Search tips
Search criteria 


Logo of jcellbiolHomeThe Rockefeller University PressEditorsContactInstructions for AuthorsThis issue
J Cell Biol. 1984 July 1; 99(1 Pt 1): 71–78.
PMCID: PMC2275626

A membrane cytoskeleton from Dictyostelium discoideum. III. Plasma membrane fragments bind predominantly to the sides of actin filaments


The binding between sonicated Dictyostelium discoideum plasma membrane fragments and F-actin on Sephacryl S-1000 beads was found to be competitively inhibited by myosin subfragment-1. This inhibition is MgATP-sensitive, exhibits a Ki of approximately 5 X 10(-8) M, and is reciprocal, since membranes inhibit the binding of 125I-heavy meromyosin to F-actin on beads. These experiments demonstrate that membrane binding and S-1 binding to F-actin on beads are mutually exclusive and, therefore, that the membrane fragments bind predominantly to the sides, rather than to the ends, of the actin filaments. This conclusion is supported by electron micrographs that show many lateral associations between membrane fragments and bead- associated actin filaments. Such lateral associations could play an important role in the organization and lateral movement of membrane proteins by the cytomusculature.

Full Text

The Full Text of this article is available as a PDF (1001K).

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press