Involvement of a cell-surface glycoprotein in the cell-sorting process of Dictyostelium discoideum (original) (raw)
Related papers
FEBS Letters, 1994
A monoclonal antibody that interferes with the EDTA-resistant adhesion of Dictyostelium discoideum slug cells recognised a carbohydrate epitope on four major antigens (95, 90, 35 and 30 kDa) in slug cells. The 35 and 30 kDa antigens were specific for stalks and spores, respectively. The 30 kDa antigen was identified as the cell surface glycoprotein, PsA. Cyclic AMP, acting via cell surface receptors, induced only the 90 kDa slug cell antigen. Slug cell adhesion proteins may be involved in cell-sorting and the glycosylation of the 95 and 90 kDa antigens appeared to be abnormal m a mutant defective in cell-sorting. Previously, a 150 kDa glycoprotein has been strongly implicated in slug cell adhesion and the present work suggests that additional glycoprotein(s) are involved.
Development, 1979
Cells disaggregated from slugs of Dictyostelium discoideum were cultured in Bonner’s salt solution in roller tubes. Cells rapidly stuck together to form an amorphous loose agglutinate which was later transformed into a spheroidal tight agglutinate surrounded by slime sheath material. Prespore cells in the loose agglutinate underwent partial dedifferentiation by starting to decompose their specific antigen until formation of the tight agglutinate, in which the antigen was resynthesized. During the process, there was some decrease in the proportion of prespore cells. Changes in the distribution of prespore and prestalk cells in the agglutinates were examined by using immunocytochemical staining. They were randomly distributed in the early agglutinates, but became well separated in 4 h agglutinates in such a way that prestalk cells were completely enveloped by prespore cells. Prestalk cells later came outside to be partially enveloped and finally occupied a hemisphere side by side with...
Separation and properties of prestalk and prespore cells of Dictyostelium discoideum
Experimental Cell Research, 1981
We describe a method of separating prestalk and prespore cells of Dictyostelium discoideum slugs using a self-generating Percoll gradient. This method gives quantitative recovery of cells and good purity. Separated prestalk and prespore cells possess different levels of the enzymes UDP galactose : polysaccharide transferase, CAMP phosphodiesterase and glycogen phosphorylase. We have used this method, as well as mechanical dissection of slugs, to examine the fate of separated prestalk and prespore cells in Dicfyostelium strains that are able to give rise to mature stalk and spore cells in cell monolayers. The results from such experiments provide direct evidence that prestalk and prespore cells from the migrating slug stage are programmed to differentiate into stalk and spore cells respectively.
Molecular and cellular biology, 1985
Polymorphisms of a major developmentally regulated prespore-specific protein (PsA) in Dictyostelium discoideum slugs are described. These polymorphisms allowed discrimination between PsA (found on the cell surface and in the extracellular matrix) and a similar extracellular but nonpolymorphic protein, ShA. The two proteins were also distinguished by their differing reactivities with a range of monoclonal antibodies and by their sensitivity to release from the sheath with cellulase. The results are discussed in terms of the molecular and genetic relationships between the cell surface and the extracellular matrix during development.
Cell differentiation, 1982
Monoclonal antibodies against a glycoprotein presumably involved in adhesion of aggregating Dictyostelium discoideum cells have been used for labeling of the antigen at the cell surface. The antigen is distributed over the whole surface of the cells, apparently in form of small clusters. The antigen appears concomitantly with the acquisition of EDTA-stable adhesiveness typical of aggregation competent cells. In contrast, discoidin I, a lectin whose accumulation during development parallels EDTA-stable adhesiveness in another strain (NC-4), is present in nearly the same amounts of growth phase and aggregating cells of AX2-214, the strain used by use. Thus, no correlation exists in this strain between the expression of discoidin I and the development of cell adhesiveness. The 80 kilodalton glycoprotein typical of aggregation competent cells has been purified by affinity chromatography on a monoclonal antibody column. The purified antigen absorbs adhesion-blocking Fab from rabbits. Ano...
Development, Growth and Differentiation, 1994
As a result of transfecting Dictyosteiium discoideum with an actin 6llacZ fusion transgene, strain HW80 was created which expresses the p-galactosidase gene product uniformly throughout development. When mixed with an excess of unmarked wild-type cells, however, HW80 cells selectively migrate to the positions of anterior-like cells surrounding the prespore cell mass, and differentiate as if they were anterior-like cells. As the proportion of HW80 cells is increased, they also sort to positions adjacent to anterior-like cells and some differentiate as prespore cells. Thus sorting of HW80 cells toward the opposite ends of the prespore cell zone supersedes how they differentiate, suggesting that position influences whether cells differentiate as anterior-like or prespore cells.
The Journal of biological chemistry, 1987
Two different types of oligosaccharides, designated type 1 and 2 carbohydrate residues, are present on the contact site A molecule, an 80-kDa glycoprotein involved in the formation of EDTA-stable cell adhesion during cell aggregation in Dictyostelium discoideum. The first precursor detected by pulse-chase labeling with [35S]methionine was a 68-kDa glycoprotein carrying type 1 carbohydrate. Conversion of the precursor into the 80-kDa form occurred simultaneously with the addition of type 2 carbohydrate. Tunicamycin inhibited type 1 glycosylation more efficiently than type 2 glycosylation. The first precursor detected in tunicamycin-treated cells by pulse-chase labeling was a 53-kDa protein lacking both carbohydrates, which was converted through addition of type 2 carbohydrate into a 66-kDa final product. Labeling of intact cells indicated that this 66-kDa glycoprotein is transported to the cell surface. Prolonged treatment with tunicamycin resulted in the accumulation within the cell...
The glycoproteins of Dictyostelium discoideum
Experimental Cell Research, 1979
The glycoproteins ofD. discoideum have been analyzed by direct binding of radio-iodinated lectins to SDS gels of the successive developmental stages. Compared with the total pattern of proteins, many changes are found in the glycoproteins during development. WGA reacts with few gel bands from the vegetative cells and most of these, including a very intense band at the top of the gel, are lost during the first few hours of development. Approximately halfway through the developmental cycle at least 14 new glycoproteins reacting with WGA begin to appear and progressively accumulate. In contrast, ConA labels many glycoproteins over the complete molecular weight range and most are unaffected during development. Lectins which bind fucose label a single component at the top of the gel of vegetative cells and this decreases rapidly as development begins. No other reactive gel bands are revealed by fucose-binding lectins until the final stages of spore and stalk formation, when four high molecular weight glycoproteins are detected. Lectins specific for terminal galactose residues and for N-acetyl-galactosamine, including the intrinsic lectins produced by D. discoideum during its development, failed to reveal any reactive glycoproteins.
Cell, 1984
All three forms of discoidin I, an endogenous Nacetylgalactosamine-binding lectin from D. discoideum, contain the amino acid sequence gly-arg-glyasp also found in fibronectin and implicated in its attachment to cells. Synthetic peptides containing these and adjacent amino acids of discoidin I block organized streaming during aggregation of D. discoideum and, at higher concentrations, block cell attachment and spreading on a plastic surface and formation of fruiting bodies. Pure discoidin I (with or without N-acetylgalactosamine) and univalent antidiscoidin I also block formation of streams during aggregation. Two mutants of D. discoideum with low levels of discoidin I apparently reflect the deficiency of this endogenous lectin by failing to form streams or to spread on plastic and by a partial failure to enter aggregates. Together, the results indicate that discoidin I functions like fibronectin to promote cell attachment and spreading as well as ordered cellular migration during morphogenesis .
The EMBO journal, 1985
Expression of developmentally regulated membrane proteins of aggregating cells of Dictyostelium discoideum is subject to several control mechanisms. One of them involves periodic cyclic-AMP pulses as signals for gene expression. To increase the probability of selecting mutants specifically defective in the contact site A (csA) glycoprotein, one of the characteristic proteins of aggregating cells, we have bypassed the requirement for both cyclic-AMP pulses and another control element by two runs of mutagenesis. A ;double bypass' mutant, HG592, was obtained which aggregated in nutrient medium where wild-type did not develop. Mutants defective in expression of the csA-glycoprotein were selected from HG592 by fluorescence-activated cell sorting and colony immunoblotting using a monoclonal antibody specific for that protein. One among 51 csA-negative mutants, HG693, specifically lacked the capability of forming EDTA-stable intercellular contacts. It acquired chemotactic responsivenes...