scholarly journals Glycocalyx Curving the Membrane: Forces Emerging from the Cell Exterior

2021 ◽  
Vol 37 (1) ◽  
pp. 257-283
Author(s):  
Joe Chin-Hun Kuo ◽  
Matthew J. Paszek
Keyword(s):  
Morphological Changes ◽  
Membrane Curvature ◽  
Surface Structures ◽  
Infectious Agents ◽  
Cell Surface Structures ◽  
Morphological Transitions ◽  
Health And Disease ◽  
Membrane Shape ◽  
Asymmetrically Distributed ◽  
Normal Health

Morphological transitions are typically attributed to the actions of proteins and lipids. Largely overlooked in membrane shape regulation is the glycocalyx, a pericellular membrane coat that resides on all cells in the human body. Comprised of complex sugar polymers known as glycans as well as glycosylated lipids and proteins, the glycocalyx is ideally positioned to impart forces on the plasma membrane. Large, unstructured polysaccharides and glycoproteins in the glycocalyx can generate crowding pressures strong enough to induce membrane curvature. Stress may also originate from glycan chains that convey curvature preference on asymmetrically distributed lipids, which are exploited by binding factors and infectious agents to induce morphological changes. Through such forces, the glycocalyx can have profound effects on the biogenesis of functional cell surface structures as well as the secretion of extracellular vesicles. In this review, we discuss recent evidence and examples of these mechanisms in normal health and disease.

scholarly journals Rapid phosphorylation and reorganization of ezrin and spectrin accompany morphological changes induced in A-431 cells by epidermal growth factor.

1989 ◽  
Vol 108 (3) ◽  
pp. 921-930 ◽  
Author(s):  
A Bretscher
Keyword(s):  
Cell Surface ◽  
Tyrosine Kinases ◽  
Time Course ◽  
Morphological Changes ◽  
Surface Structures ◽  
Human Carcinoma ◽  
Membrane Ruffling ◽  
Cell Biol ◽  
Cell Surface Structures ◽  
Associated Proteins

Addition of EGF to human carcinoma A-431 cells is known to induce membrane ruffling after approximately 2 min (Chinkers, M., J. A. McKanna, and S. Cohen. 1979. J. Cell Biol. 83:260-265) and the phosphorylation of a protein referred to as p81, a known substrate for various protein-tyrosine kinases (Cooper, J. A., D. F. Bowen-Pope, E. Raines, R. Ross, and T. Hunter. 1982. Cell. 31:263-273). Ezrin, a Mr approximately 80,000 cytoskeletal protein of the isolated chicken microvillar core, is present in actin-containing cell surface structures of a wide variety of cells (Bretscher, A. 1983. J. Cell Biol. 97:425-432). Ezrin was then found to be homologous to p81 and to be phosphorylated on tyrosine in response to EGF (Gould, K. L., J. A. Cooper, A. Bretscher, and T. Hunter. 1986. J. Cell Biol. 102:660-669). Here, the purification of ezrin from human placenta is described. Antibodies to human ezrin, together with antibodies to other microfilament-associated proteins, were used to follow the distribution and phosphorylation of these proteins in A-431 cells after EGF treatment. EGF induces the formation of microvillar-like surface structures on these cells within 30 s and these give way to membrane ruffles at approximately 2-5 min after EGF addition; the cells then round up after approximately 10-20 min. Ezrin is recruited into the microvillar-like structures and the membrane ruffles, and is phosphorylated on tyrosine and serine in a time course that parallels the formation and disappearance of these surface structures. Spectrin is recruited into the membrane ruffles and shows a similar rapid kinetics of phosphorylation, but only on serine residues, and remains phosphorylated through the rounding up of the cells. The microvillar-like structures and membrane ruffles are also enriched in fimbrin and alpha-actinin. Myosin becomes rapidly reorganized into a striated pattern that is consistent with it playing a role in cell rounding. These results show that two cortical proteins, ezrin and spectrin, become phosphorylated in a time course coincident with remodeling of the cell surface. The results are consistent with the notion that ezrin phosphorylation may play a role in the formation of cell surface projections whereas spectrin phosphorylation may be involved in remodelling of more planar areas of the cell surface.

The Role of Cytokines in the Modulation of Cell Surface Antigens of Human Melanoma

1993 ◽  
Vol 8 (3) ◽  
pp. 151-154 ◽  
Author(s):  
A. Anichini ◽  
R. Mortarini ◽  
G. Parmiani
Keyword(s):  
Cell Surface ◽  
Surface Antigens ◽  
Surface Structures ◽  
Biological Behavior ◽  
Cell Surface Antigens ◽  
Membrane Expression ◽  
Neoplastic Cells ◽  
Antigenic Modulation ◽  
Human Malignant Melanoma ◽  
Cell Surface Structures

A number of different cytokines, including IL-1α. and ß, IL-2, IL-3, IL-4, IL-6, IL-7, IL-8, IFN-α, -ß and γ, TNF-α -ß, and TGF-ß1, can modulate the expression of distinct cell surface antigens of normal and neoplastic cells. Both induction/increase of expression and reduction of expression can be achieved depending on the antigen and on the cytokine. Antigens subjected to the modulating activity of cytokines include distinct families of cell surface structures such as the molecules coded by the major histocompatibility complex (MHC), the superfamily of adhesion receptors that regulate cell-cell and cell-matrix interaction, receptors for cytokines and growth factors and tumor-associated antigens. The modulating activity of cytokines is a consequence of their influence on gene expression, protein synthesis, membrane expression and shedding of antigens from the cell surface. The changes of phenotype due to the action of cytokines can influence the signalling pathways dependent on the expression and function of cell surf ace structures. Therefore, the antigen modulating activity of cytokines can thoroughly affect the biological behavior of normal and neoplastic cells. As described here, most of the modulating effects of cytokines on different cell surface structures and the functional consequences of antigenic modulation can be verified in human malignant melanoma cells.

Interleukin 4 (BSF-1) induces growth in resting murine CD8 T cells triggered via cross-linking of T3 cell surface structures

1988 ◽  
Vol 18 (5) ◽  
pp. 767-772 ◽  
Author(s):  
Thomas Miethke ◽  
Ruth Schmidberger ◽  
Klaus Heeg ◽  
Steven Gillis ◽  
Hermann Wagner
Keyword(s):  
T Cells ◽  
Cell Surface ◽  
Cd8 T Cells ◽  
Surface Structures ◽  
Interleukin 4 ◽  
Cross Linking ◽  
Cell Surface Structures

scholarly journals Inter-individual variation in health and disease associated with pulmonary infectious agents

2018 ◽  
Vol 29 (1-2) ◽  
pp. 38-47 ◽  
Author(s):  
Kirsten C. Verhein ◽  
Heather L. Vellers ◽  
Steven R. Kleeberger
Keyword(s):  
Individual Variation ◽  
Infectious Agents ◽  
Health And Disease

scholarly journals Phosphoethanolamine cellulose enhances curli-mediated adhesion of uropathogenicEscherichia colito bladder epithelial cells

2018 ◽  
Vol 115 (40) ◽  
pp. 10106-10111 ◽  
Author(s):  
Emily C. Hollenbeck ◽  
Alexandra Antonoplis ◽  
Chew Chai ◽  
Wiriya Thongsomboon ◽  
Gerald G. Fuller ◽  
...  
Keyword(s):  
Cell Surface ◽  
Bacterial Cell ◽  
Cell Monolayer ◽  
Surface Structures ◽  
Bacterial Cell Surface ◽  
Cell Surface Structures ◽  
Bladder Cell ◽  
Type 1 Pili ◽  
Tract Infections

UropathogenicEscherichia coli(UPEC) are the major causative agents of urinary tract infections, employing numerous molecular strategies to contribute to adhesion, colonization, and persistence in the bladder niche. Identifying strategies to prevent adhesion and colonization is a promising approach to inhibit bacterial pathogenesis and to help preserve the efficacy of available antibiotics. This approach requires an improved understanding of the molecular determinants of adhesion to the bladder urothelium. We designed experiments using a custom-built live cell monolayer rheometer (LCMR) to quantitatively measure individual and combined contributions of bacterial cell surface structures [type 1 pili, curli, and phosphoethanolamine (pEtN) cellulose] to bladder cell adhesion. Using the UPEC strain UTI89, isogenic mutants, and controlled conditions for the differential production of cell surface structures, we discovered that curli can promote stronger adhesive interactions with bladder cells than type 1 pili. Moreover, the coproduction of curli and pEtN cellulose enhanced adhesion. The LCMR enables the evaluation of adhesion under high-shear conditions to reveal this role for pEtN cellulose which escaped detection using conventional tissue culture adhesion assays. Together with complementary biochemical experiments, the results support a model wherein cellulose serves a mortar-like function to promote curli association with and around the bacterial cell surface, resulting in increased bacterial adhesion strength at the bladder cell surface.

scholarly journals Mls is not a single gene, allelic system. Different stimulatory Mls determinants are the products of at least two nonallelic, unlinked genes.

1987 ◽  
Vol 166 (4) ◽  
pp. 1150-1155 ◽  
Author(s):  
R Abe ◽  
J J Ryan ◽  
R J Hodes
Keyword(s):  
T Cells ◽  
Single Gene ◽  
Surface Structures ◽  
Chromosome 1 ◽  
Gene Products ◽  
Spleen Cells ◽  
Gene Encoding ◽  
Cell Surface Structures ◽  
Genes Encoding ◽  
Polymorphic Cell

Mls determinants share with MHC products the unique property of stimulating T cells at extraordinarily high precursor frequencies. The Mls system was originally described as a single locus on chromosome 1, with four alleles, Mlsa, Mlsb, Mlsc, and Mlsd, that encode polymorphic cell surface structures. However, the fundamental issues of polymorphism and allelism in the Mls system remain controversial. To clarify these questions, a formal segregation analysis of the genes encoding Mlsa and Mlsc determinants was carried out by testing the capacity of spleen cells from progeny of (Mlsa X Mlsc)F1 X Mlsb breedings to stimulate responses by unprimed T cells and by Mlsa- and Mlsc-specific cloned T cells. The results of this analysis indicated that the gene encoding Mlsa determinants is neither allelic to nor linked to the gene encoding Mlsc determinants. Together with previous findings, these results also suggest that another strongly stimulatory type, Mlsd, in fact results from the independent expression of unlinked Mlsa and Mlsc gene products. Based on these observations, it is concluded that, contrary to conventional concepts, the stimulatory phenotypes designated as Mlsa, Mlsc, and Mlsd can be accounted for by the independent expression of the products of at least two unlinked gene loci.

Silurian Ramphoprionid polychaetes from Gotland, Sweden

2001 ◽  
Vol 75 (5) ◽  
pp. 993-1015 ◽  
Author(s):  
Mats Eriksson
Keyword(s):  
New Species ◽  
New Genus ◽  
Morphological Changes ◽  
Original Description ◽  
Surface Structures ◽  
New Genus And Species ◽  
Gradual Evolution ◽  
The Family ◽  
Stratigraphic Ranges ◽  
Stratigraphic Range

Silurian ramphoprionid polychaete annelids, represented by their jaws (scolecodonts), are described from extensive collections from Gotland, Sweden. The family Ramphoprionidae, monotypic at its original description, is sub-divided into four genera; Protarabellites Stauffer, 1933; Ramphoprion Kielan-Jaworowska, 1962; “Pararamphoprion” Männil and Zaslavskaya, 1985; and Megaramphoprion new genus. Identified species include “P.” cf. nordicus Männil and Zaslavskaya, 1985; P. rectangularis new species; P. staufferi new species; P. triangularis new species; and two Protarabellites species left in open nomenclature. Ramphoprion is represented by one new highly plastic species, R. gotlandensis, housing five distinguishable morphotypes showing gradual evolution. Megaramphoprion, which is most closely related to Ramphoprion, is represented by M. magnus new genus and species, a rare but distinctive taxon. Most species have long stratigraphic ranges within which important morphological changes can nonetheless be observed. The stratigraphic range of ramphoprionids includes, at least, the Ordovician to the Silurian. They are fairly rare in the Silurian of Gotland and where present they generally form less than 10 percent of the polychaete faunas, although occasionally reaching as much as 20 to 30 percent. Evolution, paleoecology, and surface structures of the investigated species are briefly discussed.

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