish (Raphanus sativus L.) is an important sink organ; it is morphologically diverse and contains large amounts of secondary metabolites. Sucrose metabolism is believed to be important in the development of sink organs. We measured the amounts of glucose, fructose, and sucrose in the roots of sixty three radish accessions and analyzed the association between the sugar content and the root phenotype. Fructose content correlated with the root color and length characteristics, glucose was the most abundant sugar in the roots, and the sucrose content was very low, compared to that of the hexoses in most of the accessions. Expression analysis of the genes involved in sucrose metabolism, transportation, starch synthesis, and cell wall synthesis was performed through RNA sequencing. The genes encoding sucrose synthases (SUSY) and the enzymes involved in the synthesis of cellulose were highly expressed, indicating that SUSY is involved in cell wall synthesis in radish roots. The positive correlation coefficient (R) between the sucrose content and the expression of cell wall invertase and sugar transporter proteins suggest that hexose accumulation could occur through the apoplastic pathway in radish roots. A positive R score was also obtained when comparing the expression of genes encoding SUSY and fructokinase (FK), suggesting that the fructose produced by SUSY is mostly phosphorylated by FK. In addition, we concluded that sucrose was the most metabolized sugar in radish roots.

scholarly journals The Sur7 Protein Regulates Plasma Membrane Organization and Prevents Intracellular Cell Wall Growth inCandida albicans

2008 ◽  
Vol 19 (12) ◽  
pp. 5214-5225 ◽  
Author(s):  
Francisco J. Alvarez ◽  
Lois M. Douglas ◽  
Adam Rosebrock ◽  
James B. Konopka
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Transmembrane Domain ◽  
Antifungal Drugs ◽  
Membrane Domains ◽  
Membrane Organization ◽  
Cell Wall Synthesis ◽  
Animal Cells ◽  
Drugs Analysis ◽  
Wall Growth

The Candida albicans plasma membrane plays important roles in cell growth and as a target for antifungal drugs. Analysis of Ca-Sur7 showed that this four transmembrane domain protein localized to stable punctate patches, similar to the plasma membrane subdomains known as eisosomes or MCC that were discovered in S. cerevisiae. The localization of Ca-Sur7 depended on sphingolipid synthesis. In contrast to S. cerevisiae, a C. albicans sur7Δ mutant displayed defects in endocytosis and morphogenesis. Septins and actin were mislocalized, and cell wall synthesis was very abnormal, including long projections of cell wall into the cytoplasm. Several phenotypes of the sur7Δ mutant are similar to the effects of inhibiting β-glucan synthase, suggesting that the abnormal cell wall synthesis is related to activation of chitin synthase activity seen under stress conditions. These results expand the roles of eisosomes by demonstrating that Sur7 is needed for proper plasma membrane organization and cell wall synthesis. A conserved Cys motif in the first extracellular loop of fungal Sur7 proteins is similar to a characteristic motif of the claudin proteins that form tight junctions in animal cells, suggesting a common role for these tetraspanning membrane proteins in forming specialized plasma membrane domains.

scholarly journals A Systematic Approach to Identify Recycling Endocytic Cargo Depending on the GARP Complex

2018 ◽  
Author(s):  
Sebastian Eising ◽  
Lisa Thiele ◽  
Florian Fröhlich
Keyword(s):  
Mass Spectrometry ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Lipid Composition ◽  
Systematic Approach ◽  
Endocytic Pathway ◽  
Cell Wall Synthesis ◽  
Dependent Process ◽  
Garp Complex

AbstractProteins and lipids of the plasma membrane underlie constant remodeling via a combination of the secretory- and the endocytic pathway. In the yeast endocytic pathway, cargo is sorted for recycling to the plasma membrane or degradation in vacuoles. In a previous paper we have shown a role for the GARP complex in sphingolipid sorting and homeostasis (Fröhlich et al. 2015). However, the majority of cargo sorted in a GARP dependent process remain largely unknown. Here we use auxin induced degradation of GARP combined with mass spectrometry based vacuolar proteomics and lipidomics to show that recycling of two specific groups of proteins, the amino-phospholipid flippases and cell wall synthesis proteins depends on a functional GARP complex. Our results suggest that mis-sorting of flippases and remodeling of the lipid composition are the first occurring defects in GARP mutants. Our assay can be adapted to systematically map cargo of the entire endocytic pathway.

scholarly journals A Novel Isoform of Sucrose Synthase Is Targeted to the Cell Wall during Secondary Cell Wall Synthesis in Cotton Fiber

2011 ◽  
Vol 157 (1) ◽  
pp. 40-54 ◽  
Author(s):  
Elizabeth Brill ◽  
Michel van Thournout ◽  
Rosemary G. White ◽  
Danny Llewellyn ◽  
Peter M. Campbell ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cotton Fiber ◽  
Sucrose Synthase ◽  
Secondary Cell Wall ◽  
Cell Wall Synthesis ◽  
Secondary Cell Wall Synthesis

scholarly journals The MARVEL Domain Protein Nce102 Regulates Actin Organization and Invasive Growth of Candida albicans

mBio ◽  
2013 ◽  
Vol 4 (6) ◽  
Author(s):  
Lois M. Douglas ◽  
Hong X. Wang ◽  
James B. Konopka
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Plasma Membrane ◽  
Virulence Factors ◽  
Fungal Pathogen ◽  
Invasive Growth ◽  
Cell Wall Synthesis ◽  
Content Type ◽  
Actin Organization ◽  
Domain Protein

ABSTRACTInvasive growth of the fungal pathogenCandida albicansinto tissues promotes disseminated infections in humans. The plasma membrane is essential for pathogenesis because this important barrier mediates morphogenesis and invasive growth, as well as secretion of virulence factors, cell wall synthesis, nutrient import, and other processes. Previous studies showed that the Sur7 tetraspan protein that localizes to MCC (membrane compartment occupied by Can1)/eisosome subdomains of the plasma membrane regulates a broad range of key functions, including cell wall synthesis, morphogenesis, and resistance to copper. Therefore, a distinct tetraspan protein found in MCC/eisosomes, Nce102, was investigated. Nce102 belongs to the MARVEL domain protein family, which is implicated in regulating membrane structure and function. Deletion ofNCE102did not cause the broad defects seen insur7Δcells. Instead, thence102Δmutant displayed a unique phenotype in that it was defective in forming hyphae and invading low concentrations of agar but could invade well in higher agar concentrations. This phenotype was likely due to a defect in actin organization that was observed by phalloidin staining. In support of this, the invasive growth defect of abni1Δmutant that mislocalizes actin due to lack of the Bni1 formin was also reversed at high agar concentrations. This suggests that a denser matrix provides a signal that compensates for the actin defects. Thence102Δmutant displayed decreased virulence and formed abnormal hyphae in mice. These studies identify novel ways that Nce102 and the physical environment surroundingC. albicansregulate morphogenesis and pathogenesis.IMPORTANCEThe plasma membrane promotes virulence of the human fungal pathogenCandida albicansby acting as a protective barrier around the cell and mediating dynamic activities, such as morphogenesis, cell wall synthesis, secretion of virulence factors, and nutrient uptake. To better understand how the plasma membrane contributes to virulence, we analyzed a set of eight genes encoding MARVEL family proteins that are predicted to function in membrane organization. Interestingly, deletion of one gene,NCE102, caused a strong defect in formation of invasive hyphal growthin vitroand decreased virulence in mice. Thence102Δmutant cells showed defects in actin organization that underlie the morphogenesis defect, since mutation of a known regulator of actin organization caused a similar defect. These studies identify a novel way in which the plasma membrane regulates the actin cytoskeleton and contributes to pathogenesis.

scholarly journals The Candida albicans Sur7 Protein Is Needed for Proper Synthesis of the Fibrillar Component of the Cell Wall That Confers Strength

2010 ◽  
Vol 10 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Hong X. Wang ◽  
Lois M. Douglas ◽  
Vishukumar Aimanianda ◽  
Jean-Paul Latgé ◽  
James B. Konopka
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Plasma Membrane ◽  
Wall Structure ◽  
Cell Wall Synthesis ◽  
Calcofluor White ◽  
Content Type ◽  
Membrane Compartment ◽  
Fibrillar Component ◽  
And Function

ABSTRACTTheCandida albicansplasma membrane plays important roles in interfacing with the environment, morphogenesis, and cell wall synthesis. The role of the Sur7 protein in cell wall structure and function was analyzed, since previous studies showed that this plasma membrane protein is needed to prevent abnormal intracellular growth of the cell wall. Sur7 localizes to stable patches in the plasma membrane, known as MCC (membrane compartment occupied by Can1), that are associated with eisosome proteins. Thesur7Δ mutant cells displayed increased sensitivity to factors that exacerbate cell wall defects, such as detergent (SDS) and the chitin-binding agents calcofluor white and Congo red. Thesur7Δ cells were also slightly more sensitive to inhibitors that block the synthesis of cell wall chitin (nikkomycin Z) and β-1,3-glucan (caspofungin). In contrast, Fmp45, a paralog of Sur7 that also localizes to punctate plasma membrane patches, did not have a detectable role in cell wall synthesis. Chemical analysis of cell wall composition demonstrated thatsur7Δ cells contain decreased levels of β-glucan, a glucose polymer that confers rigidity on the cell wall. Consistent with this,sur7Δ cells were more sensitive to lysis, which could be partially rescued by increasing the osmolarity of the medium. Interestingly, Sur7 is present in static patches, whereas β-1,3-glucan synthase is mobile in the plasma membrane and is often associated with actin patches. Thus, Sur7 may influence β-glucan synthesis indirectly, perhaps by altering the functions of the cell signaling components that localize to the MCC and eisosome domains.

scholarly journals A systematic approach to identify recycling endocytic cargo depending on the GARP complex

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Sebastian Eising ◽  
Lisa Thiele ◽  
Florian Fröhlich
Keyword(s):  
Mass Spectrometry ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Lipid Composition ◽  
Systematic Approach ◽  
Endocytic Pathway ◽  
Cell Wall Synthesis ◽  
Dependent Process ◽  
Garp Complex

Proteins and lipids of the plasma membrane underlie constant remodeling via a combination of the secretory- and the endocytic pathway. In the yeast endocytic pathway, cargo is sorted for recycling to the plasma membrane or degradation in vacuoles. Previously we have shown a role for the GARP complex in sphingolipid sorting and homeostasis (Fröhlich et al. 2015). However, the majority of cargo sorted in a GARP dependent process remain largely unknown. Here we use auxin induced degradation of GARP combined with mass spectrometry based vacuolar proteomics and lipidomics to show that recycling of two specific groups of proteins, the amino-phospholipid flippases and cell wall synthesis proteins depends on a functional GARP complex. Our results suggest that mis-sorting of flippases and remodeling of the lipid composition are the first occurring defects in GARP mutants. Our assay can be adapted to systematically map cargo of the entire endocytic pathway.

Microanatomy of the Periplasm of Bacillus Licheniformis

1971 ◽  
Vol 29 ◽  
pp. 262-263
Author(s):  
B.K. Ghosh
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Bacillus Licheniformis ◽  
External Environment ◽  
Permeability Barrier ◽  
Periplasmic Space ◽  
Modified Technique ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.

SEM and fluorescence imaging of callose deposition in root hair tips and suspension cultures of Streptanthus tortuosus

1990 ◽  
Vol 48 (3) ◽  
pp. 698-699
Author(s):  
K.S. Walters ◽  
R.D. Sjolund ◽  
K.C. Moore
Keyword(s):  
Cell Wall ◽  
Root Hair ◽  
Cultured Cells ◽  
Root Hairs ◽  
Callus Cultures ◽  
Callose Deposition ◽  
Culture Cells ◽  
Wall Structures ◽  
Ultraviolet Illumination ◽  
Callose Formation

Callose, B-1,3-glucan, a component of cell walls, is associated with phloem sieve plates, plasmodesmata, and other cell wall structures that are formed in response to wounding or infection. Callose reacts with aniline blue to form a fluorescent complex that can be recognized in the light microscope with ultraviolet illumination. We have identified callose in cell wall protuberances that are formed spontaneously in suspension-cultured cells of S. tortuosus and in the tips of root hairs formed in sterile callus cultures of S. tortuosus. Callose deposits in root hairs are restricted to root hair tips which appear to be damaged or deformed, while normal root hair tips lack callose deposits. The callose deposits found in suspension culture cells are restricted to regions where unusual outgrowths or protuberances are formed on the cell surfaces, specifically regions that are the sites of new cell wall formation.Callose formation has been shown to be regulated by intracellular calcium levels.

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