Junctional plasma membrane domains isolated from aggregating Dictyostelium discoideum amebae

UMMS Affiliation

Department of Cell Biology

Publication Date


Document Type



Animals; Cell Adhesion; *Cell Aggregation; Cell Fractionation; Cell Membrane; Dictyostelium; Membrane Proteins; Microscopy, Electron; Molecular Weight


Cell Biology | Life Sciences | Medicine and Health Sciences


Regions of plasma membrane involved in Dictyostelium discoideum intercellular adhesion resist solubilization with the nonionic detergent Triton X-100. Electron microscopy shows that these regions of the plasma membrane adhere to each other, forming many bi- and multilamellar structures. NaDodSO4/polyacrylamide gels of these regions contain major polypeptides at 225 kDa (residual myosin), 105 kDa, 88 kDa, 84 kDa, 47 kDa (residual actin), and 34 kDa. These membranes contain a subset of the total plasma membrane proteins, as analyzed by labeling of electrophoretically fractionated and blotted membrane proteins with radioiodinated Con A and by electrophoresis of membrane proteins from surface-labeled cells. Antibodies specific for gp80, a glycoprotein implicated in intercellular adhesion, intensely stain the 88-kDa and 84-kDa bands. Since these membrane regions resist Triton extraction, they appear to be stabilized by protein-protein interactions. Such stabilizing interactions may involve multivalent linkages with adjacent cells, or associations with intracellular actin and myosin, or both. Since these membranes appear to represent regions of intercellular contact, we call them "contact regions."

DOI of Published Version



Proc Natl Acad Sci U S A. 1986 Jul;83(13):4779-83.

Journal/Book/Conference Title

Proceedings of the National Academy of Sciences of the United States of America

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