Dynamics of Antigenic Membrane Sites Relating to Cell Aggregation in Dictyostelium Discoideum
Year: 1973
Type: article
Abstract: Membrane interaction in aggregating cells of Dictyostelium discoideum can be blocked by univalent antibodies directed against specific membrane sites. Using a quantitative technique for measuring cell association, two classes of target sites for blocking antibodies were distinguished and their developmental dynamics studied. One class of these sites is specific for aggregation-competent cells, their quantity rising from virtually 0-level during growth, with a steep increase shortly before cell aggregation. The serological activity of these structures is species specific; they are not detectable in a nonaggregating mutant, but present in a revertant undergoing normal morphogenesis. Patterns of cell assembly in the presence of antibodies show that selective blockage of these membrane sites abolishes the preference for end-to-end association which is typical for aggregating cells. A second class of target sites is present in comparable quantities in particle fractions from both growth-phase and aggregation-competent cells. Blockage of these sites leads to aggregation patterns in which the side-by-side contacts of aggregating cells are abolished. The target sites of aggregation-inhibiting antibodies are suggested to be identical or associated with the molecular units of the cell membrane that mediate cell-to-cell contacts during aggregation. The results indicate that in one cell, two independent classes of contact sites can be simultaneously active.
Source: The Journal of Cell Biology
DOI: 10.1083/jcb.56.3.647
Authors: H. Beug, F. E. Katz, G. Gerisch
Institution: Friedrich Miescher Laboratory
Language: English
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2125703976