scholarly journals Localization of concanavalin A binding carbohydrate in Chlamydomonas flagella

1984 ◽  
Vol 68 (1) ◽  
pp. 211-226
Author(s):  
B.E. Millikin ◽  
R.L. Weiss
Keyword(s):  
Electron Microscopy ◽  
Concanavalin A ◽  
Fluorescein Isothiocyanate ◽  
Surface Coat ◽  
Subsurface Zone ◽  
Flagellar Membrane

Chlamydomonas flagella are shown to possess two zones of concanavalin A (ConA) binding carbohydrate. The first zone, distinguished by a requirement for a prolonged labelling period for visualization of fluorescein isothiocyanate (FITC)-ConA fluorescence, is localized in the flagellar coat. The second zone is characterized by a rapid FITC- and [125I]ConA labelling subsequent to disruption of the flagellar membrane, but is unaffected by reagents that act only on the flagellar surface coat. Electron microscopy and ferritin-ConA labelling indicate that this subsurface zone is localized between the flagellar membrane and axoneme in the space that we term the flagelloplasm. These results are used to suggest possible functions for ConA binding glycosyl residues in flagella.

Adhesion of Phytophthora palmivora zoospores: detection and ultrastructural visualization of concanavalin A-receptor sites appearing during encystment

1975 ◽  
Vol 19 (1) ◽  
pp. 11-20
Author(s):  
V.O. Sing ◽  
S. Bartnicki-Garcia
Keyword(s):  
Electron Microscopy ◽  
Cell Surface ◽  
Concanavalin A ◽  
Solid Surfaces ◽  
Trypsin Digestion ◽  
Phytophthora Palmivora ◽  
Con A ◽  
Binding Material ◽  
Ultraviolet Microscopy ◽  
Receptor Sites

The binding of concanavalin A (Con A) to the cell surface of zoospores and cysts of Phytophthora palmivora was studied by radiometry (125I-Con A), ultraviolet microscopy (fluorescein-Con A) and electron microscopy peroxidase-diaminobenzidine technique). Zoospores were found to secrete during the early stages of encystment a Con A-binding material susceptible to trypsin digestion. This glycoprotein is contained in the so-called peripheral vesicles and is probably responsible for the adhesion of the encysting zoospores to solid surfaces.

scholarly journals Erythrocyte entry by malarial parasites. A moving junction between erythrocyte and parasite

1978 ◽  
Vol 77 (1) ◽  
pp. 72-82 ◽  
Author(s):  
M Aikawa ◽  
LH Miller ◽  
J Johnson ◽  
J Rabbege
Keyword(s):  
Electron Microscopy ◽  
Plasma Membrane ◽  
Erythrocyte Membrane ◽  
Plasmodium Knowlesi ◽  
Parasitophorous Vacuole ◽  
Initial Contact ◽  
Surface Coat ◽  
Iris Diaphragm ◽  
Erythrocyte Surface

Invasion of erythrocytes by merozoites of the monkey malaria, Plasmodium knowlesi, was investigated by electron microscopy. The apical end of the merozoite makes initial contact with the erythrocyte, creating a small depression in the erythrocyte membrane. The area of the erythrocyte membrane to which the merozoite is attached becomes thickened and forms a junction with the plasma membrane of the merozoite. As the merozoite enters the invagination in the erythrocyte surface, the junction, which is in the form of a circumferential zone of attachment between the erythrocyte and merozoite, moves along the confronted membranes to maintain its position at the orifice of the invagination. When entry is completed, the orifice closes behind the parasite in the fashion of an iris diaphragm, and the junction becomes a part of the parasitophorous vacuole. The movement of the junction during invasion is an important component of the mechanism by which the merozoite enters the erythrocyte. The extracellular merozoite is covered with a prominent surface coat. During invasion, this coat appears to be absent from the portion of the merozoite within the erythrocyte invagination, but the density of the surface coat outside the invagination (beyond the junction) is unaltered.

scholarly journals Membrane Surface Features of Blastocystis Subtypes

Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 417 ◽  
Author(s):  
John Yason ◽  
Kevin Tan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Death ◽  
Species Complex ◽  
Membrane Surface ◽  
Surface Coat ◽  
Pathogenic Potential ◽  
Morphological Differences ◽  
Carbohydrate Components ◽  
Scanning Electron

Blastocystis is a common intestinal protistan parasite with global distribution. Blastocystis is a species complex composed of several isolates with biological and morphological differences. The surface coats of Blastocystis from three different isolates representing three subtypes were analyzed using scanning electron microscopy. This structure contains carbohydrate components that are also present in surface glycoconjugates in other parasitic protozoa. Electron micrographs show variations in the surface coats from the three Blastocystis isolates. These differences could be associated with the differences in the pathogenic potential of Blastocystis subtypes. Apart from the surface coat, a plasma membrane-associated surface antigen has been described for Blastocystis ST7 and is associated with programmed cell death features of the parasite.

scholarly journals Nonuniform distribution of concanavalin-A receptors and surface antigens on uropod-forming thymocytes.

1978 ◽  
Vol 79 (1) ◽  
pp. 235-251 ◽  
Author(s):  
S de Petris
Keyword(s):  
Electron Microscopy ◽  
Normal Distribution ◽  
Concanavalin A ◽  
Cytochalasin B ◽  
Surface Antigens ◽  
Nonuniform Distribution ◽  
Inhomogeneous Distribution ◽  
Spherical Cells ◽  
Concanavalin A Receptors

Uropods can form spontaneously in a variable fraction of mouse thymocytes incubated for 30--60 min in vitro at temperatures between about 8 degrees and 37 degrees C. The majority of the cells with a typical uropod are medium and large thymocytes. The "normal" distribution of concanavalin-A receptors and antigens recognized by a rabbit anti-mouse thymocyte serum was studied on these cells by electron microscopy using ferritin-conjugated lectin or antibodies. The cells were fixed with glutaraldehyde or formaldehyde before labeling. The distribution was essentially uniform on spherical cells. On the contrary, on cells which had formed a uropod the labeled receptors and antigens appeared to be preferentially concentrated around the nucleus, and depleted over the uropod, and especially over the constriction at the base of the uropod. Uropod formation and inhomogeneous distribution were inhibited or reversed by cytochalasin B, but not by vinblastine or colchicine. When the same ligands were applied to unfixed cells, the labeled and cross-linked components capped normally towards the cytoplasmic pole of the cell. These observations are described in relation to the ability of receptors and antigens to interact with an intracellular mechanical structure, and to the mechanism of capping.

scholarly journals The Chlamydomonas kinesin-like protein FLA10 is involved in motility associated with the flagellar membrane.

1995 ◽  
Vol 131 (6) ◽  
pp. 1517-1527 ◽  
Author(s):  
K G Kozminski ◽  
P L Beech ◽  
J L Rosenbaum
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Intraflagellar Transport ◽  
Temperature Sensitive ◽  
Polystyrene Beads ◽  
Cell Biol ◽  
Flagellar Membrane ◽  
Surface Motility ◽  
Sensitive Allele ◽  
Bidirectional Movement

The Chlamydomonas FLA10 gene was shown to encode a flagellar kinesin-like protein (Walther, Z., M. Vashishtha, and J.L. Hall. 1994. J. Cell Biol. 126:175-188). By using a temperature-sensitive allele of FLA10, we have determined that the FLA10 protein is necessary for both the bidirectional movement of polystyrene beads on the flagellar membrane and intraflagellar transport (IFT), the bidirectional movement of granule-like particles beneath the flagellar membrane (Kozminski, K.G., K.A. Johnson, P. Forscher, and J.L. Rosenbaum. 1993. Proc. Natl. Acad. Sci. (USA). 90:5519-5523). In addition, we have correlated the presence and position of the IFT particles visualized by light microscopy with that of the electron dense complexes (rafts) observed beneath the flagellar membrane by electron microscopy. A role for FLA10 in submembranous or flagellar surface motility is also strongly supported by the immunolocalization of FLA10 to the region between the axonemal outer doublet microtubules and the flagellar membrane.

scholarly journals Redistribution and shedding of flagellar membrane glycoproteins visualized using an anti-carbohydrate monoclonal antibody and concanavalin A.

1986 ◽  
Vol 102 (5) ◽  
pp. 1797-1812 ◽  
Author(s):  
R A Bloodgood ◽  
M P Woodward ◽  
N L Salomonsky
Keyword(s):  
Molecular Weight ◽  
Monoclonal Antibody ◽  
High Molecular Weight ◽  
Concanavalin A ◽  
Live Cells ◽  
Surface Phenomenon ◽  
Carbohydrate Binding ◽  
Membrane Glycoproteins ◽  
Western Blots ◽  
Flagellar Membrane

Two carbohydrate-binding probes, the lectin concanavalin A and an anti-carbohydrate monoclonal antibody designated FMG-1, have been used to study the distribution of their respective epitopes on the surface of Chlamydomonas reinhardtii, strain pf-18. Both of these ligands bind uniformly to the external surface of the flagellar membrane and the general cell body plasma membrane, although the labeling is more intense on the flagellar membrane. In addition, both ligands cross-react with cell wall glycoproteins. With respect to the flagellar membrane, both concanavalin A and the FMG-1 monoclonal antibody bind preferentially to the principal high molecular weight glycoproteins migrating with an apparent molecular weight of 350,000 although there is, in addition, cross-reactivity with a number of minor glycoproteins. Western blots of V-8 protease digests of the high molecular weight flagellar glycoproteins indicate that the epitopes recognized by the lectin and the antibody are both repeated multiple times within the glycoproteins and occur together, although the lectin and the antibody do not compete for the same binding sites. Incubation of live cells with the monoclonal antibody or lectin at 4 degrees C results in a uniform labeling of the flagellar surface; upon warming of the cells, these ligands are redistributed along the flagellar surface in a characteristic manner. All of the flagellar surface-bound antibody or lectin collects into a single aggregate at the tip of each flagellum; this aggregate subsequently migrates to the base of the flagellum, where it is shed into the medium. The rate of redistribution is temperature dependent and the glycoproteins recognized by these ligands co-redistribute with the lectin or monoclonal antibody. This dynamic flagellar surface phenomenon bears a striking resemblance to the capping phenomenon that has been described in numerous mammalian cell types. However, it occurs on a structure (the flagellum) that lacks most of the cytoskeletal components generally associated with capping in other systems. The FMG-1 monoclonal antibody inhibits flagellar surface motility visualized as the rapid, bidirectional translocation of polystyrene microspheres.

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