CYTOSKELETON-BOUND POLYSOMES IN PLANTS .3. POLYSOME-CYTOSKELETON-MEMBRANE INTERACTIONS IN CORN ENDOSPERM

Over 80% of the polysomes in corn endosperm sediment along with protein bodies at 30 xg from seeds ground in cytoskeleton-stabilizing buffer. The cytoskeleton-disrupting agents, Tris-HCl, K+, heparin, and sodium deoxycholate cause polysome release, while protease K and the non-ionic detergent, PTE, are effective only in the presence of these agents, and RNase is almost without effect. We suggest that many of the polysomes in corn endosperm are associated via their ribosomes, but not mRNA or nascent polypeptides with the actin component of the cytoskeleton and only indirectly with membranes. Corn endosperm homogenates examined under the fluorescence microscope show polysomes coating individual protein bodies and co-localizing with actin, but not with ER. © 1993 Academic Press. All rights reserved.