The Cell's Biological Rods and Ropes

MRS Bulletin ◽  
1999 ◽  
Vol 24 (10) ◽  
pp. 27-31 ◽  
Author(s):  
David Boal
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Chemical Composition ◽  
Intermediate Filaments ◽  
Plant Cells ◽  
Cell Type ◽  
Animal Cells ◽  
Limited Variation ◽  
A Cell ◽  
Mechanical Elements

Despite a variety of shapes and sizes, the generic mechanical structure of cells is remarkably similar from one cell type to the next. All cells are bounded by a plasma membrane, a fluid sheet that controls the passage of materials into and out of the cell. Plant cells and bacteria reinforce this membrane with a cell wall, permitting the cell to operate at an elevated osmotic pressure. Simple cells, such as the bacterium shown in Figure 1a, possess a fairly homogeneous interior containing the cell's genetic blueprint and protein workhorses, but no mechanical elements. In contrast, as can be seen in Figure 1b, plant and animal cells contain internal compartments and a filamentous cytoskeleton—a network of biological ropes, cables, and poles that helps maintain the cell's shape and organize its contents.Four principal types of filaments are found in the cytoskeleton: spectrin, actin, microtubules, and a family of intermediate filaments. Not all filaments are present in all cells. The chemical composition of the filaments shows only limited variation from one cell to another, even in organisms as diverse as humans and yeasts. Membranes have a more variable composition, consisting of a bi-layer of dual-chain lipid molecules in which are embedded various proteins and frequently a moderate concentration of cholesterol. The similarity of the cell's mechanical elements in chemical composition and physical characteristics encourages us to search for universal strategies that have developed in nature for the engineering specifications of the cell. In this article, we concentrate on the cytoskeleton and its filaments.

Enrichment of vitronectin- and fibronectin-like proteins in NaCI-adapted plant cells and evidence for their involvement in plasma membrane-cell wall adhesion

1993 ◽  
Vol 3 (5) ◽  
pp. 637-646 ◽  
Author(s):  
Jian-Kang Zhu ◽  
Jun Shi ◽  
Utpal Singh ◽  
Sarah E. Wyatt ◽  
Ray A. Bressan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Plant Cells ◽  
Membrane Cell

The ultrastructure of Methanothrix concilii, a mesophilic aceticlastic methanogen

1986 ◽  
Vol 32 (9) ◽  
pp. 703-710 ◽  
Author(s):  
Terry J. Beveridge ◽  
Girish B. Patel ◽  
Bob J. Harris ◽  
G. Dennis Sprott
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Circular Plates ◽  
A Cell ◽  
Granular Matrix ◽  
A Chain ◽  
The Individual

Methanothrix concilii strain GP6 consists of a chain of rod-shaped cells, ca. 2.5 μm in length and 0.8 μm in width, which are encased in a tubular proteinaceous sheath. The sheath is composed of annular hoops, ca. 8.0 nm wide and 9.0 nm thick, which are stacked together to form the tube. The ends of the sheath, and therefore the cell filament, are blocked by single, multilayered, 13.5 nm thick, circular plates, designated as "spacer plugs," which contain a series of concentric rings; these also separate the individual cells within each filament. Each cell is therefore bounded by a tubular section of sheath and two spacer plugs. Completely encapsulating each cell, and lying between the sheath and cell, is an amorphous granular matrix. Overlying the plasma membrane and surrounding each protoplast is a thin veil of material which resembles a cell wall, but which is unable to maintain the rod shape when cells are extruded from the sheath.

scholarly journals Primary cell wall inspired micro containers as a step towards a synthetic plant cell

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
T. Paulraj ◽  
S. Wennmalm ◽  
D.C.F. Wieland ◽  
A. V. Riazanova ◽  
A. Dėdinaitė ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plant Cell ◽  
Plant Cell Wall ◽  
Structural Integrity ◽  
Plant Cells ◽  
Lipid Vesicles ◽  
Primary Cell Wall ◽  
Living Plant ◽  
A Cell ◽  
Lipid Tubules

AbstractThe structural integrity of living plant cells heavily relies on the plant cell wall containing a nanofibrous cellulose skeleton. Hence, if synthetic plant cells consist of such a cell wall, they would allow for manipulation into more complex synthetic plant structures. Herein, we have overcome the fundamental difficulties associated with assembling lipid vesicles with cellulosic nanofibers (CNFs). We prepare plantosomes with an outer shell of CNF and pectin, and beneath this, a thin layer of lipids (oleic acid and phospholipids) that surrounds a water core. By exploiting the phase behavior of the lipids, regulated by pH and Mg2+ ions, we form vesicle-crowded interiors that change the outer dimension of the plantosomes, mimicking the expansion in real plant cells during, e.g., growth. The internal pressure enables growth of lipid tubules through the plantosome cell wall, which paves the way to the development of hierarchical plant structures and advanced synthetic plant cell mimics.

Roles of the plasma membrane and the cell wall in the responses of plant cells to freezing

Planta ◽  
2002 ◽  
Vol 215 (5) ◽  
pp. 770-778 ◽  
Author(s):  
Tomoyoshi Yamada ◽  
Katsushi Kuroda ◽  
Yutaka Jitsuyama ◽  
Daisuke Takezawa ◽  
Keita Arakawa ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Plant Cells

scholarly journals iDePP: a genetically encoded system for the inducible depletion of PI(4,5)P2 in Arabidopsis thaliana

2020 ◽  
Author(s):  
Mehdi Doumane ◽  
Léia Colin ◽  
Alexis Lebecq ◽  
Aurélie Fangain ◽  
Joseph Bareille ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Plasma Membrane ◽  
Protein Localization ◽  
Cortical Microtubule ◽  
Plant Cells ◽  
Actin Dynamics ◽  
Animal Cells ◽  
Compensatory Mechanisms ◽  
Microtubule Organization ◽  
Membrane Contact Sites

ABSTRACTPhosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] is a low abundant lipid present at the plasma membrane of eukaryotic cells. Extensive studies in animal cells revealed the pleiotropic functions of PI(4,5)P2. In plant cells, PI(4,5)P2 is involved in various cellular processes including the regulation of cell polarity and tip growth, clathrin-mediated endocytosis, polar auxin transport, actin dynamics or membrane-contact sites. To date, most studies investigating the role of PI(4,5)P2 in plants have relied on mutants lacking enzymes responsible for PI(4,5)P2 synthesis and degradation. However, such genetic perturbations only allow steady-state analysis of plants undergoing their life cycle in PI(4,5)P2 deficient conditions and the corresponding mutants are likely to induce a range of non-causal (untargeted) effects driven by compensatory mechanisms. In addition, there are no small molecule inhibitors that are available in plants to specifically block the production of this lipid. Thus, there is currently no system to fine tune PI(4,5)P2 content in plant cells. Here we report a genetically encoded and inducible synthetic system, iDePP (Inducible Depletion of PI(4,5)P2 in Plants), that efficiently removes PI(4,5)P2 from the plasma membrane in different organs of Arabidopsis thaliana, including root meristem, root hair and shoot apical meristem. We show that iDePP allows the inducible depletion of PI(4,5)P2 in less than three hours. Using this strategy, we reveal that PI(4,5)P2 is critical for cortical microtubule organization. Together, we propose that iDePP is a simple and efficient genetic tool to test the importance of PI(4,5)P2 in given cellular or developmental responses but also to evaluate the importance of this lipid in protein localization.Research OrganismA. thaliana

Structure and development of cortical microtubule arrays in plant cells

1978 ◽  
Vol 36 (2) ◽  
pp. 264-265
Author(s):  
A.R. Hardham ◽  
B.E.S. Gunning
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Cortical Microtubule ◽  
Plant Cells ◽  
Original Description ◽  
Cell Cortex ◽  
Cortical Microtubules ◽  
Fundamental Part ◽  
Cellulose Component

Microtubules in the plant cell cortex are usually aligned parallel to microfibrils of cellulose that are being deposited in the cell wall, and are considered to function in guiding or orienting cellulose synthetase complexes that lie in or on the plasma membrane. The cellulose component is largely responsible for the mechanical reaction of the wall to turgor forces, thereby determining cell size and shape, and therefore the role of the cortical microtubules is a fundamental part of the overall morphogenetic process in plants. It is important to determine the structure of cortical arrays of microtubules and to learn how the cell regulates their development, neither of these aspects having been investigated adequately since the original description likened the microtubules to “hundreds of hoops around the cell”.

Interactions of different vegetal cells with mesomeres during early stages of sea urchin development

Development ◽  
1991 ◽  
Vol 112 (3) ◽  
pp. 881-890 ◽  
Author(s):  
O. Khaner ◽  
F. Wilt
Keyword(s):  
Sea Urchin ◽  
Normal Development ◽  
Pigment Cells ◽  
Regional Differentiation ◽  
Cell Type ◽  
Animal Cells ◽  
Cell Stage ◽  
Latent Ability ◽  
A Cell ◽  
Poorly Differentiated

It has been known from results obtained in the classical experiments on sea urchin embryos that cell isolation and transplantation showed extensive interactions between the early blastomeres and/or their descendants. In the experiments reported here a systematic reexamination of recombination of mesomeres and their progeny (which come from the animal hemisphere) with various vegetal cells derived from blastomeres of the 32- and 64-cell stage was carried out. Cells were marked with lineage tracers to follow which cell gave rise to what structures, and newly available molecular markers have been used to analyze different structures characteristic of regional differentiation. Large micromeres form spicules and induce gut and pigment cells in mesomeres, conforming to previous results. Small micromeres, a cell type not heretofore examined, gave rise to no recognizable structure and had very limited ability to evoke poorly differentiated gut tissue in mesomeres. Macromeres and their descendants, Veg 1 and Veg 2, form primarily what their normal fate dictated, though both did have some capacity to form spicules, presumably by formation from secondary mesenchyme. Macromeres and their descendants were not potent inducers of vegetal structures in animal cells, but they suppress the latent ability of mesomeres to form vegetal structures. The results lead us to propose that the significant interactions during normal development may be principally suppressive effects of mesomeres on one another and of adjacent vegetal cells on mesomeres.

Purification and immunological detection of pea nuclear intermediate filaments: evidence for plant nuclear lamins

1992 ◽  
Vol 103 (2) ◽  
pp. 407-414 ◽  
Author(s):  
A.K. McNulty ◽  
M.J. Saunders
Keyword(s):  
Nuclear Envelope ◽  
Intermediate Filaments ◽  
Plant Cells ◽  
Nuclear Lamina ◽  
Animal Cells ◽  
Nuclear Lamins ◽  
Antigenic Characterization ◽  
Major Structural Component ◽  
Nuclear Envelope Assembly ◽  
Type V

A major structural component of the inner face of the nuclear envelope in vertebrates and invertebrates is the nuclear lamina, an array of 1–3 extrinsic membrane proteins, lamins A, B and C. These proteins are highly homologous to intermediate filaments and are classified as type V. We report the first purification, antigenic characterization and immunocytochemical localization of putative plant lamin proteins from pea nuclei. We conclude that plant cells contain this ancestral class of intermediate filaments in their nuclei and that regulation of nuclear envelope assembly/disassembly and mitosis in plants may be similar to that in animal cells.

scholarly journals Intercellular trafficking via plasmodesmata: molecular layers of complexity

2020 ◽  
Author(s):  
Ziqiang Patrick Li ◽  
Andrea Paterlini ◽  
Marie Glavier ◽  
Emmanuelle M. Bayer
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Plant Cells ◽  
Functional Domains ◽  
Dynamic Interactions ◽  
Intercellular Trafficking ◽  
Multiple Routes ◽  
Molecular Components ◽  
Molecular Layers

Abstract Plasmodesmata are intercellular pores connecting together most plant cells. These structures consist of a central constricted form of the endoplasmic reticulum, encircled by some cytoplasmic space, in turn delimited by the plasma membrane, itself ultimately surrounded by the cell wall. The presence and structure of plasmodesmata create multiple routes for intercellular trafficking of a large spectrum of molecules (encompassing RNAs, proteins, hormones and metabolites) and also enable local signalling events. Movement across plasmodesmata is finely controlled in order to balance processes requiring communication with those necessitating symplastic isolation. Here, we describe the identities and roles of the molecular components (specific sets of lipids, proteins and wall polysaccharides) that shape and define plasmodesmata structural and functional domains. We highlight the extensive and dynamic interactions that exist between the plasma/endoplasmic reticulum membranes, cytoplasm and cell wall domains, binding them together to effectively define plasmodesmata shapes and purposes.

scholarly journals A pathway for cell wall anchorage of Saccharomyces cerevisiae alpha-agglutinin.

1994 ◽  
Vol 14 (7) ◽  
pp. 4825-4833 ◽  
Author(s):  
C F Lu ◽  
J Kurjan ◽  
P N Lipke
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Surface ◽  
Soluble Form ◽  
Gpi Anchor ◽  
Glycosyl Phosphatidylinositol ◽  
Experimental Support ◽  
Cell Biol ◽  
A Cell

Saccharomyces cerevisiae alpha-agglutinin is a cell wall-anchored adhesion glycoprotein. The previously identified 140-kDa form, which contains a glycosyl-phosphatidylinositol (GPI) anchor (D. Wojciechowicz, C.-F. Lu, J. Kurjan, and P. N. Lipke, Mol. Cell. Biol. 13:2554-2563, 1993), and additional forms of 80, 150, 250 to 300, and > 300 kDa had the properties of intermediates in a transport and cell wall anchorage pathway. N glycosylation and additional modifications resulted in successive increases in size during transport. The 150- and 250- to 300-kDa forms were membrane associated and are likely to be intermediates between the 140-kDa form and a cell surface GPI-anchored form of > 300 kDa. A soluble form of > 300 kDa that lacked the GPI anchor had properties of a periplasmic intermediate between the plasma membrane form and the > 300-kDa cell wall-anchored form. These results constitute experimental support for the hypothesis that GPI anchors act to localize alpha-agglutinin to the plasma membrane and that cell wall anchorage involves release from the GPI anchor to produce a periplasmic intermediate followed by linkage to the cell wall.

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