Simultaneous localization of intracellular myosin and surface concanavalin A receptor clusters using immuno-electron microscopy.

Serial sectioning and immuno-ferritin plus peroxidase labeling of ultrathin frozen sections have been used for the simultaneous localization at the electron microscopic level of surface concanavalin A (Con A) receptors and the intracellular contractile protein, myosin, in mouse splenic lymphocytes. An accumulation of intracellular myosin directly underneath the Con A-induced receptor clusters has been observed. This myosin accumulation seems to be restricted to within approximately 1,000-1,500 A from the surface of the cell. This result provides additional support for the possible occurrence of transmembrane interactions between surface receptors and intracellular contractile elements.